Chapter 8: Energy and Metabolism

Save this PDF as:
 WORD  PNG  TXT  JPG

Size: px
Start display at page:

Download "Chapter 8: Energy and Metabolism"

Transcription

1 Chapter 8: Energy and Metabolism 1. Discuss energy conversions and the 1 st and 2 nd law of thermodynamics. Be sure to use the terms work, potential energy, kinetic energy, and entropy. 2. What are Joules (J) and calories (cal)? 3. The laws of thermodynamics are sometimes stated as: In energy conversions, You can t win, and you can t break even. Explain. 4. Differentiate between: anabolism and catabolism exergonic and endergonic reactions 5. Why is ATP so darned important? What is a phosphorylated intermediate? How much ATP is in a cell at any given time? Why must cells keep a high ATP/ADP ratio? 6. What are redox reactions used for in cells? How (generally) can you tell which of two similar compounds is reduced and which is oxidized? Give some examples of compounds commonly used in redox reactions in cells. 7. What do enzymes do for cells, and how do they do it? Be sure to use the following terms: catalyst (or catalyze); activation energy, enzyme-substrate complex, active site, induced fit 8. What are the four main things that enzymes do to lower activation energy? 9. How are enzymes named (what suffixes indicate an enzyme)? 10. Explain the terms cofactor, apoenzyme, and coenzyme. 11. Discuss the effects of temperature and ph on enzyme activity. 12. What is a metabolic pathway? 13. How do cells regulate enzyme activity? Include the terms inhibitors, activators, allosteric site, and feedback inhibition; also, differentiate between irreversible and reversible inhibition and between competitive and noncompetitive inhibition. 1 of 8

2 Chapter 8: Energy and Metabolism Why do organisms need energy? How do organisms manage their energy needs? I. Energy and thermodynamics A. Living organisms require energy to do work, any change in state or motion of matter 1. energy can be expressed in units of work (kj) or heat energy (kcal); 1 kcal = kj 2. energy can change forms (energy conversion) 3. organisms carry out transformation in energy forms between potential energy (capacity to do work) and kinetic energy (energy of motion, actively performing work) 4. organisms commonly use chemical bonds for storage and transfer of (potential) energy 5. work is required for the processes of life B. Two laws of thermodynamics describe the constraints on energy usage 1. First law: the total amount of energy (+ matter) in a closed system remains constant (principle of conservation of energy) The universe is a closed system Living things are open systems 2. Second law: in every energy conversion, some energy is converted to heat energy that is lost to the surroundings, and thus cannot be used for work Also can be stated as: Every energy conversion increased the entropy of the universe. Energy converted to heat in the surroundings increases entropy (spreading of energy) Upshot: no energy conversion is 100% efficient Just to maintain their current state, organisms must get a constant influx of energy because of energy lost in conversions II. Metabolic reactions include anabolism and catabolism, and involve energy transfers A. Recall that metabolism is the sum of chemical activities in a organism B. Metabolism can be divided into anabolism (anabolic reactions) and catabolism (catabolic reactions) 1. anabolic reactions are processes that build complex molecules from simpler ones 2. catabolic reactions are processes the break down complex molecules into simpler ones C. Chemical reactions involve changes in chemical bonds and substance concentrations, along with changes in free energy 1. free energy = energy available to do work in a chemical reaction (such as: create a chemical bond) free energy changes depend on bond energies and concentrations of reactants and products 2 of 8

3 BIOL 1020 CHAPTER 8 LECTURE NOTES bond energy = energy required to break a bond; value depends on the bond left undisturbed, reactions will reach dynamic equilibrium when the relative concentrations of reactants and products is correct forward and reverse reaction rates are equal; concentrations remain constant cells manipulate relative concentrations in many ways, so that equilibrium is rare for key reactions 2. exergonic reactions the products have less free energy than reactants the difference in energy is released and is available to do work exergonic reactions are thermodynamically favored; thus, they are spontaneous, but not necessarily fast (more on activation energy later) catabolic reactions are usually exergonic ATP + H 2 O ADP + P i is highly exergonic in cellular conditions 3. endergonic reactions the products have more free energy than the reactants the difference in free energy must be supplied (stored in chemical bonds) endergonic reactions are not thermodynamically favored, so they are not spontaneous an endergonic reaction is coupled with an exergonic reaction to provide the needed energy to drive an endergonic reaction together, the coupled reactions must have a net exergonic nature reaction coupling requires that the reactions share a common intermediate(s) EXAMPLE: A B (exergonic) C D (endergonic) Coupled: A + C B + D (overall exergonic) Actually: A + C I B + D typically, the exergonic reaction in the couple is ATP + H 2 O ADP + P i anabolic reactions are usually endergonic 3 of 8

4 One way that organisms manage their energy needs is to use ATP as a ready energy source for many reactions. III. ATP is the main energy currency in cells A. Recall ATP (adenosine triphosphate) is a nucleotide with adenine base, ribose sugar, and a chain of 3 phosphate groups B. The last two phosphate groups are joined to the phosphate group chain by unstable bonds; breaking these bonds is relatively easy, and releases energy; thus: 1. hydrolysis of ATP to ADP and inorganic phosphate (P i ) releases energy ATP + H 2 O ADP + P i 2. the amount of energy released depends in part on concentrations of reactants and products, but is generally ~30 kj/mol C. Intermediates are involved when ATP hydrolysis is coupled to a reaction to provide energy; often these involve phosphorylated compounds, with the inorganic phosphate removed from ATP transferred onto another compound rather than being immediately released EXAMPLE: glucose + fructose sucrose + H 2 O (endergonic; requires ~27 kj/mol) ATP + H 2 O ADP + P i (provides ~30 kj/mol) coupled: simplified: with intermediates: glucose + fructose + ATP + H 2 O sucrose + H 2 O + ADP + P i glucose + fructose + ATP sucrose +ADP + P i glucose + fructose + ATP + H 2 O glucose-p + fructose + ADP sucrose + H 2 O + ADP + P i D. Thus, energy transfer in cellular reactions is often accomplished through transfer of a phosphate group from ATP E. Making ATP involves an endergonic condensation reaction 1. reverse of an exergonic reaction is always endergonic ADP + P i ATP + H 2 O (endergonic, usually requires more than ~30 kj/mol) 2. must be coupled with an exergonic reaction; typically from a catabolic pathway (more on that later) F. Overall, ATP is typically created in catabolic reactions and used in anabolic reactions, linking those aspects of metabolism G. Cells maintain high levels of ATP relative to ADP 1. maximizes energy available from hydrolysis of ATP 2. ratio typically greater than 10 ATP: 1 ADP H. Overall concentration of ATP still very low 1. supply typically only enough for a few seconds at best 2. instability prevents stockpiling 4 of 8

5 3. must be constantly produced 4. in a typical cell, the rate of use and production of ATP is about 10 million molecules per second 5. resting human has less than 1 g of ATP at any given time but uses about 45 kg per day Redox reactions are used to harvest energy from some chemicals; the acceptors of that energy typically cannot be used directly as energy currency. IV. Redox reactions are also used for energy transfer A. Electrons can also be used for energy transfer 1. Redox reactions: recall reduction, gain electrons; oxidation, lose electrons; both occur simultaneously in cells (generally no free electrons in cells) 2. Typically, the oxidized substance gives up energy with the electron, the reduced substance gains energy with the electron 3. Commonly occur as a chain of redox reactions or electron transfers (more on electron transport chains later) 4. As the electron is transferred to an acceptor molecule, it releases free energy that can be used for other chemical reactions 5. Typically, a proton is removed as well when an electron is removed from covalent molecules; thus, the equivalent of a hydrogen atom is transferred B. Catabolism typically involves removal of hydrogen atoms from nutrients (such as carbohydrates), and the transfer of the protons and electrons to intermediate electron acceptors 1. One common intermediate acceptor is nicotinamide adenine dinucleotide (NAD + ) Use XH 2 to represent a nutrient molecule: XH 2 + NAD + X + NADH + H + Often, the reduced form is just called NADH Reduced state stores energy, which is partially released as free energy when NADH is oxidized The free energy usually winds up being used to make ATP 2. Other commonly used acceptors are NADP +, FAD, and cytochromes NADP + /NADPH important in photosynthesis FAD/FADH2 flavin adenine dinucleotide Cytochromes small iron-containing proteins; iron serves as electron acceptor 5 of 8

6 Enzymes are a large part of the answer to how organisms manage their energy needs. Manipulation of reactions is essential to and largely defining of life, and enzymes manipulate the speed of reactions. Understanding life requires understanding how enzymes work. V. Enzymes regulate chemical reactions in living organisms A. An enzyme is an organic molecule (typically a protein) that acts as a catalyst 1. catalyst substance that increases the rate of a chemical reaction without being consumed in the reaction (the catalyst recycles back to its original state) 2. enzymes (catalysts) only alter reaction rate; thermodynamics still governs whether the reaction can occur thus, enzymes only catalyze reactions that are occurring anyway B. Enzymes (catalysts) work by lowering the activation energy of a reaction 1. all reactions have a required energy of activation (the energy required to break existing bonds) that must be supplied in some way before the reaction can proceed; also, reactants must come together 2. catalysts greatly reduce the activation energy requirement, making it easier for a reaction to occur 3. often, this reduction in activation energy is due to in part to the enzyme holding reactants (substrates) close together, which also reduces the reliance on random collisions C. Enzymes lower activation energy by forming a complex with the substrate(s) 1. the ability to form an enzyme-substrate complex is highly dependent on the shape of the enzyme 2. the site where the substrate(s) binds to the enzyme is called the active site 3. when the enzyme-substrate complex forms, there are typically shape changes in the enzyme and substrate(s) this is called induced fit 4. the enzyme-substrate complex is typically very unstable and short-lived; it breaks down into released product(s) and a 5. overall: free enzyme that is ready to be reused enzyme +substrate(s) ES complex enzyme + product(s) D. the reduction in activation energy is due primarily to four things: 1. an enzyme holds reactants (substrates) close together in the right orientation for the reaction, which reduces the reliance on random collisions 2. an enzyme may put a strain on existing bonds, making them easier to break 3. an enzyme provides a microenvironment that is more chemically suited to the reaction 4. sometimes the active site of the enzyme itself is directly involved in the reaction during the transition states 6 of 8

7 E. Enzyme names BIOL 1020 CHAPTER 8 LECTURE NOTES 1. many names give some indication of substrate 2. most enzyme names end in ase (example: sucrase) 3. some end in zyme (example: lysozyme) 4. some traditional names are less indicative of enzyme function (example: pepsin) F. Enzymes are generally highly specific 1. overall shape as well as spatial arrangements in the active site limit what enzyme-substrate complexes can readily form 2. the amount of specificity depends on the particular enzyme example of high specificity: sucrase splits sucrose, not other disaccharides example of low specificity: lipase splits variety of fatty acids from glycerol 3. enzymes are classified by the kind of reaction they catalyze G. Many enzymes require cofactors to function 1. apoenzyme + cofactor active enzyme (bound together) 2. alone, an apoenzyme or a cofactor has little if any catalytic activity 3. cofactors may or may not be changed by the reaction 4. cofactors can be organic or inorganic organic examples (coenzymes): ATP, NADH, NADPH, FADH 2 typically changed by the catalyzed reaction inorganic examples metal ions like Ca 2+, Mg 2+, Fe 3+, etc. typically not changed by the catalyzed reaction 5. most vitamins are coenzymes or part of coenzymes, or are used for making coenzymes H. Enzymes are most active under optimal conditions 1. each enzyme has an optimal temperature most effective as a catalyst at the optimal temperature rate of drop-off in effectiveness away from optimal temperature depends on the enzyme high temperatures tend to denature enzymes human enzymes have temperature optima near human body temperature (37 C) 7 of 8

8 2. each enzyme has an optimal ph again, most effective at the optimum; drop-off varies extremes of ph tend to denature enzymes a particular organism shows more variety in enzyme ph optima than in temperature optima, but most of its enzymes will still be optimal at the ph normally found in the cytosol of its cells I. Metabolic pathways use organized teams of enzymes 1. the products of one reaction often serve as substrates for the next reaction 2. removing products (by having them participate the next reaction ) improves reaction rate 3. multiple metabolic pathways exit in cells, overlapping in some areas and diverging in others J. Cells can regulate enzyme activity to control reactions 1. increase substrate amount increase reaction rate (up to saturation of available enzyme molecules) 2. increase enzyme amount increase reaction rate (as long as substrate amount > enzyme amount) 3. compartmentation of the enzyme, substrate, and products can help control reaction rate 4. inhibitors and activators of enzymes inhibitors reduce or eliminate catalytic activity activators allow or enhance catalytic activity sometime, this uses an allosteric site a receptor site on an enzyme where an inhibitor or activator can bind a common example of allosteric control is feedback inhibition, where the last product in a metabolic pathway binds to an allosteric site of an enzyme in an early step of the pathway (often the first) and inhibits activity of the enzyme irreversible inhibition enzyme is permanently inactivated or destroyed; includes many drugs and toxins reversible inhibition if inhibitor is removed, the enzyme activity can be recovered competitive inhibition inhibitor is similar in structure to a substrate; competes with substrate for binding to the active site noncompetitive inhibition binds at allosteric site, alters enzyme shape to make active site unavailable 8 of 8

MULTIPLE CHOICE QUESTIONS

MULTIPLE CHOICE QUESTIONS MULTIPLE CHOICE QUESTIONS 1. Most components of energy conversion systems evolved very early; thus, the most fundamental aspects of energy metabolism tend to be: A. quite different among a diverse group

More information

Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Two Forms of Energy

Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Two Forms of Energy Module 2D - Energy and Metabolism Objective # 19 All living organisms require energy for survival. In this module we will examine some general principles about chemical reactions and energy usage within

More information

Learning Objectives. Learning Objectives (cont.) Chapter 6: Metabolism - Energy & Enzymes 1. Lectures by Tariq Alalwan, Ph.D.

Learning Objectives. Learning Objectives (cont.) Chapter 6: Metabolism - Energy & Enzymes 1. Lectures by Tariq Alalwan, Ph.D. Biology, 10e Sylvia S. Mader Lectures by Tariq Alalwan, Ph.D. Learning Objectives Define energy, emphasizing how it is related to work and to heat State and apply two energy laws to energy transformations.

More information

Chapter 8 An Introduction to Metabolism

Chapter 8 An Introduction to Metabolism Chapter 8 An Introduction to Metabolism Sep 7 9:07 PM 1 Metabolism=all of the chemical reactions within an organism metabolic pathways are chemical reactions that change molecules in a series of steps

More information

Energy & Enzymes. Life requires energy for maintenance of order, growth, and reproduction. The energy living things use is chemical energy.

Energy & Enzymes. Life requires energy for maintenance of order, growth, and reproduction. The energy living things use is chemical energy. Energy & Enzymes Life requires energy for maintenance of order, growth, and reproduction. The energy living things use is chemical energy. 1 Energy exists in two forms - potential and kinetic. Potential

More information

Free Energy and Enzymes (Chapter 6) Outline. 1. The "extra" electrons have been stripped from other atoms in the cell.

Free Energy and Enzymes (Chapter 6) Outline. 1. The extra electrons have been stripped from other atoms in the cell. Free Energy and Enzymes (Chapter 6) Outline Growing Old With Molecular Mayhem A. Free radicals are molecules with extra electrons. 1. The "extra" electrons have been stripped from other atoms in the cell.

More information

An Introduction to Metabolism. Chapter 8

An Introduction to Metabolism. Chapter 8 An Introduction to Metabolism Chapter 8 METABOLISM I. Introduction All of an organism s chemical reactions Thousands of reactions in a cell Example: digest starch use sugar for energy and to build new

More information

LAWS OF THERMODYNAMICS First Law: E cannot be created or destroyed, only transformed. Second Law: When E is transformed, some cannot be used for work

LAWS OF THERMODYNAMICS First Law: E cannot be created or destroyed, only transformed. Second Law: When E is transformed, some cannot be used for work ENERGY, ENZYMES AND METABOLISM CHAPTER 8 Lecture Objectives What Physical Principles Underlie Biological Energy Transformations? What Is the Role of ATP in Biochemical Energetics? What Are Enzymes? How

More information

Energy Concepts. Study Objectives:

Energy Concepts. Study Objectives: Energy Concepts Study Objectives: 1. Define energy 2.Describe the 1 st law of thermodynamics Compare kinetic and potential energy, be able to give or recognize examples of each 3. Describe the major forms

More information

Define the term energy and distinguish between potential and kinetic energy.

Define the term energy and distinguish between potential and kinetic energy. Energy and Chemical Reactions Objective # 1 All living organisms require energy for survival. In this topic we will examine some general principles about energy usage and chemical reactions within cells.

More information

Chapter 8: An Introduction to Metabolism

Chapter 8: An Introduction to Metabolism Chapter 8: An Introduction to Metabolism Name Period Concept 8.1 An organism s metabolism transforms matter and energy, subject to the laws of thermodynamics 1. Define metabolism. The totality of an organism

More information

An Introduction to Metabolism

An Introduction to Metabolism Chapter 8 An Introduction to Metabolism PowerPoint Lecture Presentations for Biology Eighth Edition Neil Campbell and Jane Reece Lectures by Chris Romero, updated by Erin Barley with contributions from

More information

What affects an enzyme s activity? General environmental factors, such as temperature and ph. Chemicals that specifically influence the enzyme.

What affects an enzyme s activity? General environmental factors, such as temperature and ph. Chemicals that specifically influence the enzyme. CH s 8-9 Respiration & Metabolism Metabolism A catalyst is a chemical agent that speeds up a reaction without being consumed by the reaction. An enzyme is a catalytic protein. Hydrolysis of sucrose by

More information

Chapter Energy & Enzymes

Chapter Energy & Enzymes ANSWERS Chapter 5.2-5.6 Energy & Enzymes 1. Define energy and identify the various forms. Energy is the capacity to do work. Forms light, heat, electricity, motion. 2. Summarize the First and Second Laws

More information

Intro to Metabolism Campbell Chapter 8

Intro to Metabolism Campbell Chapter 8 Intro to Metabolism Campbell Chapter 8 http://ag.ansc.purdue.edu/sheep/ansc442/semprojs/2003/spiderlamb/eatsheep.gif http://www.gifs.net Section 8.1 An organism s metabolism transforms matter and energy,

More information

An Introduction to Metabolism

An Introduction to Metabolism Chapter 8 An Introduction to Metabolism Overview: The Energy of Life The living cell is a miniature chemical factory where thousands of reactions occur The cell extracts energy and applies energy to perform

More information

Topic 7: METABOLISM: THERMODYNAMICS, CHEMICAL EQUILIBRIA, ENERGY COUPLING and CATALYSIS (lectures 9-10)

Topic 7: METABOLISM: THERMODYNAMICS, CHEMICAL EQUILIBRIA, ENERGY COUPLING and CATALYSIS (lectures 9-10) Topic 7: METABOLISM: THERMODYNAMICS, CHEMICAL EQUILIBRIA, ENERGY COUPLING and CATALYSIS (lectures 9-10) OBJECTIVES: 1. Understand the concepts of kinetic vs. potential energy. 2. Understand the concepts

More information

CHAPTER 6 AN INTRODUCTION TO METABOLISM. Section B: Enzymes

CHAPTER 6 AN INTRODUCTION TO METABOLISM. Section B: Enzymes CHAPTER 6 AN INTRODUCTION TO METABOLISM Section B: Enzymes 1. Enzymes speed up metabolic reactions by lowering energy barriers 2. Enzymes are substrate specific 3. The active site in an enzyme s catalytic

More information

Anabolic and Catabolic Reactions are Linked by ATP in Living Organisms

Anabolic and Catabolic Reactions are Linked by ATP in Living Organisms Chapter 5: Microbial Metabolism Microbial Metabolism Metabolism refers to all chemical reactions that occur within a living a living organism. These chemical reactions are generally of two types: Catabolic:

More information

Enzymes and Metabolic Pathways

Enzymes and Metabolic Pathways Enzymes and Metabolic Pathways Enzyme characteristics Made of protein Catalysts: reactions occur 1,000,000 times faster with enzymes Not part of reaction Not changed or affected by reaction Used over and

More information

1. A covalent bond between two atoms represents what kind of energy? a. Kinetic energy b. Potential energy c. Mechanical energy d.

1. A covalent bond between two atoms represents what kind of energy? a. Kinetic energy b. Potential energy c. Mechanical energy d. 1. A covalent bond between two atoms represents what kind of energy? a. Kinetic energy b. Potential energy c. Mechanical energy d. Solar energy A. Answer a is incorrect. Kinetic energy is the energy of

More information

Enzymes and Metabolism

Enzymes and Metabolism Enzymes and Metabolism AP Biology Chapter 8 Metabolism Metabolism are all the chemical reactions in an organism Forming bonds between molecules dehydration synthesis synthesis of new muscle tissue by linking

More information

Cellular physiology ATP and Biological Energy (Lecture 15)

Cellular physiology ATP and Biological Energy (Lecture 15) Cellular physiology ATP and Biological Energy (Lecture 15) The complexity of metabolism This schematic diagram traces only a few hundred of the thousands of metabolic reactions that occur in a cell. The

More information

7/20/2015. Energy. Lecture 4 Outline (Ch. 8) Energy. What is Energy?

7/20/2015. Energy. Lecture 4 Outline (Ch. 8) Energy. What is Energy? Lecture 4 Outline (Ch. 8) I. Overview II. Thermodynamics III. Metabolism and IV. Cellular (ATP) and coupled reactions V. Enzymes and Regulation VI. Summary What is? Where does our (humans) energy come

More information

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. Name Advanced Biology Enzyme and Cellular Respiration Test Part I Multiple Choice (75 points) MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1) The

More information

Chapter 6: Energy Flow in the Life of a Cell. What is Energy? Answer: The Capacity to do Work. Types of Energy:

Chapter 6: Energy Flow in the Life of a Cell. What is Energy? Answer: The Capacity to do Work. Types of Energy: Chapter 6: Energy Flow in the Life of a Cell What is Energy? Answer: The Capacity to do Work Types of Energy: 1) Kinetic Energy = Energy of movement Light (movement of photons) Heat (movement of particles)

More information

1. Enzymes. Biochemical Reactions. Chapter 5: Microbial Metabolism. 1. Enzymes. 2. ATP Production. 3. Autotrophic Processes

1. Enzymes. Biochemical Reactions. Chapter 5: Microbial Metabolism. 1. Enzymes. 2. ATP Production. 3. Autotrophic Processes Chapter 5: Microbial Metabolism 1. Enzymes 2. ATP Production 3. Autotrophic Processes 1. Enzymes Biochemical Reactions All living cells depend on biochemical reactions to maintain homeostasis. All of the

More information

Spontaneous Reactions

Spontaneous Reactions Enzymes Spontaneous Reactions May occur quickly or slowly Enzymes speed up chemical reactions!! (But how, Ms. Robinson????) An enzyme is a macromolecule that acts as a catalyst a chemical agent that speeds

More information

Chapter 8: An Introduction to Metabolism

Chapter 8: An Introduction to Metabolism Name Period Concept 8.1 An organism s metabolism transforms matter and energy, subject to the laws of thermodynamics 1. Define metabolism. 2. There are two types of reactions in metabolic pathways: anabolic

More information

CHAPTER 8: ENERGY AND METABOLISM

CHAPTER 8: ENERGY AND METABOLISM CHAPTER 8: ENERGY AND METABOLISM CHAPTER SYNOPSIS Living organisms transform potential energy into kinetic energy to survive, grow, and reproduce. The energy that the earth receives from the sun is transformed

More information

Enzymes and Metabolism

Enzymes and Metabolism Enzymes and Metabolism Enzymes and Metabolism Metabolism: Exergonic and Endergonic Reactions Chemical Reactions: Activation Every chemical reaction involves bond breaking and bond forming A chemical reaction

More information

Cellular Energy: ATP & Enzymes. What is it? Where do organism s get it? How do they use it?

Cellular Energy: ATP & Enzymes. What is it? Where do organism s get it? How do they use it? Cellular Energy: ATP & Enzymes What is it? Where do organism s get it? How do they use it? Where does Energy come from? Ultimately, from the sun. It is transferred between organisms in the earth s lithosphere,

More information

AP Biology. From food webs to the life of a cell. Metabolism & Enzymes. Flow of energy through life. Metabolism. Chemical reactions of life

AP Biology. From food webs to the life of a cell. Metabolism & Enzymes. Flow of energy through life. Metabolism. Chemical reactions of life From food webs to the life of a cell energy Metabolism & Enzymes energy energy Flow of energy through life Life is built on chemical reactions sun transforming energy from one form to another organic molecules

More information

Homework. Due in Lab Week 2. Homework #4 (pages 9, 10 & 11) Biomolecules PreLab #2 (handout up front and on Instructor Website)

Homework. Due in Lab Week 2. Homework #4 (pages 9, 10 & 11) Biomolecules PreLab #2 (handout up front and on Instructor Website) Homework Due in Lab Week 2 Homework #4 (pages 9, 10 & 11) Biomolecules PreLab #2 (handout up front and on Instructor Website) Biological Molecules Enzymes Enzymes One of the most important groups of proteins

More information

BIOCHEMISTRY/MOLECULAR BIOLOGY

BIOCHEMISTRY/MOLECULAR BIOLOGY Enzymes Activation Energy Chemical reactions require an initial input of energy activation energy large biomolecules are stable must absorb energy to break bonds cellulose energy CO 2 + H 2 O + heat Activation

More information

The Structure and Hydrolysis of ATP

The Structure and Hydrolysis of ATP The Structure and Hydrolysis of ATP ATP drives endergonic reactions by phosphorylation, transferring a phosphate group to some other molecule, such as a reactant The recipient molecule is now called a

More information

CHAPTER 9 CELLULAR RESPIRATION: HARVESTING CHEMICAL ENERGY. Section A: The Principles of Energy Harvest

CHAPTER 9 CELLULAR RESPIRATION: HARVESTING CHEMICAL ENERGY. Section A: The Principles of Energy Harvest Section A: The Principles of Energy Harvest 1. Cellular respiration and fermentation are catabolic, energy-yielding pathways 2. Cells recycle the ATP they use for work 3. Redox reactions release energy

More information

Summary of Metabolism. Mechanism of Enzyme Action

Summary of Metabolism. Mechanism of Enzyme Action Summary of Metabolism Mechanism of Enzyme Action 1. The substrate contacts the active site 2. The enzyme-substrate complex is formed. 3. The substrate molecule is altered (atoms are rearranged, or the

More information

Metabolism & Enzymes AP Biology

Metabolism & Enzymes AP Biology Metabolism & Enzymes 2007-2008 From food webs to the life of a cell energy energy energy Flow of energy through life Life is built on chemical reactions transforming energy from one form to another organic

More information

The light comes from a set of chemical reactions, the luciferin-luciferase system Fireflies make light energy from chemical energy

The light comes from a set of chemical reactions, the luciferin-luciferase system Fireflies make light energy from chemical energy Cool Fires Attract Mates and Meals Fireflies use light instead of chemical signals to send a message to potential mates Females can also use light to attract males of other firefly species, as meals not

More information

Energy Production In A Cell (Chapter 25 Metabolism)

Energy Production In A Cell (Chapter 25 Metabolism) Energy Production In A Cell (Chapter 25 Metabolism) Large food molecules contain a lot of potential energy in the form of chemical bonds but it requires a lot of work to liberate the energy. Cells need

More information

Pathways that Harvest and Store Chemical Energy

Pathways that Harvest and Store Chemical Energy Pathways that Harvest and Store Chemical Energy Chapter 6 Pathways that Harvest and Store Chemical Energy Key Concepts 6.1 ATP, Reduced Coenzymes, and Chemiosmosis Play Important Roles in Biological Energy

More information

* Is chemical energy potential or kinetic energy? The position of what is storing energy?

* Is chemical energy potential or kinetic energy? The position of what is storing energy? Biology 1406 Exam 2 - Metabolism Chs. 5, 6 and 7 energy - capacity to do work 5.10 kinetic energy - energy of motion : light, electrical, thermal, mechanical potential energy - energy of position or stored

More information

SOME Important Points About Cellular Energetics by Dr. Ty C.M. Hoffman

SOME Important Points About Cellular Energetics by Dr. Ty C.M. Hoffman SOME Important Points About Cellular Energetics by Dr. Ty C.M. Hoffman An Introduction to Metabolism Most biochemical processes occur as biochemical pathways, each individual reaction of which is catalyzed

More information

Chapter 3: Bioenergetics

Chapter 3: Bioenergetics Chapter 3: Bioenergetics Introduction Metabolism: total of all chemical reactions that occur in the body Anabolic reactions Synthesis of molecules Catabolic reactions Breakdown of molecules Bioenergetics

More information

Chapter 19 Enzymes and Vitamins

Chapter 19 Enzymes and Vitamins 1.! What are enzymes? Be able to describe the chemical nature of enzymes and their function in biochemical reactions.! 2.! How do enzymes work, and why are they so specific? Be able to provide an overview

More information

2. Give the formula (with names) for the catabolic degradation of glucose by cellular respiration.

2. Give the formula (with names) for the catabolic degradation of glucose by cellular respiration. Chapter 9: Cellular Respiration: Harvesting Chemical Energy Name Period Overview: Before getting involved with the details of cellular respiration and photosynthesis, take a second to look at the big picture.

More information

Cellular Respiration: Harvesting Chemical Energy

Cellular Respiration: Harvesting Chemical Energy Slide 1 Chapter 9 Cellular Respiration: Harvesting Chemical Energy PowerPoint Lecture Presentations for Biology Eighth Edition Neil Campbell and Jane Reece Lectures by Chris Romero, updated by Erin Barley

More information

CHAPTER 4: Enzyme Structure ENZYMES

CHAPTER 4: Enzyme Structure ENZYMES CHAPTER 4: ENZYMES Enzymes are biological catalysts. There are about 40,000 different enzymes in human cells, each controlling a different chemical reaction. They increase the rate of reactions by a factor

More information

ENZYMES 2H 2 O 2 O 2 + 2H 2 O WHAT ARE ENZYMES? WHAT DO ENZYMES DO?

ENZYMES 2H 2 O 2 O 2 + 2H 2 O WHAT ARE ENZYMES? WHAT DO ENZYMES DO? ENZYMES WHAT ARE ENZYMES? WHAT DO ENZYMES DO? catalase 2H 2 O 2 O 2 + 2H 2 O catalase There are literally thousands of different enzymes which catalyze every major chemical reaction in the cells and bodies

More information

Cellular Respiration

Cellular Respiration Cellular Respiration So, all living things need energy in order to stay alive. The transformation of energy and matter in the body is called metabolism. Metabolism involves anabolic (build-up) and catabolic

More information

Chapter 5 Fundamentals of Human Energy Transfer

Chapter 5 Fundamentals of Human Energy Transfer Chapter 5 Fundamentals of Human Energy Transfer Slide Show developed by: Richard C. Krejci, Ph.D. Professor of Public Health Columbia College 6.18.11 Objectives 1. Describe the first law of thermodynamics

More information

Chemistry 20 Chapters 15 Enzymes

Chemistry 20 Chapters 15 Enzymes Chemistry 20 Chapters 15 Enzymes Enzymes: as a catalyst, an enzyme increases the rate of a reaction by changing the way a reaction takes place, but is itself not changed at the end of the reaction. An

More information

Cellular Respiration & Metabolism. Metabolism. Coupled Reactions: Bioenergetics. Cellular Respiration: ATP is the cell s rechargable battery

Cellular Respiration & Metabolism. Metabolism. Coupled Reactions: Bioenergetics. Cellular Respiration: ATP is the cell s rechargable battery Cellular Respiration & Metabolism Metabolic Pathways: a summary Metabolism Bioenergetics Flow of energy in living systems obeys: 1 st law of thermodynamics: Energy can be transformed, but it cannot be

More information

2-An activated enzyme made of polypeptide chain and a co-factor is (A) Coenzyme (B) Substrate (C) Apoenzyme (D) Holoenzyme

2-An activated enzyme made of polypeptide chain and a co-factor is (A) Coenzyme (B) Substrate (C) Apoenzyme (D) Holoenzyme 1-The catalytic activity of an enzyme is restricted to its small portion called (B) Passive site (C) Allosteric site (D) All Choices are correct 2-An activated enzyme made of polypeptide chain and a co-factor

More information

Cell Energetics Practice

Cell Energetics Practice Cell Energetics Practice Multiple Choice Identify the choice that best completes the statement or answers the question. 1. The ultimate source of energy for almost all living organisms is: a. heat. b.

More information

Todays Outline. Metabolism. Why do cells need energy? How do cells acquire energy? Metabolism. Concepts & Processes. The cells capacity to:

Todays Outline. Metabolism. Why do cells need energy? How do cells acquire energy? Metabolism. Concepts & Processes. The cells capacity to: and Work Metabolic Pathways Enzymes Features Factors Affecting Enzyme Activity Membrane Transport Diffusion Osmosis Passive Transport Active Transport Bulk Transport Todays Outline -Releasing Pathways

More information

Summary of Metabolic Pathways (Ch 21,23 and 25)

Summary of Metabolic Pathways (Ch 21,23 and 25) Summary of Metabolic Pathways (Ch 21,23 and 25) 21.1 Energy and Life Energy can be converted from one form to another, but can t be created or destroyed. -A consequence of this is that we need a constant

More information

Cellular Respiration and Fermentation

Cellular Respiration and Fermentation LECTURE PRESENTATIONS For CAMPBELL BIOLOGY, NINTH EDITION Jane B. Reece, Lisa A. Urry, Michael L. Cain, Steven A. Wasserman, Peter V. Minorsky, Robert B. Jackson Chapter 9 Cellular Respiration and Fermentation

More information

Microbial Metabolism. Biochemical diversity

Microbial Metabolism. Biochemical diversity Microbial Metabolism Biochemical diversity Metabolism Define Requirements Energy Enzymes Rate Limiting step Reaction time Types Anabolic Endergonic Dehydration Catabolic Exergonic Hydrolytic Metabolism

More information

Energy and Life. Energy= the ability to do work. Autotrophs= use sunlight, CO 2, and water to make their own food (sugars) PHOTOSYNTHESIS

Energy and Life. Energy= the ability to do work. Autotrophs= use sunlight, CO 2, and water to make their own food (sugars) PHOTOSYNTHESIS Energy and Life Energy= the ability to do work Autotrophs= use sunlight, CO 2, and water to make their own food (sugars) PHOTOSYNTHESIS Heterotrophs= can t make their own food, they have to eat autotrophs

More information

+ΔH gained enthalpy as reaction proceeded -ΔS means we have decreased entropy -ΔH means we have lost enthalpy(heat) (exergonic)

+ΔH gained enthalpy as reaction proceeded -ΔS means we have decreased entropy -ΔH means we have lost enthalpy(heat) (exergonic) CHAPTER ENERGY AND LIVING CELLS Life Requires Free Energy ( Bozeman biology) G= Free energy is the available(useable) energy to do work in the system Q. So during an exothermic reaction does the G go up

More information

PG1005. Lecture 10. Enzyme Function & Regulation

PG1005. Lecture 10. Enzyme Function & Regulation PG1005 Lecture 10 Enzyme Function & Regulation Dr. Neil Docherty My Teaching Objectives 1) Introduce the concept of enzymes as catalysts in terms of their effects on the activation energy and dynamics

More information

Bioenergetics. Free Energy Change

Bioenergetics. Free Energy Change Bioenergetics Energy is the capacity or ability to do work All organisms need a constant supply of energy for functions such as motion, transport across membrane barriers, synthesis of biomolecules, information

More information

Chapter 9 Cellular Respiration

Chapter 9 Cellular Respiration Chapter 9 Cellular Respiration Cells require outside energy to do cellular work. Energy flows ( (تتدفق into most ecosystems ( بيئية (أنظمة as sunlight Photosynthetic organisms trap a portion of the sunlight

More information

Regulation of Metabolism. Enzymes and Cellular Energy

Regulation of Metabolism. Enzymes and Cellular Energy Regulation of Metabolism Local (intrinsic) Control Mechanisms Enzymes and Cellular Energy Cellular metabolism consists of: Catabolism: the breakdown of organic molecules Anabolism: the synthesis of organic

More information

Chapter 7. Harvesting Energy: Glycolysis and Cellular Respiration

Chapter 7. Harvesting Energy: Glycolysis and Cellular Respiration Chapter 7 Harvesting Energy: Glycolysis and Cellular Respiration Including some materials from lectures by Gregory Ahearn University of North Florida Ammended by John Crocker Copyright 2009 Pearson Education,

More information

I N V E S T I C E D O R O Z V O J E V Z D Ě L Á V Á N Í ENZYMES

I N V E S T I C E D O R O Z V O J E V Z D Ě L Á V Á N Í ENZYMES = substances that... biological reactions 1. Provide an alternative reaction route which has a lower... energy 2. Reactions catalysed by enzymes occur under mild conditions + good yield + fast 3. Enzymes

More information

Lecture 8 Enzyme Energetics

Lecture 8 Enzyme Energetics Lecture 8 Enzyme Energetics 1 Last Lecture We talked about protein conformational change, signal cascades, phosphorylation, and ATP. We shall review these things even more in depth today 2 In this lecture

More information

Ch 4: Energy and Cellular Metabolism

Ch 4: Energy and Cellular Metabolism Ch 4: Energy and Cellular Metabolism Energy as it relates to Biology Chemical reactions Enzymes and how they speed rxs Metabolism and metabolic pathways Catabolism (ATP production) Anabolism (Synthesis

More information

An organism s metabolism transforms matter and energy, subject to the laws of thermodynamics [2].

An organism s metabolism transforms matter and energy, subject to the laws of thermodynamics [2]. GUIDED READING - Ch. 8 - AN INTRODUCTION TO METABOLISM NAME: Please print out these pages and HANDWRITE the answers directly on the printouts. Typed work or answers on separate sheets of paper will not

More information

AP Biology Chapter 8: Additional Notes:

AP Biology Chapter 8: Additional Notes: AP Biology Chapter 8: Additional Notes: I. Entropy(S) a. The entropy of an isolated system increases in the course of spontaneous change i. Examples of spontaneous change are cooling to the temperature

More information

How Enzymes Lower the E A. Barrier. Substrate Specificity of Enzymes. Enzymes catalyze reac.ons by lowering the E A barrier

How Enzymes Lower the E A. Barrier. Substrate Specificity of Enzymes. Enzymes catalyze reac.ons by lowering the E A barrier How Enzymes Lower the E A Barrier Enzymes catalyze reac.ons by lowering the E A barrier do not affect the change in free energy ( G) Instead hasten reac.ons that would occur eventually Fig. 8 15 Free energy

More information

Metabolism. Metabolism. Total of all chemical reactions that occur in the body. Bioenergetics. 1. Anabolic reactions Synthesis of molecules

Metabolism. Metabolism. Total of all chemical reactions that occur in the body. Bioenergetics. 1. Anabolic reactions Synthesis of molecules Metabolism Metabolism Total of all chemical reactions that occur in the body 1. Anabolic reactions Synthesis of molecules 2. Catabolic reactions Breakdown of molecules Bioenergetics Converting foodstuffs

More information

Figure 5. Energy of activation with and without an enzyme.

Figure 5. Energy of activation with and without an enzyme. Biology 20 Laboratory ENZYMES & CELLULAR RESPIRATION OBJECTIVE To be able to list the general characteristics of enzymes. To study the effects of enzymes on the rate of chemical reactions. To demonstrate

More information

BCOR 011 Exam 2, 2004

BCOR 011 Exam 2, 2004 BCOR 011 Exam 2, 2004 Name: Section: MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1. According to the first law of thermodynamics, A. the universe

More information

Transfers of electrons during chemical reactions (oxidation-reduction reactions)

Transfers of electrons during chemical reactions (oxidation-reduction reactions) Transfers of electrons during chemical reactions (oxidation-reduction reactions) Relocation of electrons in food molecules releases energy which can be used to synthesize ATP ATP is used to do ALL types

More information

Enzymes and Metabolic Pathways Un-lecture!

Enzymes and Metabolic Pathways Un-lecture! Enzymes and Metabolic Pathways Un-lecture! Numbers correspond to the slides, which are in your lecture notes and also posted on-line on the announcements page. 1. Characteristics of enzymes.we went over

More information

BCOR 11 Exploring Biology Exam # 2

BCOR 11 Exploring Biology Exam # 2 BCOR 11 Exploring Biology Exam # 2 Name Section For this Multiple Choice Exam you should record your choice of the best answer for each question on the SCANTRON sheet. You must use a number 2 pencil for

More information

Sindh Text Book Board, Jamshoro.

Sindh Text Book Board, Jamshoro. Chapter 3 ENZYMES Life would not be possible with out metabolic activities of the cell. This in turn is depends upon the Catalytic molecules called the enzymes. With-out enzymes, the dynamic, steady state

More information

1. Explain the difference between fermentation and cellular respiration.

1. Explain the difference between fermentation and cellular respiration. : Harvesting Chemical Energy Name Period Overview: Before getting involved with the details of cellular respiration and photosynthesis, take a second to look at the big picture. Photosynthesis and cellular

More information

Energy and Metabolism

Energy and Metabolism Chapter 6 6 Energy and Metabolism Chapter Outline 6.1 The Flow of Energy in Living Systems 6.2 The Laws of Thermodynamics and Free Energy 6.3 ATP: The Energy Currency of Cells 6.4 Enzymes: Biological Catalysts

More information

monosaccharides fatty acids amino acids

monosaccharides fatty acids amino acids Cellular Energy In order to sustain life (steady state), cells constantly expend energy in the form of ATP hydrolysis the hydrolysis of ATP yields a molecule of ADP (adenosine diphosphate) and a Phosphate

More information

Metabolism Practice Test KEY

Metabolism Practice Test KEY Biology 12 Metabolism Practice Test KEY Name: Section 1: What is an enzyme? 1. Which of the following statements is true about enzymes? a) 3D shape can vary and still be active b) they may catalyze only

More information

Oxidation of Pyruvate and the Citric Acid Cycle

Oxidation of Pyruvate and the Citric Acid Cycle Oxidation of Pyruvate and the Citric Acid Cycle Bởi: OpenStaxCollege If oxygen is available, aerobic respiration will go forward. In eukaryotic cells, the pyruvate molecules produced at the end of glycolysis

More information

Chapter 7 Active Reading Guide Cellular Respiration and Fermentation

Chapter 7 Active Reading Guide Cellular Respiration and Fermentation Name: AP Biology Mr. Croft Chapter 7 Active Reading Guide Cellular Respiration and Fermentation Overview: Before getting involved with the details of cellular respiration and photosynthesis, take a second

More information

AP BIOLOGY CHAPTER 7 Cellular Respiration Outline

AP BIOLOGY CHAPTER 7 Cellular Respiration Outline AP BIOLOGY CHAPTER 7 Cellular Respiration Outline I. How cells get energy. A. Cellular Respiration 1. Cellular respiration includes the various metabolic pathways that break down carbohydrates and other

More information

Chapter 9: Cellular Respiration: Harvesting Chemical Energy

Chapter 9: Cellular Respiration: Harvesting Chemical Energy Name Period Chapter 9: Cellular Respiration: Harvesting Chemical Energy Overview: Before getting involved with the details of cellular respiration and photosynthesis, take a second to look at the big picture.

More information

2- The conversion of 1 mol of fructose 1,6-bisphosphate to 2 mol of pyruvate by the glycolytic pathway results in a net formation of:

2- The conversion of 1 mol of fructose 1,6-bisphosphate to 2 mol of pyruvate by the glycolytic pathway results in a net formation of: Section 8 Key 1- During strenuous exercise, the NADH formed in the glyceraldehyde 3-phosphate dehydrogenase reaction in skeletal muscle must be reoxidized to NAD + if glycolysis is to continue. The most

More information

Introduction to Biology Respiration Chapter 5

Introduction to Biology Respiration Chapter 5 Introduction to Biology Respiration Chapter 5 Introduction Being alive is work. Cells organize small organic molecules into polymers such as the proteins, carbohydrates, and so forth you studied last week.

More information

The Citric Acid Cycle

The Citric Acid Cycle Mary K. Campbell Shawn O. Farrell http://academic.cengage.com/chemistry/campbell Chapter 19 The Citric Acid Cycle Paul D. Adams University of Arkansas Major pathways of glucose utilization 1 2 4 3 C 6

More information

MEMBRANE STRUCTURE AND FUNCTION

MEMBRANE STRUCTURE AND FUNCTION Chapter 5 The Working Cell: Membranes, Energy, and s Chapter 5: Big Ideas Cellular respiration Membrane Structure and Function Energy and the Cell How s Function MEMBRANE STRUCTURE AND FUNCTION Membranes

More information

8/20/2012 H C OH H R. Proteins

8/20/2012 H C OH H R. Proteins Proteins Rubisco monomer = amino acids 20 different amino acids polymer = polypeptide protein can be one or more polypeptide chains folded & bonded together large & complex 3-D shape hemoglobin Amino acids

More information

GCE A Level. Biology. Energy and respiration. сᴏᴏʟιᴏ

GCE A Level. Biology. Energy and respiration. сᴏᴏʟιᴏ GCE A Level Biology Energy and respiration сᴏᴏʟιᴏ 2013-2014 Q 1(a) Describe how ATP is synthesized by oxidative phosphorylation. [June 2012 # 1] Reduced NAD and reduced FAD are passed to the electron transport

More information

Enzymes. Enzymes are characterized by: Specificity - highly specific for substrates

Enzymes. Enzymes are characterized by: Specificity - highly specific for substrates Enzymes Enzymes are characterized by: Catalytic Power - rates are 10 6-10 12 greater than corresponding uncatalyzed reactions Specificity - highly specific for substrates Regulation - acheived in many

More information

Lipids (Biologie Woche 1 und 2; Pages 81 and 82)

Lipids (Biologie Woche 1 und 2; Pages 81 and 82) Lipids (Biologie Woche 1 und 2; Pages 81 and 82) Lipids Features Have oily, greasy or waxy consistency Relatively insoluble in water Protein and carbohydrates may be converted into lipids by enzymes an

More information

19. The Citric Acid Cycle

19. The Citric Acid Cycle 19. The Citric Acid Cycle 19.1 The Central Role of Citric Acid Cycle Play in Metabolism Evolution of aerobic metabolism - Nutrients are oxidized to carbon dioxide and water. - Organisms can obtain far

More information

Chemical system. Chemical reaction A rearrangement of bonds one or more molecules becomes one or more different molecules A + B C.

Chemical system. Chemical reaction A rearrangement of bonds one or more molecules becomes one or more different molecules A + B C. Chemical system a group of molecules that can react with one another. Chemical reaction A rearrangement of bonds one or more molecules becomes one or more different molecules A + B C Reactant(s) Product(s)

More information

What s the point? ATP! Electron Transport Chain ATP

What s the point? ATP! Electron Transport Chain ATP http://www.youtube.com/watch?v=vcpnk92uswy What s the point? Cellular Respiration The point Stage 4: is to make ATP! Electron Transport Chain ATP 2013-2014 Cellular respiration ATP accounting so far Even

More information

Section 3: Factors That Affect the Rate of Enzyme Catalyzed Reactions best

Section 3: Factors That Affect the Rate of Enzyme Catalyzed Reactions best Biology 12 Name: Metabolism Practice Test Section 1: What is an enzyme? 1. Which of the following statements is true about enzymes? a) 3D shape can vary and still be active b) they may catalyze only 1

More information