1. 2. Enzymes. 1: Biochemistry of macromolecules and metabolic pathways

Save this PDF as:
 WORD  PNG  TXT  JPG

Size: px
Start display at page:

Download "1. 2. Enzymes. 1: Biochemistry of macromolecules and metabolic pathways"

Transcription

1 1. 2 Enzymes Enzymes are referred to as biological catalysts they create new pathways that allow reactions to occur many times faster than uncatalysed reactions. Enzymes act on specific molecules called substrates. These substrate molecules bind to a region of the enzyme known as the active site. The specificity of the enzyme is due to the fact that the substrate and active site have structures that are complementary. Hence only specific substrates can fit and bind to the active site. On successful completion of this topic you will: understand the chemical principles that apply to the structures of biological building block molecules (LO1) understand the structures of biological macromolecules and the relationships to biological functions (LO2). To achieve a Pass in this unit you need to show that you can: explain the structure, catalytic function and characteristic properties of enzymes (2.2). 1

2 1: Biochemistry of macromolecules and metabolic pathways 1 Models to explain the actions of enzymes Before you start If you find some parts of this unit challenging, remember you are working at a higher level than you may be used to. In this unit it is important that you fully understand the following themes and topics before you begin: structure and function of biological molecules enzyme structure and function aerobic respiration. If you need to check your understanding of proteins, carbohydrates, lipids and nucleic acids, Unit 2 Module 1 of OCR AS Biology (P. Kennedy and F. Sochacki, 2008), offers a good introduction to the topic. If you need to check your understanding of aerobic respiration and the stages of glycolysis, link reaction, the Krebs cycle and the electron transport chain, you may find Unit 1 Module 4 of OCR A2 Biology (S. Hocking, 2008) useful. Several scientists have produced models to help explain the actions of enzymes. The lock and key hypothesis Key terms Enzyme: A protein used as a catalyst to speed up chemical reactions. Active site: The functional part of the enzyme. Substrate: A substance that binds to an enzyme s active site; it is the reactant molecule. This model explains that enzyme activity depends on the active site of the enzyme. The active site is the area or pocket on the enzyme where a substrate molecule fits. The shapes of the substrate molecule and the active site are complementary, so they are said to fit together like a key fits into a lock. When the substrate binds to the active site an enzyme-substrate complex is formed and the substrate then forms a product. The induced-fit hypothesis This model, in contrast to the lock and key hypothesis, suggests that the active site is not exactly the same shape as the substrate it is said to be in a relaxed state. When the substrate binds to the active site, the active site moulds itself to the substrate forming an enzyme-substrate complex. Only then is the active site the correct shape to catalyse the reaction. Figure 1.2.1: Enzyme structure. Substrate = H2O2 Active site Substrate Active site Molecular model of catalase Schematic model of an enzyme The schematic diagram in Figure shows the complimentary active site of an enzyme and the substrate. The molecular diagram shows the enzyme catalase and its complementary substrate hydrogen peroxide. 2

3 2 Lowering activation energy For chemical reactions to take place bonds need to be broken before new ones can be formed. The energy needed for these bonds to be broken is known as the activation energy and this is usually very high. An enzyme carries out its function by providing an alternative route for the reaction with a lower activation energy by temporarily combining with the chemicals involved in the reaction. Figure is an energy profile showing the effect of a catalyst on activation energy. Figure 1.2.2: The activation energy needed for a chemical reaction to take place is lower when a catalyst is present. Energy Activation energy without catalyst Activation energy with catalyst Reactants Products Progress of reaction 3 Factors affecting enzyme activity There are various factors that affect enzyme activity and all enzymes have their own optimum conditions. Enzyme rates depend on the surrounding conditions and substrate concentration. Conditions that affect enzyme activity therefore are temperature, ph, substrate and enzyme concentration and the presence of any inhibitors. Key terms Activation energy: Energy required to activate a chemical reaction. Denature: To change an enzyme s structure in a way that changes the shape of the active site so the enzyme is unable to function. Temperature Applying heat energy to molecules increases their kinetic energy so there will be an increased number of collisions between enzyme and substrate molecules. This in turn will increase the rate of reaction and so the products will be formed more quickly. However, applying too much heat can cause enzymes to denature. The increased vibrations and collisions put strains on the bonds of the tertiary structure and can break the hydrogen and ionic bonds. The breaking of these bonds affects the important three-dimensional shape; more importantly it changes the shape of the active site. Denaturation causes the enzyme to lose its ability to function and its function cannot be restored. Increasing the temperature initially increases the rate of reaction. The temperature that gives the maximum rate of reaction is the enzyme s optimum temperature. However, the rate will decrease if the temperature rises higher than the optimum, due to denaturation of the enzyme. Figure shows the effect of temperature on the rate of an enzyme-controlled reaction. 3

4 Enzymes inside the body work at an optimum temperature of 37 C, whereas genetic engineering techniques require high temperatures, and the enzyme DNA polymerase has an optimum temperature of 72 C. Under optimum conditions and at this temperature DNA polymerase is able to efficiently polymerise a thousand bases per minute. The amount of the target DNA sequence is doubled, leading to exponential amplification of the specific DNA fragment. Figure 1.2.3: Effect of temperature on the rate of an enzyme-controlled reaction. Rate of reaction Increasing temperature increases the rate of reaction due to increased kinetic energy Optimum temperature gives maximum rate of reaction Increasing temperature beyond the optimum temperature reduces the rate of reaction due to the breaking of bonds holding the enzyme s tertiary structure in place ph Temperature/ C The optimum ph varies for all enzymes for many enzymes the optimum ph is ph 7. However, outside their optimum ph range, enzymes are denatured because free hydrogen and hydroxide ions affect the charge of the amino acid. The threedimensional shape is altered, changing the tertiary structure of the protein and, in turn, the specific active site. Pepsin is an enzyme that works in the human body to digest proteins; it works in the stomach at ph 2. Trypsin, an enzyme in the small intestine, also digests proteins however, in contrast, this enzyme works at ph 7. Key terms Turnover rate: The number of substrate molecules converted into product molecules per unit time, known as V max. Michaelis-Menten constant: The substrate concentration needed for an enzyme to reach one half of its maximum rate known as K m. The catalysed reaction rate is equal to V max /2. Substrate concentration When you look at Figure you can see that as the substrate concentration increases, the rate of the enzyme-controlled reaction increases until all the enzymes active sites are occupied by substrate. We use the term V max, which is the maximum rate at which an enzyme catalyses a reaction and is often known as the turnover rate. When all the enzymes active sites are saturated with a complementary substrate V max is reached. The only way to speed up the reaction further is to add more enzyme. The amount of substrate needed to achieve V max is important and is often expressed as Michaelis-Menten constant, K m, which is the substrate concentration needed for an enzyme to reach one half its maximum rate. All enzymes have their own specific K m for a substrate. 4

5 Link Figure 1.2.4: A graph to show V max and K m. You will find out more about enzymes in Topic guide 1.4: Investigating enzymes. Also check out Unit 5: Chemistry for applied biologists, for enzyme kinetics. V max Reaction velocity (V 0 ) V max /2 K m Enzyme concentration Substrate concentration (S) Enzymes can convert millions of substrate molecules into products every minute, so the number of enzymes required in a reaction is less than the substrate. However, if there is a plentiful supply of substrate, the reaction can be limited by the number of enzymes present; therefore, by increasing the enzyme concentration, the rate will also increase. Remember that if there is not an abundant supply of substrate, increasing the concentration of enzyme will have no effect on the rate of reaction. Activity Answer the following questions: 1 How does temperature affect enzyme activity? 2 How does ph affect enzyme activity? 3 If all the enzymes active sites are occupied, what effect would adding more substrate have on the rate of reaction and why? 4 If there was a plentiful supply of substrate how could the rate of reaction be increased? 5 What does denature mean and how does it occur? Presence of inhibitors Enzymes: competitive inhibitors As the name suggests, competitive inhibitors compete with the substrate for the active site of the enzyme. Therefore the inhibitors are the same size and shape as the substrate to enable the complementary fit inside the enzyme s active site. However, the inhibitor cannot form a product. If competitive inhibitors are present, the rate of reaction is decreased as they stop the substrate from binding to the enzyme and producing a product. Many competitive inhibitors do not bind permanently and so their action is reversible. They bind to the enzyme s active site for a short period and then detach, leaving the enzyme active again. Enzymes: non-competitive inhibitors These inhibitors do not compete for the active site but they bind to an alternative part of the enzyme called an allosteric region. This changes the shape of the active site and means that the substrate will no longer be a complementary shape to fit into the active site. If there are enough inhibitors present they may fill all the enzymes allosteric regions and, if this happens, the reaction will stop. 5

6 Figure shows competitive inhibition and non-competitive inhibition taking place. Figure 1.2.5: Competitive inhibition and non-competitive inhibition. Substrate Competitive inhibitor interferes with active site of enzyme so substrate cannot bind Substrate Enzyme Enzyme (a) Competitive inhibition Non-competitive inhibitor changes shape of enzyme so it cannot bind to substrate (b) Non-competitive inhibition Permanent inhibitors The effect of many non-competitive inhibitors is not reversible because they bind permanently to the enzymes; the enzyme is therefore described as denatured because the shape of the active site is no longer complementary or the correct shape for its specific substrate to bind to. Checklist In this topic you should now be familiar with the following ideas about enzymes: enzymes are biological catalysts enzymes are proteins enzymes have an active site that enables them to bind to substrate molecules two models can be used to explain enzyme action the lock and key hypothesis and the induced-fit model enzymes can be affected by temperature and ph an enzyme s shape can be altered, which stops the enzyme working; this is known as denaturation the rate of reaction can be affected by the concentration of the substrate and the enzyme V max is the maximum rate reached in an enzyme-controlled reaction competitive inhibitors affect the rate of reaction by competing with the substrate molecules non-competitive inhibitors affect the rate of reaction by binding to an alternative region and changing the active site shape. The following Case study is a real life example of enzymes in action. Case study In biochemistry, fermentation is used to produce alcohol, yoghurt, vinegar and many other everyday products. Alcoholic and glycolysis fermentation both begin with glucose and are both anaerobic fermentation processes (do not require oxygen). Glycolysis uses many enzymes to transform glucose to lactic acid. Alcoholic fermentation follows the same enzymatic pathway; however, lactate dehydrogenase is replaced by pyruvate decarboxylase and alcoholic dehydrogenase. During alcoholic fermentation these two enzymes convert pyruvic acid into carbon dioxide and ethanol. 6

7 Further reading Boyle, M. & Senior, K. (2008) Biology, 3rd Edition, HarperCollins Kennedy, P., Sochacki, F. & Hocking, S. (2008) OCR Biology AS, Heinemann (Pearson Education Limited) Kennedy, P., Sochacki, F., Winterbottom, M. & Hocking, S. (2008) OCR Biology A2, Heinemann (Pearson Education Limited) Loomis, H.F. (2005) Enzymes: The Key to Health, 21st Century Nutrition Publishing Moran, L., Horton, R., Scrimgeour, G., Perry, M. & Rawn, D. (2011) Principles of Biochemistry (International Edition), 5th Edition, Pearson Acknowledgements The publisher would like to thank the following for their kind permission to reproduce their photographs: Getty Images: Martin McCarthy / E+ All other images Pearson Education We are grateful to the following for permission to reproduce copyright material: Figure 1.2.3: Table showing the effect of temperature on the rate of an enzyme-controlled reaction from Figure 4 on page 129 of Pearson s AS Biology for OCR. Used with permission. In some instances we have been unable to trace the owners of copyright material, and we would appreciate any information that would enable us to do so. 7

1. 4. 1: Biochemistry of macromolecules and metabolic pathways

1. 4. 1: Biochemistry of macromolecules and metabolic pathways 1. 4 Investigating enzymes Many factors affect the activity of enzymes and it is very easy to investigate these factors using common enzymes. Enzymes work at their optimum temperature and ph. Any changes

More information

Module 1: Enzymes Biology

Module 1: Enzymes Biology State that enzymes are globular proteins, with a specific tertiary structure, which catalyse metabolic reactions in living organisms State that enzyme action may be intracellular or extracellular Specificity,

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 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

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

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

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

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 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

1. 5. Carbohydrates. 1: Biochemistry of macromolecules and metabolic pathways

1. 5. Carbohydrates. 1: Biochemistry of macromolecules and metabolic pathways . Carbohydrates Carbohydrates are a key group of biological molecules about 0% of all the organic matter of a cell is made up of carbohydrates. This topic guide looks at their basic chemical structures

More information

ENZYME- SUBSTRATE COMPLEX

ENZYME- SUBSTRATE COMPLEX Enzymes OK.so now we ve done all of that hemistry stuff that you all love so much...let s get down to the real stuff aving just learnt about proteins, let s now look at one of the fundamental substances

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

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

Name Date Period. Keystone Review Enzymes

Name Date Period. Keystone Review Enzymes Name Date Period Keystone Review Enzymes 1. In order for cells to function properly, the enzymes that they contain must also function properly. What can be inferred using the above information? A. Cells

More information

Enzymes. A. a lipid B. a protein C. a carbohydrate D. a mineral

Enzymes. A. a lipid B. a protein C. a carbohydrate D. a mineral Enzymes 1. All cells in multicellular organisms contain thousands of different kinds of enzymes that are specialized to catalyze different chemical reactions. Given this information, which of the following

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

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

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

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

Molecular Biology 2.5- Enzymes

Molecular Biology 2.5- Enzymes Essential idea: Enzymes control the metabolism of the cell. Molecular Biology 2.5- Enzymes Nature of science: Experimental design accurate, quantitative measurements in enzyme experiments require replicates

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

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

Human Biology Higher Homework: Topic Human Cells. Sub-topic3: Cell Metabolism

Human Biology Higher Homework: Topic Human Cells. Sub-topic3: Cell Metabolism Human Biology Higher Homework: Topic Human Cells Sub-topic3: Cell Metabolism 1. During which of the following chemical conversions is A T P produced? A B C D Amino acids protein Glucose pyruvic acid Haemoglobin

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

5. The chart below indicates the elements contained in four different molecules and the number of atoms of each element in those molecules.

5. The chart below indicates the elements contained in four different molecules and the number of atoms of each element in those molecules. 1. In the diagram below, which substance belongs in area Z? 5. The chart below indicates the elements contained in four different molecules and the number of atoms of each element in those molecules. A)

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

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

National 4&5 Biology. Cells Topic Summary Notes. Learning Outcomes (National 5 learning outcomes in shaded box)

National 4&5 Biology. Cells Topic Summary Notes. Learning Outcomes (National 5 learning outcomes in shaded box) National 4&5 Biology Cells Topic Summary Notes Learning Outcomes (National 5 learning outcomes in shaded box) What you should know about CELL STRUCTURE 1 Label a typical animal cell with cell membrane,

More information

BIOCHEMISTRY (I) LIFS2210. Enzymes and Enzyme Reactions

BIOCHEMISTRY (I) LIFS2210. Enzymes and Enzyme Reactions BIOCHEMISTRY (I) LIFS2210 Enzymes and Enzyme Reactions 1 1. Enzymes: Biocatalysts Catalyst: to increase the rate or velocity of a chemical reaction without itself being changed in the overall process Catalyst

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

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

General Properties Protein Nature of Enzymes Folded Shape of Enzymes H-bonds complementary

General Properties Protein Nature of Enzymes Folded Shape of Enzymes H-bonds complementary Proteins that function as biological catalysts are called enzymes. Enzymes speed up specific metabolic reactions. Low contamination, low temperature and fast metabolism are only possible with enzymes.

More information

Cellular Respiration 1. Occurs in the Mitochondria 2. How are cells produce ATP (energy)

Cellular Respiration 1. Occurs in the Mitochondria 2. How are cells produce ATP (energy) Cellular Respiration 1. Occurs in the Mitochondria 2. How are cells produce ATP (energy) Consider the energy released by a burning peanut How is this like cellular respiration? Hyperlink What happened

More information

1. The diagram below represents a biological process

1. The diagram below represents a biological process 1. The diagram below represents a biological process 5. The chart below indicates the elements contained in four different molecules and the number of atoms of each element in those molecules. Which set

More information

AS Demonstrate understanding of life processes at the cellular level. ENZYMES

AS Demonstrate understanding of life processes at the cellular level. ENZYMES AS 91156 Demonstrate understanding of life processes at the cellular level. ENZYMES (2013: 2) The rate of photosynthesis is directly related to the availability of light. Normally, an increase in light

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

Biological cell membranes

Biological cell membranes Unit 14: Cell biology. 14 2 Biological cell membranes The cell surface membrane surrounds the cell and acts as a barrier between the cell s contents and the environment. The cell membrane has multiple

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

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

Lecture 3: Enzyme kinetics

Lecture 3: Enzyme kinetics Computational Systems Biology Lecture 3: Enzyme kinetics Fri 19 Jan 2009 1 Images from: D. L. Nelson, Lehninger Principles of Biochemistry, IV Edition, W. H. Freeman ed. A. Cornish-Bowden Fundamentals

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

green B 1 ) into a single unit to model the substrate in this reaction. enzyme

green B 1 ) into a single unit to model the substrate in this reaction. enzyme Teacher Key Objectives You will use the model pieces in the kit to: Simulate enzymatic actions. Explain enzymatic specificity. Investigate two types of enzyme inhibitors used in regulating enzymatic activity.

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

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. Ch19_PT MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1) Enzymes are members of which class of biomolecules? A) carbohydrates B) nucleic acids C)

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

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

Chapter 2. The Chemistry of Life Worksheets

Chapter 2. The Chemistry of Life Worksheets Chapter 2 The Chemistry of Life Worksheets (Opening image courtesy of David Iberri, http://en.wikipedia.org/wiki/file:camkii.png, and under the Creative Commons license CC-BY-SA 3.0.) Lesson 2.1: Matter

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

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

TECHNICAL UNIVERSITY OF MOMBASA Faculty of ENGINEERING & TECHNOLOGY

TECHNICAL UNIVERSITY OF MOMBASA Faculty of ENGINEERING & TECHNOLOGY TECHNICAL UNIVERSITY OF MOMBASA Faculty of ENGINEERING & TECHNOLOGY DEPARTMENT OF MEDICAL SCIENCES FACULTY OF APPLIED AND HEALTH SCIENCES BMLS 13M MID ENTRY ABT 4202 : BIOCHEMISTRY II INSTRUCTIONS: END

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

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

2.1 Nucleic acids the molecules of life

2.1 Nucleic acids the molecules of life 1 2.1 Nucleic acids the molecules of life Nucleic acids information molecules of the cells form new cells stored in chromosomes in nucleus of the cell in the form of a code in DNA / parts of the code are

More information

The Processes of Life. Bicester Community College Science Department

The Processes of Life. Bicester Community College Science Department B4 The Processes of Life B4 Key Questions How do chemical reactions take place in living things? How do plants make food? How do living organisms obtain energy? How do chemical reactions take place in

More information

PRESTWICK ACADEMY NATIONAL 5 BIOLOGY CELL BIOLOGY SUMMARY

PRESTWICK ACADEMY NATIONAL 5 BIOLOGY CELL BIOLOGY SUMMARY Name PRESTWICK ACADEMY NATIONAL 5 BIOLOGY CELL BIOLOGY SUMMARY Cell Structure Identify animal, plant, fungal and bacterial cell ultrastructure and know the structures functions. Plant cell Animal cell

More information

Name: Class: Date: Enzyme Practice. Multiple Choice Identify the choice that best completes the statement or answers the question.

Name: Class: Date: Enzyme Practice. Multiple Choice Identify the choice that best completes the statement or answers the question. Class: Date: Enzyme Practice Multiple Choice Identify the choice that best completes the statement or answers the question. 1. Which term is used to describe the high-energy intermediate that forms as

More information

Unit 1: Chemistry of Life Guided Reading Questions (70 pts total)

Unit 1: Chemistry of Life Guided Reading Questions (70 pts total) AP Biology Biology, Campbell and Reece, 10th Edition Adapted from chapter reading guides originally created by Lynn Miriello Name: Unit 1: Chemistry of Life Guided Reading Questions (70 pts total) Chapter

More information

Biology. Slide 1 of 34. End Show. Copyright Pearson Prentice Hall

Biology. Slide 1 of 34. End Show. Copyright Pearson Prentice Hall Biology 1 of 34 2 4 Chemical Reactions and Enzymes 2 of 34 Chemical Reactions Chemical Reactions A chemical reaction is a process that changes one set of chemicals into another set of chemicals. Example:

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

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

9-1 Notes. Chemical Pathways

9-1 Notes. Chemical Pathways 9-1 Notes Chemical Pathways Chemical Energy & Food Food provides living things with the chemical building blocks to grow and reproduce. One gram of the sugar glucose releases 3811 calories of heat energy.

More information

Cathkin High School CfE Higher Chemistry. Chemical Changes & Structure Controlling the Rate

Cathkin High School CfE Higher Chemistry. Chemical Changes & Structure Controlling the Rate Cathkin High School CfE Higher Chemistry Unit 1 : Part 1 Chemical Changes & Structure Controlling the Rate E a Page 1 of 17 Learning Outcomes Controlling the Rate Circle a face to show how much understanding

More information

Study Guide B. Answer Key. Chemistry of Life

Study Guide B. Answer Key. Chemistry of Life Chemistry of Life Answer Key SECTION 1. ATOMS, IONS, AND MOLECULES 1. An element is a certain type of atom. 2. Sketch should resemble one of the illustrations in Figure 1.2 in Section 1. Nucleus should

More information

Cellular Respiration Worksheet 1. 1. What are the 3 phases of the cellular respiration process? Glycolysis, Krebs Cycle, Electron Transport Chain.

Cellular Respiration Worksheet 1. 1. What are the 3 phases of the cellular respiration process? Glycolysis, Krebs Cycle, Electron Transport Chain. Cellular Respiration Worksheet 1 1. What are the 3 phases of the cellular respiration process? Glycolysis, Krebs Cycle, Electron Transport Chain. 2. Where in the cell does the glycolysis part of cellular

More information

Enzymes. Enzyme Structure. Enzyme Classification. CHEM464/Medh, J.D. Reaction Rate and Enzyme Activity

Enzymes. Enzyme Structure. Enzyme Classification. CHEM464/Medh, J.D. Reaction Rate and Enzyme Activity Enzymes Enzymes are biological catalysts They are not consumed or altered during the reaction They do not change the equilibrium, just reduce the time required to reach equilibrium. They increase the rate

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

Microbiology - Problem Drill 05: Microbial Metabolism

Microbiology - Problem Drill 05: Microbial Metabolism Microbiology - Problem Drill 05: Microbial Metabolism No. 1 of 10 1. Anabolism is a metabolic process where are turned into molecules. (A) Complex, simple (B) Simple, ATP (C) Simple, ATP (D) Simple, complex

More information

What happens to the food we eat? It gets broken down!

What happens to the food we eat? It gets broken down! Enzymes Essential Questions: What is an enzyme? How do enzymes work? What are the properties of enzymes? How do they maintain homeostasis for the body? What happens to the food we eat? It gets broken down!

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

* 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

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

Name: Date: Hour: OK OK OK.. I m sure you all thought that I wouldn t possibly ask you to know more for this chapter SORRY!

Name: Date: Hour: OK OK OK.. I m sure you all thought that I wouldn t possibly ask you to know more for this chapter SORRY! Biology I Cellular Respiration Name: Date: Hour: OK OK OK.. I m sure you all thought that I wouldn t possibly ask you to know more for this chapter SORRY! Now, we need a place to disassemble the molecule

More information

Section 2 1 The Nature of Matter (pages 35 39)

Section 2 1 The Nature of Matter (pages 35 39) Chapter 2 The Chemistry of Life Section 2 1 The Nature of Matter (pages 35 39) Key Concepts What three subatomic particles make up atoms? How are all of the isotopes of an element similar? What are the

More information

GCSE Additional Science

GCSE Additional Science GCSE Additional Science Module B4 The processes of life: What you should know Name: Science Group: Teacher: R.A.G. each of the statements to help focus your revision: R = Red: I don t know this A = Amber:

More information

Figure 1. Addition of a phosphate group to the non-functional form of TK leads to production of the functional form of TK

Figure 1. Addition of a phosphate group to the non-functional form of TK leads to production of the functional form of TK AQA Extra Questions on 1.4 (answers at the back) Saint David's Catholic College Q1.The enzyme tyrosine kinase (TK) is found in human cells. TK can exist in a non-functional and a functional form. The functional

More information

Chapter 9 CELLULAR RESPIRATION

Chapter 9 CELLULAR RESPIRATION Chapter 9 CELLULAR RESPIRATION HARVESTING FREE ENERGY Photosynthesis takes free energy and puts it into carbohydrates/sugars Carbohydrates can be stored for later use; light can not and neither can ATP

More information

Name Class Date SECTION 9-1 REVIEW CHEMICAL PATHWAYS. 1. cellular respiration. 2. glycolysis. 3. calorie. 4. fermentation

Name Class Date SECTION 9-1 REVIEW CHEMICAL PATHWAYS. 1. cellular respiration. 2. glycolysis. 3. calorie. 4. fermentation SECTION 9-1 REVIEW CHEMICAL PATHWAYS VOCABULARY REVIEW Define the following terms. 1. cellular respiration 2. glycolysis 3. calorie 4. fermentation M ULTIPLE CHOICE Write the correct letter in the blank.

More information

Major concepts: Notes: Capturing Cell Energy

Major concepts: Notes: Capturing Cell Energy 1. The fundamental life processes of plants and animals depend on a variety of chemical reactions that occur in specialized areas of the organism s cells. As a basis for understanding this concept: 1.

More information

Catalysis by Enzymes. Enzyme A protein that acts as a catalyst for a biochemical reaction.

Catalysis by Enzymes. Enzyme A protein that acts as a catalyst for a biochemical reaction. Catalysis by Enzymes Enzyme A protein that acts as a catalyst for a biochemical reaction. Enzymatic Reaction Specificity Enzyme Cofactors Many enzymes are conjugated proteins that require nonprotein portions

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

Cellular Respiration. Cellular Respiration. The Mighty Mitochondria. Cellular Respiration. Cellular Respiration

Cellular Respiration. Cellular Respiration. The Mighty Mitochondria. Cellular Respiration. Cellular Respiration Have you ever wondered why you need oxygen? The Process that releases energy by breaking down food molecules in the presence of oxygen That energy goes to make ATP. What does it all mean? C 6 H 12 O 6

More information

Cellular Respiration. The backwards and slightly more complicated version of photosynthesis

Cellular Respiration. The backwards and slightly more complicated version of photosynthesis Cellular Respiration The backwards and slightly more complicated version of photosynthesis Learning Outcomes I will. - Explain how glycolysis and the Kreb s cycle work and describe where these processes

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

Section 2 1 The Nature of Matter (pages 35 39)

Section 2 1 The Nature of Matter (pages 35 39) Chapter 2 The Chemistry of Life Section 2 1 The Nature of Matter (pages 35 39) Key Concepts What three subatomic particles make up atoms? How are all of the isotopes of an element similar? What are the

More information

Chemical Basis of Life Module A Anchor 2

Chemical Basis of Life Module A Anchor 2 Chemical Basis of Life Module A Anchor 2 Key Concepts: - Water is a polar molecule. Therefore, it is able to form multiple hydrogen bonds, which account for many of its special properties. - Water s polarity

More information

pencil. Vocabulary: 1. Reactant 2. Product 3. Activation energy 4. Catalyst 5. substrate 6. Chemical reaction Keep your textbooks when you are done

pencil. Vocabulary: 1. Reactant 2. Product 3. Activation energy 4. Catalyst 5. substrate 6. Chemical reaction Keep your textbooks when you are done Objectives Students will explore the importance of chemical reactions in biology Students will discuss the role of enzymes as catalysts in biological reactions. Students will analyze graphs showing how

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

What is an Enzyme? Animations

What is an Enzyme? Animations First Catalysts Manganese dioxide (a black powder) will catalyze the breakdown of hydrogen peroxide. Car exhaust pipes use catalytic converters help convert carbon monoxide (CO) and unburned hydrocarbons

More information

The effects that are in play when the enzyme-substrate complex forms: The chains needed for catalysis are in the active site

The effects that are in play when the enzyme-substrate complex forms: The chains needed for catalysis are in the active site The effects that are in play when the enzyme-substrate complex forms: The proximity effect: The orientation effect: The catalytic effect: The energy effect: The enzyme has to join up with the substrate

More information

The purpose of this lab is to investigate the impact of temperature, substrate concentration,

The purpose of this lab is to investigate the impact of temperature, substrate concentration, Lee 1 Jessica Lee AP Biology Mrs. Kingston 23 October 2013 Abstract: The purpose of this lab is to investigate the impact of temperature, substrate concentration, enzyme concentration, and the presence

More information

Enzymes: Practice Questions #1

Enzymes: Practice Questions #1 Enzymes: Practice Questions #1 1. Compound X increases the rate of the reaction below. Compound X is most likely A. an enzyme B. a lipid molecule C. an indicator D. an ADP molecule 2. The equation below

More information

Proteins. Molecular Physiology: Enzymes and Cell Signaling. Binding. Protein Specificity. Enzymes. Enzymatic Reactions

Proteins. Molecular Physiology: Enzymes and Cell Signaling. Binding. Protein Specificity. Enzymes. Enzymatic Reactions Proteins Molecular Physiology: Enzymes and Cell Signaling Polymers of amino acids Have complex 3D structures Are the basis of most of the structure and physiological function of cells Binding Much of protein

More information

Cellular Respiration: Practice Questions #1

Cellular Respiration: Practice Questions #1 Cellular Respiration: Practice Questions #1 1. Which statement best describes one of the events taking place in the chemical reaction? A. Energy is being stored as a result of aerobic respiration. B. Fermentation

More information

Cellular respiration. Cellular respiration. Respiration and fermentation. Respiration as a redox rxn. Redox reactions.

Cellular respiration. Cellular respiration. Respiration and fermentation. Respiration as a redox rxn. Redox reactions. Cellular respiration So why do we breathe? The big picture Heterotrophs cannot make their own food to supply their energy needs Instead they break down food to use the chemical energy stored in organic

More information

11 Enzymes Enzymes catalyze metabolic reactions that are crucial for life.

11 Enzymes Enzymes catalyze metabolic reactions that are crucial for life. Principles of Biology contents 11 Enzymes Enzymes catalyze metabolic reactions that are crucial for life. A computer model of the protein kinase AKT1. RAC-alpha serine/threonine-protein kinase (AKT1) is

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

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

Cellular Respiration Part V: Anaerobic Respiration and Fermentation

Cellular Respiration Part V: Anaerobic Respiration and Fermentation Cellular Respiration Part V: Anaerobic Respiration and Fermentation Figure 9.16 Electron shuttles span membrane 2 NADH or 2 FADH 2 MITOCHONDRION 2 NADH 2 NADH 6 NADH 2 FADH 2 Glucose Glycolysis 2 Pyruvate

More information

Keystone Study Guide Module A: Cells and Cell Processes

Keystone Study Guide Module A: Cells and Cell Processes Keystone Study Guide Module A: Cells and Cell Processes Topic 1: Biological Principles Cells and the Organization of Life Characteristics of Life all living things share the following characteristics:

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