Protein Function. After the Folding. Lecture 3

Size: px
Start display at page:

Download "Protein Function. After the Folding. Lecture 3"

Transcription

1 Protein Function After the Folding Lecture 3

2 Gene to gene product (protein)

3 Protein folding of nascent polypeptide chain - Immediate folding amplification

4 Proteins mediate virtually all cellular functions Cellular structure Transport across membranes Import of nutrients Export of waste Response to cellular environment: receptors Receptor ligands, e.g., hormones Biosynthesis: small molecules & polymers Biodegradation and energy metabolism Movement: muscle contraction Molecular machines

5 Two types of proteins I: Fibrous elongated, secondary structure dominant functions: structural (connective, protective, supportive) motive (muscle, ciliary proteins) e.g., cytoskeletal proteins of cell maintains cell/tissue structure anchor for membrane receptors

6 Triple helical collagen: covalent cross-links provide a tensile strength greater than steel LH helix RH supercoil crosslinked collagen fibrils

7 H-bonds, van der Waals bonds strengthen ϑ-sheets Fibroin: noncovalent forces provide flexibility & cohesion

8 Relative dimensions: 585 a.a. of globular or fibrous proteins

9 Two types of proteins II. Globular Compact spheroids <25% = active surface Enzymes (= catalytic) Transporters Receptors

10 Enzymes: remarkable catalysts Definition: Catalyst: Increases rates of reactions without participation in the reaction Enzyme: Protein catalyst -ase, e.g., kinase, transferase, reductase

11 Enzymes: remarkable catalysts Uncatalyzed: A + B A-B (1 A-B formed per day) Enzyme catalyzed: A + B A-B (1 A-B formed per msec) Enz. e.g. ENZYME WANTED for: (caffeine + brain cell stimulated brain cell)

12 Enzymes: remarkable catalysts 1) HUGE rate enhancements: 10 7 to fold 2) High degree of specificity 3) Operate under mild conditions 4) Provide amplification: Few molecules can initiate BIG response

13 AMPLIFICATION Enzyme cascade: each product stimulates the next enzyme in a multi-step pathway. 10,000 outputs for each input

14 Enzymes: high specificity of substrate recognition

15 Enzyme specificity of substrate recognition Metabolism of Washington wine (normal) CH3-CH2-OH CH3-CH=O (Ethanol) Alcohol (Acetaldehyde) Dehydrogenase (ADH) Toxic metabolism of antifreeze CH3-OH CH3=O (Methanol) ADH (Formaldehyde)

16 Enzymes are remarkable catalysts Function under mild conditions Neutral ph Physiological temperatures ~1 atm pressure e.g. Nitrogen fixation: N2 + H2 NH4 nitrogenase (Nature s way) vs. the industrial (Haber) process: ~200 atm pressure, 500ºC

17 Enzymes: remarkable catalysts 1) HUGE rate enhancements: 10 7 to fold 2) High degree of specificity 3) Operate under mild conditions 4) Provide amplification: Few molecules can initiate BIG response

18 Rate enhancement by reduction in entropy

19 Enzyme active sites: provide an special environment Brings reactants (substrates) into proximity Orients them properly for reaction Thus reduces entropy

20 Enzymes lower activation energies

21 Enzyme binds best to the transition state using multiple binding interactions

22 Also, Transporters High specificity Large rate enhancements Operate under mild conditions Provide amplification (Also, Binders e.g., receptors and serum transporters)

23 Summary How do proteins achieve catalysis? (lowering of activation energy) Provide a special environment for reaction by: Bind the substrate weakly Bind best to the transition state Binding the transition state by multiple weak interactions Reduce entropy by spatial and dynamic restriction of the substrate

24 Multi-reaction biological processes require enzyme complexes A B C D E E-1 E-2 E-3 E-4

25 Timescales ranging from psec to sec Proteins are dynamic

26 Protein dynamics Family of structures by NMR myoglobin

27 Regulating protein function: why? Prevent inappropriate protein actions Respond to cellular demands (more substrate) Prevent energy waste

28 Regulating protein function 1) Proteolytic cleavage of an enzyme precursor Protease inactivation by tight binding of inhibitor proteins, e.g., - trypsin inhibitor - α1-antiproteinase (elastase)

29 Regulating protein function 2) Cellular location Activation by translocation Nucleus Cell membrane Periplasmic space Highlights need for imaging To quantitative active forms

30 Regulating protein function (rapid) 3) Small molecule activators, inhibitors Product inhibition Substrate activation Active site inhibitors, Allosteric regulators 4) Protein regulators Inhibitor subunits Ca-calmodulin Weak interactions Dissociable

31 Regulating protein function 5) Covalent (bonded) modification More permanent a) Phosphorylation Protein-CH 2 O-H Protein-CH 2 O-PO 3-2 Regulates function and protein interactions Multiple phosphorylations: graded & complex responses Reversible: Kinase and Phosphatase (50% cell proteins are phosphorylated!) b) Oxidative Modifications involved in stress response of the cell -S-O or N-O or NO 2, etc. c) Others

32 Regulating protein function (longer term) 6) Change the amount of Protein (minutes to hours) Increase: make more protein (transcription) Decrease: protein degradation (permanent) Regulates enzyme activity Degrades errors: mis-folded, mis-assembled proteins Protein lifetime

33 Summary Protein regulation range of regulatory responses Rapid and transitory responses to cellular conditions by non-covalent interactions More permanent response by covalent modifications Longer term responses through changes in protein levels (insensitive to msec cellular changes) Understanding cellular responses req. knowledge of protein levels, protein modifications, and function

34 Isozymes: tissue and cell tailoring Def.: multiple forms of an enzyme that catalyze the same reaction, but vary in sequence, substrate affinity, maximal activity or regulatory properties Different isozymes expressed in different tissues or cell organelles Pharmaceutical targeting Diagnostic use as markers of tissue damage e.g., heart attacks or liver damage diagnosed from specific heart or liver proteins in serum

35 Cyclo-oxygenase (COX) isozymes: aspirin & Celebrex Inhibit COX-1: gastric bleeding Inhibit COX-2: inhibit pain, inflammation, fever

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

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

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

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

AP BIOLOGY 2008 SCORING GUIDELINES

AP BIOLOGY 2008 SCORING GUIDELINES AP BIOLOGY 2008 SCORING GUIDELINES Question 1 1. The physical structure of a protein often reflects and affects its function. (a) Describe THREE types of chemical bonds/interactions found in proteins.

More information

ENZYMES - EXTRA QUESTIONS

ENZYMES - EXTRA QUESTIONS ENZYMES - EXTRA QUESTIONS 1. A chemical reaction has a G o = -60 kj/mol. If this were an enzyme-catalyzed reaction what can you predict about the kinetics? A. It will exhibit very rapid kinetics. B. It

More information

Enzymes reduce the activation energy

Enzymes reduce the activation energy Enzymes reduce the activation energy Transition state is an unstable transitory combination of reactant molecules which occurs at the potential energy maximum (free energy maximum). Note - the ΔG of the

More information

http://faculty.sau.edu.sa/h.alshehri

http://faculty.sau.edu.sa/h.alshehri http://faculty.sau.edu.sa/h.alshehri Definition: Proteins are macromolecules with a backbone formed by polymerization of amino acids. Proteins carry out a number of functions in living organisms: - They

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

Helices From Readily in Biological Structures

Helices From Readily in Biological Structures The α Helix and the β Sheet Are Common Folding Patterns Although the overall conformation each protein is unique, there are only two different folding patterns are present in all proteins, which are α

More information

Lecture 4 Enzymes Catalytic proteins. Enzymes. Enzymes 10/21/10. What enzymes do therefore is:

Lecture 4 Enzymes Catalytic proteins. Enzymes. Enzymes 10/21/10. What enzymes do therefore is: Lecture 4 Catalytic proteins Are a type of protein that acts as a catalyst-speeding up chemical reactions A catalyst is defined as a chemical agent that changes the rate of a reaction without being consumed

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

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

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

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

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

Ch7 Enzymes II: Coenzymes, Regulation, Abzymes, and Ribozymes 阮雪芬 NTU

Ch7 Enzymes II: Coenzymes, Regulation, Abzymes, and Ribozymes 阮雪芬 NTU Ch7 Enzymes II: Coenzymes, Regulation, Abzymes, and Ribozymes 阮雪芬 2004/04/23 @ NTU Enzyme: Coenzyme Partners Vitamins and coenzymes Coenzyme: an organic or organometallic molecule that assists an enzyme.

More information

Structure of proteins

Structure of proteins Structure of proteins Primary structure: is amino acids sequence or the covalent structure (50-2500) amino acids M.Wt. of amino acid=110 Dalton (56 110=5610 Dalton). Single chain or more than one polypeptide

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

Lecture 15: Enzymes & Kinetics Mechanisms

Lecture 15: Enzymes & Kinetics Mechanisms ROLE OF THE TRANSITION STATE Lecture 15: Enzymes & Kinetics Mechanisms Consider the reaction: H-O-H + Cl - H-O δ- H Cl δ- HO - + H-Cl Reactants Transition state Products Margaret A. Daugherty Fall 2004

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

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

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

Lecture Notes 1. Organ Systems in Review Integumentary Musculoskeletal Respiratory Digestive Urinary Reproductive Circulatory Nervous

Lecture Notes 1. Organ Systems in Review Integumentary Musculoskeletal Respiratory Digestive Urinary Reproductive Circulatory Nervous Lecture Notes 1 Chapter 1 Introduction to Physiology Physiology is an integrative science Function and mechanism Themes in physiology Homeostasis Control systems and homeostasis The science of physiology

More information

A. A peptide with 12 amino acids has the following amino acid composition: 2 Met, 1 Tyr, 1 Trp, 2 Glu, 1 Lys, 1 Arg, 1 Thr, 1 Asn, 1 Ile, 1 Cys

A. A peptide with 12 amino acids has the following amino acid composition: 2 Met, 1 Tyr, 1 Trp, 2 Glu, 1 Lys, 1 Arg, 1 Thr, 1 Asn, 1 Ile, 1 Cys Questions- Proteins & Enzymes A. A peptide with 12 amino acids has the following amino acid composition: 2 Met, 1 Tyr, 1 Trp, 2 Glu, 1 Lys, 1 Arg, 1 Thr, 1 Asn, 1 Ile, 1 Cys Reaction of the intact peptide

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

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

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

Higher organisms ensure a continuous supply of glucose by storing it as glucose polysaccharides.

Higher organisms ensure a continuous supply of glucose by storing it as glucose polysaccharides. Glycogen Metabolism Higher organisms ensure a continuous supply of glucose by storing it as glucose polysaccharides. plants: starch animals: glycogen Glycogen granules prominent in liver and muscle cells.

More information

Chapter 3. Protein Structure and Function

Chapter 3. Protein Structure and Function Chapter 3 Protein Structure and Function Broad functional classes So Proteins have structure and function... Fine! -Why do we care to know more???? Understanding functional architechture gives us POWER

More information

Lecture 11 Enzymes: Kinetics

Lecture 11 Enzymes: Kinetics Lecture 11 Enzymes: Kinetics Reading: Berg, Tymoczko & Stryer, 6th ed., Chapter 8, pp. 216-225 Key Concepts Kinetics is the study of reaction rates (velocities). Study of enzyme kinetics is useful for

More information

Catalyst is a compound that by its addition to a reaction increases

Catalyst is a compound that by its addition to a reaction increases Chapter 23: Catalysis 21-1 Catalyst and Catalysis: Introduction Catalyst is a compound that by its addition to a reaction increases the rate of the reaction without itself being consumed or changed at

More information

Lecture 9: Glycogen phosphorylase

Lecture 9: Glycogen phosphorylase Chem*3560 Lecture 9: Glycogen phosphorylase Glycogen synthesis and breakdown govern availability of glucose in animals Glycogen is stored in the body in liver and in skeletal muscles. A normal 70 kg person

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

Biochemistry 2000 Sample Question Proteins. (1) Identify the secondary structure described in each of the following statements:

Biochemistry 2000 Sample Question Proteins. (1) Identify the secondary structure described in each of the following statements: (1) Identify the secondary structure described in each of the following statements: a. A coiled peptide chain held in place by hydrogen bonding between peptide bonds in the same chain b. A structure that

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

Regulation of enzyme activity

Regulation of enzyme activity 1 Regulation of enzyme activity Regulation of enzyme activity is important to coordinate the different metabolic processes. It is also important for homeostasis i.e. to maintain the internal environment

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

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

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

Reading Assignment: pp , ,

Reading Assignment: pp , , Chapter 6 "Mechanisms of Enzymes" Reading Assignment: pp. 158-167, 171-176, 182-187. Problem Assignment: 1, 3, and 4. I. Introduction The first objective of this chapter is to obtain a conceptual understanding

More information

Chapter 12 - Reaction Kinetics

Chapter 12 - Reaction Kinetics Chapter 12 - Reaction Kinetics In the last chapter we looked at enzyme mechanisms. In this chapter we ll see how enzyme kinetics, i.e., the study of enzyme reaction rates, can be useful in learning more

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

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 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

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

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

NO CALCULATORS OR CELL PHONES ALLOWED

NO CALCULATORS OR CELL PHONES ALLOWED Biol 205 Exam 1 TEST FORM A Spring 2008 NAME Fill out both sides of the Scantron Sheet. On Side 2 be sure to indicate that you have TEST FORM A The answers to Part I should be placed on the SCANTRON SHEET.

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

PRINCIPLES OF METABOLISM

PRINCIPLES OF METABOLISM Bryan Krantz: University of California, Berkeley MCB 102, Spring 2008, Metabolism Lecture 6 Reading: Ch. 15 of Principles of Biochemistry, Principles of Metabolic Regulation, Illustrated with Glucose and

More information

Copyright 2000-2003 Mark Brandt, Ph.D. 54

Copyright 2000-2003 Mark Brandt, Ph.D. 54 Pyruvate Oxidation Overview of pyruvate metabolism Pyruvate can be produced in a variety of ways. It is an end product of glycolysis, and can be derived from lactate taken up from the environment (or,

More information

Introduction to Proteins and Enzymes

Introduction to Proteins and Enzymes Introduction to Proteins and Enzymes Basics of protein structure and composition The life of a protein Enzymes Theory of enzyme function Not all enzymes are proteins / not all proteins are enzymes Enzyme

More information

Cyclooxygenase and NSAIDs

Cyclooxygenase and NSAIDs Cyclooxygenase and NSAIDs Cyclooxygenase An enzyme responsible for the production of prostaglandins Two forms, COX1 and COX2 Contains two separate active sites for prostaglandin synthase One side contains

More information

Enzymes: Introduction

Enzymes: Introduction Enzymes: Introduction Firefly bioluminescence is produced by an oxidation reaction catalyzed by the enzyme firefly luciferase. The oxidized substrate (product of the reaction) is in an electronically excited

More information

Enzymes. OpenStax College

Enzymes. OpenStax College OpenStax-CNX module: m44429 1 Enzymes OpenStax College This work is produced by OpenStax-CNX and licensed under the Creative Commons Attribution License 4.0 By the end of this section, you will be able

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

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

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

Lecture 8: Signal Transduction

Lecture 8: Signal Transduction Computational Systems Biology Lecture 8: Signal Transduction 1 Images from: D. L. Nelson, Lehninger Principles of Biochemistry, IV Edition Chapter 12 E. Klipp, Systems Biology in Practice, Wiley-VCH, 2005

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

The Behavior of Proteins:

The Behavior of Proteins: Mary K. Campbell Shawn O. Farrell http://academic.cengage.com/chemistry/campbell Chapter 7 The Behavior of Proteins: Enzymes, Mechanisms, and Control Paul D. Adams University of Arkansas The catalytic

More information

Carbohydrates, proteins and lipids

Carbohydrates, proteins and lipids Carbohydrates, proteins and lipids Chapter 3 MACROMOLECULES Macromolecules: polymers with molecular weights >1,000 Functional groups THE FOUR MACROMOLECULES IN LIFE Molecules in living organisms: proteins,

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

Regulation of the Citric Acid Cycle

Regulation of the Citric Acid Cycle Regulation of the itric Acid ycle I. hanges in Free Energy February 17, 2003 Bryant Miles kj/mol 40 20 0 20 40 60 80 Reaction DGo' DG TA Free Energy hanges 1 2 3 4 5 6 7 8 9 1.) itrate Synthase 2.) Aconitase

More information

Transmembrane proteins span the bilayer. α-helix transmembrane domain. Multiple transmembrane helices in one polypeptide

Transmembrane proteins span the bilayer. α-helix transmembrane domain. Multiple transmembrane helices in one polypeptide Transmembrane proteins span the bilayer α-helix transmembrane domain Hydrophobic R groups of a.a. interact with fatty acid chains Multiple transmembrane helices in one polypeptide Polar a.a. Hydrophilic

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

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

Chapter 8: Energy and Metabolism

Chapter 8: Energy and Metabolism 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

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

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

It s the amino acids!

It s the amino acids! Catalytic Mechanisms HOW do enzymes do their job? Reducing activation energy sure, but HOW does an enzyme catalysis reduce the energy barrier ΔG? Remember: The rate of a chemical reaction of substrate

More information

Chem 454 Regulatory Mechanisms in Biochemistry Review for Exam I - Spring 2003 Chapter 14 Metabolism: Basic Concepts and Design Classify organisms based on their source of energy. Describe the energy requirements

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

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

Glycolysis. The Glycolytic Pathway. The Reactions of Glycolysis. Fermentation: The Anaerobic Fate of Pyruvate. Control of Metabolic Flux

Glycolysis. The Glycolytic Pathway. The Reactions of Glycolysis. Fermentation: The Anaerobic Fate of Pyruvate. Control of Metabolic Flux Glycolysis The Glycolytic Pathway The Reactions of Glycolysis Fermentation: The Anaerobic Fate of Pyruvate Control of Metabolic Flux Metabolism of Hexoses Other Than Glucose The Glycolytic Pathway (Embden-Meyerhof-Parnas

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

The correct answer is d B. Answer b is incorrect. Transcription factors are proteins that bind DNA and trigger a change in gene expression.

The correct answer is d B. Answer b is incorrect. Transcription factors are proteins that bind DNA and trigger a change in gene expression. 1. What is a ligand? a. An integral membrane protein associated with G proteins b. A DNA-binding protein that alters gene expression c. A cytoplasmic second-messenger molecule d. A molecule or protein

More information

Cell Communication & Regulation of the Cell Cycle

Cell Communication & Regulation of the Cell Cycle Cell Communication & Regulation of the Cell Cycle 1 Why do cells need to respond to signals? 1. Need to respond to a changing environment Adaptation or a cellular response is critical for survival Glucose

More information

Introduction to Proteins; Amino Acids, the Building Blocks of Proteins

Introduction to Proteins; Amino Acids, the Building Blocks of Proteins Introduction to Proteins; Amino Acids, the Building Blocks of Proteins Reading: Berg, Tymoczko & Stryer: Chapter 2, pp. 25-34 Appendix to Chapter 2, pp. 60-61 (visualizing protein structures) Review General

More information

- hormonal regulation of both directions

- hormonal regulation of both directions Glycogen metabolism Glycogen review - 1,4 and 1,6 α-glycosidic links ~ every 10 sugars are branched - open helix with many non-reducing ends. Effective storage of glucose Glucose storage Liver glycogen

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

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

Exam 3. If I cannot read your writing I will not grade the answer and it will be assigned 0 points.

Exam 3. If I cannot read your writing I will not grade the answer and it will be assigned 0 points. Chemistry 326 Fall 2009 Name Check Section: Tuesday Wednesday Thursday Exam 3 If I cannot read your writing I will not grade the answer and it will be assigned 0 points. 1. Multiple Choice (choose the

More information

Ch. 8 Enzymes as catalysts

Ch. 8 Enzymes as catalysts Chapt. 8 Enzymes as catalysts Ch. 8 Enzymes as catalysts Student Learning Outcomes: Explain general features of enzymes as catalysts: Substrate -> Product Describe nature of catalytic sites general mechanisms

More information

4. Which of the following is always present in both conjugated enzymes and simple enzymes? A) protein B) a vitamin C) a cofactor D) a coenzyme

4. Which of the following is always present in both conjugated enzymes and simple enzymes? A) protein B) a vitamin C) a cofactor D) a coenzyme Chem 121 Sample Question Chapter 21: Enzymes and Vitamins 1. What is the function of enzymes within living systems? A) structural elements B) neurotransmitters C) catalysts D) hormones 2. Enzymes have

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

ENZYME MECHANISM C H A P T E R 7

ENZYME MECHANISM C H A P T E R 7 C H A P T E R 7 ENZYME MECHANISM Active Site Transition State Catalysis Lock and Key Induced Fit Nonproductive Binding Entropy Strain and Distortion Transition-State Stabilization Transition-State Analogs

More information

The diagram below summarizes the effects of the compounds that cells use to regulate their own metabolism.

The diagram below summarizes the effects of the compounds that cells use to regulate their own metabolism. Regulation of carbohydrate metabolism Intracellular metabolic regulators Each of the control point steps in the carbohydrate metabolic pathways in effect regulates itself by responding to molecules that

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

Lecture 10 Enzymes: Introduction

Lecture 10 Enzymes: Introduction Lecture 10 Enzymes: Introduction Reading: Berg, Tymoczko & Stryer, 6th ed., Chapter 8, pp. 205-217 (These pages in textbook are very important -- concepts of thermodynamics are fundamental to all of biochemistry.)

More information

Chapter-21b: Hormones and Receptors

Chapter-21b: Hormones and Receptors 1 hapter-21b: Hormones and Receptors Hormone classes Hormones are classified according to the distance over which they act. 1. Autocrine hormones --- act on the same cell that released them. Interleukin-2

More information

Chapter 15 Homework Assignment

Chapter 15 Homework Assignment Chapter 15 Homework Assignment The following problems will be due once we finish i the chapter: 3, 5, 6, 8, 9 Chapter 15 1 Chapter 15 Principles of Metabolic Regulation 1 Regulation of Metabolic Pathways

More information

Chapter 16 Amino Acids, Proteins, and Enzymes. Functions of Proteins. Examples of Amino Acids. Amino Acids. Nonpolar Amino Acids. Types of Amino Acids

Chapter 16 Amino Acids, Proteins, and Enzymes. Functions of Proteins. Examples of Amino Acids. Amino Acids. Nonpolar Amino Acids. Types of Amino Acids Chapter 16 Amino Acids, Proteins, and Enzymes 16.1 Functions of Proteins 16.2 Amino Acids 16.3 Amino Acids as Acids and Bases Functions of Proteins Proteins perform many different functions in the body.

More information

Lecture 3: Glycogen metabolism (Chapter 15)

Lecture 3: Glycogen metabolism (Chapter 15) Lecture 3: Glycogen metabolism (Chapter 15) Review: Glycogen breakdown (VVP Ch. 15.1) New: More on Phosphorylase (Ch. 15.1, 15.3) Glycogen synthesis (Ch. 15.2) Some on regulation (Ch. 15.3) Roll Call!

More information

Unit 2 Metabolism and Survival Summary

Unit 2 Metabolism and Survival Summary Unit 2 Metabolism and Survival Summary 1 Metabolism pathways and their control (a) Introduction to metabolic pathways This involves integrated and controlled pathways of enzymecatalysed reactions within

More information

9/23/2013. I. What provides evidence of evolution of cell signaling?

9/23/2013. I. What provides evidence of evolution of cell signaling? BI.D.: Cell communication processes share common features that reflect a shared evolutionary history. BI.D.: Cells communicate with each other through direct contact with other cells or from a distance

More information

Keystone Review Practice Test Module A Cells and Cell Processes. 1. Which characteristic is shared by all prokaryotes and eukaryotes?

Keystone Review Practice Test Module A Cells and Cell Processes. 1. Which characteristic is shared by all prokaryotes and eukaryotes? Keystone Review Practice Test Module A Cells and Cell Processes 1. Which characteristic is shared by all prokaryotes and eukaryotes? a. Ability to store hereditary information b. Use of organelles to control

More information

Ch. 20 Tricarboxylic acid cyle. TCA cycle (Kreb s cycle) or citric acid cycle: Generates 2/3 of ATP

Ch. 20 Tricarboxylic acid cyle. TCA cycle (Kreb s cycle) or citric acid cycle: Generates 2/3 of ATP Chapt. 20 TCA cycle Ch. 20 Tricarboxylic acid cyle Student Learning Outcomes: Describe relevance of TCA cycle Acetyl CoA funnels products Describe reactions of TCA cycle in cell respiration: 2C added,

More information

Fatty Acid Biosynthesis

Fatty Acid Biosynthesis Synthesis takes place in the cytosol Intermediates covalently linked to acyl carrier protein Activation of each acetyl CoA. acetyl CoA + CO 2 Malonyl CoA Four-step repeating cycle, extension by 2-carbons

More information

Chapter 2 - Chemical Foundations

Chapter 2 - Chemical Foundations Chapter 2 - Chemical Foundations I. Introduction By weight, cells are about 70% water, about 1% ions, about 6% small organic molecules (including amino acids, sugars, nucleotides), and about 23% macromolecules.

More information