Chapter 04 1 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

4.1: Introduction Metabolic processes – Many reactions form cycles or pathways

4.2: Metabolic Processes There are two (2) types of metabolic pathways: Anabolism Catabolism

Anabolism Anabolism Example: Dehydration synthesis Monosaccharide Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. CH2OH CH2OH CH2OH CH2OH O O O O H H H H H H H H H H H H H2O O HO OH H OH HO OH H OH HO OH H OH H OH H OH H OH H OH H OH Monosaccharide + Monosaccharide Disaccharide + Water

Anabolism + + H O H O H C OH HO C (CH2)14 CH3 H C O C (CH2)14 CH3 O O Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. H O H O H C OH HO C (CH2)14 CH3 H C O C (CH2)14 CH3 O O H2O H C OH HO C (CH2)14 CH3 H C O C (CH2)14 CH3 H2O H2O O O H C OH HO C (CH2)14 CH3 H C O C (CH2)14 CH3 H H Glycerol + 3 fatty acid molecules Fat molecule (triglyceride) + 3 water molecules Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Peptide bond H H H H H O O R R H O H O H H H O O N C C N C C N N C C C C N N C C C C OH OH H2O H O H H O H H H R R R R H H H H Amino acid + Amino acid Dipeptide molecule + Water

Catabolism Catabolism Ex: digestion Example: Hydrolysis Monosaccharide Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. CH2OH CH2OH CH2OH CH2OH O O O O H H H H H H H H H H H H H2O O HO OH H OH HO OH H OH HO OH H OH H OH H OH H OH H OH H OH Monosaccharide + Monosaccharide Disaccharide + Water

Catabolism + + H O H O H C OH HO C (CH2)14 CH3 H C O C (CH2)14 CH3 O O Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. H O H O H C OH HO C (CH2)14 CH3 H C O C (CH2)14 CH3 O O H2O H C OH HO C (CH2)14 CH3 H C O C (CH2)14 CH3 H2O H2O O O H C OH HO C (CH2)14 CH3 H C O C (CH2)14 CH3 H H Glycerol + 3 fatty acid molecules Fat molecule (triglyceride) + 3 water molecules Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Peptide bond H H H H H O O R R H O H O H H H O O N C C N C C N N C C C C N N C C C C OH OH H2O H O H H O H H H R R R R H H H H Amino acid + Amino acid Dipeptide molecule + Water

4.3: Control of Metabolic Reactions Enzymes Metabolic reactions include ____________ of chemical changes that must occur in particular sequences. Occur rapidly due to ________________ Control rates of metabolic reactions Lower activation energy needed to start reactions Most are globular proteins with specific shapes Not consumed in chemical reactions Substrate specific Shape of active site determines substrate Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Substrate molecules Product molecule Active site Enzyme molecule Enzyme-substrate complex Unaltered enzyme molecule (a) (b) (c)

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4.3: Control of Metabolic Reactions Enzyme Action 4.3: Control of Metabolic Reactions Enzymes Control _________ of metabolic reactions Lower _______________ needed to start reactions (catalysis) Most are __________ proteins with specific shapes Not ________________ in chemical reactions _________________ specific (target) ______________ of active site determines substrate Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Substrate molecules Product molecule Active site Enzyme molecule Enzyme-substrate complex Unaltered enzyme molecule (a) (b) (c)

Enzyme Action Rate of the reaction is dependent on: Many reactions are ________________

Enzyme Action Metabolic pathways Enzyme names commonly: Series of enzyme-controlled reactions leading to formation of a _____________ Each new substrate is the product of the _____________ reaction Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Substrate 1 Enzyme A Substrate 2 Enzyme B Substrate 3 Enzyme C Substrate 4 Enzyme D Product Enzyme names commonly: Reflect the ______________ Have the suffix ______________ Examples: sucrase, lactase, protease, lipase

Regulation of Metabolic Pathways Limited number of regulatory enzymes (determines rate of reaction) _______________ feedback _______________ enzymes control the entire pathway Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Inhibition Rate-limiting Enzyme A Substrate 1 Substrate 2 Enzyme B Substrate 3 Enzyme C Substrate 4 Enzyme D Product Enzyme can become _______ and an increase in substrate concentration will have no effect

Cofactors and Coenzymes

Factors That Alter Enzymes Remember that enzymes are proteins.

4.4: Energy for Metabolic Reactions _______________ is the capacity to change something; it is the ability to do work Common forms of energy: Energy can be changed from one form to another. Through cellular respiration, energy is transferred from molecules to make it available for cellular use.

ATP Molecules __________________________carries energy in a form that the cell can use Each ATP molecule has three parts: Energy is released when a phosphate group is removed to form ADP Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. P P P Energy transferred and utilized by metabolic reactions when phosphate bond is broken Energy transferred from cellular respiration used to reattach phosphate P P P P

Release of Chemical Energy Chemical bonds are _____________to release energy We burn glucose in a process called ______________

4.5: Cellular Respiration Occurs in a series of reactions: Summary: Carbon based molecules from food and oxygen are used to make ATP

Cellular Respiration Produces: Includes: Anaerobic reactions (without O2) – produce ________ Aerobic reactions (requires O2) - produce ___________ Sugars + O2 → CO2 + H2O

Glycolysis Series of ______________ reactions Breaks down glucose into 2 _____________ molecules Occurs in_____________________ _______________phase of cellular respiration Yields ______ ATP molecules per glucose molecule Must occur before cellular respiration Summarized by three main phases or events: (pyruvate is produced but NOT energy)

Glycolysis Event 1 - Phosphorylation Event 2 – Splitting (cleavage) Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Event 1 - Phosphorylation Phase 1 priming Glucose Carbon atom P Phosphate 2 ATP 2 ADP Fructose-1,6-diphosphate P P Phase 2 cleavage Event 2 – Splitting (cleavage) Dihydroxyacetone phosphate Glyceraldehyde phosphate P P Phase 3 oxidation and formation of ATP and release of high energy electrons P 2 NAD+ 4 ADP 2 NADH + H+ 4 ATP 2 Pyruvic acid O2 O2 2 NADH + H+ 2 NAD+ To citric acid cycle and electron transport chain (aerobic pathway) 2 Lactic acid

Glycolysis Event 3 – Production of NADH and ATP ____________ toms are released Hydrogen atoms bind to NAD+ to produce ________ NADH delivers hydrogen and high energy electrons to electron transport chain if _______ is available ADP is ________ to become ATP ____ molecules of pyruvic acid are produced _____ molecules of ATP are generated Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Phase 1 priming Glucose Carbon atom P Phosphate 2 ATP 2 ADP Fructose-1,6-diphosphate P P Phase 2 cleavage Dihydroxyacetone phosphate Glyceraldehyde phosphate P P Phase 3 oxidation and formation of ATP and release of high energy electrons P 2 NAD+ 4 ADP 2 NADH + H+ 4 ATP 2 Pyruvic acid O2 O2 2 NADH + H+ 2 NAD+ To citric acid cycle and electron transport chain (aerobic pathway) 2 Lactic acid

Anaerobic Reactions If oxygen is not available: Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. If oxygen is not available: Electron transport system cannot accept new ___________ from NADH Pyruvic acid is converted to __________ acid ___________ is inhibited ATP production is _____ than in aerobic reactions Phase 1 priming Glucose Carbon atom P Phosphate 2 ATP 2 ADP Fructose-1,6-diphosphate P P Phase 2 cleavage Dihydroxyacetone phosphate Glyceraldehyde phosphate P P Phase 3 oxidation and formation of ATP and release of high energy electrons P 2 NAD+ 4 ADP 2 NADH + H+ 4 ATP 2 Pyruvic acid O2 O2 2 NADH + H+ 2 NAD+ To citric acid cycle and electron transport chain (aerobic pathway) 2 Lactic acid

Aerobic Reactions (mitochondria) Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. If oxygen is available: Pyruvic acid is used to produce ________ Citric acid cycle ________ Electron _______ chain functions Carbon dioxide and _______ are formed Up to ___ molecules of ATP are produced per each glucose molecule Glucose High energy electrons (e–) and hydrogen ions (H+) 2 ATP Pyruvic acid Pyruvic acid Cytosol Mitochondrion High energy electrons (e–) and hydrogen ions (h+) CO2 Acetyl CoA Oxaloacetic acid Citric acid High energy electrons (e–) and hydrogen ions (H+) 2 CO 2 2 ATP Electron transport chain 32-34 ATP O 2 2e – + 2H + H 2 O

Citric Acid Cycle (Kreb’s Cycle) Begins when acetyl CoA combines with oxaloacetic acid to produce ______ acid Citric acid is changed into ___________ acid through a series of reactions Cycle ________ as long as pyruvic acid and oxygen are available Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Pyruvic acid from glycolysis Cytosol Carbon atom + P Phosphate NAD CO 2 Mitochondrion CoA Coenzyme A NADH + H + Acetic acid CoA Acetyl CoA (replenish molecule) Oxaloacetic acid Citric acid (finish molecule) (start molecule) NADH + H + CoA NAD + Malic acid Isocitric acid NAD + For each citric acid molecule: ____ ATP is produced _____ hydrogen atoms are transferred to NAD+ and FAD forming NADH and FADH2 ___ CO2 produced Citric acid cycle CO 2 NADH + H + Fumaric acid -Ketoglutaric acid CO 2 CoA FADH 2 NAD + FAD NADH + H + Succinic acid Succinyl-CoA CoA ADP + P ATP

Citric Acid Cycle (Kreb’s Cycle) Main function is

Electron Transport Chain NADH and FADH2 carry ___________ and high energy electrons to the ETC ETC is a series of enzyme complexes located in the inner membrane of the ________________ Energy from electrons transferred to _______ synthase ATP ______________ catalyzes the phosphorylation of ADP to ATP _______________ is formed (Oxygen is the final electron “carrier”) Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. ATP synthase ADP + P ATP Energy NADH + H+ Energy 2H+ + 2e– FADH2 Energy NAD+ 2H+ + 2e– FAD Electron transport chain 2e– 2H+ O 2 H2O

Summary of Cellular Respiration Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Glucose Glycolysis The 6-carbon sugar glucose is broken down in the cytosol into two 3-carbon pyruvic acid molecules with a net gain of 2 ATP and release of high-energy electrons. High-energy electrons (e–) 1 Glycolysis 2 A T P Cytosol Pyruvic acid Pyruvic acid Citric Acid Cycle The 3-carbon pyruvic acids generated by glycolysis enter the mitochondria. Each loses a carbon (generating CO2 and is combined with a coenzyme to form a 2-carbon acetyl coenzyme A (acetyl CoA). More high-energy electrons are released. 2 High-energy electrons (e–) CO 2 Acetyl Co A 3 Each acetyl CoA combines with a 4-carbon oxaloacetic acid to form the 6-carbon citric acid, for which the cycle is named. For each citric acid, a series of reactions removes 2 carbons (generating 2 CO2’s), synthesizes 1 ATP, and releases more high-energy electrons. The figure shows 2 ATP, resulting directly from 2 turns of the cycle per glucose molecule that enters glycolysis. Oxaloacetic acid Citric acid Citric acid cycle Mitochondrion High-energy electrons (e–) 2 CO 2 2 A T P Electron Transport Chain The high-energy electrons still contain most of the chemical energy of the original glucose molecule. Special carrier molecules bring the high-energy electrons to a series of enzymes that convert much of the remaining energy to more ATP molecules. The other products are heat and water. The function of oxygen as the final electron acceptor in this last step is why the overall process is called aerobic respiration. Electron transport chain 4 32–34 A T P 2e – and 2H + O 2 H 2 O

Carbohydrate Storage Carbohydrate molecules from foods can enter: Most common food type broken down to make ATP

Carbohydrate Storage Excess glucose stored as: Carbohydrates Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Carbohydrates from foods Hydrolysis Monosaccharides Catabolic pathways Anabolic pathways Energy + CO2 + H2O Glycogen or Fat Amino acids

Summary of Catabolism of Proteins, Carbohydrates, and Fats Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Food Food Proteins (egg white) Proteins (egg white) Carbohydrates (toast, hashbrowns) Carbohydrates (toast, hashbrowns) Fats (butter) Fats (butter) 1 1 Breakdown of large macromolecules to simple molecules Breakdown of large macromolecules to simple molecules Amino acids Amino acids Simple sugars (glucose) Simple sugars (glucose) Glycerol Glycerol Fatty acids Fatty acids Glycolysis Glycolysis ATP ATP Pyruvic acid Pyruvic acid 2 2 Breakdown of simple molecules to acetyl coenzyme A accompanied by production of limited ATP and high energy electrons Breakdown of simple molecules to acetyl coenzyme A accompanied by production of limited ATP and high energy electrons Acetyl coenzyme A Acetyl coenzyme A Citric acid cycle Citric acid cycle CO2 CO2 3 3 Complete oxidation of acetyl coenzyme A to H2O and CO2 produces high energy electrons (carried by NADH and FADH2), which yield much ATP via the electron transport chain ATP ATP High energy electrons carried by NADH and FADH2 High energy electrons carried by NADH and FADH2 Electron transport chain Electron transport chain ATP ATP 2e– and 2H+ 2e– and 2H+ –NH2 –NH2 CO2 CO2 ½ O2 ½ O2 H2O H2O Waste products Waste products © Royalty Free/CORBIS. © Royalty Free/CORBIS.

4.6: Nucleic Acids and Protein Synthesis Instruction of cells to synthesize ___________ comes from a nucleic acid, deoxyribonucleic acid (DNA) Central dogma of molecular biology states information flows in ___________ direction: DNA → RNA→ Proteins

Genetic Information Genetic information – Gene – Genome – Genetic Code – Codon:

Structure of DNA made of ___ strands of nucleotides which spiral (double helix) Each nucleotide contains: The ________ of each strand is a sugar-phosphate chain The bases of complementary strands hydrogen bond to each other: ___-___, ___-___ (complimentary base pairs named for N containing bases) DNA wrapped about __________ forms chromosomes

Structure of DNA S P B B P S S P B B P S S P B B P S S P B B P S S P B Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. P B S S P B B P P B S S S P B B P B P S S P S B P B B S P S P B S S P B B P S P B S S P B B P P B S S S P P B B B P S S P B S

Structure of DNA Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. (a) Hydrogen bond P G C P Thymine (T) Adenine (A) P T A P Cytosine (C) Guanine (G) P C G P P G C P P A T G C P strands Polynucleotide A G C A T C G Segment of DNA molecule T A C G T A G C A T T C A G C A G T (b) Globular histone proteins Chromatin chromosome Interphase Metaphase chromosome (c)

Animation: DNA Structure Please note that due to differing operating systems, some animations will not appear until the presentation is viewed in Presentation Mode (Slide Show view). You may see blank slides in the “Normal” or “Slide Sorter” views. All animations will appear after viewing in Presentation Mode and playing each animation. Most animations will require the latest version of the Flash Player, which is available at http://get.adobe.com/flashplayer.

DNA Replication ____________ bonds break between bases Double strands _________ and pull apart New __________ pair with exposed bases Controlled by DNA _________________ An exact copy is made through _______________ replication: every new DNA molecule is composed of one original and one new strand of DNA Occurs during ___________ in the nucleus

DNA Replication interphase Mitosis Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. G2 S G2 phase interphase Prophase Mitosis S phase: genetic material replicates Metaphase Anaphase Telophase Cytokinesis Proceed to division G1 phase: Cell growth A T Remain specialized C G Restriction checkpoint G C Apoptosis C G G1 Original DNA molecule A C G C G A A T C G A T G C C C G G T A A A T A T T A A G C G C Newly forming DNA molecules T A A C G C G C G C G T A A

Animation: DNA Replication Please note that due to differing operating systems, some animations will not appear until the presentation is viewed in Presentation Mode (Slide Show view). You may see blank slides in the “Normal” or “Slide Sorter” views. All animations will appear after viewing in Presentation Mode and playing each animation. Most animations will require the latest version of the Flash Player, which is available at http://get.adobe.com/flashplayer.

Genetic Code Specification of the correct sequence of ____________ in a polypeptide chain Each amino acid is represented by a _________ code of DNA bases The base sequence of a gene then determines the amino acid sequence in a _____________________ Since DNA stays in the nucleus, and proteins are made in the cytoplasm, DNA’s code must be copied and carried to the cytoplasm. __________ molecules accomplish this transfer of the genetic code.

RNA Molecules _______________ strand of nucleotides Each nucleotide contains: ribose, phosphate, base (A, G, C, and _______ instead of Thymine) Shorter than __________ Different types: ______ (carries code from DNA to ribosome during transcription), _____ (brings amino acids to ribosome), ______ (a component of ribosomes)

RNA Molecules Protein Synthesis involves 2 steps, each requiring RNA and enzymes Transcription Translation

RNA Molecules Transcription of Messenger RNA (mRNA): A section of ____ opens up (just where the gene coding for the particular protein is) _______ nucleotides pair up with the DNA bases on one side---uracil is used instead of thymine mRNA moves away and ____ closes up Controlled by RNA ____________ The mRNA now goes through nuclear pore and attaches to a ribosome in the cytoplasm. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. DNA RNA S P A U P S S P T A P S S P Direction of “reading” code G C P S S P C G P S S P G C P S

Animation: Stages of Transcription Please note that due to differing operating systems, some animations will not appear until the presentation is viewed in Presentation Mode (Slide Show view). You may see blank slides in the “Normal” or “Slide Sorter” views. All animations will appear after viewing in Presentation Mode and playing each animation. Most animations will require the latest version of the Flash Player, which is available at http://get.adobe.com/flashplayer.

Protein Synthesis Each ______ molecule has an attachment point for a specific amino acid Each tRNA also has a region of 3 bases called an _____________ which is attracted to complementary mRNA codons As the ribosome moves down the mRNA strand, tRNA’s bringing their _____________ are attracted to the mRNA codons Genes which are translated into __________ are expressed ____________ a.a. building blocks

Animation: How Translation Works Please note that due to differing operating systems, some animations will not appear until the presentation is viewed in Presentation Mode (Slide Show view). You may see blank slides in the “Normal” or “Slide Sorter” views. All animations will appear after viewing in Presentation Mode and playing each animation. Most animations will require the latest version of the Flash Player, which is available at http://get.adobe.com/flashplayer.

Protein Synthesis

Protein Synthesis Cytoplasm 3 Translation begins as tRNA anticodons Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Cytoplasm 3 Translation begins as tRNA anticodons recognize complementary mRNA codons, thus bringing the correct amino acids into position on the growing polypeptide chain DNA double helix Amino acids attached to tRNA Nucleus T A T A 6 tRNA molecules can pick up another molecule of the same amino acid and be reused G C G C 2 mRNA leaves the nucleus and attaches to a ribosome A T A T Polypeptide chain Messenger RNA G C DNA strands pulled apart A T A T T U A C G G G C T A G G C G G C C C G 5 At the end of the mRNA, the ribosome releases the new protein C G T U A T A C C G G C C C G A T G C G C C G A A T G C A A T Nuclear pore 4 As the ribosome moves along the mRNA, more amino acids are added Amino acids represented A T C C G C G G G C T A G G C 1 DNA information is copied, or transcribed, into mRNA following complementary base pairing A C C G U Codon 1 Methionine A A T G C G G G C T A G G C G G C C C G G Codon 2 Glycine A T T U A C C C G C C G U G C A A T C Codon 3 Serine A T T U A C C G G G C G T A A A T Messenger RNA DNA strand C Codon 4 Alanine C C G G C A C G G C A T A C G C Codon 5 Threonine G C A T G Transcription (in nucleus) G C Translation (in cytoplasm) G G C C Codon 6 Alanine C G A U A G C G G Codon 7 Glycine C

Protein Synthesis 1 2 1 The transfer RNA molecule Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. 1 2 1 The transfer RNA molecule for the last amino acid added holds the growing polypeptide chain and is attached to its complementary codon on mRNA. Growing polypeptide chain 3 4 Next amino acid 5 6 Transfer RNA Anticodon U G C C G U A U G G G C U C C G C A A C G G C A G G C A A G C G U 1 2 3 4 5 6 7 Codons 1 Peptide bond 2 2 A second tRNA binds complementarily to the next codon, and in doing so brings the next amino acid into position on the ribosome. A peptide bond forms, linking the new amino acid to the growing polypeptide chain. Growing polypeptide chain 3 4 Next amino acid 5 6 Transfer RNA Anticodon U G C C G U A U G G G C U C C G C A A C G G C A G G C A A G C G U Messenger RNA 1 2 3 4 5 6 7 Codons 1 2 Next amino acid 3 The tRNA molecule that brought the last amino acid to the ribosome is released to the cytoplasm, and will be used again. The ribosome moves to a new position at the next codon on mRNA. A 3 4 5 7 6 Transfer RNA U G C C C G C G U A U G G G C U C C G C A A C G G C A G G C A A G C G U Messenger RNA 1 2 3 4 5 6 7 Ribosome 1 2 4 A new tRNA complementary to the next codon on mRNA brings the next amino acid to be added to the growing polypeptide chain. 3 4 5 Next amino acid 6 7 Transfer RNA C G U C C G A U G G G C U C C G C A A C G G C A G G C A A G C G U Messenger RNA 1 2 3 4 5 6 7

Animation: Protein Synthesis Please note that due to differing operating systems, some animations will not appear until the presentation is viewed in Presentation Mode (Slide Show view). You may see blank slides in the “Normal” or “Slide Sorter” views. All animations will appear after viewing in Presentation Mode and playing each animation. Most animations will require the latest version of the Flash Player, which is available at http://get.adobe.com/flashplayer.

4.7: Changes in Genetic Information Only about ________ of one percent of the human genome differs from person to person

Nature of Mutations Mutations – change in genetic information (DNA) Result when: Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Code for glutamic acid Mutation Code for valine P P T T S S May or may not change the ___________ Those affecting a single gene occur during _____________ Silent Mutations have ______ affect on phenotype Direction of “reading” code P P T A S S P P C C S S (a) (b)

Protection Against Mutation ___________________ correct the mutations

Inborn Errors of Metabolism Occurs from inheriting a mutation that then alters an _____________________ This creates a block in an otherwise normal biochemical pathway

Important Points in Chapter 4: Outcomes to be Assessed 4.1: Introduction Describe the linked pathways of metabolism. 4.2: Metabolic Processes Compare and contrast anabolism and catabolism. 4.3: Control of Metabolic Reactions Describe how enzymes control metabolic reactions. Explain how metabolic pathways are regulated.

Important Points in Chapter 4: Outcomes to be Assessed 4.4: Energy for Metabolic Reactions Explain how ATP stores chemical energy and makes it available to a cell. 4.5: Cellular Respiration Describe how the reactions of cellular respiration release chemical energy. Describe the general metabolic pathways of carbohydrate metabolism.

Important Points in Chapter 4: Outcomes to be Assessed 4.6: Nucleic Acids and Protein Synthesis Describe how DNA molecules store genetic information. Describe how DNA molecules are replicated. Explain how protein synthesis relies on genetic information. Compare and contrast DNA and RNA. Describe the steps of protein synthesis. 4.7: Changes in Genetic Information Describe how genetic information can be altered. Explain how a mutation may or may not affect an organism.