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Chapter 4   Cellular Metabolism
Chapter 4   Cellular Metabolism
Chapter 4   Cellular Metabolism
Chapter 4   Cellular Metabolism
Chapter 4   Cellular Metabolism
Chapter 4   Cellular Metabolism
Chapter 4   Cellular Metabolism
Chapter 4   Cellular Metabolism
Chapter 4   Cellular Metabolism
Chapter 4   Cellular Metabolism
Chapter 4   Cellular Metabolism
Chapter 4   Cellular Metabolism
Chapter 4   Cellular Metabolism
Chapter 4   Cellular Metabolism
Chapter 4   Cellular Metabolism
Chapter 4   Cellular Metabolism
Chapter 4   Cellular Metabolism
Chapter 4   Cellular Metabolism
Chapter 4   Cellular Metabolism
Chapter 4   Cellular Metabolism
Chapter 4   Cellular Metabolism
Chapter 4   Cellular Metabolism
Chapter 4   Cellular Metabolism
Chapter 4   Cellular Metabolism
Chapter 4   Cellular Metabolism
Chapter 4   Cellular Metabolism
Chapter 4   Cellular Metabolism
Chapter 4   Cellular Metabolism
Chapter 4   Cellular Metabolism
Chapter 4   Cellular Metabolism
Chapter 4   Cellular Metabolism
Chapter 4   Cellular Metabolism
Chapter 4   Cellular Metabolism
Chapter 4   Cellular Metabolism
Chapter 4   Cellular Metabolism
Chapter 4   Cellular Metabolism
Chapter 4   Cellular Metabolism
Chapter 4   Cellular Metabolism
Chapter 4   Cellular Metabolism
Chapter 4   Cellular Metabolism
Chapter 4   Cellular Metabolism
Chapter 4   Cellular Metabolism
Chapter 4   Cellular Metabolism
Chapter 4   Cellular Metabolism
Chapter 4   Cellular Metabolism
Chapter 4   Cellular Metabolism
Chapter 4   Cellular Metabolism
Chapter 4   Cellular Metabolism
Chapter 4   Cellular Metabolism
Chapter 4   Cellular Metabolism
Chapter 4   Cellular Metabolism
Chapter 4   Cellular Metabolism
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Chapter 4 Cellular Metabolism

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Hole's Anatomy and Physiology

Hole's Anatomy and Physiology

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  • 1. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Chapter 4 Lecture PowerPoint
  • 2. 2401 Anatomy and Physiology I Chapter 4 Susan Gossett [email_address] Department of Biology Paris Junior College
  • 3. Hole’s Human Anatomy and Physiology Twelfth Edition Shier  Butler  Lewis Chapter 4 Cellular Metabolism Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
  • 4. 4.1: Introduction <ul><li>Metabolic processes – all chemical reactions that occur in the body </li></ul>There are two (2) types of metabolic reactions: <ul><li>Anabolism </li></ul><ul><ul><li>Larger molecules are made from smaller ones </li></ul></ul><ul><ul><li>Requires energy </li></ul></ul><ul><li>Catabolism </li></ul><ul><ul><li>Larger molecules are broken down into smaller ones </li></ul></ul><ul><ul><li>Releases energy </li></ul></ul>
  • 5. 4.2: Metabolic Processes <ul><li>Consists of two processes: </li></ul><ul><ul><li>Anabolism </li></ul></ul><ul><ul><li>Catabolism </li></ul></ul>
  • 6. Anabolism <ul><li>Anabolism provides the materials needed for cellular growth and repair </li></ul><ul><li>Dehydration synthesis </li></ul><ul><ul><li>Type of anabolic process </li></ul></ul><ul><ul><li>Used to make polysaccharides, triglycerides, and proteins </li></ul></ul><ul><ul><li>Produces water </li></ul></ul>CH 2 OH H H OH O H OH Monosaccharide + H HO H OH H H OH O H OH Monosaccharide H HO H OH H H OH O H OH Disaccharide H 2 O Water + H HO H H H OH O H OH H O H OH Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. CH 2 OH CH 2 OH CH 2 OH
  • 7. Anabolism Amino acid N H H C C H R Dipeptide molecule + + Peptide bond Amino acid N H H C C H H H R H O N H H C C H R H O N H C C OH R H O O N H H C C H R N H C C OH R H O O Water Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. O O H 2 O H C H Glycerol 3 fatty acid molecules + OH HO H C OH HO H C C C C OH HO H O O C C C O O O H C H Fat molecule (triglyceride) + H C H C O O O H 3 water molecules (CH 2 ) 14 CH 3 (CH 2 ) 14 CH 3 (CH 2 ) 14 CH 3 (CH 2 ) 14 CH 3 (CH 2 ) 14 CH 3 (CH 2 ) 14 CH 3 H 2 O H 2 O H 2 O Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. O
  • 8. Catabolism <ul><li>Catabolism breaks down larger molecules into smaller ones </li></ul><ul><li>Hydrolysis </li></ul><ul><ul><li>A catabolic process </li></ul></ul><ul><ul><li>Used to decompose carbohydrates, lipids, and proteins </li></ul></ul><ul><ul><li>Water is used to split the substances </li></ul></ul><ul><ul><li>Reverse of dehydration synthesis </li></ul></ul>CH 2 OH H H OH O H OH Monosaccharide + H HO H OH H H OH O H OH Monosaccharide H HO H OH H H OH O H OH Disaccharide H 2 O Water + H HO H H H OH O H OH H O H OH Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. CH 2 OH CH 2 OH CH 2 OH
  • 9. Catabolism Amino acid N H H C C H R Dipeptide molecule + + Peptide bond Amino acid N H H C C H H H R H O N H H C C H R H O N H C C OH R H O O N H H C C H R N H C C OH R H O O Water Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. O O H 2 O H C H Glycerol 3 fatty acid molecules + OH HO H C OH HO H C C C C OH HO H O O C C C O O O H C H Fat molecule (triglyceride) + H C H C O O O H 3 water molecules (CH 2 ) 14 CH 3 (CH 2 ) 14 CH 3 (CH 2 ) 14 CH 3 (CH 2 ) 14 CH 3 (CH 2 ) 14 CH 3 (CH 2 ) 14 CH 3 H 2 O H 2 O H 2 O Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. O
  • 10. 4.3: Control of Metabolic Reactions <ul><li>Enzymes </li></ul><ul><li>Control rates of metabolic reactions </li></ul><ul><li>Lower activation energy needed to start reactions </li></ul><ul><li>Most are globular proteins with specific shapes </li></ul><ul><li>Not consumed in chemical reactions </li></ul><ul><li>Substrate specific </li></ul><ul><li>Shape of active site determines substrate </li></ul>Product molecule Active site (a) (b) (c) Substrate molecules Unaltered enzyme molecule Enzyme-substrate complex Enzyme molecule Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
  • 11. Enzyme Action <ul><li>Metabolic pathways </li></ul><ul><ul><li>Series of enzyme-controlled reactions leading to formation of a product </li></ul></ul><ul><ul><li>Each new substrate is the product of the previous reaction </li></ul></ul><ul><li>Enzyme names commonly: </li></ul><ul><ul><li>Reflect the substrate </li></ul></ul><ul><ul><li>Have the suffix – ase </li></ul></ul><ul><ul><li>Examples: sucrase, lactase, protease, lipase </li></ul></ul>Substrate 1 Enzyme A Substrate 2 Enzyme B Substrate 3 Enzyme C Substrate 4 Enzyme D Product Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
  • 12. Cofactors and Coenzymes <ul><li>Cofactors </li></ul><ul><ul><li>Make some enzymes active </li></ul></ul><ul><ul><li>Non-protein component </li></ul></ul><ul><ul><li>Ions or coenzymes </li></ul></ul><ul><li>Coenzymes </li></ul><ul><ul><li>Organic molecules that act as cofactors </li></ul></ul><ul><ul><li>Vitamins </li></ul></ul>
  • 13. Factors That Alter Enzymes <ul><li>Factors that alter enzymes : </li></ul><ul><ul><li>Heat </li></ul></ul><ul><ul><li>Radiation </li></ul></ul><ul><ul><li>Electricity </li></ul></ul><ul><ul><li>Chemicals </li></ul></ul><ul><ul><li>Changes in pH </li></ul></ul>
  • 14. Regulation of Metabolic Pathways <ul><li>Limited number of regulatory enzymes </li></ul><ul><li>Negative feedback </li></ul>Inhibition Substrate 1 Substrate 2 Enzyme B Substrate 3 Enzyme C Substrate 4 Enzyme D Product Rate-limiting Enzyme A Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
  • 15. 4.4: Energy for Metabolic Reactions <ul><li>Energy is the capacity to change something; it is the ability to do work </li></ul><ul><li>Common forms of energy: </li></ul><ul><ul><li>Heat </li></ul></ul><ul><ul><li>Light </li></ul></ul><ul><ul><li>Sound </li></ul></ul><ul><ul><li>Electrical energy </li></ul></ul><ul><ul><li>Mechanical energy </li></ul></ul><ul><ul><li>Chemical energy </li></ul></ul>
  • 16. ATP Molecules <ul><li>Each ATP molecule has three parts: </li></ul><ul><ul><li>An adenine molecule </li></ul></ul><ul><ul><li>A ribose molecule </li></ul></ul><ul><ul><li>Three phosphate molecules in a chain </li></ul></ul>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 P P P Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
  • 17. Release of Chemical Energy <ul><li>Chemical bonds are broken to release energy </li></ul><ul><li>We burn glucose in a process called oxidation </li></ul>
  • 18. 4.5: Cellular Respiration <ul><li>Occurs in a series of reactions: </li></ul><ul><ul><li>Glycolysis </li></ul></ul><ul><ul><li>Citric acid cycle (aka TCA or Kreb’s Cycle) </li></ul></ul><ul><ul><li>Electron transport system </li></ul></ul>
  • 19. Cellular Respiration <ul><li>Produces: </li></ul><ul><ul><li>Carbon dioxide </li></ul></ul><ul><ul><li>Water </li></ul></ul><ul><ul><li>ATP (chemical energy) </li></ul></ul><ul><ul><li>Heat </li></ul></ul><ul><li>Includes: </li></ul><ul><ul><li>Anaerobic reactions (without O 2 ) - produce little ATP </li></ul></ul><ul><ul><li>Aerobic reactions (requires O 2 ) - produce most ATP </li></ul></ul>
  • 20. Glycolysis <ul><li>Series of ten reactions </li></ul><ul><li>Breaks down glucose into 2 pyruvic acid molecules </li></ul><ul><li>Occurs in cytosol </li></ul><ul><li>Anaerobic phase of cellular respiration </li></ul><ul><li>Yields two ATP molecules per glucose molecule </li></ul><ul><li>Summarized by three main phases or events: </li></ul><ul><ul><li>Phosphorylation </li></ul></ul><ul><ul><li>Splitting </li></ul></ul><ul><ul><li>Production of NADH and ATP </li></ul></ul>
  • 21. Glycolysis <ul><li>Event 1 - Phosphorylation </li></ul><ul><ul><li>Two phosphates added to glucose </li></ul></ul><ul><ul><li>Requires ATP </li></ul></ul><ul><li>Event 2 – Splitting (cleavage) </li></ul><ul><ul><li>6-carbon glucose split into two 3-carbon molecules </li></ul></ul>Phase 1 priming Phase 2 cleavage Phase 3 oxidation and formation of ATP and release of high energy electrons 2 ADP 2 NADH + H + 2 NAD + 2 NADH + H + 2 NAD + P ATP P P P Glyceraldehyde phosphate Glucose Dihydroxyacetone phosphate 2 4 ADP ATP 4 Fructose-1,6-diphosphate O 2 2 Pyruvic acid 2 Lactic acid To citric acid cycle and electron transport chain (aerobic pathway) Carbon atom Phosphate P P Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. O 2
  • 22. Glycolysis <ul><li>Event 3 – Production of NADH and ATP </li></ul><ul><ul><li>Hydrogen atoms are released </li></ul></ul><ul><ul><li>Hydrogen atoms bind to NAD + to produce NADH </li></ul></ul><ul><ul><li>NADH delivers hydrogen atoms to electron transport system if oxygen is available </li></ul></ul><ul><ul><li>ADP is phosphorylated to become ATP </li></ul></ul><ul><ul><li>Two molecules of pyruvic acid are produced </li></ul></ul><ul><ul><li>Two molecules of ATP are generated </li></ul></ul>Phase 1 priming Phase 2 cleavage Phase 3 oxidation and formation of ATP and release of high energy electrons 2 ADP 2 NADH + H + 2 NAD + 2 NADH + H + 2 NAD + P ATP P P P Glyceraldehyde phosphate Glucose Dihydroxyacetone phosphate 2 4 ADP ATP 4 Fructose-1,6-diphosphate O 2 2 Pyruvic acid 2 Lactic acid To citric acid cycle and electron transport chain (aerobic pathway) Carbon atom Phosphate P P Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. O 2
  • 23. Anaerobic Reactions <ul><li>If oxygen is not available: </li></ul><ul><ul><li>Electron transport system cannot accept new electrons from NADH </li></ul></ul><ul><ul><li>Pyruvic acid is converted to lactic acid </li></ul></ul><ul><ul><li>Glycolysis is inhibited </li></ul></ul><ul><ul><li>ATP production is less than in aerobic reactions </li></ul></ul>Phase 1 priming Phase 2 cleavage Phase 3 oxidation and formation of ATP and release of high energy electrons 2 ADP 2 NADH + H + 2 NAD + 2 NADH + H + 2 NAD + P ATP P P P Glyceraldehyde phosphate Glucose Dihydroxyacetone phosphate 2 4 ADP ATP 4 Fructose-1,6-diphosphate O 2 2 Pyruvic acid 2 Lactic acid To citric acid cycle and electron transport chain (aerobic pathway) Carbon atom Phosphate P P Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. O 2
  • 24. Aerobic Reactions <ul><li>If oxygen is available: </li></ul><ul><ul><li>Pyruvic acid is used to produce acetyl CoA </li></ul></ul><ul><ul><li>Citric acid cycle begins </li></ul></ul><ul><ul><li>Electron transport system functions </li></ul></ul><ul><ul><li>Carbon dioxide and water are formed </li></ul></ul><ul><ul><li>34 molecules of ATP are produced per each glucose molecule </li></ul></ul>ATP 2 ATP 2 Glucose Pyruvic acid Pyruvic acid Acetyl CoA CO 2 2 CO 2 Citric acid O 2 H 2 O 2e – + 2H + Electron transport chain ATP 32-34 Cytosol Mitochondrion High energy electrons (e – ) and hydrogen ions (H + ) High energy electrons (e – ) and hydrogen ions (h + ) Oxaloacetic acid High energy electrons (e – ) and hydrogen ions (H + ) Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
  • 25. Citric Acid Cycle <ul><li>Begins when acetyl CoA combines with oxaloacetic acid to produce citric acid </li></ul><ul><li>Citric acid is changed into oxaloacetic acid through a series of reactions </li></ul><ul><li>Cycle repeats as long as pyruvic acid and oxygen are available </li></ul><ul><li>For each citric acid molecule: </li></ul><ul><ul><li>One ATP is produced </li></ul></ul><ul><ul><li>Eight hydrogen atoms are transferred to NAD + and FAD </li></ul></ul><ul><ul><li>Two CO 2 produced </li></ul></ul>Citric acid cycle ADP + ATP Pyruvic acid from glycolysis Citric acid (start molecule) Acetyl CoA (replenish molecule) Acetic acid Oxaloacetic acid (finish molecule) Isocitric acid CO 2 CO 2 CO 2 Succinyl-CoA Succinic acid FAD FADH 2 Fumaric acid Malic acid Cytosol Mitochondrion NADH + H + NAD + NADH + H + NAD + NADH + H + NAD + CoA CoA CoA CoA P NADH + H + NAD + P CoA Carbon atom Phosphate Coenzyme A -Ketoglutaric acid Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
  • 26. Electron Transport System ATP ADP + ATP synthase Electron transport chain Energy P 2H + + 2e – 2e – 2H + NADH + H + NAD + 2H + + 2e – FADH 2 FAD O 2 H 2 O Energy Energy Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. <ul><li>NADH and FADH2 carry electrons to the ETS </li></ul><ul><li>ETS is a series of electron carriers located in cristae of mitochondria </li></ul><ul><li>Energy from electrons transferred to ATP synthase </li></ul><ul><li>ATP synthase catalyzes the phosphorylation of ADP to ATP </li></ul><ul><li>Water is formed </li></ul>
  • 27. Summary of Cellular Respiration Glycolysis Cytosol Mitochondrion A T P 2 Glucose High-energy electrons (e – ) High-energy electrons (e – ) High-energy electrons (e – ) 2e – and 2H + A T P 2 H 2 O O 2 A T P 32–34 CO 2 Pyruvic acid Pyruvic acid 2 CO 2 Acetyl Co A Citric acid Oxaloacetic acid 1 3 4 2 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. Citric Acid Cycle The 3-carbon pyruvic acids generated by glycolysis enter the mitochondria. Each loses a carbon (generating CO 2 and is combined with a coenzyme to form a 2-carbon acetyl coenzyme A (acetyl CoA). More high-energy electrons are released. 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 CO 2 ’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. 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 Citric acid cycle Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
  • 28. Carbohydrate Storage <ul><li>Carbohydrate molecules from foods can enter: </li></ul><ul><ul><li>Catabolic pathways for energy production </li></ul></ul><ul><ul><li>Anabolic pathways for storage </li></ul></ul>
  • 29. Carbohydrate Storage <ul><li>Excess glucose stored as: </li></ul><ul><ul><li>Glycogen (primarily by liver and muscle cells) </li></ul></ul><ul><ul><li>Fat </li></ul></ul><ul><ul><li>Converted to amino acids </li></ul></ul>Hydrolysis Monosaccharides Energy + CO 2 + H 2 O Glycogen or Fat Amino acids Carbohydrates from foods Catabolic pathways Anabolic pathways Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
  • 30. Summary of Catabolism of Proteins, Carbohydrates, and Fats High energy electrons carried by NADH and FADH 2 Breakdown of simple molecules to acetyl coenzyme A accompanied by production of limited ATP and high energy electrons H 2 O 2e – and 2H + Waste products – NH 2 CO 2 CO 2 Citric acid cycle Electron transport chain Amino acids Acetyl coenzyme A Simple sugars (glucose) Glycerol Fatty acids Proteins (egg white) Carbohydrates (toast, hashbrowns) Food Fats (butter) Pyruvic acid ATP ATP Breakdown of large macromolecules to simple molecules Glycolysis 1 2 3 ATP Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. © Royalty Free/CORBIS. ½ O 2 High energy electrons carried by NADH and FADH 2 Complete oxidation of acetyl coenzyme A to H 2 O and CO 2 produces high energy electrons (carried by NADH and FADH 2 ), which yield much ATP via the electron transport chain Breakdown of simple molecules to acetyl coenzyme A accompanied by production of limited ATP and high energy electrons H 2 O 2e – and 2H + Waste products – NH 2 CO 2 CO 2 Citric acid cycle Electron transport chain Amino acids Acetyl coenzyme A Simple sugars (glucose) Glycerol Fatty acids Proteins (egg white) Carbohydrates (toast, hashbrowns) Food Fats (butter) Pyruvic acid ATP ATP Breakdown of large macromolecules to simple molecules Glycolysis 1 2 3 ATP © Royalty Free/CORBIS. ½ O 2
  • 31. 4.6: Nucleic Acids and Protein Synthesis <ul><li>Instruction of cells to synthesize proteins comes from a nucleic acid, DNA </li></ul>
  • 32. Genetic Information <ul><li>Gene – segment of DNA that codes for one protein </li></ul><ul><li>Genetic information – instructs cells how to construct proteins; stored in DNA </li></ul><ul><li>Genome – complete set of genes </li></ul><ul><li>Genetic Code – method used to translate a sequence of nucleotides of DNA into a sequence of amino acids </li></ul>
  • 33. 4.1 From Science to Technology DNA Profiling Frees A Prisoner
  • 34. Structure of DNA <ul><ul><li>Two polynucleotide chains </li></ul></ul><ul><ul><li>Hydrogen bonds hold nitrogenous bases together </li></ul></ul><ul><ul><li>Bases pair specifically (A-T and C-G) </li></ul></ul><ul><ul><li>Forms a helix </li></ul></ul><ul><ul><li>DNA wrapped about histones forms chromosomes </li></ul></ul>G C G G A T C C A P G C P T P P C G P G P C P A P P P Thymine (T) Cytosine (C) Adenine (A) Guanine (G) Nucleotide strand Globular histone proteins Metaphase chromosome Segment of DNA molecule Chromatin (a) Hydrogen bonds (b) (c) Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
  • 35. DNA Replication <ul><li>Hydrogen bonds break between bases </li></ul><ul><li>Double strands unwind and pull apart </li></ul><ul><li>New nucleotides pair with exposed bases </li></ul><ul><li>Controlled by DNA polymerase </li></ul>Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. C C A T C C G G C C G C G A A T T C G C A T Newly formed DNA molecules Region of replication Original DNA molecule G G G G G G G G G C C C C C G A A A T T A A T T T T T A A A T A A T
  • 36. 4.2 From Science to Technology Nucleic Acid Amplification
  • 37. Genetic Code <ul><li>Specification of the correct sequence of amino acids in a polypeptide chain </li></ul><ul><li>Each amino acid is represented by a triplet code </li></ul>
  • 38. RNA Molecules <ul><li>Transfer RNA (tRNA) : </li></ul><ul><ul><li>Carries amino acids to mRNA </li></ul></ul><ul><ul><li>Carries anticodon to mRNA </li></ul></ul><ul><ul><li>Translates a codon of mRNA into an amino acid </li></ul></ul><ul><li>Ribosomal RNA (rRNA): </li></ul><ul><ul><li>Provides structure and enzyme activity for ribosomes </li></ul></ul><ul><li>Messenger RNA (mRNA): </li></ul><ul><ul><li>Making of mRNA (copying of DNA) is transcription </li></ul></ul>
  • 39. RNA Molecules <ul><li>Messenger RNA (mRNA) : </li></ul><ul><ul><li>Delivers genetic information from nucleus to the cytoplasm </li></ul></ul><ul><ul><li>Single polynucleotide chain </li></ul></ul><ul><ul><li>Formed beside a strand of DNA </li></ul></ul><ul><ul><li>RNA nucleotides are complementary to DNA nucleotides (exception – no thymine in RNA; replaced with uracil) </li></ul></ul>Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. DNA RNA S G S C S S S S C G T A S S S S G C A U Direction of “reading” code P P P P P P P P P P
  • 40. Protein Synthesis Messenger RNA 1 DNA information is copied, or transcribed, into mRNA following complementary base pairing 2 mRNA leaves the nucleus and attaches to a ribosome 3 Translation begins as tRNA anticodons recognize complementary mRNA codons, thus bringing the correct amino acids into position on the growing polypeptide chain 4 As the ribosome moves along the mRNA, more amino acids are added 5 At the end of the mRNA, the ribosome releases the new protein 6 Amino acids attached to tRNA Polypeptide chain Cytoplasm DNA double helix DNA strands pulled apart Transcription (in nucleus) Translation (in cytoplasm) Nucleus C Codon 1 Codon 2 Codon 3 Codon 4 Codon 5 Codon 6 Codon 7 G G G G G A A A U U C C C C C C G G G A Methionine Glycine Amino acids represented Serine Alanine Threonine Alanine Glycine DNA strand Messenger RNA A T A A T T T A T A T A T A T A T U A U A U A G C C G C G C G C G C G C G C G G C C G C C G U A C G C G G G G G G G G G G C C C C C C C C C C A A A A A T T A A T A T A T A T C G G C G C G C T A T A T A C G A T G C T A C G T A C G C G G C A T T A C G G C T T G C G C G C G C G C G C G C G C G Nuclear pore tRNA molecules can pick up another molecule of the same amino acid and be reused Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. G C C G A G G C U C T C C G A G
  • 41. Protein Synthesis Next amino acid Anticodon Codons Growing polypeptide chain 1 1 2 2 3 3 4 4 5 5 6 6 7 C U G G Ribosome 1 1 2 2 3 3 7 4 4 5 5 6 7 C C C G U C U G C G U Next amino acid Anticodon Codons 1 1 2 2 3 3 4 4 5 5 6 6 7 Peptide bond C U G C G U C C G C G U 6 Messenger RNA Transfer RNA Next amino acid 1 1 2 2 3 3 4 4 5 5 6 7 6 7 U C G G A A A A A A G G G G G G G G C C C C C C C U U U C G G A A A A A A G G G G G G G G C C C C C C C U U U C G G A A A A A A G G G G G G G G C C C C C C C U U U C G G A A A A A A G G G G G G G G C C C C C C C U U The transfer RNA molecule for the last amino acid added holds the growing polypeptide chain and is attached to its complementary codon on mRNA. 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. 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 A new tRNA complementary to the next codon on mRNA brings the next amino acid to be added to the growing polypeptide chain. 2 1 3 4 Messenger RNA Transfer RNA Next amino acid Transfer RNA Messenger RNA Transfer RNA Growing polypeptide chain Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
  • 42. 4.3 From Science to Technology MicroRNAs and RNA Interference
  • 43. 4.7: Changes in Genetic Information <ul><li>Only about 1/10 th of one percent of the human genome differs from person to person </li></ul>
  • 44. Nature of Mutations <ul><li>Mutations – change in genetic information </li></ul><ul><li>Result when: </li></ul><ul><ul><li>Extra bases are added or deleted </li></ul></ul><ul><ul><li>Bases are changed </li></ul></ul><ul><li>May or may not change the protein </li></ul>Code for glutamic acid Mutation Direction of “reading” code Code for valine (a) (b) S S S C T A P P P S S S C T T P P P Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
  • 45. Protection Against Mutation <ul><li>Repair enzymes correct the mutations </li></ul>
  • 46. Inborn Errors of Metabolism <ul><li>Occurs from inheriting a mutation that then alters an enzyme </li></ul><ul><li>This creates a block in an otherwise normal biochemical pathway </li></ul>
  • 47. 4.4 From Science to Technology The Human Metabolome
  • 48. Important Points in Chapter 4: Outcomes to be Assessed <ul><li>4.1: Introduction </li></ul><ul><li>Define metabolism. </li></ul><ul><li>Explain why protein synthesis is important. </li></ul><ul><li>4.2: Metabolic Processes </li></ul><ul><li>Compare and contrast anabolism and catabolism. </li></ul><ul><li>Define dehydration synthesis and hydrolysis. </li></ul><ul><li>4.3: Control of Metabolic Reactions </li></ul><ul><li>Describe how enzymes control metabolic reactions. </li></ul><ul><li>List the basic steps of an enzyme-catalyzed reaction. </li></ul><ul><li>Define active site. </li></ul>
  • 49. Important Points in Chapter 4: Outcomes to be Assessed <ul><li>Define a rate-limiting enzyme and indicate why it is important in a metabolic pathway. </li></ul><ul><li>4.4: Energy for Metabolic Reactions </li></ul><ul><li>Explain how ATP stores chemical energy and makes it available to a cell. </li></ul><ul><li>State the importance of the oxidation of glucose. </li></ul><ul><li>4.5: Cellular Respiration </li></ul><ul><li>Describe how the reactions and pathways of glycolysis, the citric acid cycle, and the electron transport chain capture the energy in nutrient molecules. </li></ul><ul><li>Discuss how glucose is stored, rather than broken down. </li></ul>
  • 50. Important Points in Chapter 4: Outcomes to be Assessed <ul><li>4.6: Nucleic Acids and Protein Synthesis </li></ul><ul><li>Define gene and genome. </li></ul><ul><li>Describe the structure of DNA, including the role of complementary base pairing. </li></ul><ul><li>Describe how DNA molecules replicate. </li></ul><ul><li>Define genetic code. </li></ul><ul><li>Compare DNA and RNA. </li></ul><ul><li>Explain how nucleic acid molecules (DNA and RNA) carry genetic information. </li></ul><ul><li>Define transcription and translation. </li></ul><ul><li>Describe the steps of protein synthesis. </li></ul>
  • 51. Important Points in Chapter 4: Outcomes to be Assessed <ul><li>4.7: Changes in Genetic Information </li></ul><ul><li>Compare and contrast mutations and SNPs. </li></ul><ul><li>Explain how a mutation can cause a disease. </li></ul><ul><li>Explain two ways that mutations originate. </li></ul><ul><li>List three types of genetic changes. </li></ul><ul><li>Discuss two ways that DNA is protected against mutation. </li></ul>
  • 52. Quiz 4 Complete Quiz 4 now! Read Chapter 5.

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