Transcript Document
Human Anatomy & Physiology I Chapter 4 Cell Metabolism 4-1 Chapter 4 Cellular Metabolism ________________ – all chemical reactions that occur in the body Two types of metabolic reactions Anabolism • _______ molecules are made • ________________ _____________ • larger molecules are broken down • _____________ 4-2 Anabolism Anabolism provides the substances needed for cellular growth and repair ____________________ • type of anabolic process • used to make polysaccharides, triglycerides, and proteins • _________________ 4-3 Anabolism 4-4 Catabolism Catabolism breaks down larger molecules into smaller ones Hydrolysis • ___________________ • used to decompose ____________, lipids, and proteins • water is used • reverse of dehydration synthesis 4-5 Catabolism 4-6 Control of Metabolic Reactions ____________ • control rates of metabolic reactions • lower activation energy needed to start reactions • globular proteins with specific shapes • not consumed in chemical reactions • _____________ • shape of _________ determines substrate 4-7 Control of Metabolic Reactions Metabolic pathways • series of enzyme-controlled reactions leading to formation of a product • each new substrate is the product of the previous reaction Enzyme names commonly • reflect the substrate • have the suffix – _____ • ________e, lactase, protease, ________ 4-8 Control of Metabolic Reactions Cofactors • make some enzymes active • _________________ Coenzymes • organic molecules that act as cofactors • ____________ Factors that alter enzymes • ________ • ___________ • _________ • chemicals • changes in ____ 4-9 Energy for Metabolic Reactions Energy • ____________________________________ • heat, light, sound, electricity, mechanical energy, chemical energy • ________________________________ • involved in all metabolic reactions Release of chemical energy • most metabolic processes depend on chemical energy • ___________ of glucose generates chemical energy • ________________ releases chemical energy from molecules and makes it available for cellular use 4-10 Cellular Respiration Occurs in three series of reactions 1. ___________ 2. ______________ 3. Electron transport chain Produces • ______________ • ________ • ATP (chemical energy) • heat Includes • anaerobic reactions (without O2) - produce little ATP • aerobic reactions (requires O2) - produce most ATP 4-11 ATP Molecules • each ATP molecule has three parts: • ____________________ • a ________________ • three phosphate molecules in a chain • third phosphate attached by high-energy bond • when the bond is broken, energy is transferred • when the bond is broken, ATP becomes ADP • _____________________________________ • phosphorylation requires energy released from cellular respiration 4-12 Glycolysis • series of ten reactions • breaks down glucose into ________________ • occurs in cytosol • ________________________ respiration • yields two ATP molecules per glucose Summarized by three main events 1. _________________ 2. ______________ 3. production of NADH and ATP 4-13 Glycolysis Event 1 - ______________ • two phosphates added to glucose • requires ATP Event 2 – _______(cleavage) • _-carbon glucose split into ______________ molecules 4-14 Glycolysis Event 3 – ________________ and ______ • hydrogen atoms are released • hydrogen atoms bind to _____ to produce _______ • NADH delivers hydrogen atoms to electron transport chain if oxygen is available • ____ is phosphorylated to become _______ • two molecules of _________ are produced 4-15 Anaerobic Reactions If oxygen is not available • electron transport chain cannot accept _______ • _________ is converted to lactic acid • glycolysis is inhibited • ATP production declines 4-16 Aerobic Reactions If oxygen is available – • pyruvic acid is used to produce _________ citric acid cycle begins • electron transport chain functions • carbon dioxide and water are formed • __ molecules of ATP produced per glucose molecule 4-17 Citric Acid Cycle • begins when acetyl CoA combines with _________ acid to produce citric acid • citric acid is changed into oxaloacetic acid through a series of reactions • cycle repeats as long as pyruvic acid and oxygen are available • for each citric acid molecule: • one ATP is produced • eight hydrogen atoms are transferred to NAD+ and FAD • two CO2 produced 4-18 Electron Transport Chain • NADH and FADH2 carry electrons to the ETC • ETC series of electron carriers located in cristae of mitochondria • energy from electrons transferred to ________________ • ATP synthase catalyzes the phosphorylation of ADP to ATP • water is formed 4-19 Summary of Cellular Respiration 4-20 Summary of Catabolism of Proteins, Carbohydrates, and Fats 4-21 Carbohydrate Storage Excess glucose stored as • _________ (primarily by liver and muscle cells) • fat • converted to amino acids 4-22 Regulation of Metabolic Pathways • limited number of regulatory enzymes • _________________ 4-23 Nucleic Acids and Protein Synthesis _______________ – instructs cells how to construct proteins; stored in DNA Gene – segment of DNA that codes for one protein Genome – ________________ _________ – method used to translate a sequence of nucleotides of DNA into a sequence of amino acids 4-24 Structure of DNA • two polynucleotide chains • hydrogen bonds hold nitrogenous bases together • bases pair specifically (____________) • forms a helix • DNA wrapped about histones forms chromosomes 4-25 RNA Molecules Messenger RNA (mRNA) • delivers genetic information from nucleus to the cytoplasm • single polynucleotide chain • formed beside a strand of DNA • ______________ are complementary to DNA nucleotides (exception – no thymine in RNA; replaced with uracil) • making of mRNA is transcription 4-26 RNA Molecules _______________________ • carries amino acids to mRNA • carries anticodon to mRNA • _________ a codon of mRNA into an amino acid Ribosomal RNA (rRNA) – • provides structure and enzyme activity for ribosomes 4-27 Protein Synthesis 4-28 Protein Synthesis 4-29 DNA Replication • hydrogen bonds break between bases • double strands unwind and pull apart • new nucleotides pair with exposed bases • controlled by _____ polymerase 4-30 Mutations Mutations – _________________ information Result when • __________________ deleted • bases are changed May or may not change the protein Repair enzymes correct mutations 4-31 Clinical Application ________________ PKU • enzyme that breaks down the _____________________ is missing • build up of phenylalanine causes mental retardation • treated by diets very low in phenylalanine 4-32