1

2 all chemical reactions that occur in the body Two (2) types : Anabolism Larger molecules are made from smaller ones Requires energy Catabolism Larger molecules are broken down into smaller ones Releases energy

3 Enzymes Control rates Not consumed in chemical reactions Substrate specific: Shape of active site determines substrate Product molecule Active site (a) (b)(c) Substrate molecules Unaltered enzyme molecule Enzyme-substrate complex Enzyme molecule

4 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 – ase Examples: sucrase, lactase, protease, lipase Substrate 1 Enzyme A Substrate 2 Enzyme B Substrate 3 Enzyme C Substrate 4 Enzyme D Product

5 Cofactors Make some enzymes active Non-protein component Ions or coenzymes Coenzymes Organic molecules that act as cofactors Vitamins

6 Heat Radiation Electricity Chemicals Changes in pH

7 Chemical bonds are broken to release energy We burn glucose in a process called oxidation (combustion)

8 Occurs in a series of reactions: 1.Glycolysis 2.Citric acid cycle (TCA or Kreb’s Cycle) 3.Electron transport system 4.Produces ATP

9 Includes: Anaerobic reactions (without O 2 ) – produce little ATP Aerobic reactions (requires O 2 ) – produce most of ATP needed

10 Glycolysis Cytosol Mitochondrion ATP2 Glucose High-energy electrons (e – ) 2e – and 2H + ATP2 H 2 OO 2 ATP32–34 CO 2 Pyruvic acid 2 CO 2 Acetyl CoA Citric acid Oxaloacetic acid Glycolysis Citric Acid Cycle Electron Transport Chain Electron transport chain Citric acid cycle 6-C sugar  2 3-C sugars 2 ATP Produces acetyl coenzyme A (CoA) 2 turns of cycle 2 ATP 34 ATP formed no O 2 O2O2

Breakdown of large macromolecules to simple molecules GlycerolFatty acids Food 3 High energy electrons carried by NADH and FADH 2 H2OH2O 2e – and 2H + Waste products –NH 2 CO 2 Citric acid cycle Electron transport chain Amino acids Acetyl coenzyme A Simple sugars (glucose) Proteins Carbohydrates Fats Pyruvic acid ATP Glycolysis 3 ATP ½ O 2 Formation of CoA and 2 ATP Complete oxidation, production of most of the ATP

12 Gene – segment of DNA that codes for one protein Genetic information – instructs cells how to construct proteins; stored in DNA Genome – complete set of genes Genetic Code – method used to translate a sequence of nucleotides of DNA into a sequence of amino acids 4.6: Nucleic Acids and Protein Synthesis

13 Transfer RNA (tRNA): Carries amino acids to mRNA Carries anticodon to mRNA Translates a codon of mRNA into an amino acid Ribosomal RNA (rRNA): Provides structure and enzyme activity for ribosomes Messenger RNA (mRNA): Making of mRNA (copying of DNA) is transcription

14 Inborn Errors of Metabolism Occurs from inheriting a mutation that alters an enzyme Creates a block in a biochemical pathway Only about 1/10 th of one percent of the human genome differs from person to person

15 Mutations – change in genetic information Result when: Extra bases are added or deleted Bases are changed May or may not change the protein 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 Repair enzymes: correct mutations

16

17 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

18 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

19 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

20 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

21 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

22 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