Human Physiology Unit Two

Enzymes Proteins that function as biological catalysts by lowering the energy of activation and speeding up chemical processes Enzymes are substrate specific, much like a lock and key Enzymes catalyze reactions without being changed

Enzymes How they work!

Enzymes How they work!

Enzymes Cofactors inorganic metal ions Ca2+, Mg2+, Cu2+ and others change the shape of the enzyme

Enzymes Coenzymes organic molecules derived from vitamins NAD+ and FAD+ and others carry H+ and small molecules

Enzymes

Laws of Thermodynamics 1st Law of Thermodynamics Energy is neither created or destroyed, but can change forms 2nd Law of Thermodynamics When energy changes forms it becomes more disordered (entropy)

CO2 + H2O + E C6H12O6 + O2 Photosynthesis

C6H12O6 + O2 CO2 + H2O + E Cellular respiration

Photosynthesis CO2 + H2O + E C6H12O6 + O2 C6H12O6 + O2 CO2 + H2O + E Cellular respiration This energy is used to form ATP!

Heat Heat Glucose Glucose ATP ATP

Adenosine triphosphate The fuel of living cells ATP Adenosine triphosphate The fuel of living cells

Energy released to do work in cell Energy released from food (glucose)

Metabolism All the chemical reactions in a body that involve the transfer of energy Anabolic - building up reactions - require energy (endergonic) Catabolic - tearing down reactions - release energy (exergonic)

Oxidation-Reduction Reactions

ATP production is the goal of cell respiration! One molecule of glucose yields 36 ATPs! This process is actually four: Glycolysis Transition Reaction Krebs Cycle Electron Transport System

Glycolysis Anaerobic respiration – no oxygen Cytoplasm Mitochondrion In: 1 glucose 2 ATPs Out: 2 NADH + H+ 4 ATPs (2 net) 2 pyruvic acids (C3) Anaerobic respiration – no oxygen

Anaerobic respiration – no oxygen Mitochondrion No oxygen present OR Ethanol

Transition Reaction Aerobic respiration – oxygen is present Mitochondrion Transition Reaction In: 2 pyruvic acids (C3) Decarboxylation – 2 CO2 Out: 2 NADH + H+ 2 Acetyl CoA (C2) Aerobic respiration – oxygen is present

Krebs Cycle Aerobic respiration – oxygen is present Mitochondrion In: 2 acetyl CoA (C2) Out: 6 NADH + H+ 2 FADH2 2 ATPs Decarboxylation – 4 CO2 Aerobic respiration – oxygen is present

Electron Transport System Oxygen is the final H+ acceptor Mitochondrion In: 2 NADH + H+ (Glycolysis) 2 NADH + H+ (Transition Reaction) 6 NADH + H+ (Krebs Cycle) 2 FADH2 (Krebs Cycle) X 2 = 4 ATPs X 3 = 6 ATPs X 3 = 18 ATPs X 2 = 4 ATPs ----------- 32 ATPs Oxygen is the final H+ acceptor Out: 32 ATPs 6 H2O Aerobic respiration – oxygen is present

ATP production is the goal of cell respiration! Glycolysis – 2 ATPs Transition Reaction – 0 ATPs Krebs Cycle – 2 ATPs Electron Transport System – 32 ATPs One molecule of glucose yields 36 ATPs!

Definitions Glycogen – the animal storage form of glucose Dehydration synthesis – the assembling of organic molecules by extracting water Hydrolysis – the breaking up of organic molecules using water

Dehydration Synthesis and Hydrolysis

Definitions Glycogenesis – the formation of glycogen from glucose Glycogenolysis – the conversion of glycogen to glucose Gluconeogenesis – the conversion of non-carbohydrates into glucose

Gluconeogenesis - Fats

Gluconeogenesis - Proteins

Gluconeogenesis

Organ Energy Sources

Examples of Lipid Anabolism Triglycerides Phospholipids Steroids (cholesterol, sex hormones, etc.) Prostaglandins Waxes

Examples of Protein Anabolism Glycoproteins Hemoglobin Enzymes Collagen Antibodies