Lecture 3 Flashcards
First Law of Thermodynamics
Law of conservation of energy
Second Law of Thermodynamics
Entropy –> processes move from state of order to disorder
Endergonic reactions
Energy absorbed; products have more energy (bonds are formed, bonds store energy)
What makes reactions irreversible?
Large activation energy
Exergonic reactions
Release of energy; products have less energy (bonds are broken)
Isozymes
Enzymes that catalyze the same reaction as another enzyme, but under different conditions
Enzyme catalysis
Speeds up chemical reactions without protein being altered or consumed
Law of mass action
When a reaction is at equilibrium, the ratio of the products and substrates remain constant
Factors that influence the rate of an enzyme-catalyzed reaction
Temperature, pH, substrate concentration, competitive inhibitors, allosteric modulators, metabolic pathways (feedback inhibition)
Example of isozyme action
Tyrosinase (converts tyrosine to melanin); siamese cats have an isozyme of tyrosinase that is heat sensitive; warm areas of siamese cats are white because they cannot create melanin (pigment); cold areas (nose, ears, tail) are brown because they can create melanin
Cellular regulation of metabolic pathways
- controlling enzyme concentrations
- producing allosteric and covalent modulators
- using different enzymes for reversible reactions
- isolating enzymes within organelles
- maintaining optimum ration ATP:ADP
Catabolic metabolism
Extract energy for ATP production
Depends on exergonic reactions
**release of energy
Anabolic pathways
Synthesis pathways
Energy converted to chemical bonds
Dependent on endergonic reactions
**putting energy in to get a larger product
Aerobic pathway for ATP production
Glycolysis, formation of acetyl co-A, krebs cycle, electron transport chain (ETC)
Two mechanisms for ATP production
Substrate level phosphorylation
Oxidative phosphorylation
Glycolysis
Breaking down glucose, breaking carbon-carbon bonds to get smaller molecules and release energy
Fate of pyruvate in anaerobic and aerobic conditions
Aerobic: becomes acetyl-coA then enters krebs cycle
Anaerobic: converted to lactic acid
ATP production by Krebs cycle
1 ATP
Production of ATP aerobically vs anaerobically
30-32 aerobic, 2 anaerobic
ATP production from ETC
26-28 ATP
ATP production via glycolysis
2 ATP
Citric acid cycle is also known as the
Krebs cycle
In the presence of oxygen, ATP production is _____ than in anaerobic conditions
Higher
Glycogen
Storage form of glucose, found in liver and skeletal muscle
Glycogenolysis
Breaking glycogen into glucose
Glycogenesis
Glucose into glycogen (storage form)
Gluconeogenesis
Conversion of noncarb (lactic acid, amino acids, glycerol) molecules into glucose molecules
Keto diet
Utilizes gluconeogenesis
Lipid catabolism
Lipolysis, beta oxidation
Keto acid production
Deamination of an amino acid
Clearance
Rate at which a molecule disappears from the body
Mass balance
Existing body load + intake (met. production) - excretion (met. removal)
Mass flow
Concentration x volume flow
Why is chemical and electrical disequilibrium important for physiology?
Gradients drive exchange of molecules