ANFS345: Comprehensive Overview of Energy Metabolism in Biological Systems

Energy Taken In

chemical energy, food

Biosynthesis

absorbed chemical energy to growth

Maintenance

turnover of cells, rate it deteriorates is aging

Generation of External Work

energy use outside of the body

Ways Energy is Utilized

biosynthesis, maintenance, external work

Inefficiency of Energy Use

generates heat

Food Requirements

proportional to size, small animals consume more per unit body weight

Why Different Food Requirements

small animals have more surface area per unit body mass and therefore lose more heat

Glycolysis

process to break down glucose

Glycolysis Environment

cytoplasm, anerobic

Glycolysis Reactant

glucose

Glycolysis Products

2 pyruvic acid, 2 ATP, 2 NADH2

Glucose Reaction

glucose-6-phosphate (G6P), uses 1 ADP

G6P Reaction

fructose-6-phosphate (F6P)

F6P Reaction

fructose-1,6-diphosphate (F16DP), uses 1 ATP

F16DP Reaction

glyceraldehyde-3-phosphate (GAP) and dihydroxyacetone phosphate (DHAP)

DHAP Molecule

storage form of GAP

GAP Reaction

two 1,3-diphosphoglyderic acid (1,3 PPG), produces two NADH2

1,3 PPG Reaction

3-phosphoglyceric acid (3 PG), produces 1 ATP

3 PG Reaction

2-phosphoglyceric acid (2 PG)

2 PG Reaction

phosphoenolpyruvic acid, produces two water

Phosphoenolpyruvic Acid Reaction

pyruvic acid, produces one ATP

Glycolysis ATP Utilizing Steps

GLU to G6P, F6P to F1,6DP, 1 ATP each

Glycolysis ATP Producing Steps

1,3 PPG to 3 PG, PPP to pyruvic acid, 1 ATP each, each happens twice, 4 ATP total

Glycolysis Net ATP

2 ATP

Glycolysis Water Producing Step

2PG to PPP, one water, happens twice

Glycolysis NADH2 Producing Step

GAP to 1,3 PG, 2 NADH2, one compound splits to two

Secondary Glycolysis Product

lactic acid, limits glycolysis productivity

Krebs Cycle Names

citric acid cycle, tricarboxylic acid cycle

Krebs Cycle

produces ATP in cellular respiration

Krebs Cycle Environment

mitochondria, aerobic

Krebs Cycle Reactant

pyruvic acid, from glycolysis

Krebs Cycle Products

3 NADH2, 1 FADH2, 1 GTP

Pyruvic Acid Reaction

acetyl coenzyme A (acetyl coA), produces one NADH2

Acetyl CoA Reaction

citrate

Citrate Reaction

isocitrate

Isocitrate Reaction

alpha-ketoglutarate, produces one NADH2

Alpha Ketoglutarate Reaction

succinyl coenzyme A, produces one NADH2

Succinyl Coenzyme A Reaction

succinate, produces one GTP

Succinate Reaction

fumarate, produces one FADH2

Fumarate Reaction

malate

Malate Reaction

oxaloacetate, produces one NADH2

Oxaloacetate Reaction

restart cycle with acetyle coA

Krebs NADH2 Producing Steps

isocitrate to alpha ketoglutarate, alpha ketoglutarate to succinyl coA, malate to oxaloacetate

Krebs FADH2 Producing Step

succinate to fumarate

Krebs GTP Producing Step

succinyl coA to succinate

NADH2 to ATP

potential 2.5 ATP

FADH2 to ATP

potential 1.5 ATP

GTP to ATP

potential 1 ATP

Krebs ATP

10 potential per cycle, 20 potential per glycolysis (2 pyruvic acid)

Krebs Byproduct

2 CO2

Electron Transport Chain

sequence of proteins used to move protons and electrons to produce ATP

Electron Transport Chain Environment

inner membrane of the mitochondria, aerobic

Complex I Name

NADH dehydrogenase

Complex II

succinate dehydrogenase

Complex IV Name

cytochrome oxidase

Complex III Name

cytochrome b-c

Ubiquinone

electron carrier, potent antioxidant, coenzyme Q

NADH2 to NAD Triggers

2 hydrogens into complex 1, electrons passed to ubiquinone

FADH2 to FAD Triggers

2 hydrogens passed to ubiquinone

Complex IV Action

passes electrons to oxygen to form water

Final Electron Acceptor

oxygen

Complex I Proton Capacity

move 4 protons (1)

Complex II Proton Capacity

move 0 protons

Complex III Proton Capacity

move 4 protons

Complex IV Proton Capacity

move 2 protons

NADH2 Total Proton Movement

10 protons

FADH2 Total Proton Movement

6 protons

Protons to ATP

10 in intermembrane space can yield 2.5 ATP

Proton Movement

electrons flow through complexes I, III, IV and lose energy, complexes pump protons into intermembrane space

ATP Synthase

complex v, movement of protons down gradient to produce ATP

Uncoupling Protein (UCP1)

back diffusion of protons to generate heat

UCP1 Function

heat used to keep warm, particularly during hibernation

Lactic Acid Production

produced from pyruvic acid in anaerobic conditions

Lactic Acid Breakdown

reverse reaction into pyruvic acid when oxygen is present

Fuel Categories for Work

glucose, glycogen, fatty acids

Fuel Utilization as Time Increases

glucose and glycogen decrease, fatty acids increase

Exercise to Burn Fat

long duration low intensity

Oxygen Deficit

lag in oxygen uptake during start of exercise

Post Exercise Oxygen Consumption

excess oxygen after exercise stops