Cell Metabolism Flashcards
(19 cards)
Production of ATP
Catabolic
Exergonic (release of energy, some as heat)
Metabolic Control
Control enzyme concentrations
Allosteric and covalent modulators
Use different enzymes for reversereaction
Coenzymes in Cellular Respiration
NAD+ becomes NADH
FAD becomes FADH2
Act as H+ and electron shuttles
Glycolsis
Occurs in cytosol
Splitting of sugar - breaks down glucose to pyruvate
2 ATP in, 1 glucose in
4 ATP out, 2 NADH out, 2 pyruvate out
Net 2 ATP
Transfer to mitochondria - loss of CO2, irreversible at this point, pyruvate becomes Acetyl CoA
Phosphofructokinase
Controls pathway
Adolase
Split of glucose molecule
Pyruvatekinase
Last step
Makes ATP and pyruvate
TCA Cycle
In mitochondrial matrix
1 Acetyl CoA in
3 NADH out, 1 ATP out, 1 FADH2 out, CO2 out
2 cycles/glucose
Oxidative Phosphorylation
Chemiosmosis-couples electron transport with ATP synthesis
NADH and FADH2 donate electors to electron transport chain, powers ATP synthesis
ETC
Electrons form NADH ad FADH2 lose energy in steps
End of chain- electrons are passed to oxygen forming water, H+ moves to inter membrane space
ATP Synthase
Protein molecule that makes ATP
H+ gradient - drives ATP synthase
Flow of Energy
Glucose - NADH/FADH2 - ETC - ATP
Metabolism of Glucose
Yields 38 ATP
Uses 40% of energy, rest is lost as heat
Oxygen required (aerobic)
Fermentation
No oxygen available, anaerobic
Glycolysis and process to regenerate NAD+
Alcohol Fermentation
Pyruvate converted to ethanol
Releases CO2
Irreversible
Lactate Fermentation
Converts Pyruvate to lactic acid
Revesible
Control of Cellular Respiration
Allosteric control
Negative Feedback
Phosphofructokinase
Fats
Glycerol -> glycolysis
Fatty acids -> Beta Oxidation - Acetyl CoA enters TCA cycle
Large ATP yield
Proteins
Amino acids -> kept acids - enter the TCA cycle
Low variable ATP yield
Last choice for ATP production
