Metabolism Flashcards
metabolism definition
set of chem reactions occurring in living organisms to maintain life
catabolism defintion
metabolic pathways which break down molecules into smaller units + release energy
anabolism definition
metabolic pathways that construct molecules from smaller units
how is energy released from fuel + stored
via oxidation of fuel - stored as high energy carriers NAD+ + FADH
how is glucose metabolism a redox reaction
electrons are lost from one atom and gained by another
substrate level phosphorylation
transferring phosphate directly to ADP from another molecule
oxidative phosphorylation
use of ATP synthase + energy derived from H+ gradient to make ATP
what is the glucose yield of glycolysis
net 2 ATP, 2 pyruvate + NADH
differentiate b/t preparatory + pay off phases
preparatory = rate is limited, 2 ATP used
pay off = 2 ATP produced + reduction of 2NAD+ to 2NADH
what happens to pyruvate molecules in presence of O2
transported to mitochondria + converted into acetyl CoA
what happens to acetyl CoA when it enters the citric acid cycle
produces the high energy electron carriers NADH, FADH2 + CO2
5 steps to ETC
- coenzyme strips 2 hydrogens from substrate molecule
- NADH + FADH2 deliver H atoms to coenzymes embedded in the inner membrane of the mitochondrion
- coenzyme Q releases H+ + passes electrons to cytochrome B
- e- passed along electron transport system, losing energy in a series of small steps
- oxygen accepts low energy electrons + w/ H+ forms water
describe chemiosmosis
As e- move through, they facilitate pumping of protons into inter-memb. space
-> H+ flow down conc. gradient
-> captured by ATP synthase + converted into ATP
what happens to NADH + FADH2 in the absence of O2
alternate electron acceptors replace oxygen + still allow for oxidation of the coenzymes
-> produces less energy
how does lactic acid fermentation occur
allows cell to oxidise NADH back to NAD+ in the absence of O2
-> NAD+ can be reused during glycolysis to generate ATP
