Redox reactions + glycolysis Flashcards
1
Q
End-product inhibition
A
- metabolic pathways are nearly always down regulated by the final product to avoid overproduction
2
Q
cooperativity
A
- occurs w/ two or more identical enzyme subunits forming enzyme complex
- first inhibitor molecules binds to allosteric site, induces conformation change in the subunit binds to, and partial conformation change in neighbouring units
- partial change is what facilitates binding of second inhibitor
- you now see curve w/ increasing inhibitor concentration leading to switch-like behaviour of multi-subunit enzymes - THIS CATALYZES the metabolic pathway!!!!
3
Q
Metabolic pathway
A
- first step in path way is usually catalyzed by multi-subunit enzyme negatively regulated by cooperative allostay via end product of pathway
4
Q
Catabolic pathways
A
- long and complex in order to release energy slowly
- burning glucose to carbon dioxide and water released all free energy in one reaction w/o capturing any energy for the cell
- better to do this in smaller steps, keep reaction going, half is ATP, other half is released as heat to drive reactions
5
Q
Burning of glucose
A
- it is oxidation, a redox reaction, can be efficient (releases lots of energy) when oxygen is a electron acceptor
- or inefficient when there is absense of oxygen (fermentation)
6
Q
Reduction
A
Gain of electrons
7
Q
Oxidization
A
Loss of elections
8
Q
Photosynthesis
A
- photosynthesis
- stored chemical energy
- glycolysis
- aerobic: CELLULAR RESPIRATION complete oxidation, water products: H20, C02, net energy trapped: 29 ATP
- anaerobic: FERMENTATION incomplete oxidation, waster product: organic compound, net energy trapped 2 ATP
9
Q
How is oxidation stored?
A
- in intermediate NAD, it gets reduced to NADH, NADH is later oxidized and it releases energy
10
Q
NADH
A
- temp. electron carrier (energy carrier)
- crucial for redox reactions
11
Q
ATP
A
- crucial energy carrier for non-redox reactions
12
Q
How do you know if NADH or NAD+ gets reduced?
A
- any two half reactions can be coupled in a redox reaction
- redox reactions are fully reversible
- direction of electron flow depends on which two half reactions get coupled (either flow to NAD+ or away from NADH)
13
Q
Which way does it flow when couples w/ oxygen as electron acceptor?
A
- flow away from NADH
14
Q
Which way does it flow when couples w/ glucose intermediates?
A
- electrons flow toward NAD+
15
Q
How is electron flow measured? Which way does it flow?
A
- it is measured in Volts - redox potential
- when you couple two together, electrons always flow from more negative to more positive redox potential
