L3+4 Biochem

Question 1

in ETC energy contained in metabolic fuels is released as electrons transferred from ____ and ___ to O2 by a series of Redox reactions that occur in the inner mitochondria

Answer 1

NADH and FADH2

Question 2

is the tendency of the reactants in an oxidation-reduction reaction to lose electrons

• is expressed in VOLTS
• the higher this tendency the more is the G

Answer 2

Standard Reduction Potential [E0]

Question 3

the more _____ the E0 of a redox pair, the greater the tendency of the reduced member of that pair to ____ electrons

Answer 3

negative

loose

Question 4

the more _____ the E0 of a redox pair, the greater the tendency of the oxidized member of that pair to accept electrons

Answer 4

Positive

accept

Question 5

1- electron acceptors are _________

2- electron Donors are ______ and _____

Answer 5

1- Oxygen/water

2-H+ and NAD+/NADH

Question 6

in ETC
A- (Dehydrogenases) Coenzymes : 
a1) \_\_\_\_
a2) \_\_\_\_
a3)\_\_\_\_

B- mobile electron carriers (within the mitochondria):

b1) ______
b2) ______

Answer 6

a1) NAD+
a2) FMN
a3) FAD
- -
b1) Cytochrome C
b2) Coenzyme Q

Question 7

Electron transport chain :
1-located _______ which is impermeable to most small ions
2-produces the reduced coenzymes ____ and___
3- final common pathway of _____

Answer 7

1-inner mitochondrial membrane
2- NADH and FADH
3- Aerobic metabolism

Question 8

Component of ETC:
A) complexes (fixed) :
a1- complex : leads synthesis if ATP(not part of ETC)
a2-complex : (most electronegative) composed of NADH, FMN, Fe-S centers
a3-complex: composed of FAD(initial e- acceptors), Fe-S centers, succinate dehydrogenase of Krebs cycle
a4-complex: accepts e from reduced CoQ
a5-complex_: also called cytochrome c oxidase or cytochrome aa3, the only irreversible reaction of the chain, contains copper

B) mobile e- carriers:
b1-: only lipid component in the respiratory chain, for complex 1 and 2
b2- small, water-soluble protein, contains heme, an iron atom

Answer 8

A)
1- complex 5
2- complex 1
3- complex 2
4- complex 3
5- complex 4

B)
1- Coenzyme Q
2-cytochrome C

Question 9

ETC is coupled to proton transport for ATP synthesis, it is done by ?
(proton pumps)
1-
2-
3-
because they have high energy (unlike complex _ that has low energy

Answer 9

1- complex 1
2-complex 3
3-complex 4

unlike complex 2

Question 10

oxidation of NADH+ through ETC gives ___ while oxidation of FADH2 gives ____

Answer 10

3 ATP , 2 ATP

Question 11

is the number of ATP molecules produced per O atom reduced

Answer 11

P/O ratio

Question 12

• ***inhibitors of oxidative phosphorylation:
  1) inhibitors of electron transfer:
  1a. _____: inhibits complex 1
  2a. ____ : inhibits between FMN(complex1) and CoQ
  3a. ____ : is a competitive inhibitor for complex 2
  4a. ____ : inhibits complex 3
  5a. ____, ___, ___: inhibit complex 4

Answer 12

1a. Barbiturates
2a. Rotenone
3a. Malonate
4a. Antimysin
5a. Cyanide, carbon monoxide, H2S

Question 13

• ***inhibitors of oxidative phosphorylation:
  2) inhibitors of ATP synthase:
  2a. ______ inhibits phosphorylation of ADP to ATP

3) uncouplers of oxidative phosphorylation: (electron transfer unaffected)
* ***3a. 2,4-Dinitrophenol (DNR) : before finding out it was toxic, it was used as _______ , decreases proton gradient, NO ATP synthesis
3b. physiological uncoupler is called ____

Answer 13

2a. oligomycin
3a. dietary supplement for weight loss
3b. thermogenin