Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

My Kaplan Biochemistry Ch 8-12 > Ch. 10: Carbohydrate Metabolism II > Flashcards

Ch. 10: Carbohydrate Metabolism II Flashcards

1
Q

what occurs during the citric acid/Krebs cycle (big picture)

A

acetyl-CoA is oxidized to CO2 and H2O in the mitochondria

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

how does PDH form acetyl co-A

A
  • glycolysis produces pyruvate
  • actively transported to the mitochondrion
  • oxidized and carboxylated by PDH complex
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

how does acetyl co-A form during fatty acid oxidation

A
  • thioester bond forms between carboxyl groups of fatty acids and CoA-SH in the cytosol
  • transported inside the mitochondria on a carnitine transporter
  • beta-oxidation removes two-carbon fragments
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

how does acetyl co-A form during amino acid catabolism

A
  • amino acids lose amino group through transamination

- carbon skeletons form ketone bodies

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

how does acetyl co-A form from alcohol

A

alcohol dehydrogenase and acetaldehyde dehydrogenase converts -OH to acetyl Co-A, usually to synthesize fatty acids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

why will the citric acid cycle not occur anaerobically

A

NADH and FADH2 will accumulate without oxygen for the electron transport chain, inhibiting the cycle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what occurs during citrate formation

A

Acetyl-CoA and Oxaloacetate are hydrolyzed, yielding citrate, CoA-SH, and H+

citrate synthase is the catalyst

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what occurs during citrate isomerization

A

citrate binds with aconitase, then is rehydrated to form isocitrate

ultimately hydrogen and hydroxyl group are switched to allow for later oxidative decarboxylation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what occurs during alpha-Ketoglutarate and CO2 formation

A
  • isocitrate is oxidized to oxalosuccinate by rate limiting isocitrate dehydrogenase
  • then is decarboxylated to produce alpha-ketoglutarate and CO2
  • a carbon is lost and NADH is produced
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

what occurs during succinyl-CoA and CO2 formation

A
  • alpha-ketoglutarate and CoA are brought together by alpha-ketoglutarate dehydrogenase complex (similar to PDH) to form succinyl-CoA
  • carbon is lost and NADH is produced
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what occurs during succinate formation

A

thioester of succinyl-CoA is hydrolyzed by succinylcholine CoA synthetase, producing succinate and CoA-SH

coupled to GDP–>GTP phosphorylation, which then is transferred to ADP and ATP is produced

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what occurs during fumarate formation

A

succinate is oxidized by succinate dehydrogenase on the inner mitochondrial membrane to produce fumarate

FAD reduced to FADH2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what occurs during malate formation

A

fumarate alkelene bond is hydrolyzed by fumarase to produce malate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what occurs during oxaloacetate formation

A

malate is oxidized by malate dehydrogenase to form oxaloacetate

NADH produced

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

substrates of the citric acid cycle

A

Please Can I Keep Selling Seashells For Money Officer

Pyruvate, Citrate, Isocitrate, alpha-Ketoglutarate, Succinyl-CoA, Succinate, Fumarate, Malate, Oxaloacetate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

how much ATP is produced from one glucose molecule from glycolysis through oxidative phosphorylation

A

30-32 ATP

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

how can the citric acid cycle be regulated

A
  • phosphorylation of PDH by pyruvate dehydrogenase kinase (high ATP) OR
  • dephosphorylation of PDH by pyruvate dehydrogenase phosphatase (high ADP)
18
Q

what are the control points of the citric acid cycle

A

citrate synthase, isocitrate dehydrogenase, alpha-ketoglutarate dehydrogenase complex

19
Q

how does citrate synthase control the citric acid cycle

A
  • ATP (indirect), NADH (direct), citrate (directly), succinyl-CoA (directly) allosterically inhibit citrate synthase
20
Q

how does isocitrate dehydrogenase control the citric acid cycle

A
  • inhibited by ATP and NADH

- activated by ADP and NAD+

21
Q

how does alpha-ketoglutarate dehydrogenase complex control the citric acid cycle

A
  • inhibited by succinyl-CoA, ATP, and NADH

- stimulated by ADP and calcium

22
Q

overall, what inhibits and activates the citric acid cycle

A

inhibits: high ATP, high NADH
activates: high ADP, hight NAD+

23
Q

what is the proton-motor force

A

electrochemical proton gradient generated by the complexes of the electron transport chain

24
Q

what are the two steps that occur during the electron transport chain (big picture)

A
  • electron transport along the inner mitochondrial membrane

- ADP phosphorylated to ATP

25
what occurs in the first complex of the ETC
electrons from NADH are transferred to coenzymeQ, forming NAD+ and CoQH2 four protons are moved to the intermembrane space
26
what occurs in the second complex of the ETC
electrons from succinate are transferred to coenzymeQ, forming fumarate and CoQH2 no hydrogen pumping occurs
27
what occurs in the third complex of the ETC
electrons are transferred from coenzyme Q to cytochrome C via the oxidation and reduction of cytochromes
28
what occurs during the Q cycle
**during complex three** proton motor force gradient increased as - two electrons are shuttled from from CoQH2 near the inter membrane space to CoQ near the mitochondrial matrix, and - four protons move into the inter membrane space
29
what occurs in the fourth complex of the ETC
electrons are transferred from cytochrome C to oxygen through a series of redox reactions two protons are moved across the membrane
30
where does [H+] increase in the ETC
in the intermembane space - lowers pH in intermembrane space - voltage difference between intermembrane and matrix grows
31
what enzyme uses the energy of the electrochemical gradient to phosphorylate ADP --> ATP
ATP Synthase
32
what do shuttle mechanisms do
transfer the high-energy electrons of NADH to a carrier that can cross the inner mitochondrial membrane
33
how many ATP are generate by the Glycerol 3-phosphate shuttle
1.5 ATP per molecule of cytosolic NADH
34
how many ATP are generate by the Malate-aspartate shuttle
2.5 ATP per molecule of cytosolic NADH
35
what is the F0 portion of ATP synthase
- portion of ATP synthase that spans the membrane - where proton motor force interacts with ATPSynthase - ion channel where protons travel along their gradient bak into the matrix
36
what occurs during chemiosmotic coupling
chemical energy gradient is harnessed to phosphorylate ATP as protons flow back into the matrix
37
what does the F1 portion of ATP synthase do
uses the energy released when protons move through F0 channel to phosphorylate ADP
38
what occurs during the conformational coupling mechanism
ATP is released by the synthase as a result of conformational change caused by the gradient
39
what substances regulate the rate of oxidative phosphorylation
O2 and ADP
40
what does respiratory control accomplish
citric acid and oxidative phosphorylation pathways are linked O2 levels determine rate of oxidative phosphorylation, which will determine concentration of NADH and FADH2, which will determine the rate of the citric acid cycle

My Kaplan Biochemistry Ch 8-12 (5 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions