Cellular respiration Flashcards Preview

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Flashcards in Cellular respiration Deck (21)
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1
Q

Do these transporters conduct passive or active transport? GLUT and SGLT

A

GLUT - passive

SGLT - active

2
Q

Which of the GLUT (1,2,3,4) transporters is insulin sensitive?

A

GLUT-4

GLUT-2 is NOT insulin sensitive

3
Q

What is the net ‘energy’ gain of glycolysis?

A

2 x ATP

2 x NADH (equiv to 6 ATP)

4
Q

In glycolysis, what do you start with and end with?

A

glucose -> 2 x pyruvate

5
Q

Where does glycolysis occur?

A

cytosol/cytoplasm

6
Q

Where does oxidative phosphorylation occur?

A

Mitochondria

7
Q

Where does the krebs/citric cycle occur and where is the electron transport chain (ETC) located?

A

Krebs cycle - mitochondrial matrix

ETC - inner mitochondrial membrane

8
Q

What is the name of process which imports pyruvate (from glycolysis) into the mitochondria?

A

Oxidative Decarboxylation

9
Q

What does oxidative carboxylation result in?

A

Import of pyruvate from glycolysis into the mitochondria involves oxidative decarboxylation
This produces acetyl-CoA and NADH inside the mitochondria

10
Q

What is the net (energy) gain from oxidative decarboxylation (per glucose molecule)?

A

1 x glucose = 2 x pyruvate = 2 x NADH in oxidative decarboxylation

11
Q

What is the net (energy) gain from the krebs cycle (per glucose molecule)?

A

1 x glucose = 2 x pyruvate = 2 x acetyl coA:

  • 6 x NADH
  • 2 x FADH2
  • 2 x GTP
12
Q

How is acetyl-coA formed?

A

By β-oxidation of Fatty Acids

13
Q

What is the net (energy) gain from β-oxidation of Fatty Acids to create acetyl-coA?

A

1 x NADH

1 X FADH2

14
Q

What are the NADH and FADH2 produced from glucose used for?

A

Used in the ETC (inner mt membrane) to make ATP

15
Q

Describe how the electron transport chain works.

A

Energy from oxidation (removing electrons) of NADH and FADH2 is used to pump H+ across the mitochondrial inner membrane against their concentration gradient (into the intermembrane space)
As H+ moves back across the membrane through ATP synthase (into the mt matrix), ATP is produced from ADP

16
Q

In the ETC, what is the ultimate electron acceptor?

A

Oxygen - accepts electrons (from NADH/FADH2 to make H2O)

17
Q

What is gluconeogenesis?

A

Making new glucose from non-carbohydrate sources
In liver
Process requires energy (more made at end)
Sources:
Glycerol (triglycerides), amino acids (proteins), lactate (anaerobic glycolysis)

18
Q

What is the Cori cycle?

A

During vigorous exercise, muscle metabolism switches to anaerobic glycolysis, generating lactate.
The lactate is transported to the liver, where it is converted to glucose by gluconeogenesis (requires energy)

19
Q

How are amino acids (aa) used in the urea cycle?

A

AA’s - deamination by series of trasamination reactions - urea produced in liver via urea cycle - released into blood stream.

20
Q

Which amino acid is used in the urea cycle to make urea?

A

Arginine

21
Q
Which organs use the following as energy sources?
Glucose
Fatty acids
ketones
Amino acids
A

Glucose - most tissues (brain/RBCs)
Fatty acids - most tissues (minimal in neurons)
Ketones - most tissues (not liver) BRAIN
Amino acids - fast dividing cells (particularly glutamine) e.g. enterocytes and cancer cells