Cell Metabolism 2

Question 1

What does the TCA cycle produce

Answer 1

2CO2 3 NADH 1FADH2 1GTP

Question 2

Warburg effect

Answer 2

Certain cancer cells have defects in isocitrate dehydrogenase, succinate dehydrogenase and fumerase → high rate of glycolysis and lactate production even in aerobic conditions

Question 3

Transamination

Answer 3

Transfer of an amine group from an amino acid to a keto acid forming a new pair of amino and keto acids

Question 4

Degradation of amino acids gives rise to 7 molecules

Answer 4

Pyruvate
A ketoglutarate
Succinyl coa
Fumarate
Oxaloacetate
Acetyl coa
Acetoacetyl coa

Question 5

Why does NADH need to enter mitochondria

Answer 5

To regenerate NAD+
Inner mitochondrial membrane is impermeable to NADH

Question 6

Glycerol phosphate shuttle

Answer 6

Occurs in skeletal muscle and brain
Electrons from NADH are added to dihydroxyacetone phosphate making glycerol3phosphate
Also makes FADH2 and NAD+
Hydrogen from FADH2 passed to coenzyme Q

Question 7

Malays aspartate shuttle

Answer 7

Liver kidney heart
Aspartate transaminase converts oxaloacetate to aspartate
Aspartate is pushed from mitochondria into cytoplasm
Maleate dehydrogenase converts oxaloacetate into malate

Malate-alpha-ketoglutarate antiporter pushes malate from cytoplasm into mitochondria

Question 8

Beta oxidation

Answer 8

Is the breakdown of fatty acids which occurs in the outer mitochondrial membrane leading to acetyl coA production

Question 9

Beta oxidation first step

Answer 9

1) Fatty acid is converted into acyl CoA via acyl coa synthetase also converting ATP to AMP AND PP

Question 10

What’s the second step in beta oxidation

Answer 10

Acyl coa is transported into the matrix to undergo beta oxidation in outer mitochondrial matrix
Acyl coa combines with carnitine forming acyl carnitine. Translocation shuttle carnitine and acyl carnitine across inner mitochondrial membrane

Question 11

Primary carnitine deficiency

Answer 11

Poor b oxidation take carnitine supplements

Question 12

B oxidation final step

Answer 12

Each cycle removes 2C from acyl coa producing 1 NADH and 1FADH2
Acyl coa dehydrogenase catalyses initial oxidation step

Question 13

MCADD

Answer 13

Autosomal recessive disorder which reduces efficiency of fatty acid metabolism
Must eat high carbohydrate diet and avoid fasting for more than ten hours

Question 14

How many atp maxs per turn in Karen’s

Answer 14

12

Question 15

Ketone body formation

Answer 15

Occurs in liver where fat breakdown predominates
D-3-hydroxybutyrate and acetone and acetoacetate

Question 16

Similarities and differences between lipogenesis and fatty acid degredation

Answer 16

Lipo: cytoplasm NADPH ACP
Fatty acid:outer mitochondrial membrane NAD+/FAD CoA

Question 17

Lipogenesis enzymes

Answer 17

Acetyl coa carboxylase and fatty acid synthase

Question 18

Beta oxidation of palmitoyl

Answer 18

palmitoyl coa+7FAD+7NAD++7H2O= 8 Acetyl coa+7FADH2+7NADH

Question 19

Lipogenesis

Answer 19

Acetyl coA+7 malonyl coA+14NADPH+14H+=palmitate+7CO2+6H2O+8coA-SH+14NADPH

Question 20

5 main classes of lipids

Answer 20

Free fatty acids
Truacykglycerols
Phospholipids
Glycolipids
Steroids

Question 21

Purpose of beta oxidation

Answer 21

Acetyl coa
Occurs in mitochondria

Question 22

Why is AMP produced when converting fatty acids to acyl coa

Answer 22

2 high energy bonds are broken as its a high energy reaction

Question 23

Glucogenic vs ketogenic amino acids

Answer 23

Glucogenic aa give rise to glucose precursors needed for gluconeogenesis
Ketogenic aa give ketone bodies Acetyl coa and acetoacetyl coa when degraded

Question 24

When does Acetyl coa enter the keeps cycle

Answer 24

When fat and carbohydrate metabolism is balanced as oxaloacetate is needed for entry