Energy Metab.: PDH and Krebs Cycle

Question 0

Fatty Acid energy pathway (Start with Triglycerides)

Result?

Answer 0

Triglycerides = 3 fatty acids + glycerol
Fatty acids + beta oxidation (in mitochondrium) = AcCoa

Results are AcCoa + 1 NADH + 1 FADH

Question 1

Modes of enzyme regulation

Answer 1

Feedback/Feedforward
Allosteric
Phosphorylation/Dephosphorylation
gene transcription

Question 2

Amino Acid energy pathway

Answer 2

AA = Pryuvate - PDH = AcCoa

Question 3

Glucose energy pathway

Answer 3

Glucose or Glycerol - (glycolysis) - Pyruvate = AcCoA

Question 4

PDH complex equation

Answer 4

Pyruvate + NAD+ + CoA ==> AcCoa + Co2 + NADH + H+

Question 5

PDH a.k.a, fxn, location, reaction dynamics, composition

Answer 5

Pyruvate dehydrogenase complex
Covert pyruvate to AcCoa 
Mitochondrial matrix
irreversible
3 enzymes, 5 coenzymes, 2 regulatory enzymes

Question 6

PDH Regulation

Answer 6

Products of reaction competitively inhibit complex
active form = dephosphorylated
inactive form = phosphorylated
Kinase (that phosphorylates) activated by products and inhibited by reactants

Question 7

PDH deficiency

Answer 7

Increased lactate, pyruvate and alanine
chronic lactic acidosis
severe neurological defects or death

Question 8

TCA pathway

Answer 8

Acetyl Coa + Oxaloacetate => citrate => isocitrate => Alpha-ketogluterate => succnyl coa => succinate => fumerate => L-malate => oxaloacetate

Question 9

energy producing TCA enzymes - which

located where

Answer 9

Isocitrate Dehydrogenase = NADH
Alpha-ketogluterate dehydrogenase = NADH
Succinyl CoA synthase = GTP
Succinate dehydrogenase = FADH2
Malate Dehydrogenase = NADH
location = mitochondrial matrix

Question 10

TCA energy breakdown - one cycle

Answer 10

3 NADH + H, 1 FADH2 + 1GTP = 12 ATP (one cycle)

Question 11

AcCoa Sources

Answer 11

Beta oxidation of fatty acids
PDH
Some Amino Acids

Question 12

AcCoA paths

Answer 12

Oxidation - TCA
Liver - Ketone bodies
Cytosol - biosynthesis of sterols and long chains fatty acids

Question 13

TCA regulation

Answer 13

Supply
PDH
Co-enzyme (FA and NAD+) availability
ADP + Pi availability

Question 14

Fumarase Deficiency - result

Answer 14

severe neurological impairment, encephalomyopathy, and dystonia

Question 15

TCA pathology

Answer 15

Fatal

Question 16

Pyruvate dehydrogenase deficiency

Answer 16

congenital lactic acidosis

Question 17

regulatory enzymes - inhibited by, [activated by]

Answer 17

citrate synthase - NADH and Succinyl CoA
isocitrate dehydrogenase - NADH and ATP, [ADP, Ca2+]
alpha-ketoglutarate dehydrogenase - ATP, GTP, NADH and Succinyl CoA, [Ca2+]

Question 18

anabolic function of TCA

Answer 18

supply starting materials for biosynthetic processes

Question 19

Anaplerotic reactions def., e.g.

Answer 19

Replenish intermediates of TCA
pyruvate carboxylase - turns pyruvate into oxoaloacetate
amino acids can also turn into 4 different intermediates, i.e. during fasting