Metabolic cycle regulation

Question 1

Pyruvate Carboxylase modulators

Answer 1

Positive: acetyl coa (carb flame), glucagon transcription

Question 2

G-6-phosphatase modulators

Answer 2

Positive: Glucagon transcription

Question 3

Brain AMPK kinase

Answer 3

Ca2+-calmodulin-dependent kinase B - ca2+ stimulant

Question 4

Epinephrine

Answer 4

Positive modulator for glycolysis in the muscle to produce ATP.

Question 5

Pyruvate Kinase modulators

Answer 5

Positive: F-1,6-Bis-P, Insulin via transcription
Negative: ATP, Acetyl CoA, Long Chain FA, Glucagon

Question 6

Glucagon on metabolic pathways: FA mobilization

Answer 6

Adipose tissue

Positive - PKA, Hormone-sensitive lipase

Question 7

Phosphfructokinase I modulators

Answer 7

Positive: ADP, AMP, F-2,6-BisP, Insulin via transcription
Negative: ATP, citrate

Question 8

Insulin on metabolic pathways: Glycolysis, acetyl CoA production

Answer 8

Liver & Muscle

Positive: PFK-1 by PFK2, Pyruvate DH complex, Pyruvate kinase (transcription)

Question 9

AMPK-P energy producing processes

Answer 9

Heart (glycolysis, glucose uptake, b-oxidation), Skeletal muscle (b-oxidation, glucose uptake), brain (feeding)

Question 10

AMPK Kinase modulators

Answer 10

Positive: AMP, leptin, adiponectin

Question 11

F-1,6-Biphosphatase modulators

Answer 11

Negative: F-2,6-bisP

Question 12

Insulin on metabolic pathways: Triacylglycerol synthesis

Answer 12

Adipose

Positive: Lipoprotein lipase (transcription)

Question 13

PEP Carboxylase modulators

Answer 13

Positive: Glucagon and Glucagon transcription

Question 14

Positive Modulators on most energetic steps of Krebs cycle

Answer 14

Ca2+ in the muscle only

Question 15

Negative Modulators on most energetic steps of Krebs cycle

Answer 15

ATP, NADH+H, FADH2

Question 16

Glucagon on metabolic pathways: Ketogenesis

Answer 16

Brain

Negative - acetyl-CoA Carboxylase

Question 17

Adenylate Kinase

Answer 17

Will make AMP from 2 ADPs

Question 18

Explain why pyruvate carboxylase should be active in fed states

Answer 18

Acetyl CoA is a positive modulator for PC.

Liver fed: excess acetyl Coa with OAA from excess pyruvate make citrate, citrate shuttled to cytosol for FA synthesis.

Question 19

Succinyl-CoA and odd chain FAS as a negative modulator and why

Answer 19

alpha-ketoglutarate DH and citrate synthase, want to slow down Krebs because we are going faster than ATP synthesis in ETC can occur.

Question 20

Gluconeogenesis enzymes

Answer 20

G-6-phosphatase, F-1,6-Bisphosphatase, PEP Carboxylase, Pyruvate carboxylase

Question 21

Explain why hepatocytes express an additional hexokinase isozyme

Answer 21

Hexokinase - outside the liver, lower km, energy needed by extrahepatic cell during low glucose
Glucokinase - liver is dominated by its presence, separate isozyme for glucose phosphorylation, storage needed by hepatic cells at high glucose, higher Km

Question 22

Glut 1

Answer 22

most important at fasting blood glucose levels

Question 23

Glucagon on metabolic pathways: Glycogen breakdown/synthesis

Answer 23

Liver
Breakdown - positive glycogen phosphorylase
Synthesis - negative glycogen synthase

Question 24

AMP

Answer 24

positive modulator for AMPK and AMPK kinases

Question 25

Major reactions of glycolysis

Answer 25

Hexokinase, Phophofructokinase I, Pyruvate Kinase

Question 26

AMPK-P Energy consuming procceses

Answer 26

Pancreas (insulin secretion), Liver (FA, cholesterol synthesis), Adipose (FA syntehsis and lipolysis)

Question 27

Most energetic Steps in Krebs

Answer 27

Pyruvate DH, Citrate Synthase, Isocitrate DH, alpha-ketoglutarate DH

Question 28

Glucagon on metabolic pathways: Glycolysis/gluconeogenesis

Answer 28

liver Glycolysis - negative PFK-1 Gluconeogenesis - positive FBPase-2, negative - PEP carboxykinase (as well as transcription), pyruvate carboxylase, g-6-phosphatase (all transcription

Question 29

Insulin on metabolic pathways: Glucose uptake

Answer 29

Muscle, Fat -- GLUT 4 positive | Liver - Glucokinase (transcription)

Question 30

Role and modulators of Pyruvate dehydrogenase phosphatase

Answer 30

Activate pyruvate DH via positive modulator insulin and Ca2+

Question 31

Glucokinase positive modulators

Answer 31

Insulin via transcription

Question 32

FBPase-2 modulator

Answer 32

Positive: FBPase-2

Question 33

Glut 4

Answer 33

important after a meal when insulin is released. Only depends on insulin in muscle and adipose. Stored in the ER and recruited to surface by insulin for glucose transport. Once insulin signal is gone it is brought back to the ER

Question 34

G-6-Phosphatase expression

Answer 34

only expressed in liver and kidneys

Question 35

Explain why pyruvate carboxylase should be active in the fasted states

Answer 35

Acetyl CoA is a positive modulator. Muscle Fasted: Excess acetyl CoA from B-oxidation of FA and ketone bodies from the liver. Liver Fasted: Excess acetyl CoA from B-oxidation of FA. Alanine from muscle makes pyruvate to OAA (using PC) OAA can't react with excess CoA because gluconeogenesis uses OAA to make glucose. Excess acetyl CoA used to make Ketone bodies

Question 36

GLUT 4 modulators

Answer 36

Positive: Insulin via transcription

Question 37

Insulin on metabolic pathways: Glycogen Synthesis/breakdown

Answer 37

Liver & Muscle -- positive glycogen synthase, negative glycogen phosphorylase

Question 38

Modulators for Pyruvate DH

Answer 38

Positive: AMP, NAD+, CoA Negative: ATP, NADH, Acetyl-CoA

Question 39

Hyperglycemic

Answer 39

no AMPK-kinases -- Liver kianse B1 - stress stimulant

Question 40

Role and modulators of pyruvate dehydrogenase kinase

Answer 40

inactivate pyruvate DH via positive modulator ATP

Question 41

PFK-2 modulators

Answer 41

insulin positive modulator

Question 42

AMPK modulators

Answer 42

Positive: AMPK negative: Phosphocreatine

Question 43

Insulin on metabolic pathways: Fatty acid synthesis

Answer 43

Liver | Positive: Citrate Lyase, acetyl-CoA carboxylase, FAS (transcription)

Question 44

Glut 2

Answer 44

important immediately after a meal when glucose levels increase and during gluconeogenesis