Nutrition Advice

Question 1

Main function of ATP in muscle

Answer 1

Dissociation of actin-myosin complex

Question 2

What does CK transfer?

Answer 2

a (P) from ATP –> Creatine

Question 3

Type 1 muscle

Answer 3

Slow, Red, Fatigue resistant

High Mb and Mitochondria

Question 4

Type 2a muscle

Answer 4

Intermediate

Question 5

Type 2b Muscle

Answer 5

Fast, White, High glycogen and Low mitochondria

Question 6

PFK2 difference in muscle? Why?

Answer 6

is NOT regulated by phosphorylation

It doesn’t have the SERINE target for phosphorylation by PKA

Question 7

Glucagon effect on muscle

Answer 7

none… there are no glucagon receptors

Glycogenolysis isn’t stimulated by glucagon (only epi)

Question 8

Fatty acid synthesis isoform in muscle

Answer 8

Acetyl-CoA Carboxylase II

Question 9

FA metabolism is regulated by what in muscle?

Answer 9

Malonyl CoA (control CPT enzymes)

(AMP protein kinase is another important regulator)

Question 10

In muscle, glycolysis is inhibited by

Answer 10

ATP and Citrate levels

*not PFK2

Question 11

PFK2 in cardiac muslce regulation

Answer 11

Phosphorylated and activated by insulin-depenent kinase cascade

Phosphorylation increases PFK2 kinase activity and STOPS glycolysis

Question 12

3 ways that glycogen phosphorylase is regulated (activated)

Answer 12

1. by AMP in muscle
2. Ca++ can activate via glycogen phosphorylase kinase
3. Epi can activate Adenylate cyclase, which activates cAMP-dependent protein kinase.

Question 13

AMP activation pathway (2 steps)

Answer 13

1. Atp—> ADP + Pi (((this happens during contraction)))
2. 2ADP —> ATP + AMP (((adenylate cyclase rxn)))

Question 14

What is the “master metabolic regulator”?

Answer 14

AMP Protein Kinase (AMPPK)

Question 15

Overall function of AMPPK

Answer 15

inhibits the processes that require ATP, stimulates the ones that produce ATP

Question 16

4 important functions of AMPPK

Answer 16

1. Induces GLUT4
2. Inactivates AcetylCoA Carboxylase (and Increases Malonyl Decarboxylase)
3. Inhibits HMG-CoA Reductase
4. Activates PFK2 in cardiac muscle to increase glycolysis

Question 17

Metformin function

Answer 17

Activates AMPPK via LKB1 (kinase)

Question 18

How does is fatty acid entry into mitochondria affected by AMPPK?

Answer 18

It lowers AcetylCoA carboxylase 2 (isoform in muscle)

AND it increases Malonyl CoA carboxylase

**Both of these things mean there’s a lot less Malonyl CoA floating around to inhibit CPT, so fatty acids get metabolized since they get transported into the mitochondria more readily.

Question 19

Fatty acyl chains transported as…

Answer 19

Fatty acylcarnitine

Question 20

Dephosphorylation effect on AcetylCoa Carboxylase?

What else regulates it?

Answer 20

Activates!

It is inactivated by AMPPK and Palmitoyl CoA

Question 21

Most abundant immediate source of ATP

Answer 21

Creatine Phosphate

Question 22

Creatine synthesis pathway

Answer 22

1. Glycine + Arginine –>> Guanidinoacetate + Ornithine
2. Guanidinoacetate + SAM –>> Creatine + SAH

Question 23

Where is creatine synthesized

Answer 23

Starts in Kidney, ends in liver

Question 24

Creatinine synthesis pathway and properties

Answer 24

Creatine –>> CP –>> Creatinine –>> (Excreted in urine)

This is spontaneous, constant, and based on the amount of skeletal muscle mass.

Nonenzymatic cyclization in muscle and brain

Question 25

Lactate transport?

Answer 25

Converted to Alanine by muscle for transport

Question 26

What happens after lactate is taken up by other cells

Answer 26

it is converted to pyruvate by LDH

Question 27

Anaerobic exercise progression

Answer 27

1. ATP generated from the formation of Lactate from glycogen
2. Rise in AMP = increase in PFK1 and glycogen breakdown = More ATP
3. Lactate goes on to be used by heart after conversion to pyruvate

Question 28

How much ATP from BCAAs?

Answer 28

20%

Question 29

Explain urine buffering in regards to BCAA

Answer 29

Release of NH_{<strong>3</strong>} by the muscle buffers urine as H⁺ increases during exercise