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Biochem Exam 3 > Nutrition Advice > Flashcards

Flashcards in Nutrition Advice Deck (30):
1

Main function of ATP in muscle

Dissociation of actin-myosin complex

2

What does CK transfer?

a (P) from ATP --> Creatine

3

Type 1 muscle

Slow, Red, Fatigue resistant

 

High Mb and Mitochondria

4

Type 2a muscle

Intermediate

5

Type 2b Muscle

Fast, White, High glycogen and Low mitochondria

6

PFK2 difference in muscle? Why?

is NOT regulated by phosphorylation

 

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

7

Glucagon effect on muscle

none... there are no glucagon receptors

 

Glycogenolysis isn't stimulated by glucagon (only epi)

8

Fatty acid synthesis isoform in muscle

Acetyl-CoA Carboxylase II

9

FA metabolism is regulated by what in muscle?

Malonyl CoA (control CPT enzymes)

 

(AMP protein kinase is another important regulator)

10

In muscle, glycolysis is inhibited by

ATP and Citrate levels

 

*not PFK2

11

PFK2 in cardiac muslce regulation

Phosphorylated and activated by insulin-depenent kinase cascade

 

Phosphorylation increases PFK2 kinase activity and STOPS glycolysis

12

3 ways that glycogen phosphorylase is regulated (activated)

  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.

13

AMP activation pathway (2 steps)

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

14

What is the "master metabolic regulator"?

AMP Protein Kinase  (AMPPK)

15

Overall function of AMPPK

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

16

4 important functions of AMPPK

  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

17

Metformin function

Activates AMPPK via LKB1 (kinase)

18

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

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. 

19

Fatty acyl chains transported as...

Fatty acylcarnitine

20

Dephosphorylation effect on AcetylCoa Carboxylase?

What else regulates it?

Activates! 

 

It is inactivated by AMPPK and Palmitoyl CoA

21

Most abundant immediate source of ATP

Creatine Phosphate

22

Creatine synthesis pathway

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

23

Where is creatine synthesized

Starts in Kidney, ends in liver

24

Creatinine synthesis pathway and properties

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

25

Lactate transport?

Converted to Alanine by muscle for transport

26

What happens after lactate is taken up by other cells

it is converted to pyruvate by LDH

27

Anaerobic exercise progression

  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

28

How much ATP from BCAAs?

20%

29

Explain urine buffering in regards to BCAA

Release of NH3 by the muscle buffers urine as H+ increases during exercise

30