Overview of Energy Metabolism (Biochem Ch 11) Flashcards Preview

naplan > Overview of Energy Metabolism (Biochem Ch 11) > Flashcards

Flashcards in Overview of Energy Metabolism (Biochem Ch 11) Deck (66)
Loading flashcards...
1

Overview of Energy Metabolism

1. hydrolysis and absorption
2. conversion to Acetyl CoA and reduction of NAD and FAD
3. TCA: Acetyl CoA to Co2, and reduction of NAD and FAD
4. Oxidative Phosphorylation; ETC: NADH/FADH energy released. Produces ATP. Requires O2

1. fuels are hydrolyzed in the GIT tract and absorbed
2. fuels degraded in various pathways to common intermediate Acetyl CoA.
- most energy from fuels contained in chemical bonds of Acetyl CoA
- a smaller portion of energy is concerned in reducing FAD to FADH2
3. TCA cycle oxidizes Acetyl CoA to CO2
- energy released in this process is converted by reducing NAD to NADH or FAD to FADH2
4. Oxidative Phosphorylation releases energy in NADH and FADH2 via ETC and used to product ATP
- requires O2

2

Carbohydrates are converted to?

Carbohydrates --> Glucose --> Pyruvate --> Acetyl CoA --> TCA cycle

3

Protein is converted to?

Protein --> AA --> --> Acetyl CoA --> TCA

or

Protein --> AA --> --> Pyruvate --> Acetyl CoA --> TCA

4

Fat is converted to?

Fat --> Fatty Acids --> Acetyl Coa (via beta oxidation)

5

_____ is the final common product of sugar, protein, and fat metabolism

Acetyl CoA (which then goes into the TCA cycle)

6

___ is a polymer of glucose

glycogen

7

Half of the energy from metabolic fuels is captured as ATP, the rest is ____

Half of the energy from metabolic fuels is captured as ATP, the rest is given off as heat

8

- Insulin is an anabolic hormone that promotes _____
- it is opposed by:

- Insulin is an anabolic hormone that promotes fuel storage
- opposed by:
- glucagon
- epinephrine
- cortisol
- growth hormone

9

There is a limited amount of ATP in circulation. Most of the excess energy from the diet is stored as ____

- There is a limited amount of ATP in circulation. Most of the excess energy from the diet is stored as FATTY ACIDS and GLYCOGEN (a polymer of glucose)
- FA = a reduced polymer of acetyl CoA
- Glycogen = a polymer of glucose

10

Cholesterol is required for

- membrane structure
- proteins for muscle contraction
- polysaccharides for the ICM

11

The major function of glucagon is to

respond rapidly to decreased blood glucose levels by promoting:
- the synthesis and
- release of glucose into circulation

12

Anabolic and catabolic pathways are controlled at 3 important levels:

- allosteric inhibitors and activators of rate-limiting enzymes
- control fo gerne expression by insulin and glucagon
- phosphorylation (glucaon) and dephosphorylation (insulin) of rate-limiting enzymes

13

3 major tissues for insulin are:

- liver
- muscle
- adipose tissue

14

insulin promotes

1. glycogen synthesis in the liver and muscle
2. after the glycogen stores are filled, the liver converts excess glucose to fatty acids and triglycerides
3. insulin promotes TG synthesis in adipose tissue and protein synthesis in muscle
- as well as glucose entry into both tissues

15

After a meal, most of the energy needs of the liver are met by _____

the oxidation of excess AA

16

Immediately after a meal....

blood glucose levels rise and stimulate the release of insulin

17

Tissues insensitive to insulin (aka are insulin independent)

- brain and RBC

18

brain and other nerves derive energy from

- oxidizing glucose to CO2 and water in both the well-fed and normal fasting states
- only in prolonged fasting does this situation change
- in a fast, the liver pumps as much glucose into the blood stream as possible for the brain and RBC

19

Under all conditions, RBC use _____ for all their energy needs

Under all conditions, RBC use glucose anaerobically for all their energy needs

20

_____ levels rise during an overnight fast

- Glucagon and epinephrine levels rise during an overnight fast
- these hormones exert their effects on skeletal muscle, adipose tissue, and liver

21

In response to fasting...

1. glucagon and epinephrine levels rise
2. in liver, glycogen degradation (glycogenolysis) and the release of glucose into the blood are stimulated
3. hepatic gluconeogenesis is also stimulated by glucagon, but the response is slower than that of glycogenolysis
4. the release of AA from skeletal muscle and FA from adipose tissue are both stimulated by:
- the decrease in insulin and
- by an increase in epinephrine
5. the AA and FA are taken up by the liver, where:
- the AA provide carbon skeletons and
- the oxidation of FA provides the ATP necessary for gluconeogenesis

22

Glucagon effects:

1. phosphorylation of enzymes
2. gene expression
3. allosteric inhibition, activation

23

Why don't RBC do the TCA cycle or ETC?

bc they don't have mitochondria

24

where are FA made?

FA are made in the liver and moved to the adipose tissue

25

What stimulates lipoprotein lipase?

insulin

26

the release of AA from skeletal muscle and FA from adipose tissue are both stimulated by ......

the release of AA from skeletal muscle and FA from adipose tissue are both stimulated by:
- the decrease in insulin and
- by an increase in epinephrine

27

Adipose cells get glycerol to make ___

Adipose cells get glycerol to make TG from glycolysis

28

Which GLUT Transporter is found in muscle?
- what stimulates it?

- GLUT4
- skeletal muscle is on our 4 limbs, where GLUT4 transporters are (on muscle)
- it is stimulated by insulin and exercise

29

In a fast, _______ are giving carbons to the liver to make glucose, so the brain and RBC can function properly

In a fast...muscle, RBC and fat are giving carbons to the liver to make glucose, so the brain and RBC can function properly

30

Which GLUT transporter is found in RBC?

- GLUT 1 and GLUT 3
- work via zero-order kinetics