Lecture 39 Flashcards Preview

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Flashcards in Lecture 39 Deck (30):
1

True or False:
There is always a high metabolic demand for ATP use?

False: there is variable metabolic demand for ATP

2

What happens to insulin and glucagon as blood glucose levels rise (after a meal)?

Insulin is increased and Glucagon is decreased
-Insulin:glucagon ratio increases

3

Because ruminants convert CHO in their diet to VFA's they require _____ to make glucose to fuel brain and RBCs.

Gluconeogenesis

*In these animals glucagon is released after a meal

4

How is insulin secretion different in ruminants from other mammals? What is it maintained by?

-Insulin secretion in ruminants continues after the meal has been digested (maintained)
- amino acids, glucagon, GI hormone stimulation

5

In the well-fed state what happens to the glucose once it reaches liver?

-Either stored as glycogen or converted to fat through lipolysis

6

What organs require glucose for energy?

Brain, Kidney, Liver, RBC, Muscle

7

___ works to drive liver glucose uptake when blood glucose is ____

-Glucokinase
-High

8

What happens to glucose in adipose tissue following a meal?

-Used for glycerol 3-phosphate production for TG storage

9

Following a meal the Insulin driven anabolic pathways are ____, while the glucagon-driven catabolic pathways are ____.

Active
-Inactive

10

Following a meal protein phosphatases are ____ and protein kinases are ____

-active
-inactive

11

Indicate increase/decrease or on/off following a meal:
1. GLUT4 translocation
2. Glycogenesis
3. Glycogen Synthase
4. Glycogen phosphorylase
5. Glycolysis
6. PFK II
7. PDH
8. Fructose 2,6 bisphosphate
9. Gluconeogenesis

1. Increased
2. Increased
3. On
4. Off
5. On
6. actively phosphorylating Fructose 2,6 P2
7. On
8. On
9. Off

12

What is responsible for delivering lipids to tissues for use and storage?

Chylomicrons

13

Indicate what effect high insulin is having on the following pathways:
1. Lipogenesis
2. Acetyl CoA carboxylase
3. Lipoprotein Lipase
4. Hormone Sensitive lipase
5. Lipolysis

1. On
2. On --> convert excess glucose to lipid
3. On --> deliver FA for storage
4. Off --> prevents TG breakdown
5. Off

14

True or False:
Liver metabolizes aromatic amino acids and non-hepatic tissue metabolizes branched chain amino acids.

True

15

Please indicate whether the rate of the pathway would be increased or decreased when the two conditions are compared.

1. Glucagon secretion in a Fasted state is ___ relative to the well fed state

2. Liver glycogen synthase activity in the well-fed state is ___ relative to a fasted state

3. Liver glycogen phosphorylase activity in a fasted state is ___ relative to the well-fed state

4. Muscle protein synthesis in the well-fed state is ___ relative to a fasted state

5. Adipose tissue lipolysis in a fasted state is ___ relative to a well-fed state.

1. Decreased
2. Increased
3. Increased
4. Increased
5. Increased

16

Is there more energy in stored glycogen or stored triglyceride?

Triglyceride

17

In the early fasting state what does the liver release?

Glucose from the glycogen supply

18

In early fasting liver glycogenolysis ____

Increases.
-Brain and RBC need glucose!

19

In general what is the glycogenolysis pathway?

Glucagon --> PKA --> activated phosphorylase kinase --> Glycogen phosphorylase --> Breakdown glycogen

20

When the insulin:glucagon ratio falls sufficiently during mid fasting liver ___ is increased as well as adipose tissue ____

-gluconeogenesis
-lipolysis

21

How does the liver promote gluconeogenesis during mid fasting?

-Glucagon activates liver PFK II phosphatase which decreases fructose 2,6 P2, turning gluconeogenesis on

22

How is lipolysis activated during mid fasting?

-Glucagon and epinephrine activate hormone sensitive lipase

23

What is the significance of lipolysis activation during mid fasting?

-Provides FFA for tissues to oxidize and allow diminished glucose oxidation

24

During late fasting/early starvation where is the glycerol coming from for gluconeogenesis?

-Glycerol is released from adipose tissue lipolysis which is activated by catecholamines and cortisol

25

How does the glucose requirement change during early and intermediate-late starvation?

Early on glucose requirement is high but later the brain can switch to using ketones so gluconeogenesis decreases and ketogenesis increases

26

True or False:
The liver is the only organ that can perform gluconeogenesis?

False.
The kidney can perform gluconeogenesis during prolonged fasting/starvation.

27

___ declines over time while ____ increases

-gluconeogenesis
-ketogenesis

28

Where is the glucose coming from throughout a fast?

-Early-exogenous
-As this is digested glycogen stores are broken down.
-As Glycogen is diminished gluconeogenesis kicks in
-After several days gluconeogenesis slows and ketogenesis increases

29

What happens in a starved state?

-Increased muscle protein breakdown
-Loss of digestive and nutrient processing enzymes
-Increased AA oxidation
-Increased gluconeogenesis
-Increased urea production
-Increased ammonia production

30

Indicate whether the rate of the pathway would be increased or decreased:

1. Liver gluconeogenesis in the fasted state is ___ relative to well-fed state.

2. Adipose tissue triglyceride synthesis in the well-fed state is ___ relative to the fasted state

3. Adipose tissue hormone-sensitive lipase activity in the fasted state is ___ relative to the well-fed state.

4. Liver ketone synthesis in the well-fed state is ___ relative to the fasted state

5. Red blood cell glycolysis is the well-fed state is ___ relative to the fasted state.

1. Increased
2. Increased
3. Increased
4. Decreased
5. No change