Lecture 33: Absorptive and Postabsorptive nutrient utilization Flashcards

1
Q

What is the origin of glucose in the absorptive phase/ Phase I of glucose homeostasis

A

Exogenous

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What tissues are using glucose in absorptive phase/phase 1 glucose homeostasis

A

All

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is the major rule of the brain during absorptive phase/phase 1 glucose homeostasis

A

Glucose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is the origin of blood glucose in postabsorptive/phase 2 glucose homeostasis

A

Hepatic glycogen, gluconeogenesis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What tissues are using glucose during postabsorptive/phase 2 glucose homeostasis

A

All except liver, muscle and adipose at diminished rates

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is the major fuel source to the brain during postabsorptive/phase II glucose homeostasis

A

Glucose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is the origin of blood glucose in phase III/prolonged energy deficiency

A

Hepatic and renal gluconeogenesis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What tissues are using glucose during phase 3/ prolonged energy deficiency stage

A

Brain and RBC’s, small amount by muscle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is the major fuel of the brain during phase 3/prolonged energy deficiency

A

Glucose, ketone bodies

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is the origin of blood glucose in phase IV/ prolonged energy deficiency

A

Renal and hepatic gluconeogenesis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What tissues are using glucose in phase IV/ prolonged energy deficiency

A

Brain at a diminished rate, RBC’s normal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is the major fuel of the brain in phase IV/ prolonged energy deficiency

A

Ketone bodies, glucose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Why does glucose concentration need to be controlled tightly

A

Major fuel source to the brain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

During the absorptive phase what is the depot site for glucose and AA

A

Liver

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

During absorptive phase what is the depot site for TG/FA

A

Liver, adipose tissue

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What are the 3 metabolic pools

A
  1. Glucose
  2. FA
  3. AA
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is the substrate in Kreb cycle

A

acetate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Glucose stored as

A

Glycogen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is the first step in processing of glucose

A

Glycolysis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Excess glucose can be converted to ___ in the liver

A

FA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

How is glucose converted to FA in liver

A
  1. Glucose—> pyruvate
  2. Pyruvate and oxloacetate—> citrate
  3. Citrate—> acetyl coA and oxaloacetate
  4. Acetyl CoA to FA
  5. Oxaloacetate to pyruvate
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What is the transport amino acid

A

Alanine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

How is alanine formed

A

Nitrogen—> pyruvate—> alanine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Most AA enter circulation and are channeled through ___

A

Liver

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Amino acids are delaminated which produce ___ and ___

A

Ketoanalogues and urea

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Liver selectively removes AA that can be used for ___ or ___

A

Protein synthesis or liver metabolism

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What organ produce blood proteins

A

Liver

28
Q

What are some examples of blood proteins produce by the liver

A

Leukocytes, vascular endothelial cells

29
Q

AA can be converted to ___ and ___synthesis

A

Glucose and FA synthesis

30
Q

What is the storage form of AA

A

Muscle protein

31
Q

AA can contribute to the ___ and __ pool

A

Glucose and adipose tissue pool

32
Q

What are the 3 potential fates for AA after delamination to keto-acids

A
  1. Metabolized
  2. Gluconeogenesis/ glycogenesis
  3. FA synthesis
33
Q

what are FA stored as

A

Triglycerides

34
Q

What happens to triglycerides during absorptive phase

A

TF/NEFA are repackaged in liver and transporter for storage or utilization as very low density lipoproteins (VLDL)

35
Q

During the post absorptive phase fat cells release ___ and ___

A

Glycerol and NEFA

36
Q

T of F: FA can be converted to glucose

A

False, decarboxylation of pyruvate to acetylCoA is irreversible

37
Q

___ serve as the alternative fuel source derived from FA during prolonged energy deficiency

A

Ketone bodies

38
Q

What is the only gluconeogenic VFA

A

Proprionate

39
Q

ketone bodies can be used by __ an __ during prolonged energy deficiency

A

Brain and heart muscle

40
Q

Insulins effect on glycogen synthesis

A

Increase

41
Q

Insulin effect on glucose transport

A

Increase

42
Q

Insulin effect of lipogenesis

A

Increase

43
Q

Insulin effect on lipolysis

A

Decrease

44
Q

Insulin effect on AA uptake

A

Increase

45
Q

Insulin effect on protein synthesis

A

Increase

46
Q

Insulin effect on protein degradation

A

Decrease

47
Q

Insulin effect on gluconeog

A

Decrease

48
Q

Glucagon effect of glycogenolysis

A

Increase

49
Q

Glucagon effect on gluconeogenesis

A

Increase

50
Q

Glucagon effect on lipolysis and FA oxidation

A

Increase

51
Q

Glucagon effect on ketogenesis

A

Increase

52
Q

What cells secrete insulin

A

Pancreatic B cells

53
Q

When is insulin secreted

A

In response to elevated BG

54
Q

Describe how glucose causes release of insulin

A
  1. Glucose binds GLUT2
  2. Increase ATP/ADP ratio
  3. Leads to closing K+ channels—> depolarization
  4. Open Ca2+ channels
  5. Vesicular release of insulin
55
Q

What cells secrete glucagon

A

Alpha cells

56
Q

When is glucagon release

A
  1. Low glucose
  2. High AA
57
Q

What transporter does insulin promote glucose uptake with

A

GLUT4

58
Q

What cells do not require insulin for glucose uptake

A

Neurons, hepatocytes, and erythrocytes

59
Q

Insulin stimulates glycogen synthesis by what two mechanisms

A
  1. Dephosphorylation of glycogensynthase (activated)
  2. Dephosphorylation of glycogenphosphatase (deactivated
60
Q

High levels of AA stimulate: insulin, glucagon or both

A

Both

61
Q

High levels of glucose stimulate: insulin, glucagon or both

A

Insulin

62
Q

Glucagon is stimulated by high __ and low ___

A

AA, glucose

63
Q

What can AA be transformed into

A

Proteins, triglycerides, and glucose

64
Q

Insulin promotes AA uptake in ___ and __ synthesis

A

Muscle and muscle protein synthesis b

65
Q

___stimulates gluconeogenesis

A

Glucagon

66
Q

Glucagon stimulates gluconeogenesis from ___ to prevent ___

A

AA, hypoglycemia