Starvation/Integration - Dr. Groseclose Flashcards Preview

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Flashcards in Starvation/Integration - Dr. Groseclose Deck (18):
1

Name the tissues of the body that are most dependent on glucose.

Brain, RBCs, and Muscle

2

What are the “favored” substrates of skeletal muscle?…of heart?…brain?…RBC’s?

Muscle: Fatty acids, ketone bodies, and glucose

Brain: glucose and ketone bodies (Ex. acetone)

RBC: glucose

3

What is the role of adipose tissue?

Stores triacylglycerols (by using Glucose to provide glycerol 3-phosphate) and releases Fatty acids and glycerol.

4

Discuss the formation of ketone bodies: What are the reactions? How do they influence the metabolism of skeletal muscle? Which organ forms them, and where are they used?

Ketone bodies are created via decaboxylation of acetoacetone to create acetone. Condensation of two acetone molecules form acetoacetyl CoA, which is then converted to HMG CoA. HMG CoA is then split into acetyl CoA and Acetoacetate (ketone body).

Metabolism of ketone bodies occur in the liver but is used in the skeletal muscle.

5

What are the advantages of fat (triglycerides) over glycogen as an energy-storage form?

They are more compact storage forms.

6

Which two hormones are most important for the control of energy metabolism in the body? What are their predominant effects?

Insulin and Glucagon, Insulin increases [glycogen], [protein], and [fatty acids]. Glucagon decreases [glycogen], [protein], and [fatty acids].

7

Which organs are responsive to insulin?

Muscle and adipose. Liver is not very responsive.

8

Discuss the importance of renal gluconeogenesis.

Renal Gluconeogenesis spares the energy of urea synthesis and helps to correct acidosis.

9

What is the single most important determinant of length of survival of starvation?

The ability/efficiency in the metabolism of Fat and Proteins (to a lesser extent)

10

What is the hexosamine pathway? What is the enzyme that characterizes this pathway?

The Hexoxamine pathway converts Glucose to UDP-GlcNAc (UDP-N-acetylglucosamine), which depending on feast or famine, goes to glycosylation (feast) or is converted into protein (famine)

Glutamine:fructose 5:phosphate amitransferase (GFAT)

11

What substance can be used as fuel but is NOT a stored fuel source?

Protein

12

What organ is responsible for control of making fatty acids, ketone bodies and glucose?

Liver

13

What two substances stimulates glucagon secretion?

Epinephrine and Cortisol (stress hormone)

14

What substances via the hypothalamus affect feeding behavior?

Leptin (makes people eat more) and ghrelin

15

What would you measure to determine nutrition status, biochemically?

UDP-N-acetylglucosamine (UDP-GlcNAc)

16

What does the presence of inflammation tell you about the treatment of malnutrition?

Inflammation absent = treatable via nutritional resuscitation

Inflammation present = limited effectiveness of nutritional intervetion

17

What are possible consequences of refeeding someone who has been malnourished too long?

tachycardia
tachypnea
delirium
vomiting
coma
death

18

Why are ketone bodies good to be used "in a pinch" situation when there is no glucose?

They are water soluble, need no plasma carrier or insulin, and inhibits glucose metabolism.