Ch. 12 - Bioenergetics And Regulation Of Metabolism Flashcards Preview

MCAT BioChem - All Resources > Ch. 12 - Bioenergetics And Regulation Of Metabolism > Flashcards

Flashcards in Ch. 12 - Bioenergetics And Regulation Of Metabolism Deck (13)
Loading flashcards...
1
Q

The human body at large is considered an open system. When looking at the cellular level, what sort of system is described?

A

Closed - only exchanges heat with surroundings.

2
Q

How much energy does ATP provide?

A

30 kJ/mol

3
Q

ATP is a mid level energy carrier. Why is that better than a high level energy carrier if ATP is the main currency of energy in the body?

A

If it were able to provide more energy, then more energy would be wasted. For example - if a reaction only requires 15kJ/mol and ATP is used then only 15 kJ/mol is wasted. If ATP were higher in energy, then more than 15kJ/mol would be wasted.

4
Q

Homeostasis

A

Physiological tendency toward a relatively stable state that is maintained and adjusted

5
Q

Postprandial state

A

Well fed state, occurs shortly after eating, lasts 3-5 hours after meal.

6
Q

Insulin Effect in Postprandial state

1) what are the 3 major target tissues?
2) what does insulin promote in these tissues?

A

1) liver, muscle, adipose tissue
2) liver: glycogen synthesis (after glycogen stores are filled, liver converts excess glucose to fatty acids and TAGs)
Muscle: glycogen and protein synthesis
Adipose tissue: TAG synthesis

7
Q

What 5 hormones oppose the action of insulin?

A
Cortisol
Epinephrine
Norepinephrine
Glucagon
Growth hormone
8
Q

What is the time frame that thyroxine acts over to increase metabolic rate?

A

Increase occurs after latency of several hours but may last several days.

9
Q

What is the time frame over which T3 acts?

A

Produces rapid increases in metabolic rate but has short duration.

10
Q

What is the respiratory quotient?

A

CO2 produced / O2 consumed

Differs depending on fuel being utilized

11
Q

Ghrelin

A

Secreted by the stomach in response to signals of an impending meal, signals hunger and increases appetite. Stimulates secretion of orexin

12
Q

Orexin

A

Further increases appetite, involved in alertness and sleep/wake cycle. Release triggered by ghrelin and hypoglycemia

13
Q

Leptin

A

Hormone secreted by fat cells that decrease appetite by suppressing orexin production