Physiology

Question 1

What is the main function of glucose in humans?

Answer 1

Major tissue energy source

Question 2

What are the two main pathways of extra glucose metabolism?

Answer 2

Glycolysis and the TCA Cycle

Question 3

In the glycolysis pathway what step is next?

Glucose –> Hexose phosphates —–> Triose phosphates—–> ________

Answer 3

2-Phosphoglycerate

Question 4

In the glycolysis pathway what step is next?

Glucose –> _______

Answer 4

Hexose phosphates

Question 5

In the glycolysis pathway what step is next?

Glucose –> Hexose phosphates —–> Triose phosphates—–> 2-Phosphoglycerate —–> ______

Answer 5

Phosphoenolpyruvate

Question 6

In the glycolysis pathway what step is next?

Glucose –> Hexose phosphates —–> Triose phosphates—–> 2-Phosphoglycerate —–> Phosphoenolpyruvate——>______

Answer 6

Pyruvate

Question 7

In the glycolysis pathway what step is next?
Glucose –> Hexose phosphates —–> Triose phosphates—–> 2-Phosphoglycerate —–> Phosphoenolpyruvate——>Pyruvate——->______

Answer 7

Lactate

Question 8

What 4 reason make the brain highly dependent on extracellular glucose for its energy supply?

Answer 8

It is unable to synthesize glucose
It cannot store glucose in significant amounts
It cannot metabolize substrates other than glucose and ketones
It cannot extract enough extracellular fluid glucose as entry into brain cells is not facilitated by insuling

Question 9

What does TCA cycle stand for?

Answer 9

Tricarboxylic acid cycle.

Question 10

What would a be an acceptable random plasma glucose concentration?

Answer 10

Anything less than 11 mmol/L

and more than 2.5 mmol/L

Question 11

What would be an abnormal random plasma glucose concentration?

Answer 11

Anything equal to or greater than or equal to 11.1 mmol/L

or anything less than 2.5 mmol/L

Question 12

During normal metabolism what is the main hormone that controls the plasma glucose concentration?

Answer 12

Insulin

Question 13

At what glucose concentration is insulin stimulated?

Answer 13

5 mmol/L

Question 14

How is insulin stimulated in the pancreas?

Answer 14

via glucose transporter-2 of the pancreas beta-cell

These cells produce proinsulin.

Question 15

What are the constituent parts of proinsulin

Answer 15

C-peptide & insulin

Question 16

what 3 ways does insulin work?

Answer 16

1. Insulin works by binding to specific cell-surface receptors on muscle and adipose tissue thus enhancing the rate of glucose uptake into cells.
2. Insulin induced activation of enzyme stimulates glucose incorporation into glycogen synthesis in liver and muscle. (glycogenesis)
3. Insulin inhibits the production of glucose from fats and amino acids partly by reducing these substrates by inhibiting fat and protein breakdown.