Integration of Whole Body Metabolism Flashcards
How much glucose does the brain use daily? [1 mark]
100-120g
What is >50% of the energy the brain consumes used for? [3 marks]
for Na+/K+ transport
- to maintain membrane potential
- to synthesis neurotransmitters
At what point does the plasma glucose concentration become dangerously low? [1 mark]
2.2mM
Where are fats a major energy source? [1 mark]
Cardiac muscle
Where is glucose a major energy source? [2 marks]
- Muscles
- Brain
How is energy stored in adipose tissue? [1 mark]
As triglycerides (mainly synthesised in the liver)
Which glucose transporter is found in adipose tissue? [1 mark]
GLUT4
Which organ contributes to the half of blood glucose during starvation? [1 mark]
The kidneys (via gluconeogenesis)
How does the liver get its energy? [1 mark]
Via alpha keto acids (e.g. pyruvate)
Difference between hexokinase and glucokinase? [5 marks]
- Km (H: low, G: high)
- Location (H: all tissue, G: hepatic tissue)
- Allosteric (H: yes, G: no)
- Induction by insulin (H: no, G: yes)
- Inhibition by G6P (H: yes, G: no)
What is GLUT2 driven by and what does this mean as a result [2 marks]
- Driven by concentration gradient of glucose.
- This means that GLUT2 is bidrectional.
What does glucokinase do to GLUT2 and why? [2 marks]
- Phosphorylate it.
- To facilitate storage of glucose as glycogen.
What does glucose-6-phosphatase do? [1 mark]
Converts G6P to glucose
What is creatine phosphate? [1 mark]
It’s a reservoir of phosphate to donate to ADP.
Which form of respiration is more efficient? [1 mark]
Aerobic respiration
