Glucose fuel 1

Question 1

How is glucose mostly found in the deit

Answer 1

Found in startches in 2 forms - contain alpha glycosidic bonds
amylose - straight chain
amylopectin - branch chain

Glycogen from animals - mainly a storage molecule

Question 2

What is the pathway for glucose absoption

Answer 2

Primary active transport: Na+/K+ATPase - keeps Na+ conc in cell low, K+ then leaves cell via transporter protein
SGLT moves Na+ down its conc gradient supplying energy to tranposrt Glucose with it
GLUT channels then enable glucose to leaves the enterocytes into intersital fluid->blood

Question 2

What is the challanges with glucose absobtion

Answer 2

Sugars are highly polar -> cannot diffuse across the membrane
2 methods used:
active transport: SGLT pumps Na + Glu
passive transport: GLUT channels facilitate diffusion

Question 2

How is glucose used for fuel

Answer 2

Glycolysis -> speical as it occurs in the cytosol and doesnt require mitochondria
Can occur in all cell types + some cells prefer glucose

Question 3

Why does the brain prefer Glucose

Answer 3

Fats cannot easily cross the blood brain barrier where glucose can
Glucose provides a source of energy which doesnt require as much O2 making it less likely to become hypoxic

Question 3

Why do RBC require Glucose

Answer 3

RBC have no organelles -> no mitochondria -> glycolysis is its only method to produce ATP
requires glucose

Question 4

What do retinal cells prefer glucose

Answer 4

mitochondria + lots of capillarys with O2 would refreact the optical path damaging site -> glycolysis is used

Question 5

How do muscle cells prefer fuel

Answer 5

White mucles -> fast twitch prefer glucose as often working in anerobic conditions

Red mucles -> slow twitch prefer fats for endurace as they are more reduced