26.6 Biochem: Nutritional value of CHO Flashcards
When was our diet at evolutionary optimum? What was the evidence?
30,000 years ago, ‘caveman’ diets, archaeological evidence of healthy, tall, hominid skeletons
What does fibre protect against?
Diverticulitis (maybe not protective role against cancer that was thought)
What state drives the pentose phosphate pathway? What molecule is produced and then drives this fat/cholesterol synthesis?
Pentose phosphate
NADPH
What is produced in glycolysis?
NADH
What are the A and B forms of glucose? Draw them!
A: OH is down
B: OH is up
What are the steps that occur when someone digests food (glucose pathway)? (7)
- Food- rise in blood glucose
- Pancreas releases insulin
- Glucose uptake into cells, glycogen storage in liver/muscles. Excess into fat
- Blood glucose levels decline
- Low blood glucose stimulates glucagon release into bloodstream
- Stimulation of liver cells to break down glycogen, release glucose into blood
- Blood glucose rises
What parts of the body have the ability to release free glucose?
Only liver and kidney (have glucose-6-phosphatase)
not muscles
What doers glycogen synthesis require (and where is this generated from?)
Requires glucose-6-phosphate (from dietary glucose or gluconeogenesis)
Are glucose and glycogen chemically inert or active?
Glycogen: Chemically inert
Glucose: Active
What is Pompe’s disease?
Lack of a-1,4-glucosidase (lysosomal)
(respiratory failure, death
What is a universal stress signal that indicates emergency or unfed state?
What does it stimulate?
cAMP (second messenger), stimulates glycolysis and glucose mobilisation
What is ‘fibre’?
Celluose and complex polysaccharides
What CHO selectively promotes beneficial gut bacteria?
Short chain CHO (oligosaccharides, fructosaccharides and inulin)
What suggests to us that humans are omnivores?
Why was this suggested to contribute to our intelligence?
Denture and gut structure (GI-tract for a mixed diet)
Less energy supporting a large gut, more for brains
What does a thiamin deficiency lead to? What can it result from?
Beriberi- eating white rice (with no bran)
