Question Add Ons Flashcards
What happens to lactose when lactase is not present?
It moves on in the intestine and is fermented by gut bacteria to give organic acids
= lower water potential
= irritate lining
Give an overview of the digestion of carbs.
Starch and glycogen in mouth - salivary amylase and glycosidase enzymes = maltose, disaccharides, dextrins.
MOVE ON TO JEJEUNUM AND DUODENUM
Disaccharides etc. broken down by glycosidase enzymes in brush border
What bonds does glycogen contain?
Alpha 1-4 and alpha 1-6 glycosidic bonds
What happens to lactate in the heart?
It is converted to pyruvate and then into acetyl CoA, before being fed into TCA.
What happens to lactate in the liver?
It is converted to pyruvate, then:
- into glucose by gluconeogeneic pathway
- oxidised into acetyl CoA for TCA
What is lactic acidosis?
When plasma lactate builds up to a level where it affects the plasma buffering capacity.
What is the purpose of glycolysis in RBCs?
Only form of ATP generation
Makes 2,3BPG which regulates Hb’s affinity for oxygen by decreasing it.
What is the purpose of glycolysis in adipose tissue?
It is a minor route for ATP generation
It can produce DHAP which can be converted back to glycerol phosphate and used in the production of TAGs (esterifies FA)
What is the purpose of glycolysis in skeletal muscle?
Enables production of ATP under anaerobic conditions.
What may increased LDLs and a family history of heart disease indicate?
Familial hypercholesterolaemia.
What do bile salt sequestrants do?
Increase disposal of cholesterol from the body.
How does NADPH oxidase work and where is it found?
Found in cell membranes.
It uses electron from NADPH to transfer over the membrane and generate its own ROS.
Would hyperventilation aid a free diver?
No because:
1) . This rids of CO2 = Hb affinity for O2 increases and therefore won’t release O2 at tissues as easily.
2) . High CO2 = urge to breathe, so ridding of CO2 surpresses this urge and may lead to unconsciousness.
How does acidosis lead to sickle cell crisis?
More H+ in blood than normal = decreases Hb affinity for O2.
Hb is now more likely to polymerise and this leads to sickle cell crisis.
How do hydrophobic interactions affect entropy?
More hydrophobic interactions decrease disorder and therefore decrease entropy
Why do marfans and homocystinuria appear similar?
Marfans is a mutation which causes Fibrillin 1 to mutate. In homocystinuria, homocysteine binds to lysine residues on Fibrillin1, also altering its shape and therefore, changing its function.