Question Add Ons Flashcards

0
Q

What happens to lactose when lactase is not present?

A

It moves on in the intestine and is fermented by gut bacteria to give organic acids
= lower water potential
= irritate lining

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
1
Q

Give an overview of the digestion of carbs.

A

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

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What bonds does glycogen contain?

A

Alpha 1-4 and alpha 1-6 glycosidic bonds

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What happens to lactate in the heart?

A

It is converted to pyruvate and then into acetyl CoA, before being fed into TCA.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What happens to lactate in the liver?

A

It is converted to pyruvate, then:

  • into glucose by gluconeogeneic pathway
  • oxidised into acetyl CoA for TCA
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is lactic acidosis?

A

When plasma lactate builds up to a level where it affects the plasma buffering capacity.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is the purpose of glycolysis in RBCs?

A

Only form of ATP generation

Makes 2,3BPG which regulates Hb’s affinity for oxygen by decreasing it.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is the purpose of glycolysis in adipose tissue?

A

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)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is the purpose of glycolysis in skeletal muscle?

A

Enables production of ATP under anaerobic conditions.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What may increased LDLs and a family history of heart disease indicate?

A

Familial hypercholesterolaemia.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What do bile salt sequestrants do?

A

Increase disposal of cholesterol from the body.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

How does NADPH oxidase work and where is it found?

A

Found in cell membranes.

It uses electron from NADPH to transfer over the membrane and generate its own ROS.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Would hyperventilation aid a free diver?

A

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 well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

How does acidosis lead to sickle cell crisis?

A

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 well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

How do hydrophobic interactions affect entropy?

A

More hydrophobic interactions decrease disorder and therefore decrease entropy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Why do marfans and homocystinuria appear similar?

A

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.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Define diabetes

A

A group of metabolic disorders characterised by chronic hyperglycaemia. It can be caused by insulin resistance or beta cell destruction.

17
Q

What is a sign and a symptom?

A

Symptom is so ring they tell you, a sign is something you see.

18
Q

What effect does metformin have?

A

It inhibits gluconeogenesis

19
Q

What is glaucoma?

A

It is pressure in the eye from increased osmotic pressure

20
Q

What is amylin?

A

From beta cells and surpresses appetite whilst slowing gastric emptying.

21
Q

What does overproduction of adrenaline and noradrenaline do?

A

Tremors, hyperglycaemic, hypertension, sweating, palpitations.

22
Q

Where is noradrenaline in the CNS?

A

Post ganglionic neurone of the sympathetic pathway

23
Q

What is backers dystrophy?

A

Deficiency of dystrophin rather than lack of it

24
Q

What are the effects of TH?

A
  • increases bone uptake of calcium
  • ovulation
  • increase BMR = weight loss, increased motility of GI tract and heat intolerance
25
Q

What is the proper name for galactose transferase?

A

Galactose 1 phosphate uridyl transferase

26
Q

What are the main carbs found in a western diet and what digests them?

A
Cellulose - undigested
Sucrose - sucrase
Lactose - lactase
Glycogen - numerous enzymes
Starch - amylase
27
Q

Why would cardiac arrest affect the heart and CNS more than skeletal muscle?

A

Heart and CNS don’t have stores of glycogen etc for anaerobic respiration, so whereas the skeletal muscle can continue to respire anaerobically for a short time to produce ATP, the heart and CNS cannot = not oxygen stops them from respiring and therefore functioning.

28
Q

Why may weak aromatic acids cause death?

A

They act as uncoupling proteins and dissipate the pmf in mitochondria.
At first, the victim would lose fat stores, as glucose is used up very quickly due to quick dissipation = subcutaneous fat reserves used next. Heat would rise and eventually a coma and death would occur.

29
Q

What does production of ketone bodies require?

A

1) . Low insulin to glucagon ratio

2) . Mobilisation of fatty acids and availability to be oxidised in liver

30
Q

Compare and contrast TAGs and glycogen.

A

TAGS - in adipose tissue, biggest energy store, more stored energy per C atom

Glycogen - in liver, small energy store, less energy per C atom

31
Q

Why is fatty acid synthesis not simply a reversal of beta oxidation, and why is this good?

A

Beta oxidation contains irreversible reactions and is exergonic, so can’t be the same as synthesis.
This is good as it allows better control (they can be done independently) and greater flexibility by using different substrates and enzymes

32
Q

What happens to the carbon skeleton in amino acid metabolism?

A

It becomes glucogenic amino acids (for carb metabolism) or ketogenic amino acids (for lipid metabolism, ketone body generation or acetyl CoA production).

33
Q

What does glutamate dehydrogenase do?

A

Converts glutamate to alpha keto glutarate to produce NH4+ and NADH

34
Q

What is a synonymous mutation?

A

One in which the amino acid isn’t changed

35
Q

Why may autosomal recessive diseases persist in humans?

A

There may be an advantage to carrier status

Reproductive compensation - parents have more children

36
Q

What is the difference between mutations in BMD and DMD?

A

BMD usually has a mutation which remains in frame, DMD causes a frame shift

37
Q

What is a polysome?

A

A cluster of ribosomes attached to a mRNA molecule

38
Q

What is an inversion?

A

A rearrangement of the linear DNA in a chromosome

39
Q

What are the 2 types of intercalated disc in cardiac muscle?

A

1) . Gap junctions - allow passage of ions so action potential can spread
2) . Adherens junctions - anchor actin to the nearest sarcomere

40
Q

What are telomeres?

A

They are the ends of the chromosome which protect it from damage