Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

FOM > Carbohydrates 2 > Flashcards

Carbohydrates 2 Flashcards

1
Q

Where can we get glycogen from in our diet?

A

Meat

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

Can we digest cellulose?

A

No

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

Where in our diet can we get oligosaccharides?

A

Contains linked galactose, found in peas beans and lentils

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

What does salivary amylase hydrolyse?

A

The 1,4 glycosidic bonds in starch

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

Are carbohydrates digested in the stomach?

A

no

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

Where and what is the duodenum?

A

It is the shortest part of the small intestine where most chemical digestion takes place. It precedes the jejunum.

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

What enzyme works in the duodenum to break down carbohydrates?

A

Pancreatic amylase - hydrolyses 1,4 bonds as in mouth

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

What happens in the jejunum?

A

Final digestion by mucosal cell surface enzymes

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

What enzymes are contained within the jejunum and what are their functions?

A

Isomaltase - hydrolyses the 1,6 bonds
Glucoamylase - releases glucose from non-reducing ends
Sucrase - Hydrolyses sucrose
Lactase - Hydrolyses lactose

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

What is the function of high sodium levels in glucose transport within the intestinal lumen?

A

Glucose symporter - High sodium levels drive glucose across the membrane

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

How does the glucose leave the epithelial cell into the blood?

A

Through a glucose uniporter - facillitates downhill eflux (diffusion)

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

Which other monosaccharide uses other gradients to facilitate its transport?

A

Galactose

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

Which sugar binds to the channel protein GLUT 5 and simply moves down its concentration gradient?

A

Fructose

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

What is the function of cellulose within the gut?

A

Increases faecal bulk and decreases transit time

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

What are cellulose polymers broken down by gut bacteria to produce?

A

CH4 and H2

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

What can cause disaccharidase deficiencies?

A

Genetic condition
Severe intestinal infection
Other inflammation of the gut lining
Drugs injuring the gut wall
Surgical removal of the tissue
Characterised by abdominal distension and cramps

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

How would you diagnose disaccharidase deficiencies?

A

Enzyme tests of intestinal secretions - checking for lactase maltase and sucrase activity low levels of enzymes might reflect low levels of disaccharide?

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What reasons are behind high lactase activity in western white adults?

A

High cattle domestication

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What happens when lactase is deficient?

A

Causes disaccharide deficiency symptoms - Gas build up and irritant acids - caused by undigested lactose being broken down by gut bacteria
Diarrhoea

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Why does lactase deficiency cause diarrhoea?

A

Lactose is osmotically active - drawing water from the gut in to the intestinal lumen

21
Q

How can lactose intolerance symptoms be avoided?

A

Avoiding milk products
Using milk products treated with fungal lactase
Supplementing diet with lactase

22
Q

What happens to glucose after it is absorbed by the intestinal epithelium cells?

A

Enters hepatic portal vein and travels to the liver

23
Q

What is the effect of hepatocytes on absorbed glucose?

A

They immediately phospohorylate them to into glucose-6 phosphate

24
Q

Why can’t glucose 6 phosphate leave the cell?

A

GLUT transporters won’t recognise it - traps glucose within the cell

25
Q

What are the catalysts involved with glucose phosphorylation?

A

Glucokinase (liver) and hexokinase (other cells)

26
Q

When is most glucose trapped in the liver?

A

After a meal, glucokinase phosphorylates all the glucose quickly.

27
Q

When is glucokinase turned on?

A

Turned on at high glucose levels

28
Q

Why is hexokinase able to grab glucose effectively?

A

It has a low KMax (high affinity for glucose)

29
Q

Why isn’t hexokinase able to continuously grab glucose?

A

It is easily satisfied because of its low vmax

30
Q

What are the potential products of g 6 p?

A

ATP, Glycogen, NADPH

31
Q

Where can you find 90% of the glycogen in the body?

A

Skeletal muscles and the liver

32
Q

What happens to glycogen when blood glucose levels fall?

A

Glucose 6 phosphatase converts the GP to glucose

33
Q

What happens to glycogen that is trapped in the muscle?when blood glucose is low

A

There is no glucose 6 phosphate
Glycogen —> Glucose 6 Phosphate —-> Lactate

34
Q

How does glycogenin begin the process of glycogen synthesis?

A

Binds the glucose from uracil-diphosphate-glucose to form chains of approximately 8 glucose residues. It’s a polymer, binding the first few molecules of glucose.

35
Q

What enzyme takes over after glucogenin?

A

Glycogen synthase

36
Q

How are chains foromed in glycogen?

A

Glycogen branching enzyme breaks the chains formed by glycogen synthase and then reattach these chains via alpha 1-6 bonds to give branch points

37
Q

How are glucose monomers removed from the end of glycogen chains?

A

They are removed one by one from the non-reducing ends as G-1-P

38
Q

What enzyme releases G-1-P from glycogen?

A

Glycogen phosphorylase

39
Q

What is the result of the transferase activity of the de-branching enzyme?

A

It removes three glucose residues and connects them to the nearest non-reducing end via 1,4 glycosidic bonds

40
Q

What is the result of the glucosidase activity of the debranching enzyme on the last glucose residue?

A

Breaks the 1,6 glycosidic bond to release a free glucose monomer.

41
Q

What happens to glucose 6 phosphate that enters the liver?

A

It is de-phosphorylated to form glucose

42
Q

What happens to G6P that enters the muscle?

A

Substrate phosphorylation of ADP forming atp, glycolysis forming lactate. (For muscle contraction)

43
Q

What is von gierkes disease characterised by?

A

Liver glucose-6-phosphatase deficiency

44
Q

What are the symptoms of von gierkes disease?

A

High liver glycogen levels
Low blood glucose concentrations
High blood lactate - Lacticacidaemia

45
Q

Why is there a high level of lactate in von gierkes disease?

A

Lactate produced by the skeletal muscle cannot be reconverted into glucose by the liver - a process which requires glucose - 6 - phosphatase

46
Q

What is the treatment for von gierkes disease?

A

Carbohydrate feeding

47
Q

What is McCardle’s disease characterised by?

A

Skeletal muscle phosphorylase deficiency results in high glycogen levels and no increase in blood glucose levels after exercise. Glycogen phosphorylase is responsible for removing glucose 6 phosphate groups from glycogen

48
Q

What are the symptoms of McCardle’s disease?

A

Weakness and cramps after exercise

FOM (101 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions