Brainscape's Knowledge GenomeTM

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


See full index

Science For Medicine > Carbohydrates > Flashcards

Carbohydrates Flashcards

You may prefer our related Brainscape-certified flashcards:
Biology 101 flashcards
1
Q

What are the major carbohydrates in the diet

A 
Glucose
Oligosaccharides containing (alpha 1-6) linked galactose
Lactose
Sucrose
Maltose
Fructose
Starch
Glycogen
Cellulose
Hemicellulose
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are carbohydrates digested to produce

A

Glucose, galactose and fructose

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

Can carbohydrates be digested in the stomach

A

No

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

Where does the final digestion take place and what enzymes are used

A

Jejunum

Using mucosal cell-surface enzymes

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

How are carbohydrates digested in the mouth

A

By salivary amylase hydrolyses which break α1-4 bonds of starch

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

How are carbohydrates digested in the duodenum

A

By pancreatic amylase which hydrolyses which break α1-4 bonds of starch

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

What type of muscosal cell surface enzymes are there

A

Isomaltase - hydrolyses α1-6 bonds
Glucoamylase - removes glucose sequentially from non-reducing ends
Sucrose - hydrolyses sucrose
Lactase - hydrolyses lactose.

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

Where can muscosal cell-surface enzymes be found

A

In the jejunum

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

What does a high Vmax mean

A

It is an efficient enzyme

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

What does a low Km mean

A

The enzyme has a high affinity for the substrate

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

What do glucokinase and hexokinase do

A

The phosphorylate glucose to glucose-6-phosphate

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

Where are glucokinase and hexokinase found

A

Glucokinase in the liver

Hexokinase in other tissues

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

Does glucokinase have a high or low Vmax and how does this affect its function.

A

High Vmax

Its an efficient enzyme so glucose will be phosphorylated quickly

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

Does hexokinase have a high or low Km and how does this affect its function

A

Low Km
It has a high affinity for the substrate but as it has a low Vmax so at low glucose concentration it cannot grab glucose effectively.

(Low Vmax means tissues are easily satisfied and will not constantly grab glucose)

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

What is the first step of glycogen synthesis

A

Glycogenin covalently binds to glucose from UDP-glucose to produce chains of about 8 glucose residues

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

What is the second step of glycogen synthesis

A

Glycogen synthase extends the glucose chains

17
Q

What is the third step of glycogen synthesis

A

The chains are then broken down using a glycogen branching enzyme and re-attached using α1-6 bonds to give branch points

18
Q

What is the first step of glycogen degradation

A

Glucose monomers are removed one at a time from the non-reducing ends to form glucose-1-phosphate using glycogen phosphorylase

19
Q

What enzyme is used in the first step of glycogen degradation

A

Glycogen phosphorylase

20
Q

What is the second step of glycogen degradation

A

The glucose near the branch is removed using a 2 step process by de-branching enzyme.

21
Q

What type of activity does the de-branching enzyme have

A

Transferase activity

It removes a set of 3 glucose residues and attaches them to the nearest non-reducing end using α1-4 bonds

22
Q

What is the third step of glycogen degradation

A

Glucosidase removes the final glucose by breaking a α1-6 bond to release free glucose

23
Q

What is the fourth step of glycogen degradation

A

An unbranched chain is produced which can be further degraded or built up as needed

24
Q

What is the function of glycogen in the liver

A

It is converted from G-1-P to G-6-P then using glucose phosphatase converted to glucose which can be transferred into the blood

25
Q

What is the function of glycogen in skeletal muscle

A

Is uses substrate-level phosphorylation to undergo glycolysis which produces ATP for muscle contraction

26
Q

What is the function of glycolysis

A

The cellular degradation of the simple sugar, glucose, to yield ATP as an energy source.

27
Q

What is the function of lactate dehydrogenase

A

To reduce pyruvate to lactate and oxidise NADH to replenish NAD+ stores for glycolysis

28
Q

In what cycle is pyruvate dehydrogenase used

A

Cori cycle

29
Q

What is the function of pyruvate dehydrogenase

A

to oxidse pyruvate to acetyl CoA

Science For Medicine (1 decks)

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