Carbohydrate digestion

Question 1

What are the principal dietary constituents (x6)

Answer 1

Carbohydrate
Fat
Protein 
Vitamins
Minerals
Water

Question 2

How does the body take in water

Answer 2

Orally

Through the skin

Question 3

What are the monosaccharides

Answer 3

Glucose, Galactose, Fructose

Question 4

How many Carbons are in in the monosaccharides

Answer 4

Glucose and Galactose = 6

Fructose = 5

Question 5

What type of sugar is glucose

Answer 5

A reducing sugar (it gets oxidised)

Question 6

What type of sugar is fructose

Answer 6

A oxidising sugar (it gets reduced)

Question 7

Are monosaccharides soluble in water

Answer 7

Yes

Question 8

Where are monosaccharides absorbed

Answer 8

The Small Intestine

Question 9

What are the Disaccharides

Answer 9

lactose, Sucrose, Maltose

Question 10

What monosaccharides make up lactose

Answer 10

Glucose and Galactose

Question 11

What monosaccharides make up sucrose

Answer 11

Fructose and glucose

Question 12

What monosaccharides make up maltose

Answer 12

glucose and glucose

Question 13

What links the monomers of a disaccharide

Answer 13

Glycosidic bonds

Question 14

What is a glycosidic bond?

Answer 14

Covalent bond between hydroxyl and anomeric carbon 1 of glucose

Question 15

Where is maltose found

Answer 15

It is the breakdown product of starch

Question 16

Where is lactose found

Answer 16

Main sugar in milk

Question 17

What is common of maltose and lactose

Answer 17

They both have the anomeric carbon available for oxidation and so are REDUCING SUGARS

Question 18

Where is sucrose found

Answer 18

Table sugar

Question 19

What portion of diet is sucrose

Answer 19

25%

Question 20

Is sucrose a reducing sugar?

Answer 20

No

It does not have an anomeric carbon free so there is no oxidation site

Question 21

What are the 3 polysaccharides

Answer 21

Starch
Cellulose
Glycogen

Question 22

What does starch consist of

Answer 22

Many glucose monomers linked together

Question 23

What are the two types of starch structures

Answer 23

Amylose

Amylopectin

Question 24

What are features of amylose

Answer 24

the glucose are in a straight line with a1-4 bonding

Can have 1000s of glucose residues

Question 25

What portion of diet is amylose

Answer 25

20-25%

Question 26

What are the features of amylopectin

Answer 26

It is branched (every 24-30 residues is attached a1-6)

Question 27

What portion of our diet is amylopetin

Answer 27

75-80%

Question 28

Where is cellulose found

Answer 28

Plant cell walls

Question 29

What links the monomers in Cellulose

Answer 29

B-1,4 glycosidic bonds

Question 30

How is cellulose digested

Answer 30

By bacteria in the gut

Question 31

Where is glycogen found

Answer 31

Animals (animal storage of glucose)

Question 32

What are the features of glycogen

Answer 32

A1-4 linkage with branches every 6-12 residues

Question 33

Where is glycogen found in the body

Answer 33

90% liver and muscle

Question 34

How do the proportions of muscle in the liver and muscle vary

Answer 34

There is more glycogen in muscle by volume | There is more glycogen in liver by concentration

Question 35

What can pack for glucose: glycogen or starch

Answer 35

Glycogen

Question 36

Why store glucose in polymers

Answer 36

prevents cells lysing

Question 37

What enzyme initially starts to break down polymers and where

Answer 37

Amylase breaks down the A1-4 bonds | In the saliva

Question 38

What isomer of glucose will glucose transporters recognise

Answer 38

D-glucose

Question 39

Does amylase operate in the stomach?

Answer 39

No - its too acidic

Question 40

What transporter carries glucose and galactose across the enterocytes

Answer 40

The SGLUT-1 transports | Sodium dependant hexose transporter

Question 41

How does the sodium exit with cell

Answer 41

Via the sodium/potassium pump

Question 42

What transporter carries glucose and galactose out of the enterocytes

Answer 42

Glut-2 | This is facilitated transport and not active

Question 43

How does fructose enter the enterocyte

Answer 43

Through Glut-5 receptor

Question 44

How does fructose leave the enterocyte

Answer 44

Through Glut-2