Carbohydrates - questions

Question 1

What three elements do carbohydrates contain?

Answer 1

CHO

Question 2

List two functions of carbohydrates

Answer 2

Energy store
structural
cell recognition
metabolism

Question 3

Monosaccharides are defined as polyhydroxy carbonyl compounds. What are the two sorts of carbonyl group?

Answer 3

aldehyde

ketone

Question 4

How many carbon atoms are there in glucose?

Answer 4

6

Question 5

Is glucose an aldose or a ketose?

Answer 5

aldose

Question 6

What is an epimer?

Answer 6

1. Different compounds (structures) with the same molecular formula
2. differ by configuration at only one carbon

Question 7

What is a chiral carbon atom?

Answer 7

C atom with 4 different groups bonded to it

Question 8

In a-glucose is the –OH group on C1 above or below the ring?

Answer 8

below

below ring is a. above ring is b

Question 9

What is the name of the bond that joins two monosaccharides together to form a disaccharide?

Answer 9

glycosidic

Question 10

What two monosaccharides make up lactose ?

Answer 10

galactose and glucose

Question 11

In maltose are the two glucose units joined by an a1-4 or a b1-4 bond?

Answer 11

.

Question 12

What is a reducing sugar?

Answer 12

Reducing sugar: the monosaccharide with the free anomeric C can reform a straight chain =>

carbonyl (-C=O) group can be oxidised (-COOH).

If the sugar is oxidised it acts as a reducing agent.

Question 13

Name a common non-reducing disaccharide

Answer 13

.

Question 14

State two properties that are important for storage polysaccharides

Answer 14

a links readily degraded by enzymes

highly branched - rapid release of monosaccharide

Question 15

What are the names of the two molecules that make up starch?

Answer 15

Amylose

Amylopectin

Question 16

What type of glycosidic bonds are present in glycogen?

Answer 16

a links

a1-6 branches every 10-12 glucose units

Question 17

What type of glycosidic bonds are present in cellulose?

Answer 17

B-(1-4) linked glucose

Question 18

What do alternate glucose units do in order to form a straight chain of cellulose?

Answer 18

rotated 180 degrees from previous one (flipped)

Question 19

What is the name of the polysaccharide found in insect exoskeletons?

Answer 19

Chitin

Question 20

What is the name of the polysaccharide found in bacterial cell walls whose formation is inhibited by penicillin?

Answer 20

peptidoglycan (murein)

Chains of heteropolysaccharide made up of repeating N-acetyl glucosamine (NAG) and N-acetyl muramic acid (NAM)