Chapter 7: Carbohydrates and Glycobiology

Question 1

Carbohydrates are produced from …

Answer 1

CO2 and H2O via photosynthesis in plants

Question 2

This is the smallest carbohydrate

Answer 2

Glyceraldehyde

Question 3

This is the largest carbohydrate

Answer 3

Amylopectin

Question 4

Carbohydrates functions:

Answer 4

• energy source and energy storage
• structural component of cell walls and exoskeleton
• informational molecules in cell-cell signaling

Question 5

When carbohydrates are covalently linked with proteins, this forms …

Answer 5

glycoproteins and proteoglycans

Question 6

What are the two types Monosaccharides?

Answer 6

Aldoses and Ketoses

Question 7

An aldose contains an ______ functionality

Answer 7

aldehyde

Question 8

A ketoses contains a _____ functionality

Answer 8

ketone

Question 9

What are epimers?

Answer 9

Diastereomers of two sugars that differ only in the configuration around one carbon atom

Question 10

What is an anomeric carbon?

Answer 10

The formal carbonyl carbon becomes a new chiral center

Question 11

How to determine if the anomer is alpha or beta?

Answer 11

The formal oxygen becomes a hydroxyl group. The position of the hydroxyl group determines if the anomer is alpha or beta. If the hydroxyl group is on the opposite side of the rings (trans), its alpha. If the hydroxyl group is on the same side as the ring (cis), its beta.

Question 12

What is the configuration of an anomer is the hydroxyl group is in the cis position?

Answer 12

beta

Question 13

Six-membered oxygen-containing rings are called …..

Answer 13

Pyranoses

Question 14

Five-membered oxygen-containing rings are called …

Answer 14

Furanoses

Question 15

Two sugar molecules can be joined via ____________ between an anomeric carbon and a hydroxyl carbon

Answer 15

Glycosidic bond

Question 16

What is maltose?

Answer 16

Maltose is a disaccharide made from glucose

Question 17

Natural carbohydrates are known as …

Answer 17

Polysaccharides

Question 18

True or False:

Polysaccharides do not have a defined molecular weight

Answer 18

True

Question 19

What is glycogen?

Answer 19

A branched homopolysaccharide of glucose

Question 20

What is the function of glycogen in animals?

Answer 20

Functions as the main storage polysaccharide in animals

Question 21

Glucose monomers form ______ linked chains. (linear forms)

Answer 21

alpha 1, 4

Question 22

Branch-points with ________ linkers every 8-12 residues

Answer 22

alpha 1, 6

Question 23

What is Starch?

Answer 23

A mixture of two homopolysaccharides of glucose

Question 24

Define Amylose

Answer 24

An unbranched polymer of (alpha 1,4) linked residues

Question 25

Define Amylopectin

Answer 25

Branched like glycogen but the branch-points with (alpha 1,6) linkers occur every 24-30 residues

Question 26

What is the main storage polysaccharide in plants?

Answer 26

Starch

Question 27

Glycogen and starch often form _____ in cells

Answer 27

granules

Question 28

True or False:

Glycogen and amylopectin have one reducing end but many nonreducing ends

Answer 28

True

Question 29

What are the three types of storage carbohydrates?

Answer 29

• Glycogen
• Amylose
• Amylopectin

Question 30

Which of the three types of storage carbohydrates is linear?

Answer 30

Amylose

Question 31

What is the bond used to make a linear storage carbohydrate?

Answer 31

alpha 1,4

Question 32

Which of the three storage carbohydrate are branched?

Answer 32

Glycogen and amylopectin

Question 33

True or False:

Only alpha 1,6 linker is used for glycogen and amylopectin

Answer 33

FALSE

Both alpha 1,4 and alpha 1,6 are used in glycogen and amylopectin

Question 34

What is cellulose?

Answer 34

An unbranched homopolysaccharide of glucoes

Question 35

Cellulose has ____ linkers

Answer 35

Beta 1,4

Question 36

This is the most abundant polysaccharide in nature

Answer 36

Cellulose