Chapter 3: Biological Molecules

Question 1

What are the functions of carbohydrates?

Answer 1

Energy stores
Provide energy
Respiratory substrates
Receptors (eg. Glycoproteins)
Builds macromolecules

Question 2

What monomer makes up cellulose?

Answer 2

B- glucose

Question 3

How is the structure of cellulose related to its function?

Answer 3

B-glucose monomers arranged in straight chains
Chains joined together by hydrogen bonds
Provides strength and structure

Question 4

What are the similarities of starch and glycogen?

Answer 4

They are both compact
Homopolysaccharides: Both hava a-glucose monomers
Contain branched structures
Insoluble- do not affect osmotic potential

Question 5

What is the rest for reducing sugars?

Answer 5

Benedicts test
Sample must be in solution. Add benedicts reagent. Heat test tube in water bath. Brick red for a positive test.
Reducing sugar examples: glucose, galactose, fructose, lactose, maltose
Non reducing sugar example: sucrose

Question 6

Why does ice float and how does it allow sea life to go on?

Answer 6

• less dense than water because molecules spread out
• open lattice structure
• forms an insulating layer for water underneath
• -> water below doesnt freeze
• -> organisms do not freeze

Question 7

Name the bond between a-glucose and fructose

Answer 7

1,6-glycosidic bonds

Question 8

Order of most to least soluble carbohydrates

Answer 8

Glucose, ribose, amylose, amylopectin

Question 9

Tests for Biological Molecules

Answer 9

Benedicts- Reducing sugars
Biuret- Protein
Iodine- Carbohydrates