2.2 Biological Molecules

Question 1

What is a molecule?

Answer 1

When two atoms bond together and they are much more complex

Question 2

What is a monomer?

Answer 2

A repeating biological unit
(Eg. Nucleotide)

Question 3

What is a polymer?

Answer 3

Is a set of repeating monomers
( eg.DNA)

Question 4

When are atoms most stable?

Answer 4

When their outer energy shell is full

Question 5

What is a condensation reaction?

Answer 5

• covenant bonds are formed
• H20 is formed
• larger molecule formed

Question 6

What is a hydrolysis reaction ?

Answer 6

• covalent bind broken
• water molecules USED
• smaller molecules

Question 7

What are hydrogen bonds and how are they formed?

Answer 7

• When slightly positive and negative charge become close
• these bonds are weak
• yet in polymers there are thousands to help keep the molecule in its shape

Question 8

What are intramolecular bonds?

Answer 8

These are bond inside molecules

Question 9

What are intermolecular bonds?

Answer 9

These are bonds in between molecules

Question 10

What are simple sugars?
Characteristics
Formula

Answer 10

• they are monosaccharides
• they have 3-6 carbons bonded
• sweet

Cn (H20)n

Question 11

How do two monochaccrides join?
What is the bond called?

Answer 11

They will join with a covalent bond to form a disaccharide

A glycocidic bond

Question 12

What can a glycocidic bond be broken by?

Answer 12

By hydrolysis ( break down with water)

Question 13

What is alpha glucose?
Example

Answer 13

form of glucose where at anomeric carbon, the position of hydroxyl group is in downward direction

Glucose

Question 14

What is beta glucose?

Answer 14

form of glucose where at anomeric carbon the position of hydroxyl group is in upward direction.

Question 15

What are some characteristics of glucose molecules?

Answer 15

• Polar
• Soluble in water due to hydrogen bonds in hydroxyl groups and water molecules

Question 16

Describe the role and structure of pentose sugars

Answer 16

• Pentose monosachharides
• 5C
• Ribose / Deoxyribose

Question 17

Describe the structure and function of amylose

Answer 17

• Alpha glucose monomers
• 1,4 glycosidic bonds
• Unbranched
• Forms a coiled helical structure
• Polysaccharide is more compact and soluble than glucose
• Energy store in plants
• Insoluble (doesn’t affect water potential of cell)

Question 18

Describe the structure and function of amylopectin

Answer 18

• 1,4 and 1,6 glycosidic bonds
• few branches = many terminal ends for hydrolysis into glucose

Question 19

Describe the structure and function of glycogen

Answer 19

• 1,4 and 1,6 glycosidic bonds
• Highly branched
• Many terminal ends for rapid hydrolysis into glucose
• Compact
• Insoluble

Question 20

Describe the structure and function of cellulose

Answer 20

• Long straight chain of B glucose
• 1,4 glycosidic bonds
• strong ( provides strength to support plant cell walls)
• Insoluble
• Exposed hydroxyl groups on carbon2 allowing hydrogen bonds to form between cellulose molecules

Question 21

What is starch made of?

Answer 21

Amylose and amylopectin

Question 22

What is maltose made up of?

Answer 22

• it’s malt sugar
• glucose + glucose
• formed from two alpha glucose
• 1,4 alpha glycocidic bonds

Question 23

What is lactose?

Answer 23

• milk/sugar
• glucose + galactose
• forms a 1,6 alpha glycocidic bond

Question 24

What is sucrose made of?

Answer 24

• house hold sugar
• glucose + fructose
• forms a 1,6 glycosidic bond