1.2 Biological Molecules

Question 1

What is a monomer

Answer 1

Smaller units from which a larger molecule is made

Question 2

What is a polymer

Answer 2

Lots of monomers joined together

Question 3

What are monosaccharides

Answer 3

Simple monomer carbohydrates

Question 4

What 3 monosaccharides are there

Answer 4

Glucose, Fructose and Galactose

Question 5

What is a disaccharide

Answer 5

2 monosaccharides joined together

Question 6

What 3 disaccharides are there

Answer 6

Sucrose, Lactose, Maltose

Question 7

What bond occurs between the 1,4 carbons

Answer 7

A glycosidic bond

Question 8

What reaction joins the 2 monosaccharides together and how does this occur

Answer 8

A condensation reaction and it removes water to allow a 1,4 glycosidic bond to the oxygen

Question 9

How is the glycosidic bond broken

Answer 9

A hydrolysis reaction will break the bond due to the addition of water

Question 10

What is a polysaccharide

Answer 10

A chain of monosaccharides

Question 11

How does the structure of a polysaccharide affect its function

Answer 11

1) They are very compact - so large numbers can be easily stored
2) The glycosidic bonds are easily broken - lots of energy can be
released quickly
3) They’re not very soluble - allows for no osmotic movements

Question 12

What are the properties of starch

Answer 12

Made of a-glucose
The helix structure makes it good for storage

Question 13

What 2 polysaccharides make up starch

Answer 13

Amylose
Amylopectin

Question 14

What are the properties of amylose

Answer 14

Long, Unbranched and Coiled
- Coiled structure makes it compact so good for storage

Question 15

What are the properties of amylopectin

Answer 15

Long and Branched
- Branches allow enzymes to break it down easily so glucose can
be released quickly

Question 16

What are the properties of cellulose

Answer 16

Polymer of b-glucose
Forms chains which run parallel to the hydrogen bonds to form microfibrils ; which are strong

Question 17

What are the properties of glycogen

Answer 17

Made of a-glucose
Has a branched structure
Less dense + more soluble than starch
- broken down quicker
- higher metabolic rates

Question 18

What are lipids made up of

Answer 18

Hydrocarbons

Question 19

What are the 2 types of lipids

Answer 19

1) Triglycerides
2) Phospholipids

Question 20

What are the properties of triglycerides

Answer 20

Insoluble and non-polar
Contains 3 fatty acids which are attached to 1 glycerol
When combined together they form an ester bond

Question 21

What are the properties of phospholipids

Answer 21

Phosphate head is polar and hydrophilic
Tails are non polar and hydrophobic
Contains a phosphate head, 1 glycerol and 2 fatty acids

Question 22

What are the functions of proteins

Answer 22

Protection- antibodies
Enzymes
Hormones

Question 23

What are proteins made up of

Answer 23

NH2 = amino group
COOH = Carboxylic acid group
R group = Side chain - can be made up of anything

Question 24

What happens in the primary structure of a protein

Answer 24

Linear sequence of amino acids

Question 25

What happens in the secondary structure of a protein

Answer 25

Repeating pattern of peptide chains
Alpha helices and beta pleated sheets are involved

Question 26

What happens in the tertiary structure of a protein

Answer 26

3D folding of the secondary structure

Question 27

What happens in the quaternary structure of a protein

Answer 27

3D structure that involves more than 1 polypeptide

Question 28

What is a fibrous proteins

Answer 28

Have long polypeptide chains but have little tertiary structure

Question 29

What is a globular protein

Answer 29

Large proteins that have complex tertiary structures

Question 30

What is the test for a non-reducing sugar

Answer 30

1) Add HCl to the solution and add to a water bath for 5 mins
2) Add NaHCO3 to the solution
3) Test that the pH is now alkaline
4) If alkaline repeat the reducing sugars test