Biological Molecules

Question 1

Definition of monomer

Answer 1

Small units that make up larger molecules

Question 2

Definition of polymers

Answer 2

They are large molecules made up of a large number of monomers

Question 3

Carbohydrates and proteins,monomers are joined together by ___________ reactions,with the elimination of a water molecule

Answer 3

Condensation

Question 4

Blinds between polymers can be broken down through________,using a water molecule

Answer 4

Hydrolysis

Question 5

Two isomers of glucose

Answer 5

A-glucose
B-glucose

Question 6

6 important properties of water in biology are

Answer 6

1. It is a metabolite in which many metabolic reactions (condensation,hydrolysis and photosynthesis)
2. It is the solvent where metabolic reactions occur (the cytoplasm is 70-95% water)
3. Relatively high heat capacity (buffers temp change, large amount of energy is needed to raise temperature of large bodies of water,maintain a relatively stable temperature)

4.relatively high latent heat of vaporisation (loosing small amounts of water through evaporation has a cooling effect)

5.strong cohesion between water molecules (supports columns of water in xylem for the transpirations tread and produces surface tension where water meets air)

6. Ice is less dense than water (lakes do not freeze completely so organisms not killed as temperature falls)

Question 7

How are glycogen and starch formed

Answer 7

When many glucose units are condensed together through a chemical reaction.
The glucose unit which makes up glycogen and starch are a glucose

Question 8

How are disaccharides formed?

Answer 8

suagrs whose molecules are form when hexose sugar molecules react together by means of a condensation reaction

Question 9

Examples of disaccharides

Answer 9

Glucose + glucose = maltose

Glucose +fructose= sucrose

Glucose +galactose =lactose

Question 10

Glucoses structure and function

Answer 10

Structure:
Hexose monosacharide with a ring structure
Two isomers, a glucose and b-glucose

Function:
Soluble molecule that is used for respiration,stored as glycogen or starch as energy reserves or used in structural molecules

Question 11

Function of amylose and amylopectin

Answer 11

Stores energy

Question 12

Function of glycogen

Answer 12

Energy store in animals
Stores excess glucose in muscle and liver cells

Question 13

Function of cellulose

Answer 13

Provides structural support in plants
Prevents lysis during osmosis

Question 14

Definition of saturated

Answer 14

Chain that contains no double bonds

Question 15

Properties of triglycerides

Answer 15

Not water soluble
Saturated molecules are usually solid at room temp
They are synthesised by the formation of three ester bonds between 1 glycerol molecules and 3 fatty acids

Question 16

Properties of phospholipids

Answer 16

They have a hydrophilic head and a hydrophobic tail

They form a phospholipid bilayer. (double layer of molecules or atoms that are closely packed together)

Question 17

Function of triglycerides

Answer 17

Long hydrocarbon tail that stores energy
Breakdown products that can be used as a respiratory substrate
Can be stored without affecting water potential

Question 18

How can the hydrophobic properties of lipids be utilised ?

Answer 18

They hydrophobic properties can be utilised in water proofing in biological organisms such as the cuticle of leaves, exoskeleton of some insects and bird feathers

Question 19

What are the four main carbon-based molecules common to all life

Answer 19

Carbohydrates,lipids,proteins, nucleic acids

Question 20

Which two types of biological molecules act as the main stores of energy

Answer 20

Carbohydrates and lipids

Question 21

What are the units of a polymer called

Answer 21

Monomers

Question 22

What are the monomers of the disaccharide sucrose

Answer 22

Glucose and fructose

Question 23

What us an anion? Give an example

Answer 23

Negatively charged ion, such as nitrate ions (NO3-)

Question 24

Which type of biological molecule forms the major part of plasma membranes

Answer 24

Lipids/ phospholipids

Question 25

Give three named examples of globular proteins

Answer 25

Haemoglobin, insulin, enzymes (pepsin)

Question 26

How can the presence of reducing sugars be measured quantitively?

Answer 26

Reagent test strips colorimetry

Question 27

Which isomer of glucose makes up glycogen

Answer 27

A glucose

Question 28

What are the three main groups of lipids

Answer 28

Triglycerides
Phospholipids
Cholesterol

Question 29

What is the test for lipids

Answer 29

Emulsion test

Question 30

Which types of molecules are triglycerides made of

Answer 30

Glycerol and fatty acids

Question 31

Which type of lipid is common in plasma membranes

Answer 31

Phospholipids

Question 32

Which three elements are commmon in plasma membranes

Answer 32

Carbon
Hydrogen
Oxygen

Question 33

What makes lipids unsaturated

Answer 33

Carbon-carbon double bonds

Question 34

Which chemical is used in the biochemical test for starch

Answer 34

Iodine/potassium iodide

Question 35

what is starch made of

Answer 35

made of long chains of glucose and consists of two compounds \mylose and amylopectin

Question 36

what is amylose

Answer 36

an unbranched polymer

Question 37

features of starch (could come up as a six marker)

Answer 37

1)insoluble
2)does not affect water potential so water is not drawn into the cell by osmosis
3)is large and insoluble so it doesnt diffuse out of the cell
4)is compact;can store a lot in a small space
5)when hydrolysed it forms a glucose which is easily transported and readily used in respiration
6)the branched ends can be acted on by enzymes realsing glucose monomers