1.1 Biological molecules

Question 1

What is a macromolecule?

Answer 1

A complex molecule with a large molecular mass

Question 2

What is a polymer?

Answer 2

A large, complex molecule made of repeating monomers joined together in chains

Question 3

What is a monomer?

Answer 3

A small repeating subunit that can join together in chains to form polymers

Question 4

What monomers join together to form carbohydrates?

Answer 4

Monosaccharides

Question 5

What monomers join together to form proteins?

Answer 5

Amino acids

Question 6

What monomers join together to form DNA?

Answer 6

Nucleotides

Question 7

What is a condensation reaction?

Answer 7

A reaction that releases water

Question 8

What is a hydrolysis reaction?

Answer 8

A reaction that uses water to split up molecules

Question 9

What is metabolism?

Answer 9

All the chemical reactions that take place in a living organism

Question 10

What is an isomer?

Answer 10

Molecules with the same molecular formula but with the atoms connected in a different way

Question 11

What bond is formed between monosaccharides?

Answer 11

Glycosidic bond

Question 12

What is a disaccharide?

Answer 12

Two monosaccharides joined together by a glycosidic bond

Question 13

What is a polysaccharide?

Answer 13

Two or more monosaccharides joined together

Question 14

What is amylose?

Answer 14

Long, unbranched chain of alpha glucose

Question 15

what is amylopectin?

Answer 15

long, heavily branched chain of alpha glucose

Question 16

What is the function of starch?

Answer 16

To store glucose for energy

Question 17

What is starch made up of?

Answer 17

Polysaccharides of alpha glucose: amylose and amylopectin

Question 18

How is starch suited for its function? (2 reasons)

Answer 18

It is insoluble in water so doesn’t affect water potential or cause osmosis. It is very compact so can store lots in a small space.

Question 19

What is glycogen?

Answer 19

An alpha glucose polysaccharide made with excess glucose

Question 20

How is glycogen suited for its function? (2 reasons)

Answer 20

Lots of branches allow glucose to be released quickly. Very compact so lots of glucose can be stored in a small space.

Question 21

What is cellulose made up of?

Answer 21

Long, unbranched chains of beta-glucose

Question 22

What are microfibrils?

Answer 22

Strong fibres made of cellulose chains linked by hydrogen bonds.

Question 23

How is cellulose suited for its function? (1 reason)

Answer 23

Strong fibres enable good structural support in the cell wall

Question 24

Glucose + glucose = ?

Answer 24

Maltose

Question 25

Glucose + fructose = ?

Answer 25

Sucrose

Question 26

Glucose + galactose = ?

Answer 26

Lactose

Question 27

What type of bonds hold together beta-glucose chains that form cellulose?

Answer 27

Hydrogen bonds

Question 28

Are lipids polymers?

Answer 28

No

Question 29

Which elements make up lipids?

Answer 29

Carbon, oxygen and hydrogen

Question 30

Are lipids soluble in water?

Answer 30

No

Question 31

How can we test for lipids?

Answer 31

Emulsion tests

Question 32

Are lipids soluble in alcohol and acetone?

Answer 32

Yes

Question 33

What roles do lipids play in cell membranes? [2]

Answer 33

Phospholipid bilayer transports lipid soluble molecules through the membrane, cell membrane is kept flexible

Question 34

What roles do lipids play in protection?

Answer 34

Layers of fat surround and protect internal organs in animals and humans from damage

Question 35

Why is it useful that lipids are insoluble in water? [2]

Answer 35

Their presence doesn't affect water potential, they act as a waterproofing layer in both plant and animal cells

Question 36

How do lipids act as insulation?

Answer 36

They are poor conductors of heat, so help prevent heat from escaping to maintain our normal body temperature

Question 37

Why are lipids a good store of energy?

Answer 37

They can release large amounts of energy at a time

Question 38

Name two types of lipids

Answer 38

Phospholipids and triglycerides

Question 39

What is a dipeptide?

Answer 39

Two amino acids bonded together

Question 40

What is a polypeptide?

Answer 40

More than two amino acids bonded together

Question 41

What is a protein?

Answer 41

One or more folded polypeptides

Question 42

How is a peptide bond formed?

Answer 42

Condensation reaction between the carboxyl group group one amino acid and the amino group of another

Question 43

What two substances are formed when two amino acid molecules join together?

Answer 43

- dipeptide - water

Question 44

What type of bond forms between amino acid molecules?

Answer 44

Peptide bond

Question 45

How can we test for protein?

Answer 45

Add buret solution, shake, presence of protein causes colour to change from blue to purple

Question 46

What is the primary structure of protein?

Answer 46

The order of amino acid sequence in the polypeptide chain

Question 47

What does the primary structure of protein determine?

Answer 47

The way the chain will fold

Question 48

What are the secondary structures of protein?

Answer 48

alpha helices and beta pleated sheets

Question 49

How do the secondary structures of protein form?

Answer 49

Hydrogen bonds form between non-adjacent amine and carboxyl groups in the amino acid chain

Question 50

How many different amino acids make up all living things?

Answer 50

20

Question 51

How is the shape of an enzyme's active site determined?

Answer 51

The enzyme's tertiary structure

Question 52

What is an intracellular enzyme?

Answer 52

An enzyme that is used by the cell it was made in

Question 53

What is an extracellular enzyme?

Answer 53

An enzyme that works outside the cell it was made in

Question 54

How is activation energy reduced?

Answer 54

Enzyme-substrate complexes bend the bonds of the substrate

Question 55

What is the induced fit model?

Answer 55

The idea that the active site of an enzyme is not perfectly complimentary, and instead changes shape as the enzyme-substrate complex forms, bending the bonds in the substrate.

Question 56

What are the two types of enzyme inhibitor?

Answer 56

- competitive inhibitors -non-competitive inhibitors

Question 57

Name four factors that affect enzyme activity

Answer 57

Temperature, pH, substrate concentration, enzyme concentration

Question 58

How does a competitive inhibitor work?

Answer 58

Inhibitor with a similar shape to the substrate binds to the enzyme's active site, preventing the substrate from binding

Question 59

How does a non-competitive inhibitor work?

Answer 59

Inhibitor binds to allosteric site of the enzyme, causing active site to change shape, preventing the substrate from binding

Question 60

Which type of inhibitor can be overcome by increasing the substrate concentration?

Answer 60

competitive inhibitors

Question 61

What does pH stand for?

Answer 61

Potential for Hydrogen

Question 62

What ion can be increased to make a solution more acidic?

Answer 62

H+ ions

Question 63

What ion can be increased to make a solution more alkaline?

Answer 63

OH- ions

Question 64

What is an R group?

Answer 64

The variable group that differentiates different amino acids