Unit 1 - Biological molecules

Question 1

Name 3 monosacharrides

Answer 1

glucose, fructose, galactose

Question 2

Name 3 disaccharides

Answer 2

maltose, sucrose, lactose

Question 3

Maltose

Answer 3

two alpha glucose

Question 4

Sucrose

Answer 4

glucose + fructose

Question 5

Lactose

Answer 5

glucose + galactose

Question 6

What are the bonds in polysaccharides?

Answer 6

glycosidic bonds

Question 7

What type of reaction forms disaccharides?

Answer 7

condensation reactions

Question 8

What type of reaction is maltose broken down into two alpha glucose monosaccharides?

Answer 8

hydrolysis

Question 9

Name 3 polysaccharides of glucose?

Answer 9

starch, glycogen, cellulose

Question 10

Name 3 structures of starch

Answer 10

helical, insoluble, highly branched

Question 11

Describe the test for reducing sugar

Answer 11

add Benedict’s solution and heat, colour change to brick red

Question 12

Describe the test for non-reducing sugars (sucrose)

Answer 12

add acid and boil, cool and add alkali, add Benedict’s and heat, colour change to brick red

Question 13

Describe the test for starch

Answer 13

add iodine solution, colour change to blue-black

Question 14

Describe the test for lipids

Answer 14

add ethanol and shake, add distilled water, milky emulsion forms

Question 15

What are triglycerides made up of?

Answer 15

glycerol and three fatty acids

Question 16

What type of bonds are in triglycerides?

Answer 16

ester bonds

Question 17

Functions of triglycerides

Answer 17

energy store and source, insulation, waxy cuticles, protection

Question 18

What are phospholipids made up of?

Answer 18

glycerol, two fatty acids and phosphate group

Question 19

What do phospholipids form when mixed with water?

Answer 19

monolayers and micelles

Question 20

What bonds do amino acids form in condensation reactions?

Answer 20

peptide bonds

Question 21

What is a polypeptide?

Answer 21

long chains of amino acids

Question 22

What is the primary protein structure?

Answer 22

sequence of amino acids held by peptide bonds

Question 23

What is the secondary protein structure?

Answer 23

folded into alpha helix or beta pleated sheet held by hydrogen bonds

Question 24

What is the tertiary protein structure?

Answer 24

3D shape, folded and held by hydrogen, ionic, disulphide bonds all determined by the primary structure

Question 25

What is the quaternary protein structure?

Answer 25

more than one polypeptide chain, held by hydrogen, ionic, disulphide bonds, not all proteins have a quaternary structure

Question 26

What two categories can proteins be separated in to?

Answer 26

fibrous and globular

Question 27

Describe the induced-fit model of enzyme action.

Answer 27

substate binds to active site and enzyme-substate complex is formed, active site changes shape so it's complementary to substrate, reduces activation energy

Question 28

How do competitive inhibitors work?

Answer 28

inhibitor is similar shape to substrate, binds to active site, less enzyme-substrate complexes formed

Question 29

What are components of a DNA nucleotide?

Answer 29

phosphate group, deoxyribose and nitrogenous base

Question 30

What the complementary base pairs in DNA?

Answer 30

adenine - thymine cytosine - guanine

Question 31

What do two nucleotides form in a condensation reaction?

Answer 31

phosphodiester bond

Question 32

What is a DNA molecule?

Answer 32

a double helix with two polynucleotide chains held together by hydrogen bonds between specific complementary base pairs

Question 33

What are the components of an RNA nucleotide?

Answer 33

phosphate group, ribose sugar, nitrogenous base

Question 34

What are the complementary base pairs in RNA?

Answer 34

adenine - uracil cytosine - guanine

Question 35

Describe the process of semi-conservative DNA replication

Answer 35

DNA helicase breaks the hydrogen bonds between the complementary base pairs which unwinds the double helix, each strand acts as a template stand, free DNA nucleotides are attracted to the exposed complementary bases, DNA polymerase joins nucleotides in a condensation reaction

Question 36

What are the components of an ATP nucleotide?

Answer 36

adenine, ribose and three phosphate groups

Question 37

What is ATP hydrolysed into and what enzyme does this?

Answer 37

adenosine diphosphate (ADP) and an inorganic phosphate group (Pi) , ATP hydrolase

Question 38

Name 5 properties of water

Answer 38

metabolite, solvent, high specific heat capacity, large latent heat of vaporisation, strong cohesion

Question 39

Why is it important water is a metabolite?

Answer 39

for metabolic reactions such as condensation and hydrolysis

Question 40

Why is it important water is a solvent?

Answer 40

for metabolic reactions to occur

Question 41

Why is it important water has a high specific heat capacity?

Answer 41

to buffer temperature change

Question 42

Describe the role of iron ions

Answer 42

haemoglobin binds with oxygen

Question 43

Describe the role of sodium ions

Answer 43

co-transport of glucose/ amino acids sodium moved out by active transport creates a sodium concentration gradient affects water potential

Question 44

Describe the role of phosphate ions

Answer 44

joins nucleotides in phosphodiester bonds, used in ATP, hydrophilic part of phospholipid bilayer

Question 45

Describe how an ATP molecule is formed from its component molecules.

Answer 45

condensation reaction of adenine, ribose and three phosphates, ATP synthase

Question 46

Why is ATP a suitable energy source for cells to use?

Answer 46

Releases relatively small amount of energy so little energy lost as heat, Releases energy instantaneously, Can be rapidly re-synthesised, does not leave cells

Question 47

Describe how ATP is resynthesised in cells.

Answer 47

from ADP and phosphate, by ATP synthase, during respiration/ photosynthesis

Question 48

How is the hydrolysis of ATP is used in cells.

Answer 48

to provide energy for other reactions, to add phosphate to other substances and make them more reactive