AS CORE CONCEPTS (new + detailed)

Question 1

what is the structure of water

Answer 1

1 slightly negative oxygen atoms
2 slightly positive hydrogen atoms

Question 2

define polar / dipole molecule

Answer 2

opposite charges attract to each other creating hydrogen bonds to form between

Question 3

define high specific heat capacity and its importance to water

Answer 3

• taking in or out a large amount of energy to raise the temperature to 1 degree
• the temperature of water does not change rapidly meaning aquatic organisms can function and survive

Question 4

explain the importance of cold conditions in water (freezing + ice)

Answer 4

• less dense than liquid water so it floats
• acts as a habitat for organisms
• insulation below

Question 5

define and explain the importance of high latent heat of vaporisation to water

Answer 5

• taking a large amount of energy to evaporate water
• organisms don’t have to loose a great deal of energy so they sweat to cool themselves

Question 6

define and explain solvents importance to water

Answer 6

• dissolves in water
• can dissolve ionic and polar substances meanings its universal
• dissolves oxygen for respiration

Question 7

explain why cohesions importance to water

Answer 7

• hydrogen bonds
• water travels up xylem tubes allowing transport
• surface tension allows water to meet air so organisms can use this for habitat

Question 8

what do magnesium ions do?

Answer 8

help plants with chlorophyll

Question 9

what do nitrate ions do?

Answer 9

make DNA + animo acids

Question 10

what do calcium ions do?

Answer 10

strengthen bones and cell walls

Question 11

what do phosphate ions do?

Answer 11

make ATP + ADP

Question 12

what do iron ions do?

Answer 12

haemoglobin, oxygen in cells

Question 13

what elements for carbohydrates contain?

Answer 13

carbon
hydrogen
oxygen

Question 14

3 examples of monosaccharides

Answer 14

glucose
fructose
galactose

Question 15

3 examples of monosaccharides

Answer 15

glucose
fructose
galactose

Question 16

3 examples of disaccharides

Answer 16

maltose
sucrose
lactose

Question 17

3 examples of polysaccharides

Answer 17

glycogen
cellulose
starch

Question 18

Explain Benedict’s test

Answer 18

Test for sugars
Reducing sugars: heat in water bath for 5 minutes and should turn from blue to yellow/orange/brick red
Non reducing sugars: add hydrochloric acid then neutralise with sodium hydrogen carbonate , should turn blue to brick red

Question 19

Test for starch

Answer 19

Iodine
Orange -> blue/black

Question 20

What’s the difference between alpha and beta glucose

Answer 20

Alpha glucose has its carboxyl group below whilst beta glucose has its above

Question 21

What is the structure of starch?

Answer 21

Made up of 2 polysaccharides of a-glucose
Amylose: unbranched, 1-4 glycosidic bonds
Amylopectin: contains 1-4 and 1-6 glycosidic bonds

Question 22

What is starch structure related to its function?

Answer 22

Helical because of angles on glycosidic bonds - compact, storage
Insoluble - doesn’t affect water potential
Branched chains - more efficient hydrolysis for respiration
Large - can’t leave cell

Question 23

What is the function of glycogen?

Answer 23

Main storage of energy in animals, stores in muscle and liver cells

Question 24

What is the structure of glycogen?

Answer 24

Polysaccharides of alpha glucose with branded chains
1-4 and 1-6 glycosidic bonds

Question 25

What is the structure of glycogen?

Answer 25

Polysaccharides of alpha glucose with branded chains
1-4 and 1-6 glycosidic bonds

Question 26

what is glycogens structure related to function?

Answer 26

Branched - rapid hydrolysis into glucose to meet demands of cells
Insoluble- doesn’t affect water potential
Compact - good for storage

Question 27

What is the function of cellulose?

Answer 27

• structural strength in cell walls: hydrogen bonds found between parallel chains of microfibrils

Question 28

What is the structure of cellulose?

Answer 28

Polysaccharides of beta glucose monosaccharides joined together by 1-4 glycosidic bonds.
Form straight chains
For,a microfibrils from hydrogen bonds forming between molecules giving it strength

Question 29

What is cellulose structure related to function?

Answer 29

Hydrogen bonds form between chains - collective strength to the cell wall