Biological Molecules

Question 1

what makes up polysaccharides/nucleotides

Answer 1

monosaccharides

Question 2

what makes proteins

Answer 2

amino acids

Question 3

what makes lipids

Answer 3

fatty acids and glycerol

Question 4

what makes maltose

Answer 4

a glu + a glu

Question 5

what makes lactose

Answer 5

b glu + galactose

Question 6

what makes sucrose

Answer 6

a glu + fructose

Question 7

describe monosaccharides (4)
hexoses and pentoses

Answer 7

sugars
dissolve easily
hexoses = glucose/fructose/galactose
pentoses = ribose/deoxyribose

Question 8

what does alpha glucose look like

Answer 8

OH group on right is on the top, switch around

Question 9

what does beta glucose look like

Answer 9

OH group on the bottom, no switch around

Question 10

function of monosaccharides

Answer 10

source of energy in respiration - C-H = release of energy

make larger molecules - glucose makes starch/glycogen/cellulose,

Question 11

glucose bonds

Answer 11

glycosidic bonds

Question 12

what is the proces of breaking apart disacchardes

Answer 12

hydrolysis

Question 13

joining monosaccharides to form glycosidic bonds

Answer 13

condensation

Question 14

describe polysaccharides

Answer 14

many monosaccharides + glycosidic bonds
not sugars
glucose converted into polysaccharides (glycogen/starch)

Question 15

properties of polysaccharides as storage (4)

Answer 15

dissolves easily
osmotic properties
reactive
can be converted back

Question 16

what are the four polysaccharides

Answer 16

amylose
amylopectin
starch
cellulose

Question 17

describe amylose (5)

Answer 17

condensation of a-glucose
1,4 linked
chains are curved
helical structure
compact molecule

Question 18

describe amylopectin

Answer 18

condensation from a-glucose
1,4 + 1,6 linked
branched

Question 19

describe starch/glycogen

Answer 19

amylose + amylopectin

Question 20

describe cellulose cell wall (4)

Answer 20

polymer of b-glucose
rotate every 180 degrees
weak hydrogen bonds BUT many = strong
slow rate of breakdown

Question 21

describe in detail how fibres are formed and properties of cell wall (4)

Answer 21

60-70 cellulose molecules cross linked to form microfibrils to form fibres in bundles
high tensile strength
withstand large pressure from osmosis
permeable

Question 22

difference between glycogen and amylopectin

Answer 22

glycogen more branched

Question 23

describe fatty acids (3)

Answer 23

unsaturated - double bonds
mono/poly saturated
plants = unsaturated

Question 24

how to form an ester

Answer 24

alcohol + acid

Question 25

describe triglyceride

Answer 25

fats and oils glycerol + fatty acid → glyceride glycerol = 3OH three hydrophobic tails = insoluble

Question 26

ratio of oxygen: carbon of triglycerides compared to carbohydrates

Answer 26

lower ratio

Question 27

function of triglycerides (3)

Answer 27

energy reserves insulator oxidised into water

Question 28

describe phospholipids (4)

Answer 28

triglyceride - one fatty acid + phosphate group soluble phosphate group is hydrophilic makes up phospholipid bilayer

Question 29

how many amino acids are present

Answer 29

20

Question 30

definitio of primary structure of proteins

Answer 30

sequence of amino acids in a straight chain

Question 31

definition secondary structure of proteins

Answer 31

regular order of amino acids due to hydrogen bonds | a helix/b pleated sheets

Question 32

describe a helix and b pleated sheets

Answer 32

shape due to hydrogen bonding between -CO- and -NH- | looser shape caused by hydrogen bonding - broken by pH and temp.

Question 33

definition of tertiary structure of protein

Answer 33

folding and coiling of chain due to interactions between R groups

Question 34

example of tertiary structures

Answer 34

lysozyme/myoglobin/haemoglobin

Question 35

bonds in tertiary structure

Answer 35

hydrogen bonds disulfide bonds ionic bonds weak hydrophobic interactions

Question 36

definition of quarternary structure

Answer 36

protein molecule made of two or more polypeptides

Question 37

describe properties of globular proteins (4)

Answer 37

spherical water soluble prosthetic group hydrophilic outside, hydrophobic inside

Question 38

example of globular protein

Answer 38

haemoglobin

Question 39

describe properties of fibrous protein (2)

Answer 39

structural protein | insoluble

Question 40

example of fibrous protein + description (5)

Answer 40

``` collagen three polypeptides hydrogen bonds hold triple helix cross links make fibrils - fibres high tensile strength ```

Question 41

describe properties of water (7)

Answer 41

``` solvent transport medium high specific capacity high latent heat of vaporisation ice is less dense than liquid high surface tension and cohesion water is reagent ```