Unit 1 - Biological Molecules

Question 1

why is water a polar molecule

Answer 1

the oxygen has a small negative charge
and the hydrogen have a small positive charge

Question 2

what bond joins water molecules together

Answer 2

hydrogen bond
(they are weak)

Question 3

what is meant by specific heat capacity

Answer 3

the amount of energy needed to change 1kg of something by 1 degree

Question 4

does water have a high or low SHC

Answer 4

very high

Question 5

what happens when you heat water / try to change the SHC

Answer 5

the heat energy goes towards weakening or breaking the hydrogen bonds

Question 6

what is meant by water being a good solvent

Answer 6

lots of substances can dissolve in water

Question 7

what is an advantage to water being a good solvent

Answer 7

it can be used to transport substances

Question 8

what is it called when water molecules stick together

Answer 8

cohesion

Question 9

what is an advantage to cohesion

Answer 9

large collums of water can travel in the xylem

Question 10

examples of a metabolic reaction

Answer 10

photosynthesis
aerobic respiration

Question 11

give 2 examples of carbohydrates

Answer 11

sugar
starch

Question 12

what is a hexose sugar

Answer 12

a sugar with six carbon atoms

Question 13

what is a monosaccharide

Answer 13

a single sugar molecule

Question 14

give 3 examples of monosaccharides

Answer 14

glucose
galactose
fructose

Question 15

are monosaccharides soluble in water

Answer 15

yes

Question 16

what does hydrophillic mean

Answer 16

-water loving
-dissolves in water

Question 17

what is a pentose monosaccharide

Answer 17

a monosaccharide with 5 carbon atoms

Question 18

give an example of a pentose monosaccharide

Answer 18

ribose

Question 19

what is a disaccharide

Answer 19

when 2 monosaccharides are chemically joined

Question 20

what is a polysaccharide

Answer 20

3 or more monosaccharides chemically joined

Question 21

if the OH group is on the bottom which isomer of glucose is it

Answer 21

alpha glucose

Question 22

if the OH group is on the top which isomer of glucose is it

Answer 22

beta glucose

Question 23

what type of bond is formed when alpha glucose is joined

Answer 23

glycosidic

Question 24

is glucose soluble in water and why

Answer 24

yes, extremely
because it has a large amount of hydroxyll groups

Question 25

how do plant cells store glucose

Answer 25

as starch

Question 26

what is amylose

Answer 26

a polymer of alpha glucose molecules

Question 27

what shape is amylose and why is it benefical

Answer 27

its a helix shape so its very compact

Question 28

how is amylopectin different to amylose structually

Answer 28

amylopectin is branched whereas amylose isnt

Question 29

is starch soluble in water and how does it help its function

Answer 29

its not soluble which means it doesnt cause water to enter the cell by osmosis

Question 30

how is cellulose stong

Answer 30

hydrogen bonds form between its straight chains

Question 31

what bond joins amino acids together

Answer 31

peptide bond

Question 32

what is the role of ribosomes

Answer 32

site of protein synthesis

Question 33

what is it called when you join 3 or more amino acids

Answer 33

a polypeptide

Question 34

how can you change the tertiary structure of an enzyme

Answer 34

by heating it as the shape of the active site has changed

Question 35

what is meant by the tertiary structure of a protein

Answer 35

the 3 dimensional arrangement of its polypeptide chain

Question 36

what is the quaternary structure of a protein

Answer 36

shows us how the subunits fit together to form a larger structure

Question 37

features of a globular protein

Answer 37

- spherical shape - soluble in water

Question 38

why are globular proteins soluble in water

Answer 38

they have hydrophillic amino acids on their surface

Question 39

where are the hydrophobic amino acids in a globular protein

Answer 39

in the centre

Question 40

give 3 examples of a globular protein

Answer 40

haemoglobin insulin lysozyme

Question 41

what is the role of haemoglobin

Answer 41

to bind to oxygen in the lungs

Question 42

how does haemoglobins featres make it seful for its purpose

Answer 42

haemoglobin has 4 haem molecules and 1 haem molecule binds to 1 oxygen molecule so each haemoglonin molecule can carry 4 oxygen molecules

Question 43

how do hormones carry out their function

Answer 43

by binding to specific receptor molecules

Question 44

where is lysozymes found

Answer 44

saliva and tears

Question 45

what are functions of globular proteins

Answer 45

enzymes hormones oxygen carrying proteins

Question 46

what are the functions of fibrous proteins

Answer 46

structural proteins like in bones or walls of arteries

Question 47

what is the structure of a fibrous protein

Answer 47

long rope like molecules

Question 48

features of fibrous proteins

Answer 48

- long rope like - insoluble in water

Question 49

give 3 examples of fibrous proteins

Answer 49

collagen keratin elastin

Question 50

what is the structure of a triglyceride

Answer 50

1 glycerol 3 fatty acids

Question 51

what bonds hold glycerol and fatty acids together

Answer 51

ester bonds

Question 52

what does the enzyme lipase do in the digestive system

Answer 52

breaks down the ester bonds of a triglyceride so you get glycerol and 3 fatty acids

Question 53

are triglycerides polar or non polar

Answer 53

non polar meaning theyre hydrophobic so they dont dissolve in water

Question 54

what is the structure of a phospholipid

Answer 54

1 glycerol 2 fatty acids and a phosphate group

Question 55

why is a phospolipid partially hydrophillic

Answer 55

because the phosphate group is negatively charged so is hydrophillic but the fatty acids are hydrophobic

Question 56

what is a phospholipid bilayer

Answer 56

when the phospholipids position themselves so the phosphate group interacts with water but the fatty acids dont

Question 57

what is a monomer

Answer 57

small units which larger molecules are made from

Question 58

what is a polymer

Answer 58

molecules made from a large number of monomers