Jan 2009 wjec unit 1

Question 1

What is found in bones + teeth?

Answer 1

Calcium

Question 2

Non reducing sugar?

Answer 2

Sucrose

Question 3

Found in chlorophyll in leaves?

Answer 3

magnesium

Question 4

A polysaccharide found in plant cell walls?

Answer 4

cellulose

Question 5

Found attached to lipids in the plasma membrane?

Answer 5

phosphate

Question 6

A large quantity of energy is needed to raise its temp?

Answer 6

water

Question 7

Bonds in primary structure?

Answer 7

peptide bonds

Question 8

Bonds in the Secondary structure?

Answer 8

Peptide bonds
Hydrogen bonds

Question 9

Bonds in tertiary structure?

Answer 9

Peptide
Hydrogen
Disulphide
Ionic

Question 10

How does quaternary structure of a protein differ from tertiary structure?

Answer 10

quaternary has 2 or more polypeptide chains present
has a non protein group attached

Question 11

Example of a quaternary protein?

Answer 11

Haemoglobin
collagen
insulin

Question 12

Monosaccharide X in cellulose ?

Answer 12

beta glucose

Question 13

Bond formed between 2 hexose sugars?

Answer 13

glycosidic bond

Question 14

2 structural differences between starch + cellulose?

Answer 14

cellulose is cross linked in straight chains whereas starch is coiled
Starch is alpha
Cellulose is beta

Question 15

Cellulose units arranged in a complete molecule + how this arrangement gives high tensile strength?

Answer 15

cellulose has long chains cross linked by Hydrogen bonds and rotated by 180 degrees
Hydrogen bonds form between OH groups of adjacent parallel chains to form microfibrils
cellulose molecules are rotated by 180 degrees whereas starch is not
starch has alpha glucose whereas cellulose is beta
starch has 1,4 and 1,6 whereas cellulose only has 1,4

Question 16

Mitochondria site?

Answer 16

site of ATP synthesis + aerobic respiration

Question 17

Chloroplast?

Answer 17

provides photosynthetic pigments for photosynthesis site of photosynthesis

Question 18

Ribosomes?

Answer 18

site of protein synthesis

Question 19

Why they differ in appearance?

Answer 19

they are cut in 2 different planes
longitudinal + transversal

Question 20

2 ways in which an animal cell differ from a plant cell?

Answer 20

plant cells have a cell wall, animal cells dont
plant cells contain a permanent vacuole
animal cells do not
animal cells do not have plasmodesmata

Question 21

An animal cell ions?

Answer 21

high outside - diffusion

low in side

ions out - high
active transport

Question 22

What does micro villi do to ensure a rapid rate of diffusion?

Answer 22

micro villi - increases surface area for diffusion

Question 23

Diffusion?

Answer 23

membrane is highly folded
high to low
thin

Question 24

Explain how active transport of sodium ions out of the cell helps to ensure a rapid rate of diffusion of sodium ions into the cell?

Answer 24

moving Na+ ions out of the cell, reduces their concentration + creates a greater difference in concentration between the inside + outside

Question 25

Temp on diffusion?

Answer 25

increasing the temp, increases the rate of diffusion as the molecules gain more kinetic energy which leads to an increase in successful collisions
that produces a product

Question 26

Straight line?

Answer 26

diffusion
through the phospholipid bilayer e.g co2 + oxygen

Question 27

Facilitated diffusion?

Answer 27

through protein carriers

Question 28

Why is the lines for diffusion and active transport different?

Answer 28

diffusion - no carriers, only be limited by concentration
if it was similar wont do it
facilitated diffusion - more rapid movement of molecules which is reliant on protein carriers which can be limiting

Question 29

Water potential def?

Answer 29

tendency of water molecules to move out of asystem

Question 30

Plasmolysed cell diagram?

Answer 30

plasma membrane
no vacuole
cell wall

Question 31

What evidence on diagram shows water potential of the cell sap must be higher than that of sucrose solution?

Answer 31

cell membrane has pulled awa from the cell wall

Question 32

Why the water potential at T must be equal to S?

Answer 32

cell wall becomes fully permeable + sucrose diffuses into T until concentration is the same

Question 33

What type of inhibition would decrease by increasing the conc of substrate?

Answer 33

competitive

Question 34

Free enzyme at 5 degrees?

Answer 34

kinetic energy is low, therefore few successful collisions between the enzyme substrate

Question 35

70 degrees

Answer 35

Temp is higher, kinetic energy is higher
enzyme is denatured because the hydrogen bonds in the active site is broken because they could not withstand the vibrations,
no complexes formed, no product produced

Question 36

3 differences between the effects of temp on immobilised and free enzyme?

Answer 36

1) activity of immobilised enzymes as greater between 0 and 40 degrees
above 40 degrees, free

2) enzymes begin to denature, whereas immobilised enzymes start at 50 degrees

3 )immobilised enzymes are active at all temps except 40

free enzyme completely denatured at 70 degrees
immobilised enzyme is completely denatured at 80 degrees

Question 37

How does trapping enzyme to an inert matrix explain differences?

Answer 37

shape of enzyme is maintained

Question 38

1 use of immobilised enzymes in medicine?

Answer 38

pregnancy tests
testing blood sugar

Question 39

Phase where chromosomes are in middle of equator?

Answer 39

metaphase

Question 40

Structure middle of chromosome?

Answer 40

centromere

Question 41

Function of spindle fibres?

Question 42

Prophase?

Answer 42

shorten + thicken and spindle forms

Question 43

Interphase?

Answer 43

period of intense activity which includes replication of DNA

Question 44

formation of 2 nuclei?

Answer 44

telophase

Question 45

Differences between mitosis + meiosis?

Answer 45

Meiosis - 2 divisions
4 daughter cells
daughter cells are genetically identical
Mitosis
1 division
2 daughter cells
daughter cells - genetically identical