June 2009 wjec unit 1

Question 1

Centrioles?

Answer 1

not in plant cell but in animal cells

Question 2

Mitochondria?

Answer 2

in both plant cells and animal cells

Question 3

Chloroplast?

Answer 3

in plant cells and not in animal cells

Question 4

Mitochondrion?

Answer 4

has DNA
has cristae
inner membrane
outer membrane
ribosome

Question 5

Function of mitochondria in cells?

Answer 5

site of atp synthesis to provide energy for aerobic respiration

Question 6

Type of cell in where you would expect to find large numbers for mitochondria?

Answer 6

liver
muscle cell

Question 7

Why do they contain large numbers of mitochondria?

Answer 7

It is high metabolically active and therefore needs a large amount of ATP, therefore needs a large amount of mitochondria

Question 8

Metaphase?

Answer 8

both chromosomes on equator, chromatids on either side

Question 9

Anaphase?

Answer 9

4 v or u shaped, centromere pointing towards centrioles
Replication of DNA , replication of organelles

Question 10

the uprights of the ladder

Answer 10

sugar phosphate backbone
alternating energy

Question 11

Bonds in DNA?

Answer 11

H bonds

Question 12

Explain the difference between secondary and tertiary structure of protein molecules?

Answer 12

secondary structure is folding of polypeptide chain held by hydrogen bonds
tertiary is folding of helix or secondary structure
held by bonds between R groups
covalent, disulphide bridges, ionic, salt bridges, hydrophobic interactions, hydrogen, vdw

Question 13

Explain how the distribution of charged and uncharged parts determine the position a protein will take up in the membrane

Answer 13

charged groups will associate with hydrophilic heads
uncharged groups will associate with hydrophobic heads

Question 14

how would the protein position itself within the membrane?

Answer 14

will associate with heads only

Question 15

Cell wall labelled?

Answer 15

cell membrane
cell wall
cytoplasm
vacuole membrane / tonoplast
cell vacuole
plasmodesmata

Question 16

2 ways by which materials move between cell x and cell y?

Answer 16

diffusion
osmosis
active transport
facilitated diffusion

Question 17

One change through the microscope?

Answer 17

cytoplasm shrinks

Question 18

Water potential def?

Answer 18

tendency of water molecules to move out of a system

Question 19

Value of pressure potentials in cells at incipient plasmolysis?

Answer 19

0

Question 20

Show reaction between 2 molecules of glucose + the products that are formed?

Answer 20

1 O and 2 H = removed
elimination of water
molecules joined by O2 atoms

Question 21

Glucose + Glucose?

Answer 21

maltose

Question 22

What is the inorganic molecule that is released during the reaction?

Answer 22

water

Question 23

Type of reaction of joining?

Answer 23

condensation

Question 24

Polymerisation def?

Answer 24

Joining together of monomers to make a larger molecule

Question 25

Describe the mechanism by which competitive inhibitors decrease the activity of enzymes?

Answer 25

inhibitor competes with substrate to bind with active site
inhibitor binds to fit into the active site
with inhibitor bound substrate is unable to bind inhibitor is complementary shape as substrate
the greater the concentration of substrate, the less inhibtion

Question 26

Possible use for discoveries made by devulpalle and Mooser?

Answer 26

add iron sulphate to toothpaste to prevent formation of plaque