January 2014 Unit 1 wjec

Question 1

Circle around component with nitrogen?

Answer 1

rectangular base

Question 2

2 differences between DNA and RNA?

Answer 2

DNA nucleotide contains the pentose sugar deoxyribose whereas RNA nucleotide contains the sugar ribose
Thymine is found in DNA and base uracil in RNA

Question 3

1 difference between these cells in meiosis and cells in mitosis?

Answer 3

cells = diploid whereas cells in haploid
4 cells produced in comparison to 2 as a result of 2 divisions

Question 4

Importance of meiosis?

Answer 4

Produces genetic variation
haploid gametes which allow diploid state to be restored at fertilisation in zygote

Question 5

Bond in monosaccharide?

Answer 5

Ester

Question 6

Reaction in breakdown of monoglyceride?

Answer 6

Hydrolysis

Question 8

Why are triglycerides not considered polymers?

Answer 8

Glycerol and fatty acids have different structures

Question 9

What type of fatty acid is oleic acid?

Answer 9

unsaturated
conrains at least 1 c doube bond c
not fully saturated with H atoms

Question 10

Functions of triglycerides in a mammal ?

Answer 10

thermal insulation
waterproofine
source of metabolic water
protection of delicate internal organs
buoyancy

Question 11

Represented by X in a chemical reaction?

Answer 11

activation energy

Question 12

Only reaction succinate dehydrogenase can catalyse?

Answer 12

The active site (of succinate dehydrogenase) has a specific shape;
Succinate has a complementary shape;
(and therefore) {fits/ binds/ bonds to} into the active site;

Question 13

What factor is limiting rate of reaction?

Answer 13

concentration of succinate

Question 14

Use evidence from the graph to support decision?

Answer 14

II As the concentration of the {succinate increases {the
rate of reaction/production of fumarate increases};

Question 15

What is limiting the rate of reaction?

Answer 15

The concentration of succinate dehydrogenase/ enzyme;
all of its active sites are occupied

Question 16

Explain how malonate inhibits succonate dehydrogenase?

Answer 16

Malonate has a similar shape to {succinate/ substrate /
malonate has a complementary {shape/structure} the active site;

Malonate {binds/ competes} to the active site;
Prevents succinate binding / fewer enzyme-substrate complexes
are formed;

Question 17

Function of nucleus?

Answer 17

contains DNA which codes for protein synthesis

Question 18

Function of ribosome?

Answer 18

synthesis proteins

Question 19

Golgi body?

Answer 19

packages and modifies proteins

Question 20

How is mitochondria appear different?

Answer 20

they have been cut in different planes

Question 21

2 structures found in prokaryotic cells that = also found in mitochondria?

Answer 21

loop f DNA
70s ribosomes
plasma membrane

Question 22

2 differences between mitochondria and prokaryotic cells such as bacteria?

Answer 22

Mitochondria
Has a double membrane
No cell wall;
No capsule;
No flagellum
No mesosome;
No plasmids;

Question 23

Function of partially permable membrane in this bosensor?

Answer 23

Allows the glucose molecules to pass through to the enzyme layer
Prevents the passage of other solutes
so they can’t affect results

Question 24

How the concentration of gluose is transmitted to the display?

Answer 24

glucose broken down by enzyme
the hydrogen peroxide/oxygen} is {detected/absorbed} by electrode;
an electric signal is generated
the greater the concentration of {glucose/hydrogen peroxide/oxygen}
the greater the signal;

Question 25

Why the enzyme involved is called glucose isomerase?

Answer 25

The enzyme converts glucose into it’s isomer fructose /

Question 26

biochemical test that could be used to show product has not been contaminated by enzyme?

Answer 26

add biuret solution
solution would remain blue

Question 27

2 advantages of immbolised enzymes?

Answer 27

can be reused
greater stability over wider pH