June 2006 WJEC unit 1

Question 1

1 structure present in prokaryotic cells?

Answer 1

B

Question 2

1 structure absent from prokaryotic cells?

Answer 2

C

Question 3

explain how it is possible to tell that it is a view using an electron rather than a light microscope?

Answer 3

detailed mitochondria
ribosomes visible

Question 4

which of the 2 structures A to E are found in large numbers in a cell with a high level of metabolic activity?

Question 5

apart from the presence of inhibitors and substrate concentrations : state 3 factors that affect the rate of an enzyme controlled reaction?

Answer 5

pH
temp
enzyme concentration

Question 8

How does a competitive inhibitor work?

Answer 8

have a molecular shape complementary to the active site and similar to that of the substrate so they compete for the active site

Question 9

How is the form of secondary structure held together?

Answer 9

through peptide bonds
Hydrogen bonds

Question 10

Name the type of bonds?

Answer 10

Hydrogen
disulphide
ionic bonds

Question 11

State the highest level of protein structure shown in the diagram?

Question 14

Cellulose structure?

Answer 14

individual cellulose consists of long chain beta glucose units
these glucose monomers are joined by beta 1.4 glycosidic bonds to make a straight, unbranched chain
beta link rotates adjacent glucose molecules by 180 degrees

Question 15

Chromatids can be first seen using a light microscope?

Answer 15

prophase

Question 16

Significant of mitosis and why it is important to plants?

Answer 16

Produces cells that are genetically identical to the parent- providing genetic stability
important in plants - asexual reproduction

Question 17

explain in terms of water potential why there is no change at this point?

Question 18

How does the information given show that the root hairs take up the ions by active transprt

Question 19

why at low temps, potassium uptake continues after addition of potassium cyanide?

Answer 19

diffusion is not affected by cyanide