DNA & Proteins

Question 1

Name the shape of DNA and its contents.

Answer 1

DNA is a double standard helix held by complimentary base pairs

Question 2

What does DNA carry?

Answer 2

Do you know, carries genetic information for making proteins

Question 3

Name the four DNA bases

Answer 3

Adenine, cytosine, guanine and thynine.

Question 4

Describe the DNA base pairing rule

Answer 4

A is always pair with T and C always pair with G

Question 5

What does the base sequence determine?

Answer 5

The base sequence determines amino acid sequence in proteins

Question 6

Define the term gene

Answer 6

A gene is a section of DNA, which codes for a protein

Question 7

Describe the role of a messenger mRNA

Answer 7

mRNA is a molecule, which carries a complimentary copy of the genetic code from the DNA, in the nucleus, to a ribosome , where the protein is assembled from amino acids

Question 8

State that the variety of protein shapes and functions arises from the sequence of amino acids

Question 9

Give the functions of the following protein types; structural, enzymes, hormones, antibodies and receptors

Answer 9

Structural proteins offer help to the cells.
Enzymes proteins speed up chemical reactions for remain unchanged from the reaction.
Antibodies attack and destroy bacteria.
Hormones are chemical messengers
Receptors respond to signals and transmit messages to the interior of the cell.

Question 10

State that enzymes function as biological catalysts and are made by all living cells

Question 11

Describe the role of enzymes

Answer 11

Enzymes speed up cellular reactions and are unchanged in the process.

Question 12

What does enzyme substrate complex form?

Answer 12

facilitating reactions

Question 13

Describe the role of the active site of an enzyme

Answer 13

The shape of the active site of the enzyme molecule is complimentary to It’s specific substrate(s)

Question 14

Give an example of an enzyme which carries out degradation reaction, including its substrate and product

Answer 14

Degradation reactions break molecules down, for example amylase breaks down
starch into maltose.

Question 15

What do synthesis reactions do?

Answer 15

Build up molecules

Question 16

Give an example of an enzyme which carries out a synthesis reaction, including its substrate and product

Answer 16

Synthesis reactions build molecules up for example phosphorylase builds up glucose-
1-phosphate into starch.

Question 17

Explain the term optimum conditions

Answer 17

Each enzyme is most active in its optimum conditions.

Question 18

Name two factors which can affect enzyme activity

Answer 18

Temperature and pH

Question 19

Explain what happens to an enzyme when it is heated far beyond its optimum temperature

Answer 19

Enzymes can be denatured, resulting in a change in their shape which will affect the
rate of reaction.