DNA And Protein Synthesis P5

Question 1

What is DNA made up of ?

Answer 1

Nucleotides

Question 2

How many different nucleotides are there in DNA?

Answer 2

Four different types of DNA

Question 3

What does each nucleotide consist of?

Answer 3

One sugar molecule, one phosphate group and one base.

Question 4

Each DNA nucleotide consists of one sugar molecule, one phosphate group and one base.

Which of these is common to all DNA nucleotides?

Which of these varies?

Answer 4

The sugar and phosphate molecules are common to all DNA nucleotides.

The base varies.

Question 5

What molecules form the backbone to the DNA strands?

Answer 5

Sugar and phosphate molecules in the nucleotide.

Question 6

What does a base join to?

Answer 6

Sugar molecule

Question 7

What are the four different bases found in a DNA molecule?

Answer 7

Adenine (A)

Thymine (T)

Cytosine (C)

Guanine (G)

Question 8

What does each base link to?

Answer 8

A base on the opposite strand in the helix.

Question 9

What are the pairings for complimentary base pairing?

Answer 9

A always pairs up with T

C always pairs up with G

Question 10

Proteins are polymers made up of what?

Answer 10

Amino acids

Question 11

What decides the order of amino acids in a protein?

Answer 11

It is the order of bases in a gene that decides the order of amino acids in a protein.

Question 12

What do the order of the base in a gene decide?

Answer 12

The order of amino acids in a protein.

Question 13

How many bases code for each amino acid?

Answer 13

Each amino acid is coded for by a sequence of three bases in the gene called a triplet.

Question 14

What amino acid does triplet AGG code for?

Answer 14

Arginine

Question 15

What amino acid does triplet CTT code for?

Answer 15

Leucine

Question 16

Where is DNA found?

Answer 16

In the cell nucleus.

Question 17

Why can’t the DNA move out of the cell nucleus?

Answer 17

Because it’s really big

Question 18

How does the cell get information from the DNA to the cell cytoplasm?

Answer 18

This is done using a molecule called messenger RNA (mRNA).

Question 19

What is mRNA?

Answer 19

A polymer of nucleotides but shorter (than DNA) and only one strand.

Question 20

What base does mRNA use instead of thymine(T)?

Answer 20

Uracil (U)

Question 21

What does uracil (U) pair with?

Answer 21

Adenine (A)

Question 22

Where are proteins synthesised?

Answer 22

In the cytoplasm

Question 23

Describe how proteins are made (4 stages)

Answer 23

1 The DNA contains the gene for coding the protein.
2 In the nucleus, the two DNA strands unzip. The DNA is used as a template to make mRNA. Base pairing ensures the mRNA is complementary to the opposite DNA strand.
3 The mRNA molecule then moves out of the nucleus and into the cytoplasm, where it attaches to a ribosome.
4 Amino acids are then joined together in the correct order by the ribosomes, following the order of the triplets in the mRNA. This makes the protein coded for by the gene.

Question 24

Explain how a gene codes for a protein. (2 marks)

Answer 24

Each triplet of bases in a gene code Doran amino acid (1 mark)
The order of triplets in a gene determines the order of amino acids in a protein (1 mark)