1.3 DNA and Production of Proteins

Question 1

Describe the structure of a DNA molecule

Answer 1

DNA is a double stranded helix held together by complementary base pairs

Question 2

Identify the four bases that are involved in determining the DNA code of an organism

Answer 2

Adenine (A)
Thymine (T)
Cytosine (C)
Guanine (G)

Question 3

State the base pair rule and describe how the two complementary strands of a DNA molecule are held together

Answer 3

Adenine bonds with Thymine (Apple Tree)
Cytosine bonds with Guanine
(Collins, Gemma)

The bonding between the complementary base pairs hold the two strands of the DNA molecule together like the rungs of a ladder. REMEMBER; Straight letters go together and curly letters go together

Question 4

State the function of the genetic code contained within a DNA molecule

Answer 4

The DNA code is contained within the sequence of the bases. The base sequence of a gene determines the amino acid sequence in the protein that it codes for

Question 5

Identify the term used to describe a section of DNA which codes for one protein

Answer 5

A section of DNA which codes for one protein is called a gene

Question 6

State the function of a ribosome

Answer 6

Ribosomes are the site of photosynthesis where the mRNA strand is “read” and an amino acid chain is built

Question 7

Describe the role of messenger mRNA in protein synthesis

Answer 7

Messenger mRNA carries a complementary copy of the DNA gene code from the nucleus to a ribosome

Question 8

Identify the simplest sub-unit of a protein

Answer 8

The simplest sub-unit of a protein is an amino acid. A protein is a long chain made up of repeating sub-units called amino-acids. There are 20 different types of amino acid sub-unit in proteins