Unit 1 - DNA and the Genome - Structure of DNA

Question 1

Nucleic Acids

Answer 1

Nucleic acids are a group of molecules made of the same basic sub unit - the nucleotide.

Question 2

Nucleotide composition

Answer 2

Base (usually shown as rectangle)
Sugar (usually shown as a pentagon)
Phosphate (usually shown as a circle)

Question 3

Genetic information

Answer 3

Genetic information is stored via the base sequence. This sequence determines the shape and functions of proteins produced in the ribosome.

Question 4

DeoxyriboNucleic Acid composition

Answer 4

Two chains of nucleotides, twisting in the infamous double helix shape. Held together by the hydrogen bonds between bases (weak), and the sugar-phosphate backbone (strong)

Question 5

Prime ends of sugar

Answer 5

Sugar bonds with its own phosphate on 5’ end and to another phosphate on 3’ end.
(5’ end is on 4th corner of pentagon, don’t get confused)

Question 6

Sugar- phosphate backbone

Answer 6

Strong chemical bond between phosphate of one nucleotide and the 3’ carbon in the sugar of another nucleotide joins nucleotides together to form a chain or strand.

Question 7

Polynucleotides

Answer 7

Long chains of nucleotides.

Question 8

Bases

Answer 8

4 different pairs - 
Adenosine (A-T)
Thymine (T-A)
Cytosine (C-G)
Guanine (G-C)
Bases are described as being complementary to one another (match up)

Question 9

DNA base pair rules and bonds

Answer 9

Joined by weak hydrogen bonds between complementary base pairs.
Adenine always joins to Thymine
Cytosine always pairs with Guanine

Question 10

Antiparallel Strands

Answer 10

When hydrogen bonds form between bases of polynucleotide strands, the strands run in opposite directions. (One strand from 5’ to 3’ and the other from 3’ to 5’)