Nucleic Acids

Question 1

Deoxyribonucleic acid which is present in nearly all living organisms as the carrier of genetic information. A double helix made up of two polynucleotide chains, running antiparallel to each other, with the negative sugar-phosphate backbone on the outside and organic bases bonded together by Hydrogen bonds in the centre of the helix. The nucleotides have a deoxyribose sugar and the bases adenine, thymine, guanine or cytosine.

Answer 1

DNA

Question 2

Complex chemicals made up of an organic base, a sugar and a phosphate. They are the basic units of which the nucleic acids DNA and RNA are made.

Answer 2

Nucleotide

Question 3

Polynucleotide

Answer 3

A polymer of monomers called nucleotides.

Question 4

Phosphodiester bond

Answer 4

The bond formed by a condensation reaction between the phosphate group of one nucleotide and the pentose sugar of another nucleotide.

Question 5

Part of a nucleotide - either adenine, thymine, cytosine, guanine or uracil.

Answer 5

Organic base

Question 6

RNA

Answer 6

A polynucleotide which contains nucleotides that have the pentose sugar ribose rather than deoxyribose and contains the bases adenine, uracil, guanine or cytosine. Can be either mRNA, tRNA or rRNA.

Question 7

Specific rules for how the bases pair together. Adenine pairs with thymine with 2 hydrogen bonds. Guanine binds with cytosine with 3 hydrogen bonds.

Answer 7

Complimentary base pairing

Question 8

Semiconservative replication

Answer 8

The process in which the double helix of a DNA molecule unwinds and each strand acts as a template on which a new strand is constructed.

Question 9

DNA helicase

Answer 9

Enzyme that acts on a specific region of the DNA molecule to break the hydrogen bonds between the bases causing the two strands to separate and expose the nucleotide bases in that region

Question 10

Enzyme that joins DNA nucleotides together in a condensation reaction (forming phosphodiester bonds) during DNA replication.

Answer 10

DNA polymerase

Question 11

ATP (Adenosine triphosphate)

Answer 11

An activated nucleotide found in all living organisms, which is produced during respiration and acts as an energy carrier. The hydrolysis of ATP (catalyzed by ATP hydrolase) leads to the formation of adenosine diphosphate (ADP) and inorganic phosphate, with the release of energy.

Question 12

A nucleotide which combines in a condensation reaction, catalysed by ATP synthase, with a phosphate molecule to form ATP.

Answer 12

ADP

Question 13

An enzyme which catalyses the formation of ATP.

Answer 13

ATP Synthase

Question 14

An enzyme which catalyses the hydrolysis of ATP.

Answer 14

ATP Hydrolase

Question 15

Group of enzymes that catalyse the formation of polymers from monomers

Answer 15

Polymerases