Nucleic Acids - Yr 1

Question 1

DNA

Answer 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 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.

Question 2

Nucleotide

Answer 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.

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

Organic base

Answer 5

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

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

Complimentary base pairing

Answer 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.

Question 8

Double helix

Answer 8

Structure of DNA made up of 2 strands of nucleotides running in opposite directions.

Question 9

Semiconservative replication

Answer 9

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 10

DNA helicase

Answer 10

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 11

DNA polymerase

Answer 11

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

Question 12

ATP (Adenosine triphosphate)

Answer 12

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 13

ADP

Answer 13

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

Question 14

ATP Synthase

Answer 14

An enzyme which catalyses the formation of ATP.

Question 15

ATP Hydrolase

Answer 15

An enzyme which catalyses the hydrolysis of ATP.

Question 16

Polymerases

Answer 16

Group of enzymes that catalyse the formation of polymers from monomers

Question 17

Specific heat capacity

Answer 17

The amount of energy needed to change the temperature of 1kg of the substance by 1℃.

Question 18

Latent heat of Vaporisation

Answer 18

The heat energy needed to change the substance from a liquid at its boiling point into gas at the same temperature.

Question 19

Cohesion

Answer 19

Attraction between molecules of the same type. It is important in the movement of water up a plant.

Question 20

Surface tension

Answer 20

The tension of the surface film of a liquid caused by the attraction of the particles in the surface layer by the bulk of the liquid.

Question 21

Solvent

Answer 21

The liquid in which a solute is dissolved to form a solution.

Question 22

Inorganic ions

Answer 22

Formed when an element or compound, that does not contain carbon, gains or loses electrons to become negatively or positively charged, for example: hydrogen ions, phosphate ions, iron ions and sodium ions.

Question 23

Transparent

Answer 23

A material that allows light to pass through so that objects behind can be distinctly seen.