Nucleic Acids Definitions

Question 1

Double Helix

Answer 1

the shape of a DNA molecule due to the coiling of the two sugar phosphate backbone strands into a right-handed spiral configuration

Question 2

Monomer

Answer 2

molecule that when repeated makes a monomer

• amino acids are monomers of protein
• nucleotides are the monomers of nucleic acid

Question 3

Nucleotide

Answer 3

molecule consisting of a five carbon sugar, a phosphate group and a nitrogenous base.

Question 4

Polynucleotide

Answer 4

large molecule containing many nucleotides

Question 5

DNA polymerase

Answer 5

enzymes that catalyse formation of DNA from activated deoxyribose nucleotides using single stranded DNA as a template

Question 6

Helicase

Answer 6

enzymes that catalyse the breaking of hydrogen bonds between the nitrogenous pairs of bases in a DNA molecule

Question 7

Semi-conservative replication

Answer 7

How DNA replicates this results in two new molecules each one of which contains one old strand and one new strand, the old strand is conserved in each molecule

Question 8

Gene

Answer 8

a length of DNA that codes for a polypeptide or for a length of RNA that is involved in regulating gene expression

Question 9

Polypeptide

Answer 9

a polymer that is made of many amino acid units joined together by peptide bonds - insulin is a polypeptide of 51 amino acids

Question 10

Protein

Answer 10

a large polypeptide of 100 or more amino acids - however the terms are often used synonymously and insulin may be described as a small protein

Question 11

Transcription

Answer 11

the process of making messenger RNA from a DNA template

Question 12

Translation

Answer 12

formation of a protein at ribosomes by assembling amino acids into a particular sequence according to the coded instructions carried from DNA to the ribosome by mRNA