1.5: Nucleic acids and their functions

Adeninosine triphosphate

What ATP stands for.

ATPase

The enzyme that hydrolyses the bond between the second and third phosphate in ATP.

30\.6

The amount of kJs that one mole of ATP releases.

Phosphorylation

The addition of phosphate to ADP.

ATP synthetase

The enzyme that reverses ADP and an inorganic phosphate ion to ATP via a condensation reaction.

Watson and Crick

Recieved a nobel prize for discovering the structure of DNA.

Deoxyribose Nucleic Acid

What DNA stands for.

Nucleotide

Contains one phosphate, a sugar and an organic base.

Polynucleotides

Multiple nucleotides held together in a strand.

Adenine and thymine

Has two hydrogen bonds formed.

Cytosine and guanine

Has three hydrogen bonds formed.

Purines

What the largest bases are known as, adenine and guanine, due to their two nitrogen containing rings.

Pyrimidines

What the smallest bases are known as, thymine and cytosine, due to their single nitrogen containing rings.

Anti-parallel

Strands that run in opposite directions

Ribonucleic acid

What RNA stands for.

Uracil

Replaces thymine in RNA.

Messenger RNA

What mRNA stands for.

Transfer RNA

What tRNA stands for.

Ribosomal RNA

What rRNA stands for.

Cloverleaf

The shape tRNA creates.

Semi-conservative

Replication used by DNA.

DNA helicase

Enzyme used to split the hydrogen bonds between the bases.

DNA polymerase

Matches and lays down nucleotides to build the new daughter strand.

DNA ligase

Binds together DNA fragments by forming phosphate bridges.

Meselson and Stahl

Proved semi-conservative replication.

N14

Nitrogen isotope used in normal DNA.

Filial

What F stands for in genetics, e.g. F1, F2.

Exergonic

Reaction that releases energy.

Endergonic

Reaction that takes in energy.

Triplet code

A code of three bases that codes for a specific amino acid.

Codon

Term for one triplet code.

Degenerate

Term that means some amino acids can have more than one triplet code.

Met

Start code.

Transcription

The creation of mRNA using a template strand of DNA.

Translation

Creation of a polypeptide chain using mRNA and tRNA.

RNA polymerase

Forms bonds between ribonucleotides aligned at the template strand.

Exons

Parts of a DNA strand that code for polypeptides.

Introns

Parts of a DNA strand that do not code for polypeptides.

Endonucleases

Used by RNA polymerase to remove introns.

Anti-codons

Complementary amino acids that correspond to a codon.

Initiation

Phase of translation where codon and anti-codons meet and create hydrogen bonds.

Elongation

Phase of translation where peptide bonds are catalysed and the tRNA detaches for another to take its place.

Amino acid activation

Process in which an amino acid binds to tRNA, requires ATP.

Termination

Phase of translation where the ribosome-mRNA-polypeptide complex separates.

Polysome

When multiple ribosomes are attached to one mRNA strand, each producing a separate polypeptide.

One gene one-polypeptide

Hypothesis that explains how DNA encodes information.

Density gradient centrifugation

Process used by Meselson and Stahl to prove semi-conservative replication, where tubes are spun and viewed under UV light and move depending on their density in the caesium chloride solution.

Caesium chloride

Solution used by Meselson and Stahl in the density gradient centrifugation to prove semi-conservative replication.

Adenine and guanine

The purines - the two largest bases due to their two nitrogen containing rings.

Cytosine and thymine

The pyrimidines - the two smallest bases due to their single nitrogen containing ring.

Nitrogenous base, pentose sugar and a phosphate group

What do all nucleotides contain?

Pre-mRNA

What a mRNA strand is known as before the introns are removed.