Gene Expression

Anticodon

Three consecutive bases on the tRNA

Codon

Three consecutive bases on the mRNA

Deletion mutation

A mutation on the DNA where a base(s) is removed, resulting in a frame shift

DNA

Deoxyribose nucleic acid, A joins with T, C joins with G. Double stranded, helix shaped large molecule, a whole chromosome. Deoxyribose sugar

Enzyme

A folded protein which acts as a biological catalyst to speed up the rate of a chemical reaction in an organism

Frameshift

Change in bases that the ribosome reads

Gene

A piece of DNA which codes for the making of a protein / feature

Gene expression

The process where the instructions on our DNA are converted into a functional protein, includes transcription, translation and protein folding

Genotype

The genetic make-up of an organism for a feature

Insertion mutation

A mutation on the DNA where a base(s) is added resulting in a frame shift

Metabolic pathway

A series of enzyme-controlled reactions, where the product of one reaction becomes the substrate of the next

Missense mutation

A change of the base on the DNA which codes for a different amino acid. This may or may not alter the shape of the protein and therefore it's function

mRNA

Messenger RNA. Made during transcription in the nucleus. Carries the instructions to the ribosome to make a polypeptide chain. Contains codons

Mutagen

Environmental factor which causes the mutation e.g. agent orange, X-rays etc

Mutation

A permanent change in the bases on the DNA

Non-sense mutation

A change of the base on the DNA which changes the instructions, so a STOP codon occurs in the wrong place. Protein is greatly affected

Peptide bond

Bond formed between 2 amino acids during translation

Phenotype

The physical appearance of a feature

Point mutation

A change of only one or a few bases on the DNA

Protein

A substance made up of many amino acids joined together to form a polypeptide chain, which gets folded into a functional protein (enzymes are a type of protein)

Redundancy

The fact that multiple codons code for the same amino acid, e.g. CCU, CCC, CCA and CCG all code for the amino acid Pro

RNA

Ribonucleic acid. A bond with U and G bonds with C. Three types, tRNA, mRNA and rRNA. Single stranded and shorter than DNA. Sugar is ribose

Same-sense mutation

A change of the base on the DNA where the bases still code for the same amino acid. This is due to the redundancy of the genetic code

Silent mutation

A mutation that is neither favourable nor harmful, that remains in a population

Start codon

The start signals on the mRNA which initiates translation. Always AUG

Stop codon

These 3 codons on the mRNA (UAA, UAG, UGA) do not code for an amino acid therefore telling the ribosome where to stop translation.

Substitution mutation

A mutation where the base(s) on the DNA are swapped

Transcription

The process by which DNA going to mRNA, occurs in the nucleus. Controlled by RNA polymerase

Translation

The process by which mRNA going to polypeptide chain, occurs in the cytoplasm on the ribosome

Triplet

Three consecutive bases on the DNA

tRNA

Transfer RNA. Carries an amino acid to the ribosome. 3 bases on the mRNA = an anticodon