Y12 GENE EXPRESSION - nucleotides to redundant code

Stop codon

UAA, UAG, UGA - 3 nucleotides where transcription stops

Promoter

3 nucleotides on DNA where RNA polymerase attaches and unwinds it.

Terminator

Base sequence where transcription stops.

RNA polymerase

Enzyme causes DNA helix to unwind ahead of transcription

Pyrimidine

Bases such as thymine and cytosine (T + C). Has a single ring structure.

Coding strand

Strand of DNA where mRNA is an exact copy of this DNA strand (U instead of T). Not used for transcription.

Start codon

AUG - 3 nucleotides where transcription starts.

Nucleotide

Monomer of nucleic acids made up of a 5-carbon sugar, a phosphate group, and a nitrogenous base

Purine

Classification of bases such as adenine and guanine (A + G). Has a double ring structure.

RNA

Ribonucleic acid. A single strand nucleic acid important in protein synthesis

Uracil

Base found in RNA only. Present instead of THYMINE

Polypeptide

Long chain of amino acids joined together by peptide bonds

Transcription

Making of mRNA using free nucleotide base pairing against DNA template strand. DNA sequence in a gene is copied

Template strand

Free nucleotide base paid match this DNA strand during transcription.

mRNA

Single stranded polynucleotide which copies section DNA sequence to carry out of nucleus for proteins to be made. (messenger RNA)

Translation

Information carried by mRNA is converted into specific sequence of amino acids to form a polypeptide/protein

tRNA

Transfer RNA. Attaches to amino acids found in cytoplasm based on 3 bases on end of tRNA (anti-codon)

Codon

3 bases on mRNA read by anti-codons on tRNA to make proteins

Anti-codon

Group of three bases on a tRNA molecule that are complementary to an mRNA codon

Reductant code (redundancy):

Genetic code is referred to this as some codons (UUU, UUC..) code for same amino acid.

Only different in last base.