HB Protein Synthesis (Central Dogma)

Codon

three-nucleotide sequence on messenger RNA that codes for a single amino acid

Anticodon

group of three bases on a tRNA molecule that are complementary to the three bases of a codon of mRNA

RNA types

messenger, transfer, ribosomal

Transcription

synthesis of an RNA molecule from a DNA template

Translation

Process of synthesizing proteins from mRNA.

tRNA (transfer RNA)

The form of RNA that carries each amino acid to the ribsome to form the polypeptide chain (protein)

RNA polymerase

Enzyme that synthesizes RNA from DNA template.

post-transcriptional modification

the modifications that occur to an mRNA transcript. Include: splicing of introns, addition of 5' cap, addition on poly-A-tail and rearranging of exons

post-translational modification

Changes to the new protein that may be critical to its final function, like folding, phosphorylating or glycosylating

point mutation

Gene mutation involving changes in one or a few nucleotides.

frameshift mutation

mutation that involves the insertion or deletion of a nucleotide in the DNA sequence

translocation mutation

occur when a segment of DNA is swapped with a segment of DNA from another chromosome

inversion mutation

Mutation in which a chromosome piece reattaches to original chromosome but in reverse orientation

nonsense mutation

A mutation that changes an amino acid codon to one of the three stop codons, resulting in a shorter and usually nonfunctional protein.

duplication mutation

a type of chromosomal mutation in which a segment of DNA is copied multiple times in the genome

Number of codons

64

Number of amino acids

20

Introns

Noncoding segments of nucleic acid that lie between coding sequences.

Exons

Coding segments of eukaryotic DNA.

The site of transcription in eukaryotes

occurs in the nucleus

poly-A tail

a sequence of 50-250 adenine nucleotides added onto the 3' end of a pre-mRNA molecule

5' cap

A modified form of guanine nucleotide added onto the nucleotide at the 5' end of a pre-mRNA molecule.

Prokaryotic protein processing

not much modification because transcription and translation happen simultaneously

~linked geographically and molecularly

~no processing of mRNA

silent mutation

A mutation that changes a single nucleotide, but does not change the amino acid created.

chromosomal deletion mutation

large segment of DNA is lost from a chromosome