2.1.3 Protein synthesis

Codon

Codon

A sequence of three nucleotide bases in DNA or mRNA that codes for a specific amino acid during protein synthesis.

Gene

A segment of DNA that contains the instructions for producing a specific polypeptide or functional RNA molecule.

Triplet code

The genetic code where a sequence of three nucleotides (codon) codes for one amino acid.

Non-overlapping

Refers to the characteristic of the genetic code where each nucleotide is part of only one codon, allowing for flexibility in amino acid sequences.

Degenerate

The property of the genetic code where multiple codons can code for the same amino acid, increasing redundancy and mutation tolerance.

Universal

Describes the feature of the genetic code where the same codons code for the same amino acids in almost all living organisms.

Start codon

The specific codon (AUG) that signals the beginning of protein synthesis and the incorporation of the amino acid methionine.

Stop codon

Codons (UAA, UAG, UGA) that signal the termination of protein synthesis, leading to the release of the polypeptide chain.

Transcription

The process of synthesizing mRNA from a DNA template in the nucleus.

Translation

The process of decoding mRNA to build a polypeptide chain in the ribosome.

mRNA

Messenger RNA that carries the genetic information from DNA to the ribosome for protein synthesis.

tRNA

Transfer RNA that brings specific amino acids to the ribosome based on the codons on mRNA during translation.

DNA

Deoxyribonucleic acid, the molecule that carries the genetic instructions for the development, functioning, growth, and reproduction of all known organisms.

Sense strand

The DNA strand with a sequence matching the mRNA (except for T and U) during transcription.

Antisense strand

The DNA strand used as a template during transcription to synthesize mRNA.

Template strand

The DNA strand used by RNA polymerase to synthesize mRNA during transcription.

Ribosome

A cellular organelle where protein synthesis occurs, composed of rRNA and proteins.

Mutation

Changes in the DNA sequence that can lead to alterations in the structure and function of proteins.

Point mutation

A mutation affecting a single nucleotide, which can be substitutions, deletions, or insertions.

Frame shift

A type of mutation caused by insertions or deletions of nucleotides, leading to a shift in the reading frame during translation.