The flow of genetic information from DNA to RNA to Protein

Genes control phenotypic traits through

The expression of proteins

The process by which genetic information is expressed involves two main steps:

transcription and translation

The synthesis of RNA from a DNA template. This process occurs in the nucleus of eukaryotic cells and results in the formation of messenger RNA (mRNA).

Transcription

The synthesis of proteins using the information carried by mRNA. This process occurs in the cytoplasm, where ribosomes read the mRNA sequence and assemble the corresponding polypeptide chain.

Translation

a region of DNA that can be expressed to produce a functional product, either a polypeptide (protein) or an RNA molecule.

Gene

describes the flow of genetic information within a biological system:

The central dogma of molecular biology

DNA is transcribed into

RNA

RNA is translated into

protein.

Genetic Information Written in Codons Is Translated into

Amino Acid Sequences

The sequence of nucleotides in DNA provides a code for

constructing proteins

The genetic instructions for the amino acid sequence of a polypeptide are written in DNA and RNA as a series of nonoverlapping three-base "words" called codons.

Triplet Code

The process of converting the nucleotide sequence of mRNA into the amino acid sequence of a polypeptide. This involves a change in language from nucleic acids to proteins.

Translation

the set of rules that dictates how the nucleotide sequence of mRNA is translated into the amino acid sequence of a protein.

The genetic code

Nearly all organisms use

an identical genetic code, highlighting the universality of this system.

Each codon (three nucleotides) specifies

one amino acid.

There are 64 possible codons (43), but only 20 amino acids, so

some amino acids are specified by more than one codon (redundancy).

A sequence of three nucleotides in mRNA that specifies an amino acid.

Codon

The RNA copy of a gene that carries genetic information from the DNA to the ribosome.

mRNA (messenger RNA)

The molecular machine that reads mRNA and assembles amino acids into proteins.

Ribosome