3.3.1 Transcription

DNA replication

The process by which DNA is copied to allow cells to divide and produce replicates.

Helicase

An enzyme that unzips the DNA during the replication process.

Protein synthesis

The process where genes are exposed to produce proteins.

RNA polymerase

The enzyme that unzips DNA and helps in the synthesis of mRNA during transcription.

Genetic code

A sequence of bases in DNA that provides instructions for making specific polypeptides.

Transcription

The process of copying information from DNA into a new molecule of mRNA.

mRNA

Messenger RNA; the RNA molecule that transfers genetic code from the nucleus to the ribosomes for protein synthesis.

Template strand

The DNA strand that is transcribed to form the mRNA molecule.

Coding strand

The strand of DNA that carries the genetic code and has the same sequence as the mRNA.

Hydrogen bonds

Weak bonds between complementary base pairs in DNA that stabilize its structure.

Phosphodiester bonds

Strong bonds between adjacent nucleotides within a DNA strand.

Gene expression

The process by which specific genes are turned on or off to produce necessary proteins for the cell.

Codon

A sequence of three bases in DNA or mRNA that encode for a specific amino acid.

Stop codon

A codon that signals the termination of protein synthesis.

Complementary base pairing

The specific pairing of bases in DNA (A with T, C with G) that is essential during transcription.

Nuclear pores

Protein-based channels in the nuclear envelope that regulate the passage of molecules in and out of the nucleus.