Protein Synthesis and the Genetic Code

Flashcards about Protein Synthesis, Transcription, Translation, and the Genetic Code

Transcription

The synthesis of RNA using DNA as a template.

What is the role of RNA polymerase in transcription?

It binds to a site on the DNA, unwinds the DNA, moves along the template strand, positions RNA nucleotides, links RNA nucleotides by covalent bonds, and detaches the assembled RNA.

What is the antisense strand?

The strand of DNA that is used as a template for mRNA synthesis, having a complementary code to the mRNA.

What is the sense strand?

The strand of DNA that is not used as a template and has the same code as the mRNA (coding strand).

Why is the stability of DNA templates essential?

The sequence of bases must remain the same to express the gene into the right protein.

Gene expression

The process by which information carried by a gene has observable effects on an organism.

Genome

All of an organism's genetic material.

Proteome

The entire set of proteins expressed by a given cell, tissue, or organism.

Transcriptome

All the RNA molecules transcribed from a genome.

Cell differentiation

Involves switching on and expressing particular genes while not expressing others.

What does making a polypeptide mean?

Linking together amino acids in the correct sequence with covalent/peptide bonds.

Translation

The synthesis of polypeptides from mRNA.

What is the role of mRNA in translation?

Has a binding site that the ribosome can bind to and a sequence of codons that specifies the amino acid sequence, along with start and stop codons.

What is the role of tRNA in translation?

Has an amino acid attached to the 3’ end and an anticodon with 3 nucleotides complementary to the mRNA sequence.

What is the role of Ribosomes in translation?

Complex structure with a small subunit (mRNA binding site) and a large subunit (3 tRNA binding sites and a catalytic site).

What is Degeneracy (in the context of genetic code)?

Different codons can code for the same amino acid.

What is Universality (in the context of genetic code)?

The genetic code is used by all living organisms.

Gene mutation

A change in the sequence of bases in a gene, which can potentially change the structure of the polypeptide that the gene codes for.

What does sickle cell disease involve?

A genetic disorder caused by a mutation in both copies of a person's HBB gene.