Gene Expression: From Transcription to Translation

These flashcards cover key concepts related to gene expression, focusing on the processes of transcription and translation, as well as mutation types and effects.

What is the process of translating mRNA into a polypeptide called?

Translation.

What enzyme is responsible for synthesizing pre-mRNA from a DNA template?

RNA polymerase.

What are the key molecular components of translation?

mRNA, tRNA, and rRNA.

Who cracked the Universal Genetic Code in 1966?

Marshall Nirenberg and Heinrich Matthaei.

What are the three stages of translation?

Initiation, Elongation, Termination.

What is a codon?

A three-nucleotide sequence in mRNA that specifies a particular amino acid.

What is the role of transfer RNA (tRNA) in translation?

tRNA brings the appropriate amino acids to the ribosome, matching its anticodon with the mRNA codon.

How is a tRNA 'charged' with the correct amino acid?

By enzymes known as aminoacyl-tRNA synthetases.

What terminates the translation process?

A stop codon (UAA, UAG, or UGA) and release factors.

What are point mutations?

Changes to single bases in the DNA sequence.

What type of mutation replaces a codon with a stop codon?

Nonsense mutation.

Define a silent mutation.

A change in a codon that does not result in a change in the amino acid.

What is the primary structure of a protein?

The sequence of amino acids joined by peptide bonds.

What process involves the addition of amino acids one by one to a growing polypeptide chain?

Elongation.

What is a mutation?

A change in the nucleotide sequence of a genome.

What do initiation factors (IFs) do during translation?

They aid in the initiation process of translation.

What is the function of ribosomes?

To synthesize polypeptides by catalyzing the formation of peptide bonds.

What is the role of elongation factors (EFs) in translation?

They assist in the elongation stage by facilitating codon recognition and peptide bond formation.

What happens during the termination stage of translation?

The polypeptide is released and the translation assembly disassembles.

What is the effect of frameshift mutations?

They often cause extensive changes to the amino acid sequence due to the shifting of the reading frame.