Gene Expression and Regulation

These flashcards encompass key concepts, processes, and definitions related to gene expression and regulation as covered in the lecture notes.

What is the purpose of DNA in cells?

DNA provides the instructions that tell the cell what to do.

What process converts DNA to mRNA?

Transcription.

What is the role of mRNA in gene expression?

mRNA carries the nucleotide sequence from DNA, which is translated into protein.

During transcription, which strand of DNA is read?

Only one strand, known as the template strand.

What is the term for the process that translates mRNA into proteins?

Translation.

What type of RNA is synthesized from a gene coding for a protein?

Messenger RNA (mRNA).

What distinguishes RNA from DNA in terms of sugar?

RNA contains ribose, while DNA contains deoxyribose.

Which base in DNA is replaced by uracil in RNA?

Thymine.

How many codons signal to stop translation?

Three stop codons.

What is a codon?

A sequence of three nucleotides that codes for an amino acid.

Why are there only 20 amino acids from 64 possible codons?

Because multiple codons can encode the same amino acid, making the code redundant.

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

tRNA interprets the nucleotide language of mRNA and transfers the correct amino acid to the ribosome.

What is the first step of transcription?

Initiation, where RNA polymerase binds to the promoter region of DNA.

What occurs during transcription termination?

RNA polymerase encounters a termination signal and detaches from the DNA.

How does the ribosome function during protein synthesis?

It coordinates the pairing of tRNA anticodons with mRNA codons to synthesize proteins.

What mutation involves the substitution of one nucleotide for another?

Nucleotide substitution.

What type of mutation involves the insertion of additional nucleotide pairs?

Insertion mutation.

What type of mutation involves the deletion of nucleotide pairs?

Deletion mutation.

What is the significance of the methionine (met) tRNA?

It initiates the translation process by base-pairing with the start codon (AUG).