Biology 1305 Chapter 17

What is pre-mRNA?

The initial RNA transcript that undergoes processing to become mRNA.

What signals the start of transcription?

Promoters signal the transcription start point.

What is the genetic code?

A set of rules that defines how the sequence of nucleotides in mRNA is translated into amino acids.

What happens during the elongation phase of transcription?

RNA polymerase adds nucleotides to the growing RNA strand.

What is the role of transcription factors?

They mediate the binding of RNA polymerase to the promoter.

What occurs during termination of transcription in eukaryotes?

RNA polymerase transcribes the polyadenylation signal and the RNA transcript is released.

What is the role of the release factor in translation termination?

It promotes hydrolysis when the ribosome reaches a stop codon.

What is a polypeptide?

A chain of amino acids that folds into a functional protein.

What is the significance of the 5' and 3' ends of mRNA?

They indicate the directionality for translation and transcription.

What is the structure of tRNA?

tRNA has an amino acid attachment site and an anticodon that pairs with mRNA codons.

What is the difference between bacterial and eukaryotic transcription termination?

Bacterial mRNA can be translated immediately, while eukaryotic mRNA undergoes processing.

What is the function of the small ribosomal subunit during translation initiation?

It binds to mRNA and helps recruit the initiator tRNA.

What are universal codons?

Codons that specify the same amino acid across different organisms.

What is the significance of the TATA box?

It is a DNA sequence that indicates where a genetic sequence can be read and decoded.

What is the process of RNA processing?

The modification of pre-mRNA into mature mRNA, including capping, polyadenylation, and splicing.