Protein Synthesis: Transcription Flashcards

Questions and Answers

What are the steps of transcription?

Termination (correct)

Elongation (correct)

Initiation (correct)

Translation

What happens during initiation of transcription?

The RNA polymerase binds to a DNA molecule at the promoter region (the TATA box).

What happens during elongation of transcription?

RNA binds to DNA and reads the DNA strands, using one strand of DNA as a template to assemble nucleotides into mRNA.

What happens during termination of transcription?

RNA polymerase reaches a spot of DNA called the termination signal, and the mRNA and RNA polymerase release from the DNA. Signup and view all the answers

What is the process that makes the nucleotide chain functional?

mRNA processing Signup and view all the answers

What happens during mRNA processing?

Introns are snipped out, ligase rejoins the exons, and a guanine triphosphate cap and a poly A tail are added. Signup and view all the answers

What happens during translation?

mRNA makes proteins. Signup and view all the answers

What are the sites for tRNA attachment called?

E, P, and A sites. Signup and view all the answers

What is the start codon?

AUG, it adds the amino acid MET. Signup and view all the answers

What are the stop codons?

UAG, AAA, UGA. Signup and view all the answers

How many amino acids and codons are there?

20 amino acids and 64 codons. Signup and view all the answers

What happens during initiation during translation?

Ribosomes attach to the mRNA at the start codon, and tRNA molecules bring in amino acids to match the codons. Signup and view all the answers

What happens during elongation during translation?

New tRNA fills the A & P sites of the ribosome, and amino acids are added to the polypeptide chain. Signup and view all the answers

What happens during termination during translation?

The ribosome reaches a stop codon and mRNA releases from the ribosome. Signup and view all the answers

Study Notes

Transcription Process

Transcription involves three main steps: initiation, elongation, and termination.

Initiation of Transcription

RNA polymerase binds to the promoter region of DNA, particularly at the TATA box.

Elongation of Transcription

RNA reads the DNA strands using one strand as a template and assembles nucleotides to form mRNA.

Termination of Transcription

RNA polymerase encounters a termination signal, leading to the release of mRNA and the polymerase from the DNA strand.

mRNA Processing

This process modifies the nucleotide chain to make it functional by removing introns (non-coding sequences) and joining exons (coding sequences).
A guanine triphosphate cap is added to the 5' end, while a poly A tail is added to the 3' end, allowing the mRNA to exit the nucleus into the cytoplasm.

Translation Process

During translation, mRNA directs the synthesis of proteins.

tRNA Attachment Sites

The ribosome has three sites for tRNA attachment: E (exit), P (peptidyl), and A (aminoacyl).

Start Codon

The start codon is AUG, which signals the incorporation of the amino acid methionine (MET) into the growing polypeptide chain.

Stop Codons

There are three stop codons: UAG, UAA, and UGA, which signal the end of protein synthesis.

Codons and Amino Acids

There are 64 possible codons, which code for 20 different amino acids.

Initiation of Translation

Ribosomes attach to mRNA at the start codon, facilitating the delivery of amino acids by tRNA that match the codons.

Elongation During Translation

New tRNA molecules fill the A and P sites of the ribosome, resulting in the sequential addition of amino acids to the growing polypeptide chain.

Termination During Translation

The process concludes when the ribosome reaches a stop codon, leading to the release of mRNA from the ribosome, completing protein synthesis.

Description

Explore the essential steps of transcription in protein synthesis with these flashcards. Each card details critical processes such as initiation, elongation, and termination to enhance your understanding of molecular biology.