D1.2 - Protein Synthesis Flashcards
What is the role of RNA polymerase?
RNA polymerase catalyzes the synthesis of mRNA by reading the DNA template and building a complementary RNA strand.
What is translation in protein synthesis?
The process of synthesizing a polypeptide based on the genetic information encoded in mRNA.
What is a codon?
A sequence of three nucleotides in mRNA that corresponds to a specific amino acid.
What is the difference between free and bound ribosomes?
Free ribosomes synthesize proteins for use within the cell, while bound ribosomes produce proteins for secretion or incorporation into membranes.
What is the primary structure of proteins?
The linear sequence of amino acids in a polypeptide chain, determined by the genetic code.
What is reverse translation?
The process of deducing possible mRNA and DNA sequences from a given amino acid sequence.
What are the three main steps of transcription?
- Initiation: RNA polymerase binds to the promoter. 2. Elongation: RNA strand is synthesized. 3. Termination: Transcription stops at a termination sequence.
What is transcription in protein synthesis?
The process of copying genetic information from DNA into a complementary RNA molecule, specifically mRNA.
Where does translation occur?
Translation occurs on ribosomes, which are composed of proteins and ribosomal RNA.
What is the start codon in translation?
The start codon is usually AUG, which signals the beginning of translation.
What does degeneracy in the genetic code mean?
Multiple codons can code for the same amino acid.
What is the function of tRNA in translation?
tRNA molecules bring amino acids to the ribosome and have an anticodon that pairs with the mRNA codon.
What are the steps of translation?
- Initiation: Ribosome binds to mRNA and recognizes the start codon. 2. Elongation: tRNAs bring amino acids, forming peptide bonds. 3. Termination: A stop codon is reached, and the polypeptide is released.
What are stop codons?
Stop codons (UAA, UAG, UGA) signal the termination of translation.
How does protein synthesis differ in prokaryotes and eukaryotes?
In prokaryotes, transcription and translation occur simultaneously; in eukaryotes, transcription occurs in the nucleus and mRNA is processed before translation.
