Topic 5: Protein Synthesis - Translation Flashcards
What is the difference between DNA and a gene?
DNA is the master blueprint that holds the code for protein synthesis. DNA directs the order of amino acids in a polypeptide. Genes are segments of DNA that code for a molecule that has a function.
What are the three types of RNA discussed in class and can you name their function?
Messenger RNA = Code for DNA template strand is copied with complementary base pairs resulting in a strand of mRNA. = Transcription
Transfer RNA = Have specific areas that contain specific triplet code that allows for tRNA to carry only a specific amino acid. Grows polypeptide
Ribosomal RNA = structural component of ribosomes. The organelle where protein synthesis occurs. Helps translate message from mRNA into polypeptide.
What is the immediate end product of Transcription in eukaryotes?
mRNA molecule
How many base pairs encode one single amino acid? What is the sequence called?
Three base pairs, called a codon
What is involved with pre-mRNA processing and why are each of these steps critical for proper protein synthesis?
5’ cap: Helps mRNA to be exported to be exported. Prevents degradation of mRNA. Assists ribosomal binding during translation.
Poly A Tail: prevents degradation of mRNA.
Splicing: splice out noncoding regions of RNA (introns) and bind exons together.
How is RNA processing different in prokaryotes and eukaryotes?
In prokaryotes, RNA processing happens in the cytoplasm. There is also as shine Dalgarno sequence tells where ribosomes where to bind because there are multiple start sites.
In eukaryotes RNA processing happens in the nucleus and has initiation factors that brings in the large subunit. Does not have shine Dalgarno sequences
Describe the role of introns and exons and how these and how these can create protein variability?
Introns are non-coding regions in the DNA removed by the spliceosomes. Alternative splicing puts exons together in different sequences creates different mRNA and proteins. The OG sequence can create many different proteins.
What is the role of tRNA?
have specific areas that contain specific triplet code (anticodon) that allows each tRNA to carry only a specific amino acid.
How does tRNA work with mRNA and ribosomes during protein translation?
anticodon of tRNA will complementary base pair with codon of mRNA at the ribosome adding its specific amino acid to growing polypeptide chain.
What are the three different sites of a ribosome and what happens at each of these site?
P site: holds the tRNA carrying the growing polypeptide chain
A site: holds the tRNA with the next amino acid to be added to the chain
E site: releases the tRNA from the ribosome
