1-2 Protein Synthesis Flashcards
What is a gene?
A gene consists of a unique sequence of nucleotides that codes for a functional protein or an RNA molecule.
What are exons and introns?
Exons are coding segments of DNA, while introns are non-coding segments of DNA found in genes in eukaryotes.
What is transcribed and translated in eukaryotes in terms of introns and exons?
Both exons and introns are transcribed, but only the information in exons is translated to form a polypeptide.
Where does transcription occur in eukaryotic cells?
Transcription occurs in the nucleus.
What is the role of mRNA in protein synthesis?
mRNA carries the code from the DNA strand to the ribosome for translation into a polypeptide.
What are the roles of tRNA and rRNA in protein synthesis?
tRNA shuttles specific amino acids to the ribosome, while rRNA is involved in forming ribosomes.
How are DNA codons, RNA codons, anticodons, and amino acids related?
DNA codons are transcribed to RNA codons, which pair with tRNA anticodons to specify amino acids.
What is the directionality of DNA strands?
DNA strands are directional and are read 5’ to 3’.
What is the purpose of DNA?
The purpose of DNA is to act as a blueprint to make proteins required for a cell to function.
What is RNA?
RNA stands for ribonucleic acid and is made from RNA nucleotides.
How does RNA differ from DNA?
RNA is single-stranded, contains uracil instead of thymine, is a temporary store of genetic information, and contains ribose sugar.
What is the structure of transfer RNA (tRNA)?
tRNA has a 3D clover-leaf shape and is about 80 nucleotides long.
What is the function of tRNA?
tRNA transfers specific amino acids to the ribosome for polypeptide synthesis.
What is the composition of ribosomes?
Ribosomes are composed of 60% rRNA and 40% protein.
What are micro RNA (miRNA)?
miRNA are small RNA molecules, around 22 nucleotides long, that regulate gene expression after transcription.
What is the process of transcription?
Transcription is the process where the genetic message in DNA is copied into mRNA.
What happens during the formation of mRNA?
DNA unwinds, RNA polymerase adds complementary RNA bases, and mRNA elongates.
What are exons and introns in relation to mRNA?
Exons are coding regions that are translated into proteins, while introns are removed during mRNA processing.
What is translation?
Translation is the process of decoding mRNA to form an amino acid sequence.
What initiates the process of translation?
The start codon ‘AUG’ initiates translation.
What is the significance of the triplet code?
The triplet code allows 64 different combinations, sufficient to code for 20 amino acids.
What occurs at the ribosome during translation?
The ribosome scans mRNA, tRNA brings amino acids, and amino acids are joined by peptide bonds.
What is a stop codon?
A stop codon is a codon that does not code for an amino acid and terminates translation.
