2c:Genes and DNA replication Flashcards
What are nucleic acids?
Nucleic acids are information molecules that encode instructions for the synthesis of proteins.
What are the three main forms of RNA?
The three main forms of RNA are mRNA, rRNA, and tRNA.
What is the genetic code?
The genetic code is a universal triplet code that is degenerate and determines how genetic information is transcribed and translated into functional proteins.
What are the steps in gene expression?
The steps in gene expression include transcription, RNA processing in eukaryotic cells, and translation by ribosomes.
What is the structure of genes?
Genes are composed of exons, introns, and promoter and operator regions.
What is the prokaryotic trp operon?
The prokaryotic trp operon is a simplified example of a regulatory process in gene regulation.
What are amino acids?
Amino acids are the monomers of a polypeptide chain that form proteins.
What is the role of the rough endoplasmic reticulum and Golgi apparatus?
They are involved in the export of proteins from a cell via the protein secretory pathway.
What is the process of protein synthesis?
Protein synthesis involves transcription, RNA processing, and translation.
What occurs during transcription?
During transcription, the DNA sequence of the gene is copied into RNA nucleotides in the form of mRNA.
What is a codon?
A codon is a group of three adjacent RNA nucleotides that codes for a specific amino acid.
What are start and stop codons?
Start codons signal the initiation of translation (e.g., AUG), while stop codons signal termination (e.g., UAA, UAG, UGA) and do not code for an amino acid.
What is the structure of genes composed of?
Genes are composed of various components including a promoter region, introns, exons, termination sequences, and operator regions.
What is the significance of the genetic code?
The genetic code is universal, unambiguous, degenerate, and non-overlapping.
What is the role of DNA helicase?
DNA helicase unwinds DNA by breaking the hydrogen bonds between base pairs.
What is the leading strand in DNA replication?
The leading strand is replicated continuously from the 3’ end using a single RNA primer.
What are Okazaki fragments?
Okazaki fragments are short pieces of DNA synthesized on the lagging strand during replication.
What is the role of DNA ligase?
DNA ligase joins Okazaki fragments together to form a continuous strand.
What are telomeres?
Telomeres are repeated DNA sequences at the ends of chromosomes that protect them from fusion.
What is the function of telomerase?
Telomerase catalyzes the synthesis of telomere sequences at the ends of DNA.
