Chp 10-11 Worksheet Flashcards
What are the three parts of a nucleotide?
Phosphate group, pentose sugar, nitrogenous base.
What are three differences between DNA and RNA?
DNA is double-stranded, uses deoxyribose, and contains thymine; RNA is single-stranded, uses ribose, and contains uracil.
Why is DNA replication considered semiconservative?
Each new DNA molecule consists of one original and one newly synthesized strand.
What is the function of the origin and termination sequences in DNA replication?
Origin initiates replication; termination stops the process.
Why does the lagging strand form Okazaki fragments?
DNA polymerase synthesizes only in the 5’ to 3’ direction, creating discontinuous fragments on the lagging strand.
What enzymes are involved in forming the replication fork?
Helicase, topoisomerase, single-strand binding proteins (SSBs), primase.
What are the functions of RNA primase and DNA ligase?
Primase synthesizes RNA primers; ligase joins Okazaki fragments.
How do bacterial and eukaryotic DNA replication differ?
Bacteria have circular chromosomes with one origin; eukaryotes have linear chromosomes with multiple origins.
What are the three main genetic processes and their purposes?
DNA replication (copy DNA), transcription (mRNA from DNA), translation (protein synthesis).
Where do genetic processes occur in bacteria and eukaryotes?
Bacteria: cytoplasm; Eukaryotes: nucleus (DNA replication, transcription), cytoplasm (translation).
What is the Central Dogma of molecular biology?
DNA → RNA → Protein.
Why is the Central Dogma unidirectional?
Information flows only from DNA to RNA to protein. The processes of transcription (DNA to RNA) and translation (RNA to protein) are highly specific and rely on the precise sequence of nucleotides in DNA and RNA.
What are the three types of RNA and their functions?
mRNA (carries code), rRNA (forms ribosome), tRNA (transfers amino acids).
What are the stages of transcription?
Initiation, elongation, termination.
What are the stages of translation?
Initiation, elongation, termination.
What are the parts of the prokaryotic ribosome?
mRNA, large and small subunits, A site, P site, E site.
What occurs at the A, P, and E sites of the ribosome?
A: tRNA entry, P: peptide bond formation, E: tRNA exit.
What are the steps of conjugation?
Donor attaches via pilus, transfers plasmid, recipient becomes donor.
What is transformation?
Bacteria absorb foreign DNA from their environment.
What is transduction?
DNA transfer via a virus (bacteriophage).
What is the difference between horizontal and vertical gene transfer?
Horizontal: between organisms; Vertical: parent to offspring.
Why is horizontal gene transfer beneficial for bacteria?
It increases genetic diversity and adaptability.
How do bacterial and eukaryotic genomes differ?
Bacteria: circular, haploid; Eukaryotes: linear, diploid/polyploid.
How do bacterial and eukaryotic translation differ?
Bacteria: simultaneous with transcription, smaller ribosomes; Eukaryotes: separate from transcription, larger ribosomes.
What are the steps of binary fission?
DNA replication, cell elongation, septum formation, cell division.
Why is asexual reproduction beneficial and disadvantageous for bacteria?
Beneficial: rapid growth; Disadvantageous: low genetic diversity.
What is the complementary DNA for 5’-AUG-UCA-CAC-GAG-UGG-GUU-CUU-UGA-3’?
3’-TAC-AGT-GTG-CTC-ACC-CAA-GAA-ACT-5’.
What is the function of helicase?
Unwinds DNA by breaking hydrogen bonds.
What does DNA polymerase do?
Synthesizes new DNA strands.
What role does topoisomerase play?
Relieves supercoiling tension.
What is the function of single-strand binding proteins (SSBs)?
Prevents DNA strands from reannealing.
What signals RNA polymerase to start and stop transcription?
Promoter (start), terminator (stop).
What are start and stop codons in translation?
Start: AUG; Stop: UAA, UAG, UGA.
What is the genetic code?
A set of codons that specify amino acids.
How do mutations affect gene expression?
They alter DNA sequences, potentially changing proteins.
What is a plasmid?
Small circular DNA in bacteria that carries extra genes.
Why is the 3’-OH group important in DNA replication?
It allows DNA polymerase to add nucleotides.
What is the function of the F plasmid in conjugation?
Enables gene transfer between bacterial cells.
