Genetics Flashcards
What is the genome?
What makes up the genome of
1) Bacteria and eukaryotes
2) viruses
All genetic material of microorganism
- DNA chromosomes and plasmids
- DNA or RNA strands
What are chromosomes?
Neatly packaged DNA that contains genes
How do chromosomes come packaged in:
- Eukaryotes
- Bacteria
- protozoa/fungi
- Eukaryotes: Chromosomes in nucleus
- Bacteria: Circular chromosomes/plasmids
- Protozoa/fungi: Chromosome in nucleus/ plasmids
How do:
- Eukaryotes
- Bacteria
Package their chromosomes
- DNA around proteins, in nucleus,
- Diploid or Haploid
- Circular, single, haploid
What is a gene?
What are the three types?
Segment of chromosome that encodes protein or RNA
- Genes that encode proteins
- genes that encode RNA
- Genes that regulate
What is the difference in genotype and phenotype?
Genotype= Genetic makup
Phenotype= What you see
What are nucleotides?
What do they consist of?
Monomers of DNA
- A phosphate group
- A pentose sugar
- a nitrogenous base
How do prokaryote (bacteria) package their genome?
How many origins of replication do they have?
- Single,circular chromosome with multiple plasmids
- one origin of replication
How do eukaryotes package their genome?
How many origin of replication do they have?
- Multiple linear chromosomes with some plasmids (humans do not have plasmids)
- Many origin of replication
How do phosphate groups bind to nucleotides?
What elements make it up?
They are negatively charged
- Phosphorus with 4 oxygen atoms
How many phosphate groups do nucleotides typically have?
3
What is different about the pentose sugar of:
- DNA
- RNA
- DNA: has pentose sugar deoxyribose
- lacks a hydroxyl group
- RNA: Has pentose sugar ribose
How do different nitrogenous bases bind together?
A binds T via 2 hydrogen bonds
G bind C via three hydrogen bonds
What are they different types of nitrogenous bases?
Adenine (A)= purine
Thymine (T)= pyrimidine
Guanine (G)= purine
Cytosine (C)= pyrimidine
How do all the parts of nucleotdes bond together?
Pentose sugar binds directly to nitrogenous base by glycosidic bonds
Phosphate bonds to pentose sugar by phosphodiester bond
What are:
- Replication fork
- Replisome
- Place where DNA helix is unwound and strands are replicated
- 30 proteins involved in replicating DNA
What is transcription?
What is reverse transcription?
- Transcription: Conversion of DNA to RNA
- Reverse Transcription: conversion of RNA to DNA
What is different about RNA?
- its strands?
- Its nitrogen bases?
- Single Stranded
- Uses Uracil instead of thymine (binds to adenine)
What are the steps to transcription (bacteria)?
- Initiation
- Elongation
- Termination
What happens during the initiation of transcription?
- DNA double helix unwinds, forms transcription bubble
- RNA polymerase identifies transcription start site
What happens during Elongation phase of transcription?
- RNA polymerase adds nucleotides (substitute U for T)
- RNA polymerase moves along DNA and reforms double helix
What happens during the termination phase of transcription?
mRNA transcript is released
What is Translation replication?
RNA is used to synthesize proteins
How is mRNA read during translation?
- Read in triplet codons (3 nucleotides at a time)
- Each codone corresponds to specific amino acids
