Lecture 8: Microbial Genetics Flashcards
What is the study of:
-What genes are
-How they carry information
-How information is expressed
-How genes are replicated
Genetics
What is the study of genetics?
-What genes are
-How they carry information
-How information is expressed
-How genes are replicated
What is a segment of DNA that encodes a functional product, usually a protein?
Gene
What refers to all of the genetic material in a cell?
Genome
What is the molecular study of genomes?
Genomics
What refers to the genes of an organism?
Genotype
What refers to the expression of the genes, aka observable traits?
Phenotype
What are small circular molecules of DNA?
Plasmids
Do plasmids autonomously replicate?
Yes
What requires that it carry information required for their own replication, and often for one or more cellular traits
that are not essential for normal bacterial metabolism, growth or reproduction
and
can confer survival advantages?
Plasmids
What are fertility factors, resistance factors, bacteriocin factors, virulence plasmids, cryptic plasmids?
Types of plasmids
What type of genome structure is:
-genome in two structures (nuclear DNA and extranuclear DNA)
-several linear chromosomes
-Located in membrane bound nucleus
Eukaryotic genome structure
What type of genome structures is:
-genome in two structures (chromosomes and plasmids)
-circular chromosome
-located in the nucleoid, in cytoplasm
Prokaryotic genome structure
What is:
-the duplication of chromosomal and extrachromosomal DNAs
-Occurs before cell division
-Vertical transmission
DNA replication
Are DNA strands antiparallel?
Yes
What are adenine, thymine, cytosine, and guanine?
The polymer of nucleotides
DNA strands are double helix associated with what?
Proteins
What is the deoxyribose-phosphate to a DNA strand?
the “back bone”
What holds together strands between AT and CG?
Hydrogen bonds
What is this process:
-parental molecule
-separation of parental strands into templates
-formation of new strands complementary to template strands?
Semiconservative DNA replication
Is DNA replication bidrectional?
Yes
What is an anabolic polymerization process, requires monomers (nucleotides) and energy?
DNA replication
What replicates DNA in preparation for cell division?
DNA replication
What starts at the Origin of Replication (Ori), opened up by DNA helicase and copied by DNA polymerase III?
DNA replication
What is the flow of bacteria’s genetic information?
- Within a cell central dogma (they follow DNA to MRNA to protein)
- Between generations of cells (parental cells to daughter cells aka dna replication or vertical transmission)
- between cells of the same generation (horizontal transfer) occurs when the different cells share the same genetic information and join genetic information to create recombinant cells
What are these:
- Within a cell central dogma (they follow DNA to MRNA to protein)
- Between generations of cells (parental cells to daughter cells aka dna replication or vertical transmission)
- between cells of the same generation (horizontal transfer) occurs when the different cells share the same genetic information and join genetic information to create recombinant cells
the three different routes of the flow of bacteria’s genetic information
Which cell is capable of:
-transformation
-transduction
-conjugation
Recombinant cell from a horizontal transfer
What are double-stranded DNA made up of?
Nucleotides
Adenine pairs with what?
Adenine pairs with Thymine
Guanine pairs with what?
Guanine pairs with Cytosine
What compiles guanine, cytosine, adenine, and thymine?
the structure of DNA
Adenine and thymine pair with how many hydrogen bonds?
2 hydrogen bonds
Guanine and cytosine pair with how many hydrogen bonds?
3 hydrogen bonds
What is euchromatin?
loosely packed histone complex, region where histone complex are further apart and exposed certain gene segments and exposed are most likely to be transcribed by proteins in that cells
What is heterochromatin?
tightly condensed/ packed, the histone complex is not accessible so no transcription activity going on in this region
How are eukaryotic chromosomes packaged?
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double stranded DNA wrap around histones to create nucleosome, that is linked by linker DNA
Note size increase throughout the process
Are plasmids double stranded DNA?
Yes
What is the prokaryotic chromosomal packaging process like?
Don’t use histone, only histone-like protein.
These form loop anchor proteins, organizing the double helix DNA
The origin of replication in plasmids are driven by?
Promoter
Do certain promoters dictate the number of plasmids that a bacterial cell can have?
Yes
Mitochondrial DNA and chloroplast DNA refer to what?
Extranuclear DNA in eukaryotic genome structures
Will both strands be templates in DNA semiconservative replication?
Yes, both parental strands become templates
3’ hydroxl group
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Which enzyme that unwinds parental double helix at replication forks?
Helicase enzyme
Enzymes that participate in DNA replication
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Which enzyme binds to and stabilizes single-stranded DNA until it is used as a template?
Single-strand binding protein
Which enzyme relieves overwinding strain ahead of replication forks by breaking, swiveling, and rejoining DNA strands?
Topoisomerase enzyme
Which enzyme synthesizes and RNA primer at 5’ end of leading strand and at 5’ end of each Okazaki fragment of lagging strand?
Primase enzyme
Which enzyme uses parental DNA as a template, synthesizes new DNA strand by adding nucleotides to an RNA primer or a pre-existing DNA strand?
DNA polymerase III
Which enzyme removes RNA nucleotides of primer from 5’ end and replaces them with DNA nucleotides?
DNA polymerase I
Which enzyme joins Okazaki fragments of lagging strand; on leading strand, joins 3’ end of DNA that replaces primer to rest of leading strand DNA?
DNA ligase
How many locations for origin of replication for prokaryotic cells?
1 origin of replication location on each chromosome and on each plasmid
How many locations for origin of replication for eukaryotic cells?
Several origin of replications on 1 chromosome and 1 plasmid
What process is used to duplicate DNA and prepare for cell division?
DNA replication
What is the role of helix in the initiation of DNA replication?
Helicase will open up the DNA strand to unzip the double helix
What relieves the strain in a double stranded DNA during initiation of DNA replication?
Topoisomerase
What adds complementary RNA primer during initiation of DNA replication?
Primase-enzyme (5-10 bps)
What adds DNA nucleotides (dNTPs) that are complementary to the template DNA into the reaction during elongation?
DNA polymerase III
What is the process of leading strand synthesis?
Elongation
Describe the lagging strand synthesis (elongation)
Explain DNA polymerase’s proofreading activity
DNA polymerase proofread newly made DNA
Mismatched bases are pulled out and replaced
Nucleotide excision repair
Race between finishing replication and fidelity
What is it when enzymes correct errors in base pairing?
Mismatch repair
What is it when a nuclease cuts out and replaces damaged stretches of DNA?
Nucleotide excision repair
What are mutations from DNA replications called?
spontaneous mutations
What is an anabolic polymerization process, that requires monomers and energy (nucleotides)
DNA replication
What process starts at the origin of replication (Ori), opened up by DNA helicase?
DNA replication
What is the DNA replication overview?
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Explain DNA replication: rolling circle replication?
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What are the differences between prokaryotic vs eukaryotic DNA replication?
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What is the difference between mismatch repair vs nucleotide excision repair?
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