Microbial Genetics Flashcards
What is the building block, nucleotide, composed of?
- Nitrogenous base
- Five carbon sugar (ribose or deoxyribose)
- Three phosphate groups
Deoxyribose is in ___ and Ribose is in ____.
DNA, RNA
What are the five components of nucleic acids?
Purine Pyrimidines Sugars Nucleoside Nucleotide
True/False. Purines could be adenine or guanine and consist of two joined carbon rings with 5 and 6 members.
True.
What are the components of Pyrimidines?
Cytosine
Thymine
Uracil
A ____ has a phosphate added on the 5’ position and _____ has a sugar bound to a purine or pyrimidine base.
Nucleotide, Nucleoside
How many carbon rings make up pyrimidines?
six
Ture/False. The sugar of a nucleic acid is connected to the nitrogenous base via position 5.
False. Its connected via position 1
What connects the nitrogenous base of a nucleic acid to position 1 of the sugar?
Glycosidic bond from N1 of pyrimidine and N9 of purine
True/False. A always matches with T in 2 hydrogen bands and G always matches with C in 3 hydrogen bands.
True.
From which end is a sequence read from start to finish?
5’ to 3’ end
What does the coding or sense strand have the same sequence as?
mRNA
The template or antisense strand directs the synthesis of mRNA via ____.
Complementary base pairing
What is the first step of DNA replication?
The helicases unwind the parental double helix.
True/False. The leading strand is synthesized continuously in the 5’ to 3’ direction by DNA polymerase.
True
How is the lagging strand of DNA replication synthesized?
Synthesized discontiuously
What makes up the Okazaki fragment?
Primase synthesizes a short RNA primer which is extended by DNA polymerase
What happens after the RNA primer is replaced by another DNA polymerase during replication?
DNA ligase joins the Okazaki fragment to the growing strand
What pairs with Adenine in RNA?
Uracil
What is the location of both DNA and RNA?
DNA - Nuclear location
RNA - Cytoplasmic location
True/False. Prokaryotic cells are polycistronic or monotronic and Eukaryotic cells are polycistronic.
False. Prokaryotic are only polycistronic and Eukaryotic are polycistronic or monotronic.
Single RNA polymerase is a characteristic of _____ cells and RNA polymerase I, II, and III is a characteristic of _____ cells.
Prokaryotic cells, Eukaryotic cells
There are ___ nucleotides and ___ amino acids in each codon.
4 nucleotides and 20 amino acids
What changes the sequence of DNA?
Mutations
Can any base pair of DNA be mutated?
Yes
How do induced mutation mutagens act directly?
By modifying a particular base or being incorporated into the nucleic acid
What are silent mutations?
Mutations without apparent effect: there can be a base change in DNA without a change in amino acids or there can be a change in amino acids but no function change for protein
What occurs in Missense mutation?
There is a change in codon, amino acid and protein function
___ is a change in a coding codon to a termination codon, resulting in premature termination.
Nonsense mutation
Frameshift mutation
Inserting or deleting number of base pairs other than a multiple of 3
What is transformation?
Acquisition of new genetic markers by incorporation of added DNA
What is the “mating” between two bacteria involving transfer of genetic material?
Conjunction
_____ is the transfer of bacterial gene from one to another by a phage and ____ is the movement of a genetic material to a new site in the genome.
Transduction, Transposition
