Microbial Genetics Flashcards
What is the building block of nucleic acid?
nucleotide
- composed of a nitrogenous base, a five-carbon sugar, and up to three phosphate groups
Describe purines and pyrimidines
purine: 2 ring, adenine or guanine
pyrimidine: 1 ring, cytosine or thymine/uracil
What is the central dogma of genetics?
DNA ->(transcription)-> RNA ->(translation)-> Proteins
Describe the two strands of DNA in transcription/replication
coding/sense strand: same sequence as mRNA
template/antisense strand: directing synthesis of mRNA via complementary base pairing
Explain the actions of the leading and lagging strands
leading strand is synthesized continuously in 5’->3’ direction by DNA polymerase
lagging strand is synthesized discontinuously in the 3’->5’ direction
- primase synthesizes short RNA primer which is extended by DNA polymerase into Okazaki fragmets
What is Spontaneous mutation?
random mutations in the background that are always happening
What are Induced mutations?
mutagens act directly by modifying a particular base, or being incorporated into the nucleic acid
What is a Silent mutation?
mutations without apparent effect
What is a Missense mutation?
a change in codon, which causes a change in amino acid, which causes a change in protein function
What is a Nonsense mutation?
change in coding codon to a termination codon, so premature termination
What are Frameshift mutations?
inserting or deleting a number of base pairs other than 3
What is Transformation?
acquisition of new genetic markers by incorporation of added DNA
(uptake of DNA)
What is Conjunction?
mating between two bacteria involving transfer of genetic material
What is Transduction?
transfer of bacterial gene from one to another by a phage
What is Transposition?
movement of a transposon to a new site in the genome
