Final Exam: Microbial Genetics Flashcards
What is the building block of nucleic acids
Nucleotide
What are nucleic acids composed of?
- an nitrogenous base
- five carbon sugar
- up to 3 phosphate groups
What are the 4 components of nucleic acids?
- purines
- pyrimidines
- sugars
- nucleotide
component of nuceic acids that have a 6 carbon ring
pyrimidines
component of nucleic acids that consists of 2 joined carbon rings with 5 and 6 members
purines
how are elements in a nitrogenous base labeled?
numerically
purines: 1-9
Pyrimidines: 1-6
How are elements in sugar labeled?
numerically with ‘
ex: 3’ or 5’
how is sugar connected to the nitrogenous base
position 1’
how is the nitrogenous base linked to position 1 of the sugar?
by glycosidic bond from N1 of pyrimidine and N9 of purine
A always matches with ___, by ____ hydrogen bonds?
T; 2
G always matches with ___, by ___ hydrogen bonds
C; 3
What is the central dogma of genetic info.
DNA –Transcription–> RNA–Translation–> Protein
What is the DNA coding/Sense strand?
has the same sequence as mRNA
What is the DNA template/Antisense strand?
directing synthesis of mRNA via complementary base pairing
In which direction is the DNA sequence read?
5’ to 3’
replication would produce two copies that each contained one of the original strands and one new strand.
Semi conservative replication
What are the 3 steps of synthesis of the leading and lagging strands of DNA?
- synthesis of Okazaki fragment
- Joining of okazaki fragment in lagging strand
- synthesis of new okazaki fragment
List the 5 steps in DNA Replication.
- Helicases unwind the parental double helix
- single stranded binding P stabilize the unwound parental DNA
- Leading strand is synthesized continuously in the 5’ to 3’ direction by DNA polymerase
- Lagging strand is synthesized discontinuously
- After RNA primer is replaced with DNA, DNA ligase joins the Okazaki fragment to the growing strand
Where is DNA found in a cell?
Nucleus
Where is RNA found in a cell?
Cytoplasm
Which type of ribosome is present in bacteria?
70S
what are the 2 subunits of the 70S bacterial ribosome?
50S and 30S
Which type of ribosome is present in mammals?
80S
What are the 2 subunits of the 80S mammalian ribosome?
60S and 40S
T/F Prokaryotic cells use a single RNA polymerase during transcription
T
T/F Eukaryotic cells use a single RNA polymerase during transcription
F. use RNA polymerase I,II,III
T/F. There are no introns used in prokaryotic transcription
T
T/F prokaryotic transcription is monotronic?
F. Polycistronic
T/F there is no 5’ cap in prokaryotic Transcription
T
How many nucleotides are there in each codon?
4 nucleotides and 20 AAs
changes in the sequence of DNA
Mutations
What are the 6 diff types of mutations
- spontaneous
- induced
- silent
- missense
- Nonsense
- Frameshift
Type of mutation where mutagens act directly by modifying a particular base or being incorporated into the nucleic acid
Induced mutation
Type of mutation where there is no apparent effect
Silent mutation
Type of mutation where there is a change in codon, Change in AA, and change in protein function
Missense mutation
Type of mutation where there is a change in a coding codon to a termination codon, resulting in premature termination
Nonsense mutation
Type of mutation inserting or deleting number of bp other than multiple of 3
Frameshift mutation
What are 4 ways of genetic transfer of bacteria?
- Transformation
- conjunction
- transduction
- transposition
What is transformation
acquisiton of new genetic markers by incorporation of added DNA
What is conjunction?
“mating” between 2 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
