microbial genetics Flashcards
Genome
sum of all cells genetic material
genomics
the study of an organisms complete set of genetic material
Genetics
Study of hereditary
What are chromosomes made up of?
DNA: made of nucleotides
-Deoxyribose
-Nitrogenous base (AT, CG)
-phosphate group (backbone)
Difference between genotype and phenotype
genotype: genetic makeup of cell/organism
Phenotype: expression of genes as a trait
What does anti-parallel stands mean?
the sugar phosphate backbone on one strand is upside down relative to the other strand (5’ end 3’ end)
What is the 5 prime end and 3 prime end?
-5 prime end- attached to a phosphate group
-3 prime end- hydroxyl group (oxygen and hydrogen)
Replication of DNA
What does it mean that DNA is semi-conservative?
Each parental strand act as a template for new daughter strand. One strand is kept from parent.
DNA is always synthesized from which end to which end?
5’ to 3’ end of the new strand
Why cant strands be replicated the same way?
Because they are anti-parallel from each other. DNA polymerase can only move from 5 to 3’ end.
What happens during the lagging strand?
-DNA polymerase has to synthesize backwards
-multiple RNA primers and DNA polymerase
-synthesized discontinuously (Okazaki fragments) by DNA ligase
What does DNA polymerase do and RNA primer do in DNA Replication?
DNA polymerase- adds nucleotides to new DNA strand
RNA primer- initiates the 5’3 direction
Bacterial DNA replication
bi-directional replication of a circular DNA molecule
Transcription
DNA to RNA (mRNA is made)
mRNA
Read by Ribosomes to make proteins, carries coding info
tRNA
carries individual amino acids to the ribosomes
rRNA
reading order of amino acids and linking them together
Where is transcription made in eukaryotes and prokaryotes
Eukaryotes- occurs in nucleus
Prokaryotes- occurs in cytoplasm
During transcription what enzyme is used, what direction does it move and where does it start?
DNA dependent RNA polymerase binds to a promoter, moves in 5’3 direction
RNA has ____ instead of _____
Uracil instead of thymine
AU CG
Translation
RNA to protein
Language of mRNA is in form of ______
Codons 1 set of 3
How many sets of codons are there? Where is the start and stop? Amino acids?
-64 sets or 61
-Start: AUG–> methionine
-Stops: UAA , UAG, UGA
20 amino acids
Why are there so many codons for the same amino acids?
In case of a mutation, amino acid does not change then protein will not change
