Chapter 7 Microbial Genetics Flashcards
DNA
deoxyribonucleic acid
-encodes the genetic instructions used in the dvlpt and functioning of all known living organisms and many viruses
Genetics
the study of inheritance and inheritable traits as expressed in an organisms genetic material
Genome
- entire genetic complement of an organism
- includes its genes and nucleotide sequence
Phosphodiester bonds
covalently bonded pentose molecules that connects the sides of the DNA ladder
-strong
Nitrogenous bases
Adenine
Thymine
Guanine
Cytosine
Complementary Bases
Adenine-Thymine/Uracil
Guanine-Cytosine
Prokaryotic Genome
- Nucleoid: circular DNA
- plasmids
- RNA + ribosomes
- haploid
Haploid
single chromosome copy
-one copy of each genes
Plasmids
- small circular pieces of DNA that replicate independently
- separate from nucleoid
- not essential for normal metab, growth, + reproductions
- survival advantage
types of Plasmids
1 fertility factors
2 resistance factors
3 bacteriocin factors
4 virulence plasmids
Fertility Factors Plasmids
ability to produce sex pilus
Resistance Factors Plasmids
R factors,
antibiotic resistance
Bacteriocin Factors Plasmids
toxins produced by bacteria to inhibit growth of other closely related bacteria
Virulence Plasmids
code of virulence factors
DNA replication
- generates a complementary structure of the 2 strands of DNA
- semiconservative
- anabolic polymerization process
Process of Bacterial DNA replication
- begins at origins site
- DNA polymerase replicates DNA from 5’ to 3’
- Strands are antiparallel new strands are synthesized differently
- -leading strand is synth continuously
- -lagging strand is synth discontinuously
Genotype
set of genes in the genome
-genotype determines phenotype
Phenotype
physical features and functional traits of the organism
Gene Function
- TRANSCRIPTOIN
- TRANSLATION
- CENTRAL DOGMA OF GENETICS
TRANSCRIPTION
information in DNA is copied as RNA
TRANSLATION
polypeptides are synthesized from RNA
-participants: mRNA, tRNA, ribosomes+ rRNA
Central Dogma of Genetics
- DNA is transcribed to RNA
- RNA is translated to form polypeptide
transcription + translation in bacteria
cytoplasm
-coupled: transcrip+translat happen at the same time
3 steps of Transcription
1 initiation
2 elongation
3 termination
- all stages require additional protein factors
- initiation + elongation require energy (GTP)
transcription + translation in bacteria
- occurs in cytoplasm
- coupled: transcrip+translat happen at the same time
Nucleoid
- prokaryotic version of nucleus
- circular DNA
transcription in eukaryotes
- RNA transcription occurs in nucleus
- -3 types of RNA polymerase, numerous transcription factors
- mRNA is processed before translation
where is the location of DNA in prokaryotes
in nucleoid of cytoplasm and in plasmids
histones are found in_____
bacteria, archaea, or eukarya
histones are found in archaea and eukarya
type of nucleic acid in bacteria
circular or linear dsDNA
semiconservative
-new DNA is composed of 1 original + 1 daughter
anabolic polymerization process
- requires monomers + energy (ATP)
- deoxyribonucleotides (dGTP) serve both functions
Leading Strand
- continuous synthesis
- creating 5’ to 3’ starting on 5’
Lagging strand
- discontinuous synthesis
- creating 5’ to 3’ starting on 3’