Ch 13 Flashcards
genome
the complete collection of genes in a bacterial cell
gene
unit of heredity, a DNA sequence
T/F: plasmids are not part of the nucleoid
true
plasmids
small DNA molecules that carry genes that are not essential, but may be helpful
T/F: plasmids are living
false
what shape do plasmids have?
circular
DNA and RNA are polymers of
nucleotides
nucleotides are linked together by ________ bonds
phosphodiester
Purines have a double/single ring
double
Pyrimidines have a double/single ring
single
Purines: Adenine, Guanine, Cytosine, Thymine, Uracil
Adenine
Guanine
Pyrimidines: Adenine, Guanine, Cytosine, Thymine, Uracil
Cytosine
Thymine
Uracil
A and T(U) pair by 2/3 H bonds
2
C and G pair by 2/3 H bonds
3
Positive supercoiling tightens/loosens DNA strands
tightens
Negative supercoiling tightens/loosens DNA strands
loosens
T/F: tightly wound DNA is better for replication and transcription
False
DNA in most bacteria is circular/linear
circular
replicon
portion of the genome that contains an origin and is replicated as a unit
replication fork
where DNA is unwound
Replisome
12 proteins involved in replication
Helicase
unzips DNA by disrupting H-bonds
DNA synthesis is (5’ to 3’) / (3’ to 5’)
5’ to 3’
Enzymes require:
- a template
- a primer
- dNTPs
dNTPs
deoxynucleotide triphosphates
(dATP, dTTP, dCTP, dGTP)
Topoisomerases
prevents supercoiling by unwinding double helix
Primase
synthesizes short complementary strands of RNA primers
The lagging stand
the antiparallel strand to the leading strand
DNA ligase
forms phosphodiester bond between 3’ -OH and 5’ phosphate
enzyme used for DNA proofreading
DNA polymerase III
what is a catenane
2 circular DNA fragments linked together like a chain
the ___ strand of DNA directs mRNA synthesis
template
Promoter
binding site for RNA polymerase located at the start of the gene
Shine-Delgarno sequence
helps initiate translation by aligning ribosome with start codon
