unit 6 Flashcards
primary sourse of hereditary material
Dna sometimes rna
dna is stored how
nitrogen base sequences
what do viruses use to encode genetic material
rna
pyrimidines
single structure (bases C,U,T)
conserved base pairing rules for dna and rna
pyrimidines only pair with purines
purines
double ring structure (bases A,G)
prokaryotic chromosomes
circular (smaller genome)
eukaryotic chromosomes
linear (larger genome)
plasmids
small extra chromosome, double strand, circular dna
prokaryotes plasmids are found in
cytosol
eukaryotic plasmids are found in
nucleus
what ensures continuity of hereditary info
dna replicaion
what allows transmission of a complete genmone to next generation that happens before cell division
genetic info copied
dna replication is
semiconcervative
semiconservative replication means
a dna molecule will contain one new and one original strand
influences replication process
directionality in dna
dna terminal phosphate group
5’ end
hydroxl terminus
3’ end
nucleotides can only be added in what direction
5’-3’ direction
dna polymerase
synthesis new stand of dna, requires rna primers, attaches to 3’ end
ligase
join dna fragments on the lagging strand
genetic info flow
dna-rna-protien
rna molecules used to
facilitate protien synthesis using dna info
ribosomes
contain rna and assembles protien
transcription
process where an enzyme directs the formation of a mrna molecule
during transcription
dna strands seperated, one becomes template stand other is a coding strand
template strand
depends on gene being transcribed
rna polymerase synthesizes
mrna in 5’-3’ direction by reading 3’-5’, copies gene by base pairing with noncoding strand
mrna
transcribed property of a gene
mRNA
carries genetic info to ribosome, then used to direct protien synthesis, condon (3 base sequence)
tRNA
recruited by ribosomes to create polypeptide directed by mrna, anti codon (3 base sequence of trna), anti codon+codon= growing polypeptide
rRNA
protien assemble, where pairing occures, created primart polypeptides
series of enzyme regulated mods to mRNA transcript in eukaryotes
- adding a poly-a tail(A bases, increases stablility, exporting from nuclues
- add GTP cap to other end- protect transcrpit and help attach to ribosome
interons
sequences of mRNA that dont code for amino acids not included in mature RNA
exons
sequences of mrna that code for amino acids, retained in rna processing, connected in mature mrna
alternative splicing
splicing introns and connecting exons, diff varitions of exon combos lead to diff protons
translation of mrna
polypeptide
translation occures on ribosome
prokaryotes- cytocolic
eukaryotes- + ER ribosomes
prokarytoic translation
occures while mrna is being transcribed
retrovirus
introduce viral rna into host -reverse transcriptace
-copies viral rna into vrial dna
-dna is incorperated into host genome
-reversible
translation relationship between rna molecules
trna-mrna-rrna adds to growing chain
initiation
rrna interacts with mrna at first codon
codon
3-amino acids
start codon
AUG- met
trna
bring correct amino acid to correct place directed by mrna
elongation- trna anti codon complements what
mrna codon
rna adds amino acid
trna brings amino acid
termination
stop codon is reached newly synthesized polypeptide is released
regulatory sequences
promote or inhibit protien synthesis, interaction with regulatory protiens
epigenetic changes are reversible modifications
histones tight or loose packing regulates gene acess
function in tissue function comes from
precense of protiens
transcription factors
promote or inhibit transcription
operons
prokaryotes closely linked genes that produce a single mrna during transcription
operator
inhibits or promotes transcription by binding with regulatory protiens
lac operon
considered causing it to be turned off
inducers
molecules that bind to regulatory protiens and cause a change of shape
glucose in lac operon
high other protiens low not present
promotors
dna sequences rna polymerase and transcription facrors bind to state tans.
horizontal acquisation
in prokaryotes transformation-transduction-conjugation- transposition
pcr
denature- primer- replicate dna
