40 terms

Genetics Exam 3

Transcription, Translation
STUDY
PLAY
ribose, uracil
Differences between rna and dna
mRNA
carries info from DNA and is template for polypeptide synthesis
rRNA
RNA molecules that are components of ribosomal subunits (4 in eukaryotes and 3 in prokaryotes)
tRNA
small RNA molecule that translates a codon into an amino acid in protein synthesis.
anticodon
three base sequence complementary to a specific codon in mRNA
RNA, proteins
DNA codes for ___, RNA codes for ____
transcription
making RNA strand from DNA
translation
making a polypeptide under the direction of an mRNA molecule
codon
sequence if three adjacent nucleotides in an mRNA molecule, specifying either an amino acid or a stop signal in protein synthesis.
c-value paradox
# of basepairs and the complexity of the organism have no correlation
deoxyribose, phosphoric acid, and a base
compenents of DNA
purine
A, G. Double ring.
pyrimidine
C,T. Single ring.
phosphodiester bonds
5'-3'-5'-3' bonds
3 bonds
how many hydrogen bonds on G-C
2 bonds
how many bonds are in A-T
semiconservative replication
both parental strands are maintained
replication origin
where replication begins
replication fork
where parental strands seperate and new strands start
initiation
generating a fork
helicase
hydrolyzes ATP to drive unwinding
single stranded binding protein
stabilizes the DNA strands after they split so they don't go back together
gyrase
swivel mechanism that relieves the stress of unwinding
exonuclease function
function of DNA polymerase that removes the last nucleotide in case of error
DNA ligase
stiches together the pieces of a lagging strand
1. recognize a single restriction site
2. recognized without regard to source of DNA
3. Number of cuts=number of restriction sites present
characteristics of restriction enzymes
dideoxy sequencing method
lacks the 3'-OH group so synthesis terminates. Used to show order of bases.
RNA polymerase
enzyme that initiates RNA synthesis. Doesn't need primer.
RNA polymerase I
type of polymerase in eukaryote that is used for ribosomal DNA
RNA polymerase II
transcribes all protein coding genes and some small nuclear RNAs
RNA polymerase III
transfer RNA, 5s component of ribosomal RNA
primary transcript
RNA molecule produced from DNA template. Sometimes serves as mRNA, but in Eukaryotes it's processed first
introns, exons, poly-a tail, cap
Compenents of mRNA splicing
spliceosomes
nuclear particles where RNA splicing takes place
snRNP's
small ribonucleo-protein particles U1, U2, U3, U5, U6
codon
3 adjacent bases in mRNA
anticodon
3 adjacent bases in tRNA
evidence for genetic code
3 bases inserted or deleted and proteins are still synthesized.
frameshift mutations
mutations that add or delete a base pair and shift the reading frame
wobble concept
the first two base pairs are what are most important in a codon, the third is more flexible.