mutations
What is the difference between loss of function and gain of function mutations?
loss of function: causes protein to not work properly, usually is recessive
gain of function: typically acts as dominant
What three parts make up the transcriptional unit>
promoter, coding sequence, terminator
Where does RNA splicing take place?
nucleus
What are the three different types of RNA and what are their functions?
Ribosomal RNA- structural/functional components of ribosome
Messenger RNA- carries genetic code for proteins
Transfer RNA- helps incorporate amino acids into polypeptide chain
Explain the structure of an amino acid
alpha carbon, hydrogen, amino group (+H3N), carboxyl group (COO-), side chain
What is a reverse mutation?
a mutation that changes a mutant phenotype back to a wild-type phenotype
What are the two sequences involved with bacterial initiation of transcription?
-10 consensus sequence- Pribnow box
-35 consensus sequence
What are the three consensus sequences that are involved with RNA splicing
5' splice site (GU), 3' splice site (AG), branch point (an "A" 18-40 nucleotides upstream of a 3' splice site)
explain the central dogma
DNA to RNA to protein
primary- amino acids linked by peptide bonds
secondary- alpha helixes and beta sheets
tertiary-3-D protein structure
quaternary- 2+ polypeptide chains
What are two systems of DNA repair?
mismatch repair, direct repair, base excision repair, nucleotide-excision repair
RNA poly I: transcribes large RNAs
RNA poly 2: transcribes pre-mRNA
RNA poly 3: transcribes tRNAs
What are the 4 systems of mRNA modification?
addition of the 5' cap, addition of the poly-A tail, RNA splicing, RNA editing
Who proposed that genes and proteins are colinear?
Crick
What are the 4 stages of translation?
charging tRNAs, initiation, elongation, termination
Cystic Fibrosis and lactose intolerance are examples of _______ mutations
loss of function
What makes up the holoenzyme?
What are the two types of alternative processing?
alternative splicing and multiple 3' cleavage sites
what is the definition of a gene?
a set of nucleotides that specifies the amino acid sequence of a protein
What is the enzyme that is involved with charging tRNAs?
aminoacyl tRNA synthetase
What are three types of chemically induced mutations (mutagens) ?
base analogs, alkylating agents, deaminating chemicals, hydroxylamine, oxidative radicals, radiation, intercalating agents
What 5 things are needed for eukaryotic initiation of transcription?
transcription factors, basal apparatus, transcriptional activator proteins, enhancers, RNA polymerase II
What are the sizes of the large and small subunits of bacterial and eukaryotic rRNA?
bacterial: large-50S, small-30S (total-70S)
eukaryotic: large-60S, small 40S (total-80S)
Who came up with the "one gene, one enzyme" hypothesis?
Beadle and Tatum
What are the components needed for initiation of translation?
mRNA, small ribosomal subunit, large ribosomal subunit, initiation factors, fMet, GTP