RNA/transcription
What is the central dogma
refers to flow of genetic info: DNA --> RNA --> PROTEIN
What is semi conservative replication?
Each half of the original DNA molecule is joined with a new complementary DNA strand.
what is a genome? what are the 3 type sof dna it contains
haploid set of dna, unique, moderately rep, highly rep
Who first determined the stucture of dna
watson and crick
List 3 structural differences bt RNA and DNA
1. DNA nucleotides contain deoxyribose sugars, RNA nucleotides have ribose sugars
2. RNA has a free hydroxyl group on the 2'-carbon atom of the ribose sugar
3. thymine, one of the two pyrimidines found in DNA, is replaced by uracil in RNA
4. single stranded vs double stranded
Where does DNA replication begin on the chromosome and describe to roles of topoisomerase?
origin of replication.
topoisomerase relieves tensions of supercoiled dna
If don’t release tension, can break dna/ defragment dna - bloom's syndrome more prone to mutations/cancer
What is an SNP
most common form of genetic variation
What are the 4 bases? How do they pair up and how many bonds do they have? what type of bonds are they?
a/t 2 hydrogen bonds vs g/c 3 bonds sugar phosphate on outside.
What is the function of mRNA? Of tRNA?
What does the m and t stand for?
mRNA = messenger RNA, Carries genetic code for proteins
tRNA = transfer RNA, helps incorporate amino acids into eukaryotic polypeptide chain
What are the differences between synthesis of leading and lagging strand?
leading is continuous, lagging is discontinuos
what are the hardy Weinberg assumptions?
(1) random mating (i.e, population structure is absent and matings occur in proportion to genotype frequencies), (2) the absence of natural selection, (3) a very large population size (i.e., genetic drift is negligible), (4) no gene flow or migration, (5) no mutation,
What is the purpose of translation?
make protein
What is a promoter? What are the other 2 critical parts of the transcription unit?
1. promoter: DNA sequence that the transcription apparatus recognizes and binds to, indicates which of the two DNA strands is to be read as the template and the direction of transcription. The promoter also determines the transcription start site, the first nucleotide that will be transcribed into RNA
RNA coding region, Terminator
What are some differences from prokaryotes in the genome structure of eukaryotic cells that affect how replication takes place?
size of eukaryotic genomes req multiple origns, circular v linear, histone proteins
what alter genotype frequencies? Give an example
non random mating, inbreeding
What is the process of translation?
The mRNA attaches to a Ribsome. tRNA brings amino acids to the mRNA and they bond together to make a protein. The protein the breaks away form the ribsome.
List the steps of transcription in bacteria and briefly explain what occurs in each step
1. Initiation, in which the transcription apparatus assembles on the promoter and begins the synthesis of RNA
2. Elongation: DNA is threaded through RNA polymerase, and the polymerase unwinds the DNA and adds new nucleotides, one at a time, to the 3' end of the growing RNA strand
3. Termination: the recognition of the end of the transcription unit and the separation of the RNA molecule from the DNA template
What are telomeres and why do we need them?
ends of chromosomes, prevent erosion of genetic material, protective cap, prevent chromosomes from fusing together
What is a blast search?
tool to screen database to compare dna sequence with existing dna sequences
What is the process of Replication?
*2 strands of double helix unzip, forming replication forks
*New bases are added
*Each new DNA molecule has one original strand and one new strand
*DNA polymerase is an enzyme that joins individual nucleotides to produce a new strand of DNA
*DNA may be lost from the tips of chromosomes