sequence of DNA or RNA that provides the complete set of hereditary information
What is a chromosome?
a physical unit of the DNA genome
What is a gene?
a functional unit of the genome, a sequence of DNA that encodes an RNA that may encode a protein
how many pairs of chromosome are in human?
23 pairs
Who discovered transformation? and what is significant about it?
Frederick Griffith, Discover transforming principle, which is genetic material could be Protein or DNA.
Who determined that the transforming principle is DNA? How?
1. Avery-Macleod-McCarty
2. Purified material treated with enzymes that degrade protein and RNA-> Purified material retained. Purified material treated with DNA degrading enzyme -> material is destroyed
Who determined that DNA is the genetic material of viruses? is DNA the only genetic material for viruses?
1. Hershey & Chase
2. No, DNA and RNA
What is transfection?
When DNA is introduced to eukaryotic cells, they gain new trait.
What is a nucleoside? What is a nucleotide?
1. base and sugar
2. base, sugar, and phosphate
What is the sugar for DNA
Deoxyribose
What is the sugar for RNA?
Ribose
What are pyrimidine bases?
Thymine(T) and Cytosine(C)
Adenime(A), Guanine(G), and Uracil belong to what group of base?
Purine
What is the bond formed b/w the base and sugar of DNA?
Glycosidic
What bond forms b/w the sugar and the phosphate of DNA?
Phosphodiester bond
What made up the backbone of the Polynucleotide?
Sugar and Phosphate
What is a polynucleotide?
long chain of nucleotides linked by 5'-3' phosphodiester linkages
What are the different b/w DNA and RNA?
1. DNA doesn't have 2' OH, RNA does
2. DNA is double strand, and RNA is single strand
3. DNA has Thymine(T), and RNA has uracil(U).
Who proposed the the double-helix structure for DNA?
Watson and Crick
What 3 pieces of evidence were used to make the DNA double-helix?
1. X-ray from Rosalind
2. Density of DNA
3. Chargaff rule: proportion of G same as C, and A same as T
What made the DNA and anion?
The phosphate group
What is the result of base stacking of DNA?
forms a strong hydrophobic interaction b/w bases
What is the bonds form b/w complementary bases? how many bonds form b/w A-T and G-C?
Hydrogen bonds
A-T has 2 H-bond
G-C has 3 H-bond
how are bases of DNA pair? how are the two strands oriented?
A-T and G-C
Antiparallel
What is the most common conformation of DNA found in cell?
B-form
What is the Different b/w B form, a form, and z form of DNA
A form is found in DNA-protein complexes, right-handed, narrower and deeper major groove, and broader and shallow minor groove
B form major conformation found in cell, right-handed
Z form found in solution of high concentration of positively charge ions, left handed.
True/false. Supercoiling occurs in both open and closed DNA
False, Supercoiling occurs only in closed DNA, no free ends.
what consider to be closed DNA?
circular DNA (prokaryotes) and linear DNA (eukaryotes) anchored to a protein scaffold.
What is topology?
Overall comformation of DNA
What does Topoisomearase do?
remove DNA supercoiling
how many type of topoisomerase are there?
what are their functions?
2 types:
Type I topoisomerase produce single strand break, do not require ATP
Type II topoisomerase produce double strand break, require ATP
What is Gyrase?
type II topoisomerase found in prokaryotes
introduces negative supercoiling
what is topoisomers?
Same DNAs can be in different topology
What is a linking number of supercoiling DNA? what are linking number characteristic?
number of time a strand has to pass the other strand to completely separated.
Lk is always an interger and invariable in close DNA.
What is twist Number(Tw)?
The number of helical turns of one strand
What is writhing number(Wr)?
The number of crossovers of helical axis
What is negative supercoiling and positive supercoiling?
Negative supercoiling is twisting in the opposite direction to the two strands
positive supercoiling is twisting in the same direction as the two strands
if the change in LK is negative, what does this mean? if Change in LK is positive?
Change LK negative -> negatively supercoiled
Change LK positive -> positively supercoiled
true/false. Negative supercoiling can be converted into untwisting of the double helix
true
What state of supercoiling is thermophilic bacterial DNAs and why?
positively supercoiled
keep the DNA from denaturing at high temperature
What state of supercoiling does Nucleosome introduce to eukaryotes?
Negative supercoiling
Sequence of only one strand is often used to indicate DNA's genetic information. True/false
True
What is a sense strand and antisense strand?
coding
template
How are genetic information flow?
DNA->RNA->protein
What is the RNA that produce protein?
Messenger RNA (mRNA)
what regions must an mRNA have?
5'UTR, coding, and 3'UTR region
Bacterial transcription and translation occur in the same place. True/false
true
Bacteria translation starts after transcription is complete. True/False
True
Where do eukaryotic transcription occurs?
Nucleus
Where do eukaryotic translation occurs?
cytoplasm
What is the different b/w eukaryotic and prokaryotic gene?