DNA Structure (Lecture 8) Flashcards
What are the parts of a nucleotide?
Phosphate, Base, Sugar
What is the difference between a ribose and deoxyribose?
Ribose has two OH while deoxyribose has an OH and an H
What are purines and pyrimidines?
Purine has a double ring structure (Adenine and Guanine)
Pyrimidine is a single ring structure (Cytosine, Thymine, Uracil)
What does a Phosphate look like?
Adenine
Base symbol?
Nucleotide?
Nucleotide symbol?
Nucleoside?
Nucleoside symbol?
Adenine
Base symbol: A
Nucleotide: Deoxyadenosine 5’ monophosphate
Nucleotide symbol: dAMP
Nucleoside: Deoxyadenosine
Nucleoside symbol: dA
Guanine
Base symbol?
Nucleotide?
Nucleotide symbol?
Nucleoside?
Nucleoside symbol?
Guanine
Base symbol: G
Nucleotide: Deoxyguanosine 5’ monophosphate
Nucleotide symbol: dGMP
Nucleoside: Deoxyguanosine
Nucleoside symbol: dG
Thymine
Base symbol?
Nucleotide?
Nucleotide symbol?
Nucleoside?
Nucleoside symbol?
Thymine
Base symbol: T
Nucleotide: Deoxythymidine 5’ monophosphate
Nucleotide symbol: dTMP
Nucleoside: Deoxythymidine
Nucleoside symbol: dT
Cytosine
Base symbol?
Nucleotide?
Nucleotide symbol?
Nucleoside?
Nucleoside symbol?
Cytosine
Base symbol: C
Nucleotide: Deoxycytidine 5’ monophosphate
Nucleotide symbol: dCMP
Nucleoside: Deoxycytindine
Nucleoside symbol: dC
What is this strand called?
DNA polynucleotide strand
What is this strand called?
RNA polynucleotide strand
What kind of bonds do T-A pairs have? How many?
What kind of bonds do C-G pairs have? How many?
T-A pairs have two hydrogen bonds
C-G pairs have three hydrogen bonds
What kind of sugar does DNA have?
What kind of sugar does RNA have?
DNA had deoxyribose sugar (no oxygen here)
RNA has ribose sugar (an OH group here)
What is a phosphodiester linkage?
A phosphodiester linkage connects the 5’ - phosphate group and the 3’ -OH group of adjoining nucleotides
How do the two DNA strands run in correlation to one another?
The strands run in opposite directions; they are antiparallel
In RNA what replaces thymine (T)?
In RNA, uracil (U) replaces thymine (T)
DNA vs. RNA
Sugar?
Bases?
5’ end?
Size?
Strands?
Sugar
DNA is deoxyribose
RNA is ribose
Bases
DNA: A,T,C,G
RNA: A,U,C,G
5’ End
DNA: Monophosphate,
RNA: Triphosphate
Size
DNA: Very large
RNA: Smaller
Strands
DNA: Double
RNA: Single
What is the DNA backbone?
The DNA backbone is deoxyribose sugars linked by a phosphate
Eukaryotic Genome Organization
- DNA duplex is how big in diameter?
DNA duplex 2 nm in diameter
Eukaryotic Genome Organization
- Nucleosome fiber how big in diameter?
Nucleosome fiber 10 nm in diameter
Eukaryotic Genome Organization
- Chromatin fiber how big in diameter?
Chromatin fiber 30 nm in diameter
Eukaryotic Genome Organization
- Coiled chromatin fiber how big in diameter?
Coiled chromatin fiber 300 nm in diameter
Eukaryotic Genome Organization
- Coiled coil is how big in diameter?
Coiled coil 700 nm in diameter
Eukaryotic Genome Organization
- Condensed chromatid is how big in diameter?
Condensed chromatid 1400 nm in diameter
How we go from double-stranded DNA into a Metaphase Chromosome? (Or how to pack 2 meters of DNA into the nucleus of a cell)?
Histones/Histones removed
Info slide
DNA is interesting, but we are interested in changes in DNA that results in a new allele. What are these changes referred to as?
DNA is interesting, but we are interested in changes in DNA that results in a new allele. These changes are referred to as mutations.
The Importance of Mutations
What are mutations?
Mutations: sustainer of life and cause of great suffering
- Source of all genetic variation, which further provides the raw material for evolution
- Source of many diseases and disorders
The Importance of Mutations
What are mutations useful for?
- Useful for probing fundamental biological processes
- Identifying mutant genes that alter development are useful for identifying the function of that gene.
- Example, Wnt genes involved in patterning the vertebrate axis now known to be at the center of colon cancer.
Greater than 80% of all colon cancers are caused by mutations in how many genes?
Greater than 80% of all colon cancers are caused by mutations in just one gene, APC.
