DNA/replication Flashcards
What are the three components of a nucleotide?
Nitrogen containing base
Pentose sugar
Phosphate group
Deoxyribose nucleic acid has?
Hydrogen on 2 prime end instead of OH
Ribose has?
Hydroxide (OH) on 2 prime end
Where is the phosphate group on a nucleotide
The 5 prime end
The 3 prime is what on a nucleotide
Nitrogen containing base
Purines are?
Adenine and guanine
Pyrimidines are ?
Cytosine
Thymine
What is DNA for
To replicate and utilize information
What do the hydrogen bonds do
Hydrogen bonds between complementary nucleotides is what keeps the two stands of DNA helix together
Antiparallel structure in DNA
Is when the DNA pairs with the opposing DNA stand, they are going In the opposite direction.
5’——-3’
3’——-5’
Who gets credit for the double helix?
Crick/ and Watson but Roslin was the one to discover (women)
Where does DNA replication start?
Origin of replication- this is where the two strands of DNA are spectated
What does topoisomerase do
It corrects “overwinding” ahead of the replication forks by breaking, swiveling, and rejoining DNA strands
Helicase
In DNA replication, this enzyme unzips the DNA helix structure resulting in a replication fork
Primase
Makes a small piece of RNA called a “primer” that allows DNA polymerase to begin
DNA polymerase
Adds DNA bases from 5’ to 3’ end one at a time
Okazaki fragments
Since DNA polymerase works 5 to 3 prime, the lagging strand that goes 5 to 3 prime need to be separated into chunks
DNA ligase
Seals DNA strands of the new replicated daughter and parent strands to make one continuous strand
Why is DNA replication semiconservative
Because each DNA molecule is made up of one conserved DNA strand and a new one
How many hydrogen bonds does T-A have
2
How many hydrogen bonds do G-A have?
3
Single strand binding proteins
Bonds to the single strand DNA and help stabilize
Radiation can do what to DNA
Cause a Thymine Dimer where they are bonded together
How many pairs of chromosome do we have
23 pairs, 46 total
22 are somatic
1 is sex
Base analogs
Are look alike to the base this is what chemotherapy is
How many enzymes help with DNA repair
50
Mutagen
Errors in the DNA that are not corrected
Interphase in cell cycle
What are the cell sub-phases
Primarily cell growth but not cell division. Most cells spend most of their time
Cancer is an exception to this
G1 is where cell grows
Synthesis- synthesizing of DNA
G2 cell grows and prepares to divide
Mitosis
Is active cell division
Division of nucleus
Eukaryotic cells
Syntheisis
Is where DNA replication occurs
G2 phase of interphase
Prepare for microtubials make 4 tubes
Cytokinesis
Is the division of cytoplasm
Meiosis
Produces sex cells( gametes
One copy of each chromosome
Centromere
Is where two sister chromatids are joined together to make one chromosome
What is a gene
A region of DNA
A specific sequence of nucleotides ( thousands of base pairs in length
How many genes do humans approximately have?
30,000 to 40,000
Where does transcription begin
Promoter TATA box
RNA polymerase recognizes it
Initiation of RNA for gene expression
RNA polymerase binds to promoter; DNA strands unwind then initiate RNA synthesis
Elongation in RNA synthesis
Polymerase moves downstream , unwinds DNA elongates transcript 5’ to 3’
