DNA Flashcards
What is DNA
a biological molecule that stores instructions for building proteins, the building blocks of life
what is DNA made up of
nucleotides that are linked together to form long chains.
- phosphate group
- deoxyribose sugar
- nitrogen base (Adenine, Guanine, Cytosine, Thymine)
what are the sugars and phosphates for
they make up the backbone of the DNA
how do nucleotides form DNA
Nucleotides ‘stack’ one on top of another.
What does DNA look like
DNA ladder twists to form the double helix structure.
what does A pair with
T
what does C pair with
G
how does DNA store information
- DNA is a code
- the nitrogen bases form a sequence which are instructions for a protein
what direction is DNA synthesized in
5’ to 3’
leading strand
continuous synthesis along the 3’ to 5’ parent template
(contuniuous)
lagging strand
staggered synthesis along the 5’ to 3’ template.
(pieces)
where are new nucleotides added
to the 3’ end of the growing strand
helicase
unwinds/unzips template DNA
primase
adds a small piece of RNA (primer: “signal” to start building new DNA here) to the template strands
DNA polymerase
- removes the primer
- begins to build/synthesize new strands –> it adds free nucleotides to the 3’ end of the new DNA strand 5’–> 3’
DNA ligase
“molecular gluer” that joins together fragments on the lagging strand
Single strand binding proteins (SSB’s)
holds the the strands from binding back together
