Download Deoxyribonucleic Acid (DNA)

Deoxyribonucleic Acid (DNA)
The Information of Life
Pop Quiz: What do you know about DNA???
• What organelle is the “control center” of the
cell?
– Nucleus
• What structures are found in the nucleus?
– Chromosomes
• What are chromosomes composed of?
– DNA wrapped around proteins
• How do genes and chromosomes control the
activity of the cell?
– By producing proteins that regulate cellular
functions.
Pop Quiz: What do you know about DNA???
The Structure of DNA
• Long molecule made up of
___________.
• Three basic components:
– 5-carbon _____ (Deoxyribose)
– _________ group
– ___________ base
• ________ formed by sugar and
phosphate groups.
• Nucleotides can be joined together
in ____ order.
– Any sequence of bases is possible.
The Structure of DNA
• ___________ ____ determines type of
nucleotide.
• Two Families:
– Purines
• _______ and _______
– Pyrimidines
• ________ and _______
History of DNA
• ________ discovers DNA contains almost ____
percentages of ___________ _____ (____).
– _______ = _______ ; _______ = _______
• “Chargaff’s rules”
History of DNA
• ________ ________
identifies pattern of DNA
using _____ diffraction
(____).
– Did not reveal _________ of
DNA
– Showed strands in DNA were
_______ around each other.
• Shape of _____.
– Angle of ___ suggested ___
strands in structure.
History of DNA
• James ______ & Francis _____ (____)
– Discovered structure of DNA.
– Model was ______ _____.
• Two strands wrapped around each other (_______
______).
– Discovered ________ bonds could form between
___________ bases.
• _______ pairs with _______ (___ bonds)
• ________ pairs with ______ (______ bonds)
– Principle of ____ _______.
• Explained Chargaff’s rules
History of DNA
• James Watson &
Francis Crick
(1953)
– Discovered
structure of
DNA.
– Model was
double helix.
• Twisted ladder.
DNA and Chromosomes
• __________: DNA located in _______ in
form of ___________.
– Number _______ widely between _______.
– Humans = 46 chromosomes (23 pairs).
DNA Length
• DNA molecules are very ____.
• Prokaryote: DNA length = 1.6 mm; Cell size = 1.6
µm.
• DNA is ____ __ longer than cell.
• Eukaryotes
– DNA packed even more tightly.
• Over __ _ in length and contains over __ _______ base pairs!
• How is so much DNA folded into tiny
chromosomes?
Chromosome Structure
• Chromosomes consist
of ___ & _______.
– Packed tightly
together to form
________.
• DNA is tightly coiled
around proteins
known as ________
to form
____________.
– Pack with one
another to compact
further and form
_____ ______.
Chromosome Structure
• Chromatin in __________ = bowl of _________.
• Chromatin during _______ = __________ pairs
(__).
DNA Replication
• Structure Meets Function
– ___________ of DNA explained how it could be
___________.
• Each strand can be used to make the other
strand.
– ____ _______ allows for ______________ of
other half.
– ___________ strands.
DNA Replication
• Cell must _________ its DNA
before dividing.
– Each new cell has ________ set
of DNA molecules.
DNA Replication
• Cell must duplicate its
DNA before dividing.
– Each new cell has
complete set of DNA
molecules.
• DNA molecules
________ into ___
strands.
– Serves as ________ for
new strand.
DNA Replication
• Replication occurs
at ___________
_____.
– ________ of sites
in genome.
– Occurs in ____
directions.
• Why?
DNA replication animation
DNA Replication
• Replication carried
out by _______.
– “_____” DNA by
breaking ________
bonds.
– DNA __________
• Polymerizes
individual
___________.
• “_________” each
each new DNA strand
• Each new DNA
molecule has ___
_________ and ___
___ strand.
Real-time DNA replication