BIOLOGY 154 Lecture Notes - Lecture 2: Guanine, Cytosine, Chromosome

45 views6 pages
15 Sep 2016
Department
2 Molecular Biology
Genome
the complete set of genes or genetic material in a cell or organism
how life stores information
DNA
molecule that carries genetic information for most of life
only exception is viruses
composed of four different chemical units called nucleotide bases
adenine
guanine
cytosine
thymine
A-T and C-G pairs
sequence and pattern of DNA bases carries genetic information
nucleotide bases linked together by enzyme DNA polymerase
two DNA strands twist around each other to form double helix
Proteins
make up all the structural parts of life
machinery that gets everything done
making more DNA
a life form is mostly protein and water
genes are coding units for proteins
Roles of DNA in cell
1. Replication
a. used as template to make more DNA
b. inheritance
c. DNA replication generates mutations
c.i. leads to vaccine and drug challenges
c.ii. HIV does it differently than we do
c.ii.1. opportunities for new drug targets
2. Transcription
a. used to make an RNA copy of its genetic information (not make RNA)
b. make functional, non-coding molecules
Note
Both replication and transcription depend on complementarity
complementarity is the chemical affinity between bases such that the most stable
chemical form of a DNA double is is A-T and C-G
find more resources at oneclass.com
find more resources at oneclass.com
Unlock document

This preview shows pages 1-2 of the document.
Unlock all 6 pages and 3 million more documents.

Already have an account? Log in
DNA replication consists of enzymes (proteins) splitting apart the double helix and then using
the pattern of bases as a template to create the other strand
old strand used as template
if sequence of one strand of the DNA double helix know, then can predict the
complementary strand
end up with two helices from one helix
Polymerase Chain Reaction (PCR)
PCR uses complementary base pairs and DNA replication to isolate and amplify specific DNA
sequences
Pull out specific gene / DNA sequence from a very small source (hair or drop of blood)
can be used to find the very small amounts of HIV genome that is present in an infected
person’s blood
PCR is multiple rounds of DNA replication
melts the helix apart at high temperature
becomes single stranded
cool so primer starts replication in the area of interest
primer is the “hook” that is complementary to piece of DNA that you want to
pull out
taq polymerase extends
allow extension of new complementary strand until you have a new double stranded
region
melt and start all over again until amplified the region millions of times
Primer 1 and 2 for each strand and copies only in between where the two primers are
find more resources at oneclass.com
find more resources at oneclass.com
Unlock document

This preview shows pages 1-2 of the document.
Unlock all 6 pages and 3 million more documents.

Already have an account? Log in

Get OneClass Notes+

Unlimited access to class notes and textbook notes.

YearlyBest Value
75% OFF
$8 USD/m
Monthly
$30 USD/m
You will be charged $96 USD upfront and auto renewed at the end of each cycle. You may cancel anytime under Payment Settings. For more information, see our Terms and Privacy.
Payments are encrypted using 256-bit SSL. Powered by Stripe.