|
Nucleic Acids
Components
(Nitrogen) Bases
Purines
Adanine
Guanine
Double Ring
Pyramidines
Cytosine
Uracil
Thymine
Single Ring
Made from rings of Carbon and Nitrogen
Bases Pair through hydrogen bonds
A complementary with T (double bond)
G complementary with C (triple bond)
bases changed together through pentose sugar
ribose
with oxygen
deoxyribose
with out oxygen
Base + a Sugar = Nucleoside
e.g. adenosine
throw in 3 phosphor = ATP (aka the universal high energy carrier)
as in cAMP
second messenger
eg. guaninosine
as in GTP
used in proten synthesis
carbohydrate metabolims
secondary messengers
eg. cytosinosine
as in CTP
Base + Sugar + Phosophor = Nucleotide
polynucleotides = multiple Nucleotides = DNA or RNA
phosphor can link to sugars to each other allowing for these nucleotide chains
Nucleotides are acids
AMP, TMP, UMP, GMP = RNA acid composition
dAMP, dTMP, dCMP, dGMP = DNA acid composition
RNA
Bases Used
A, G, U, C
Definition
differences between DNA and RNA
Double vs Single Stranded
T vs U
dR vs R sugar
chains of nucleoside 5' monophosphates
joined via 3'5' phosphodiester bonds
strands bound through hydrogen bonds to form the double helix are anti-parallel (5'->3' on side, 3' ->5' on other side)
DNA
Bases Used
A, G, T, C
Strands of DNA held together by hydrogen bonds between bases
Genetic information stored as sequence of basis along chain
DNA sequences only code how to make proteins
proteins are amino acids chained together
3 bases together code an amino acid
= codon
introns - that do not contain info
exons - contain info for an acid
64 total present in DNA (in any organism)
61 Amino acids
3 Stop codes
degenerate - several codes for same amino acid possible
a sequence of codons to produce a protein is a gene
gene expression - process of creating the protein
6.4 x 109 base pairs
20 - 30 thousand genes
DNA is folded into certain structures (p. 182)
chromatin
DNA + Proteins (histones)
5 types of histones
H1, H2a, H2b, H3, H4
general mess of DNA when not organized in to chromosomes
nucleosome
core of 4 histones + DNA wrapped around this core
nucleofilament
H1's used to create tighter packing together of nucleosomes
nucleofilaments are then coiled/twisted
chromosomes
chromatin sections organized in to recognizable arangements
46 total = 23 pairs
only present during cell division
DNA Replication
process of making copies of DNA
each strand is copied separately = semi-conservatively
ie. unzipped and each side copied
1. DNA aProtein
melts the DNA (splits the hydrogen bonds)
at origin of replication - start of copy alone
requires ATP
2. DNA Helicase
continues break/melt of DNA
requires ATP
3. SSBP
Single Stranded Binding Proteins
Prevents DNA strands from reconnecting during replication
covers/binds to open strands
4. Primase (RNA Polymerase)
places section of RNA on to open strand
RNA primer needed before DNA can be made
5. DNA Polymerase III
Creates the complimentary strand of DNA, ie. performs the copy
DNA after primer
6. DNA Polymerase I
removes RNA primers and replaces it with DNA
| 
