Class notes Intro to biology

Amino N-R Hydroxyl R
-
OH



Carboxyl R-con Phosphate
R-0-
Carbonyl R-cadm-co Sylfhydryl R-



5 Carbon


Suga
Nitrogenous base

pyrimidines : one
ring (cytosine thymine uracil
, ,




Purines : two viny (ademine , guanine


Draw DNA sugar us RNA sugar
Ribose




i
in RNA

G' O

Ha
H


P H
I




Only 3 Structures in Nucleic Acids


yers .
1 primaryStructure : Sequence e A , T, C , G



-
hydrophilic

nadrophobic
Secondary
.
2 structure : local double stranded
folding : DNA
-
2 Sugar phosphates on outside

3
i Carbon backbone
-




·
S -

Backbones are anti parakel
-
Purine always pares wl pyrimidine


-At
Cell membranes are selective barriers 3. tertiary structure : Overall
folding
-
DNA wraps around proteins called history

-
Strands coil and compact into sorral levels of organization




⑳
Does not based on structure
-

cherry ,
primary



Compare DNA vs RNA
DNA : RNA :
Deoxyribose Ribosa
-




-
double strandel -

single stranded


enotypePhoea
-




Selectivepermeabilitya -very stable
-

self replicates
-




-
less Stable

transcribed from DNA



X How does the secondary structure of DNA




-amom
Store information so well ?

-
Base pairing : Complementary base pairing and stability
molecules
-

CompactS tructure : twisted doublehclix



Watson and Cricks model of DNA
31
5
- Hydrogen
G ...




- Gr ...

How Substances more across lipid
/
bilayers
-
...
a
sion




solutes
1
. T-.. a
separation of
3
gi



Diffusion
2 .




Chargafs we are
3


Equilibriummore
.




or
How Substances
move acros




·
hyper tonic : higher concentratio of soluty


hypotonic : lower concentration of solute

isotonic : equal concentration of solutes