GENE EXPRESSION : REGULATION
cells Store info in DNA's nucleotide sequence
↳ transmitted via cell division
31 1 Nucleic Acids encode
.
genetic information in their nucleotide sequence
·
2 types of nucleic acids :
DNA (deoxyribonucleic acid) RNA (ribonucleic acid),
o
RNA key role in protein synthesis pyrimidine bases
regulating gene expression
= :
+
NHz
·
covalently bonded nucleotide chain
·
Nucleotide made up of : 5C sugar,
3 either
nitrogenous
deoxyribose
base, + phosphate group
or ribose
No cytosine (C
0-
--p-0-CH0 MyCONH
(AGvore
Base nucleotides connected via phosphodiester bonds
·
-
thymineThe
I
H
↳
when phosphate group of nucleotide is covalently I
phosphate
of o bonded to sugar unit of another nucleotide
unc
group
Ribose sugar to form sugar-phosphate backbone
0 DNA long double-stranded helix
·
=
-O-P-0-CHe Base (A G T orD) pairs
"complementary purine bases :
I
O pairing between
, ,
base
I
↑ -↑
C C
purines pyrimidines (A-T G C) for DNA Ni
I
-
+
↓
,
phosphate
oit
C
it
>
-
A-T has 2 H-bonds, G-c has 30G-C is
stronger Fr guanine (G)
group
NN
·
RNA complementary base pairs is A-U , G C
-
Deoxyribose sugar DNA doesn't have any restriction adenine
·
on nucleotide
sequence
>
-
near infinite combinations
31 2 Genetic information
.
typically flows from DNA to RNA to protein
I
DNA Parent DNA's helix "unzips" as H-bonds are broken , two
·
·Taughtends
Replication
original strands =
templates for new daughter strands
Information· DNA's info determines protein's shape = function
Flow
Transcription
-
the process by which RNA is synthesized from DNA
#
copied in "same language"
·
>
-
nucleotides
·
Translation -
the process by which a protein is synthesized from DNA
changing "languages" nucleotides that make up nucleic acids - amino acids that make up proteins
·
-
·
central dogma =
basic flow of info in all DNA- > RNA >
- proteins