Concept
14
.
4
:
Translation
is
the
RNA-directed
synthesis
of
a
polypeptide
Molecular
components
of
translation
·
Trans fer
RNA-
transfer
amino
acids
from
the
cytoplasmic
pool
of
amino
acids
to
a
growing
polypeptide
in
a
ribosome
↳
by
synthesizing
them
from
other
compounds
or
by
taking
them
up
from
the
surrounding
solution
↳
a
cell
keeps
cytoplasm
stocked
with
all
20
amino
acids
-
↳
the
ribosome
adds
each
amino
acid
brought
to
it
by
a
tRNA
to
the
growing
end
of
a
polypeptide
↳
made
of
proteins
and
RNAs
The
structure
and
Function
of
Tran sfer
RNA
51
into
a
certain
amino
acid
·
ex
:
codon
=
5
:
66c
-
3
base-pairs
with
a
particular
complementary
codon
on
an
MRNA
molecule
anticodone
3'-CCG-5'
single
RNA
strand-80
nucleotides
long
Written
3
+
G
each
+RNA
is
used
repeatedly
-
pickup
amino
acid
,
deposit
onto
polypeptide
at
·
transcribed
from
DNA
templates
i
ribosome
,
leave
ribosome
and
get
ready
to
start
over
and
Tyr-tRN A
·
accurate
translation
of
a
genetic
message
requires
two
instances
of
molecular
recognition
↳
Aminoacy)-tRNA
synthetases
:
an
enzyme
that
joins
each
amino
acid
to
the
appropriate
tRNA
↳
20
,
join
each
amino
acid
to
the
right
tRNA
·
20
↳
charged
tRNA
1
.
The
amino
acid
and
the
appropriate
tRNA
enter
the
active
site
of
the
specific
Synthetase
2
.
Using
,
ATP
,
the
synthetase
catalyzes
the
covalent
bonding
of
the
amino
acid
to
its
specific
+RNA
3
.
The
tRNA
charged
with
its
amino
acid
,
is
released
by
the
Synthetase
second
,
pairing
of
the
tRNA
anticodon
wh
appropriate
codon
anticodon
OntR
ne
Tyu
codon
on
MENA
·
Wobble
-
flexibility
in
the
base
pairing
rules
in
which
the
nucleaticle
at
the
Send
e
of
a
fRNA
anticodon
can
form
hydrogen
bonds
with
more
than
one
kind
of
base
in
the
③
-
third
position
(s'
end)
of
a
codon
·
In
ex
:
3'-UCU-S
'
SAGAJ
Argin
See
The
structure
and
function
of
Ribosomes
Next
amino
acid
to
be
·
URNA
=
most
abundant
type
of
QNA
W
L
-
added
to
polypeptide
chain
A
stimAbiding
st
a
sing
size
use
para
subunit
=
*
small
subunit
MRNA
↓
With
codon
in
A
site
binding
site
MRNA
Building
a
Polypeptide
·
translation
=
initiation
,
elongation
,
and
termination
↳
all
require
protein
"factors"
,
energy
through
GTP
hydrolysis
·
Ribosome
Association
and
Initiation
↳
brings
together
an
MRNA
,
a
tRNA
bearing
the
first
Amino
acid
of
the
polypeptide
,
and
the
two
subunits
of
a
ribosome
I
.
small
ribosomal
Subunits
binds
to
an
MRNA
Jrequires
initiation
factors
2
.
The
arrival
of
a
large
ribosomal
subunit
completes
initiatin
complex
·
elongation
of
the
polypeptide
chain
1.
codon
recognition
2
.
pepticle
bond
formation
3
.
Translocation
termination
of
Translation
·
release
factor
-
>
UAG
,
VAA
,
UGA
