Protein Synthesis
Part II: Genetic Code and
Translation
Which is single stranded?
7%
1.
93%
2.
DNA
RNA
Where in the cell does transcription take
place?
0%
ol
gi
G
ol
e
cu
Va
Bo
d
s
le
u
uc
N
m
0%
y
0%
on
dr
ia
0%
ito
ch
5.
M
4.
la
s
3.
yt
op
2.
Cytoplasm
Mitochondria
Nucleus
Golgi Body
Vacuole
C
1.
100%
If a DNA strand has the following sequence
of base pairs – A C T G G T C C A A , then
the mRNA strand would have what
100%
sequence?
G
...
A
G
C
C
C
A
U
G
U
G
T
A
C
T
C
G
C
G
U
T
A
C
G
...
0%
...
0%
...
0%
C
4.
A
3.
G
2.
TGACCAGGTT
ACTGGTCCAA
TGUCCUGGTT
UGACCAGGUU
T
1.
mRNA is synthesized in the nucleus and
travels to the cytoplasm to meet up with
which organelle?
80%
13%
7%
0%
N
uc
le
u
s
e
so
m
so
Ly
G
ol
gi
so
Bo
d
m
e
y
0%
ib
o
5.
R
4.
on
dr
ia
3.
ito
ch
2.
Mitochondria
Ribosome
Golgi Body
Lysosome
Nucleus
M
1.
Genetic Code
Quick Review of Proteins…
Monomer: Amino Acid
 20 different amino acids!
 The properties of proteins are determined
by the order of the amino acids

The Genetic Code!
RNA contains 4 different bases: A, G, C, U
 The genetic code is read three letters at a
time
 Each “word” of the coded message is
three base pairs long


These “words” are called codons
RNA Sequence:
UCGCACGGU
Read sequence 3 bases at a time
UCG – CAC
– GGU
Each set of three bases is a codon.
 Each codon represents a different amino
acid

…more genetic code
AUG is the start codon
 In addition there are 3 different stop
codons.
 Stop codons are like the period at the end
of a sentence.

Using your mRNA codon chart,
what amino acid would a ribosome
call for if the codon was A A C ?
13%
7%
in
e
ro
s
Ty
Ly
e
ar
ag
in
sp
A
lu
ta
m
G
si
ne
0%
in
e
0%
in
e
5.
la
n
4.
yl
a
3.
80%
en
2.
Phenylalanine
Glutamine
Asparagine
Lysine
Tyrosine
Ph
1.
Translation
RNA and Ribosomes work
together to produce proteins
Transfer RNA
For translation we need a new
type of RNA
 Transfer RNA (tRNA) is
responsible for carrying
different amino acids to the
ribosome.
 tRNA has a three base
sequence called an
anticodon

Steps in Translation
mRNA attaches to the ribosome
 tRNA brings in the amino acids
 Anticodons match with codons
 Peptide bonds form between amino acids

Translation


Translation continues until a stop codon is read
The newly formed protein is released
Where in the cell does translation, the second part
of protein synthesis, take place?
Mitochondria
Nucleus
Golgi body
Cytoplasm
3
4
5
6
7
8
9
10
21
22
23
24
25
26
27
28
29
30
11
12
0%
G
13
14
15
0%
m
la
s
yt
op
le
u
uc
N
ito
ch
2
M
1
0%
s
on
dr
ia
0%
16
C
4.
y
3.
bo
d
2.
ol
gi
1.
17
18
19
20
Molecules called tRNA’s are floating
around the cytoplasm carrying what?
mRNA’s
Glucose
DNA
Nucleotides
Amino Acids
2
3
4
5
6
7
8
9
10
21
22
23
24
25
26
27
28
29
30
11
12
13
14
15
16
s
ds
0%
17
Ac
i
m
in
o
N
1
0%
A
lu
c
G
m
0%
tid
e
os
A’
s
RN
0%
e
0%
le
o
5.
uc
4.
A
3.
N
2.
D
1.
18
19
20
An mRNA codon is made up of how
many nitrogen bases?
1
3
6
24
3.
4.
1
2
3
4
5
6
7
8
9
10
21
22
23
24
25
26
27
28
29
30
11
12
0%
3
0%
1
0%
13
14
0%
15
16
17
18
24
2.
6
1.
19
20
What protein would be synthesized
from the following mRNA strand?
ACUUUCGAAUAC
5
6
7
8
9
10
21
22
23
24
25
26
27
28
29
30
11
12
13
15
16
17
0%
ni
ne
–
cy
...
gl
u.
..
–
in
e
yl
a
re
o
en
14
Th
4
Ph
3
0%
...
la
n
–
ni
ne
re
o
2
Th
1
0%
in
e
ph
4.
0%
ro
s
3.
Ty
2.
...
Threonine – phenylalanine
– glutamate – tyrosine
Phenylalanine – leucine –
methionine – valine
Tyrosine – glutamate –
phenylalanine – threonine
Threonine – cysteine –
arginine – histidine
1.
18
19
20