1. Quick recap!
Write down the following:
The shape of a DNA molecule is…
The four DNA bases are…
These bases are joined by…
A gene is a short section of DNA coding
for a…

2. Protein manufacture
WALT: To describe the processes involved in making
proteins.
WILF:
~ Recall how proteins are made up of amino acids. (D)
~ Spot how the order of bases in DNA controls the
sequence of amino acids produced in a protein. (D)
~ Describe how the sequence of amino acids joined
together is unique in each protein. (C)
~ Explain the stages involved in transcription. (B)
~ Explain the stages involved in translation. (B)
~ Compare these two processes. (A/A*)

3. Protein manufacture  Making
proteins  Protein synthesis
This happens in two stages:
Transcription  ‘Copying’
Translation

4. Transcription
Where? Inside the nucleus.
What? The weak hydrogen
bonds between the DNA
strands are broken and the
strands separate.
One DNA strand is used as a
template.
Complementary bases pair up
to the template, forming
messenger RNA (mRNA).
mRNA does not have the
base thymine (T). Adenine (A)
pairs with uracil (U) instead.
mRNA

5. What would be the
mRNA be?
ACTTAGCG
UGAAUCGC
Remember mRNA has no
thymine, you replace this
with uracil (U).

6. So far…
~ DNA has been unzipped.
~ One DNA strand has acted like a
template.
~ messenger RNA bases have paired up
with the template, remember A-U and C-G
~ the DNA strand has been ‘copied’ onto
the mRNA
~ this now leaves the nucleus

7. Protein manufacture  Making
proteins  Protein synthesis
This happens in two stages:
Transcription  ‘Copying’
Translation  ‘Changing into
something different’

8. Translation
tRNA
Where? In the cytoplasm.
amino acids
Protein (polypeptide)
mRNA
ribosome
The mRNA is decoded in
groups of 3 (triplet or
codon)

9. So translation…
~the mRNA attached to a ribosome.
~ the ribosome decodes the mRNA in
groups of 3.
~ for each codon or triplet, a tRNA
molecule brings a specific amino acid.
~ this continues forming a chain of amino
acids or polypeptide.

10. Why?
enzymes
The amino acid chain
or polypeptide can
muscle tissue
then twist and fold in
order to form a
hormones
protein.
Proteins are used
throughout the body.

11. DNA double helix is
separated.
The mRNA
acts as a
code for
tRNA. =
Translation
mRNA joins
onto a
ribosome.
Amino acids
on
A chain of amino neighbouring
acids is a poly- tRNA join
peptide.
together.
mRNA is made
using DNA strand. =
Transcription.
mRNA leaves
nucleus and enters
cytoplasm.
The poly-peptide chain
folds to form a protein
which is used in the
cell or exported to the
body.

12. True or false?
1. Transcription and translation are two processes which
make proteins.
2. mRNA has the following bases, adenine, thymine,
cytosine and guanine.
3. Transcription takes place inside the nucleus.
4. Translation takes place inside the nucleus.
5. The mRNA strand is decoded by the ribosomes in
groups of 4.

13. So far…
~ DNA has been unzipped.
~ One DNA strand has acted like a
template.
~ messenger RNA bases have paired up
with the template, remember A-U and C-G
~ the DNA strand has been ‘copied’ onto
the mRNA
~ this now leaves the nucleus

14. Translation
tRNA
Where? In the cytoplasm.
amino acids
Protein (polypeptide)
mRNA
ribosome
The mRNA is decoded in
groups of 3 (triplet or
codon)

15. So translation…
~the mRNA attached to a ribosome.
~ the ribosome decodes the mRNA in
groups of 3.
~ for each codon or triplet, a tRNA
molecule brings a specific amino acid.
~ this continues forming a chain of amino
acids or polypeptide.

16. Why?
enzymes
The amino acid chain
or polypeptide can
muscle tissue
then twist and fold in
order to form a
hormones
protein.
Proteins are used
throughout the body.

17. Describe as fully as you can how different
proteins are made from the genetic code
of DNA. (6m)