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…

Protein manufactureWALT: 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*)

Protein manufacture Making proteins Protein synthesisThis happens in two stages:

Transcription ‘Copying’ Translation

TranscriptionWhat? 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.

Where? Inside the nucleus.

mRNA

What would be the mRNA be?

ACTTAGCGUGAAUCGC

Remember mRNA has no thymine, you replace this with

uracil (U).

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

Protein manufacture Making proteins Protein synthesisThis happens in two

stages:

Transcription ‘Copying’ Translation ‘Changing into something different’

TranslationWhere? In the cytoplasm.

ribosome

mRNA

The mRNA is decoded in groups of 3 (triplet or codon)

tRNA Protein (polypeptide)

amino acids

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.

Why? The amino acid chain or polypeptide can then twist and fold in order to form a protein.

Proteins are used throughout the body.

enzymes

muscle tissue

hormones

DNA double helix is separated.

mRNA is made using DNA strand. = Transcription.mRNA leaves nucleus and enters cytoplasm.

mRNA joins onto a ribosome.

The mRNA acts as a code for tRNA. = Translation Amino

acids on neighbouring tRNA join together.

A chain of amino acids is a poly-peptide.

The poly-peptide chain folds to form a protein which is used in the cell or exported to the body.

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.

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

TranslationWhere? In the cytoplasm.

ribosome

mRNA

The mRNA is decoded in groups of 3 (triplet or codon)

tRNA Protein (polypeptide)

amino acids

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.

Why? The amino acid chain or polypeptide can then twist and fold in order to form a protein.

Proteins are used throughout the body.

enzymes

muscle tissue

hormones

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