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National 5 Cell Biology
Producing Proteins
We are learning to:
• State what is meant by a gene
• State that mRNA carries the genetic code from
DNA in the nucleus to a ribosome for protein
synthesis
• Describe how a protein is synthesised at a
ribosome
• Explain how the sequence of DNA bases
determines protein structure and function
What I'm looking for:
•
•
•
•
A definition of a gene
A description of the structure of a protein
Function of mRNA
Labelled diagram showing how DNA produces
proteins
• A flow chart to show how DNA determines the
protein produced
• A table showing examples of proteins
What makes organisms different?
Organisms differ because they have different genes.
 Humans have human genes
 Gerbils have gerbil genes
Nobody else in the whole
world has the same DNA as
you!
 Bananas have (yes,
you’ve guessed it)
banana genes!
Genes
Genes are a
section of DNA
Each gene codes
for a protein
Proteins
DNA and Proteins
The sequence of bases on a DNA molecule
determines the sequence of amino acids in a
protein
A
A
T
C
T
G
C
A
T
G
G
C
A
T
C
A
G
T
Coding for a protein
A different sequence of bases on a DNA molecule
produces a different sequence of amino acids in a
protein.
A A
T
C
T
G
C
A
T
G
G
C
A
T
C
A
G
T
Building a protein
DNA contains the instructions
for building a protein
DNA is found only in the nucleus
Animal cell
Proteins are assembled using
amino acids at structures called
Ribosomes
How do the
instructions to
build the protein
get from the
nucleus to the
ribosomes?
Messenger RNA
Instructions in nucleus
Messenger RNA carries a copy of the
code from the DNA to the ribosomes.
Animal cell
Assembly of amino
acids at ribosomes
DNA  mRNA  Protein
Order of DNA bases
Order of amino acids
Structure of protein
Function of protein
I can:
• State what is meant by a gene
• Explain how the sequence of DNA bases
determines protein structure and function
• State that mRNA carries the genetic code from
DNA in the nucleus to a ribosome for protein
synthesis
• Describe how a protein is synthesised at a
ribosome