7.3 Translation

The following diagram shows polysomes.

Define the term 'polysome'.

[1 mark]

Polysomes are present in both prokaryotic and eukaryotic cells.

Identify whether the polysomes in the diagram at part a) are prokaryotic or eukaryotic.

[1 mark]

State a reason for your answer at part b) i).

[1 mark]

Describe one advantage of polysomes.

[1 mark]

The diagram below shows the secondary structure of a protein.

Identify structures S and U.

[2 marks]

The structure of a protein is held together by different types of chemical bonds.

Label the bonds R and T in the diagram.

[2 marks]

Describe how the bond at T forms and the way it contributes to the secondary structure of a protein.

[2 marks]

Explain how a mutation would affect the primary structure of a protein.

[1 mark]

The diagram below shows a ribosome producing proteins that are to be secreted from the cell. In order for this to occur, the ribosome must bind to organelle X.

State the name of organelle X.

[1 mark]

Binding to Y will result in the ribosome moving towards organelle X and binding to Z.

Identify Y and Z in the diagram.

[2 marks]

State the effect that binding to Y would have on the process of translation.

[1 mark]

Describe the path of the protein after it is produced, until it is secreted out of the cell.

[2 marks]

One mark is available for clarity of communication throughout this question.

Ribosomes play an important role during the process of translation.

Describe the structure of ribosomes.

[4 marks]

Outline the steps involved in the initiation of translation.

[3 marks]

Proteins are large, complex molecules that have several levels comprising their structure.

Describe the tertiary structure of proteins.

[6 marks]