Organelles & Compartmentalisation (HL IB Biology)

The mitochondria are organelles within a eukaryotic cell that show compartmentalisation.

State what is meant by compartmentalisation.

In addition to the mitochondria, identify two other compartmentalised structures with double membranes characteristic of a eukaryotic cell.

Describe and explain the importance of the double membrane in mitochondria.

[3]

[1]

Post-translational modifications occur more slowly in eukaryotic cells as proteins are processed by other organelles.

[2]

State the function of the mitochondria.

Compare the structure of mitochondria with that of the chloroplasts.

Alpers Syndrome is an autosomal recessive disease caused by a mutation in the POLG gene, a gene which codes for a key mitochondrial protein. This mutation prevents replication of mitochondria, fundamentally impacting the function of muscle, nerves and the brain.

Suggest why Alpers syndrome affects these key organs in particular.

Alpers disease affects approximately 1 in 100 000 individuals. There are 68.35 million people in the UK.

Calculate the number of individuals in the UK with Alpers disease.

Complete the table to identify the eukaryotic cell organelles and describe their structures.

The ability to isolate organelles led to progress in the understanding of organelle structures and function.

Describe the technique used to separate cellular organelles by size.

Explain the order in which the organelles in the table in part (a) would be collected using the method described in part (i).

The pancreas is an organ responsible for the production of digestive enzymes which are secreted into the small intestines to break down molecules for absorption.

Describe the process carried out in pancreatic cells to prepare enzymes produced at the ribosomes, for secretion from the cell.

Pancreatic cells have adaptations that include many mitochondria.

Explain the role of mitochondria in the function of pancreatic cells as described in part (c).