Eukaryotic cell ultrastructureEdexcel International A Level Biology: Mind map

Exam questions on Eukaryotic cell ultrastructure

1. A student examines an electron micrograph of an acinar cell from the pancreas, which secretes the digestive enzyme amylase. The cell has a large amount of rough endoplasmic reticulum, a prominent Golgi apparatus and many small vesicles close to the cell surface membrane.
   Explain why this cell having a large amount of rough endoplasmic reticulum is an advantage.2 marks
2. Tay-Sachs disease is an inherited disorder in which a lysosomal enzyme that breaks down a lipid is missing. The lipid builds up inside nerve cells, which swell and become damaged.
   Explain why the lipid builds up inside the nerve cells.2 marks
3. Pancreatic cells were given a short pulse of a radioactively labelled amino acid and then transferred to a medium containing only unlabelled amino acids. After 3 minutes most radioactivity was in the rough endoplasmic reticulum. After 20 minutes most was in the Golgi apparatus. After 60 minutes most was in vesicles near the cell surface membrane and in the medium surrounding the cells.
   Describe the pathway taken by the labelled protein, as shown by these results.3 marks