Exam questions

Question 1

Describe
the structure and characteristics of these molecules. (bilayer)?

Answer 1

This is a phospholipid. It is made from a hydrophilic phosphate head(1) and two hydrophobic fatty acid tails (1).

Question 2

Describe
the process shown in Figure 3 (exocytosis)?

Answer 2

This is exocytosis. (1)
It is when a vesicle fuses with the cell surface membrane. (1)
The contents of the vesicle are released out of the cell. (1)

Question 3

Suggest
TWO reasons why some organelles are membrane bound?

Answer 3

The membrane forms a barrier between the organelle and the cytoplasm so the membrane can control the entry and exit of substances into and out of the organelle. (1)
The barrier formed by the membrane allows different conditions inside the organelle and in the cytoplasm. (1)