What causes the phosphate heads of phospholipids to become polar?
The phosphate heads are joined to water molecules by hydrogen bonds.
The phosphate heads are insoluble in water.
The phosphate heads become ionised in water.
The phosphate heads are joined to water molecules by covalent bonds.
C
The statements describe some events in the process of exocytosis of glycoprotein molecules.
1 Membrane of the Golgi body folds around glycoprotein molecules.
2 Vesicle binds to and fuses with the cell surface membrane.
3 Vesicle attached to microtubules moves through the cytoplasm.
4 Secretory vesicle forms.
What is the correct order of events for exocytosis?
1→4→2→3
1→4→3→2
2→3→1→4
4→1→3→2
B
Where in the cell surface membrane are the carbohydrate chains of glycoproteins and glycolipids mainly located?
glycoproteins
glycolipids
inner surface
inner surface
inner surface
outer surface
outer surface
inner surface
outer surface
outer surface
D
Visking tubing is often used as a model during experiments to investigate osmosis in plants.
What could Visking tubing be used to represent?
cell surface membrane
cell wall
tonoplast
key
✓ = represents
x = does not represent
✓
✓
✓
✓
x
✓
✓
x
x
χ
✓
✓
B