Plant cell membrane composition alters as temperature changes. At the start of the cold season, the proportion of phospholipids with unsaturated fatty acids increases in the chickpea, Cicer arietinum. Chickpea plants that fail to make this adjustment do not survive. Suggest how a higher proportion of phospholipids with unsaturated fatty acids helps plants, such as chickpea, survive decreases in temperature.
State why triglycerides and phospholipids cannot be called polymers.
State two structural differences between triglycerides and phospholipids.
Platelets metabolise linoleic acid to produce a molecule called thromboxane. When blood loss occurs, platelets release thromboxane. It acts on smooth muscle cells in arterial walls. This makes the arteries constrict, which lowers blood flow. Explain why the narrowing of arteries after blood loss is an example of cell signalling.