2024 · Paper 1 · Question 1 · 8 marks
SaveFigure 1 shows the structure of a fatty acid molecule and the structure of a glycerol molecule.
On Figure 1, draw a circle around the part of the fatty acid molecule and the part of the glycerol molecule that is removed to form a bond in a triglyceride molecule.
Name the bond formed between a fatty acid and glycerol in a triglyceride molecule.
Name the reaction involved in forming a bond between a fatty acid and glycerol in a triglyceride molecule.
Bond
Reaction

Table 1 shows information about three fatty acids.
Name the fatty acid shown in Table 1 that is a saturated fatty acid.

The melting point is the temperature at which a solid changes state to be a liquid.
Use Table 1 to describe the relationship between fatty acid structure and fatty acid melting point.

The ratio of saturated to unsaturated fatty acids in a cell-surface membrane determines the extent of the membrane's fluidity.
Scientists provided a cell culture of mouse phagocytes with liquid broth rich in unsaturated fatty acids.
The scientists observed:
• an increase in the proportion of phospholipids in the phagocytes containing unsaturated fatty acids • more phagocytosis.
Suggest and explain why there was more phagocytosis.