▶️ Answer/Explanation
6 (a)
Diffusion is the net movement of particles from a region of their higher concentration to a region of their lower concentration (down a concentration gradient) .
The energy for diffusion comes from the kinetic energy of the random movement of molecules.
6 (b)(i)
Carbon, hydrogen, oxygen .
Note: All carbohydrates (including starch, glycogen, and cellulose) and fats are made of these three elements.
6 (b)(ii)
Cellulose (or sucrose, fructose) .
Explanation: Plants synthesize cellulose from glucose to build cell walls. Sucrose is also made from glucose for transport in the phloem .
6 (c)(i)
Cell membrane .
Explanation: The dialysis tubing is a partially permeable membrane that controls which substances can enter or leave the model cell, similar to a cell membrane’s function .
6 (c)(ii)
Glucose moved out because it is a small, soluble molecule that can fit through the pores of the dialysis tubing. Starch did not move out because it is a large, insoluble molecule (polymer) that is too big to pass through the pores.
6 (d)
Amylase .
Explanation: Amylase is the enzyme responsible for breaking down starch into simple reducing sugars (maltose).