Question

question 17
which of the processes below uses atp as a source of energy?
○ diffusion
○ osmosis
○ moving substances from an area of lower to higher concentration
○ facilitated diffusion
○ filtration

question 18
in the diffusion activity why does congo red take longer to diffuse compared to the other dyes?
○ it is a complex carbohydrate
○ it has a large molecular weight
○ it is acidic
○ it does not dissolve in agar

Explanation:

Question 17

• Diffusion: Passive transport, no ATP needed (moves from high to low concentration).
• Osmosis: Passive (water movement), no ATP.
• Moving from lower to higher concentration: Active transport, requires ATP (against concentration gradient).
• Facilitated diffusion: Passive (uses transport proteins, high to low), no ATP.
• Filtration: Passive (driven by pressure), no ATP.

• Diffusion rate is inversely related to molecular weight. Larger molecules diffuse slower. Congo red’s slow diffusion is due to its large molecular weight.
• It is not a complex carbohydrate, acidity or solubility in agar don’t explain diffusion rate here.

Answer:

moving substances from an area of lower to higher concentration

Question 18