transport protein + Factors affecting exchange

Question 1

Aquaporins:

Answer 1

are transport proteins that speed up the transport of water in and out of the cell.

Question 2

Carrier proteins:

Answer 2

are involved in facilitated diffusion and active transport. They differ from channel proteins as they are very selective. Whether it is transport or active depends on what material it is moving.

Question 3

Glucose transporter:

Answer 3

passively transports glucose from high to low concentration.

Question 4

Sodium/Potassium pump:

Answer 4

transports ions that are normally tricky to transport. Requires ATP as it goes against the concentration gradient.

Question 5

Factors affecting exchange:
Surface area to volume ratio:

Answer 5

As volume increases the surface-to-volume area decreases, thereby decreasing the rate of exchange and efficiency of the cell. This is due to less of the relative surface area being exposed to the extracellular environment for exchange as compared to the volume. This is why cells are small as they need to be efficient in getting nutrients from the extracellular and expelling waste otherwise issues occur to the cell health due to not being able to carry out cellular reactions due to not having the correct inputs and outputs.

Question 6

Factors affecting exchange:
Concentration gradient:

Answer 6

the greater the difference in concentration the faster the exchange will be as the gradient is steeper (further from equilibrium)

Question 7

Factors affecting exchange:
Nature of materials:

Answer 7

small and uncharged particles move much easier than those that are larger or charged. Channel proteins don’t require energy, carrier proteins do. Proteins or endo or exocytosis may be required for larger or charged particles.