Cell Transport Mechanisms and Functions

The video tutorial covers membrane transport mechanisms, including diffusion, osmosis, and active transport. It explains the role of protein channels and pumps, such as the sodium-potassium pump, in maintaining cell function. The tutorial also discusses the effects of isotonic, hypertonic, and hypotonic solutions on cells and highlights practical lab techniques for studying these processes.

What is the primary characteristic of simple diffusion?

• It moves substances from low to high concentration.

• It moves substances from high to low concentration without energy.

• It requires energy input.

• It involves carrier proteins.

Which molecules can easily pass through a cell membrane by simple diffusion?

• Glucose molecules

• Large proteins

• Charged ions

• Oxygen molecules

Which type of solution causes a cell to swell and potentially burst?

• Isotonic

• Neutral

• Hypotonic

• Hypertonic

What is the role of aquaporins in the cell membrane?

• They facilitate rapid water transport.

• They transport glucose.

• They are involved in protein synthesis.

• They pump ions against their gradient.

What is the role of ATP in active transport?

• It acts as a channel for ions.

• It is not involved in active transport.

• It provides energy for moving substances against their concentration gradient.

• It facilitates passive diffusion.

What is the main difference between facilitated diffusion and active transport?

• Facilitated diffusion requires energy, active transport does not.

• Facilitated diffusion involves vesicles, active transport does not.

• Facilitated diffusion moves substances against their gradient, active transport does not.

• Facilitated diffusion does not require energy, active transport does.

In a neuron, what happens when sodium channels open?

• Potassium ions enter the cell.

• The cell remains unchanged.

• The cell becomes more positive inside.

• The cell becomes more negative inside.

What happens to the electrical potential of a neuron when potassium ions exit the cell?

• The cell becomes more negative inside.

• The cell becomes depolarized.

• The cell becomes more positive inside.

• The cell remains unchanged.

What is the function of vesicles in cellular transport?

• They facilitate passive diffusion.

• They transport substances via endocytosis and exocytosis.

• They are involved in osmosis.

• They provide energy for active transport.

In the practical experiment with potato samples, why is it important to control variables?

• To change the color of the potatoes.

• To increase the size of the potatoes.

• To maintain consistent results and reduce errors.

• To ensure the potatoes are fresh.