Cell Transport Mechanisms and Processes

The video covers the movement of substances across membranes, focusing on diffusion, osmosis, and active transport. Diffusion is a passive process where particles move from high to low concentration. Osmosis, a special case of diffusion, involves water moving across a semi-permeable membrane. Active transport requires energy to move substances against a concentration gradient. The video also discusses the effects of osmosis on animal and plant cells, including turgor pressure and plasmolysis, and provides study tips for mastering these concepts.

What is the primary characteristic of diffusion?

• It requires energy input.

• It moves substances from low to high concentration.

• It is a passive process.

• It only occurs in solids.

Which factor does NOT affect the rate of diffusion?

• Concentration gradient

• Temperature

• Color of the particles

• Particle size

Osmosis involves the movement of which substance?

• Glucose

• Ions

• Water

• Proteins

What happens to red blood cells in a hypotonic solution?

• They become crenated.

• They remain unchanged.

• They shrink.

• They swell and may burst.

In a hypertonic solution, what occurs to plant cells?

• They swell and burst.

• They undergo plasmolysis.

• They remain unchanged.

• They become turgid.

What is turgor pressure?

• Pressure exerted by the cell wall on the cell contents

• Pressure exerted by the cell contents on the cell wall

• Pressure exerted by the vacuole on the cell membrane

• Pressure exerted by the cytoplasm on the nucleus

How does salting preserve food?

• By causing bacterial cells to lose water

• By increasing water content

• By providing nutrients

• By adding flavor

What distinguishes active transport from diffusion and osmosis?

• It occurs only in plant cells.

• It is a passive process.

• It requires energy input.

• It moves substances from high to low concentration.

Which energy source is used in active transport?

• Glucose

• ATP

• Water

• Oxygen

Which of the following is an example of a substance actively transported in the body?

• Carbon dioxide

• Oxygen

• Glucose

• Water