Transport of Substances in and out of Cells: Diffusion, Osmosis, and Active Transport

The video tutorial explains essential cell processes, focusing on three main transport mechanisms: diffusion, osmosis, and active transport. Diffusion involves the movement of particles from high to low concentration, influenced by factors like temperature and surface area. Osmosis is the diffusion of water through a partially permeable membrane. Active transport moves substances against the concentration gradient, requiring energy. The importance of surface area to volume ratio in cell transport is also discussed, with examples from single-cell and multicellular organisms.

What is the primary factor that drives diffusion in cells?

• Volume

• Temperature

• Concentration gradient

• Surface area

How does increasing the temperature affect the rate of diffusion?

• Has no effect

• Increases the rate

• Stops diffusion

• Decreases the rate

Why is a high surface area to volume ratio beneficial for single-celled organisms?

• It prevents cell division

• It reduces energy consumption

• It enhances material exchange efficiency

• It increases cell size

What adaptation in fish gills increases the rate of oxygen diffusion into the blood?

• Thick membranes

• Low blood supply

• High concentration of oxygen in water

• Slow water flow over gills

What is osmosis?

• Movement of solutes from concentrated to dilute solution

• Movement of solutes from dilute to concentrated solution

• Movement of water from dilute to concentrated solution

• Movement of water from concentrated to dilute solution

What distinguishes active transport from diffusion?

• It does not involve membranes

• It occurs only in plants

• It moves substances down the concentration gradient

• It requires energy

Why is active transport important for cells?

• It allows cells to expel waste

• It enables cells to obtain essential substances even when concentrations are high inside

• It helps in cell division

• It maintains cell shape