Cell Transport Mechanisms and Functions

This video reviews Chapter 5, focusing on homeostasis and cell transport. It explains how cells maintain balance through the cell membrane's selective permeability, allowing certain molecules to pass. The video covers passive transport, including diffusion and osmosis, and active transport, such as the sodium-potassium pump. It also discusses facilitated diffusion, ion channels, and the processes of endocytosis and exocytosis, emphasizing the role of ATP in energy-requiring processes.

What is the primary function of the cell membrane in maintaining homeostasis?

• To randomly allow substances to enter and exit the cell

• To prevent any substances from entering or exiting the cell

• To selectively allow certain substances to enter and exit the cell

• To allow all substances to enter and exit the cell freely

Which of the following best describes passive transport?

• Movement of molecules from high to low concentration using energy

• Movement of molecules from high to low concentration without using energy

• Movement of molecules from low to high concentration using energy

• Movement of molecules from low to high concentration without using energy

What happens to a cell in an isotonic solution?

• The cell shrinks

• The cell swells

• The cell remains the same size

• The cell bursts

In a hypertonic solution, what is the effect on a cell?

• The cell remains the same size

• The cell bursts

• The cell swells

• The cell shrinks

What is the role of carrier proteins in facilitated diffusion?

• They assist in the movement of molecules across the membrane without using energy

• They use energy to move molecules against the concentration gradient

• They randomly allow molecules to pass through the membrane

• They prevent molecules from crossing the membrane

How do ion channels differ from facilitated diffusion?

• Ion channels require energy to function

• Ion channels allow ions to pass through in response to electrical or chemical signals

• Ion channels prevent ions from passing through the membrane

• Ion channels randomly open and close without any signals

What is the main energy source used in active transport?

• Glucose

• Carbon dioxide

• ATP

• Oxygen

What is the function of the sodium-potassium pump?

• To randomly move sodium and potassium ions across the cell membrane

• To create a charge difference across the cell membrane using energy

• To create a high concentration of sodium and potassium ions inside the cell without energy

• To move sodium and potassium ions from high to low concentration without energy

What process involves the cell membrane engulfing substances to bring them into the cell?

• Osmosis

• Facilitated diffusion

• Exocytosis

• Endocytosis

Which process involves the expulsion of substances from the cell?

• Exocytosis

• Endocytosis

• Osmosis

• Facilitated diffusion