Cell Membrane Structure and Function

The video tutorial covers the cell membrane's structure and function, emphasizing its role in maintaining homeostasis. It explains the lipid bilayer and protein channels, detailing passive and active transport processes, including diffusion, facilitated diffusion, and osmosis. The tutorial also discusses osmotic conditions like hypotonic, hypertonic, and isotonic environments, and how they affect water flow. The composition of the cell membrane, including its selectively permeable nature, is highlighted, explaining the importance of polar and non-polar interactions in forming a strong double-layered structure.

What is the primary function of the cell membrane?

• To regulate the movement of substances in and out of the cell

• To provide energy to the cell

• To produce proteins

• To store genetic information

What is the cell membrane primarily composed of?

• Carbohydrates

• Proteins

• Lipids

• Nucleic acids

What is the role of protein channels in the cell membrane?

• To store energy

• To facilitate the movement of large or charged particles

• To produce lipids

• To replicate DNA

Which process does not require energy to move substances across the cell membrane?

• Active transport

• Facilitated diffusion

• Exocytosis

• Endocytosis

What is osmosis specifically the diffusion of?

• Glucose

• Lipids

• Proteins

• Water

In a hypotonic environment, where does water flow?

• Out of the cell

• Into the cell

• Equally in and out of the cell

• Does not move

What does isotonic mean in terms of solute concentration?

• Higher inside the cell

• Higher outside the cell

• No solute present

• Equal inside and outside the cell

What characteristic of the cell membrane allows it to be selectively permeable?

• Its single lipid layer

• Its double lipid layer

• Its nucleic acid content

• Its carbohydrate content

Why do the lipid tails in the cell membrane face each other?

• They are polar and attract water

• They are non-polar and avoid water

• They repel each other

• They are attracted to water

What percentage of the human body is water, influencing the structure of the cell membrane?

• 80%

• 60%

• 50%

• 70%