AS Level Biology: Cell Membrane

What is the structure of the cell membrane?

• Protein layer with no phospholipids or cholesterol

• Solid layer of cholesterol with no phospholipids

• Single layer of phospholipids with no embedded proteins or cholesterol

• Phospholipid bilayer with embedded proteins and cholesterol

Explain the function of the cell membrane.

• The function of the cell membrane is to regulate the passage of substances into and out of the cell.

• The function of the cell membrane is to store nutrients for the cell.

• The function of the cell membrane is to provide structural support for the cell.

• The function of the cell membrane is to produce energy for the cell.

Describe the fluid mosaic model of the cell membrane.

• The fluid mosaic model describes the structure of the cell membrane as a static and unchanging structure

• The fluid mosaic model describes the structure of the cell membrane as a solid protein layer with no lipids

• The fluid mosaic model describes the structure of the cell membrane as a fluid lipid bilayer with embedded proteins.

• The fluid mosaic model describes the structure of the cell membrane as a rigid single layer of lipids

Discuss the different types of transport across the cell membrane.

• Passive transport includes photosynthesis, endocytosis, and pinocytosis, while active transport includes exocytosis and phagocytosis.

• Passive transport includes diffusion, active transport, and osmosis, while active transport includes facilitated diffusion and primary active transport.

• Passive transport includes filtration, engulfment, and engulfment, while active transport includes endocytosis and exocytosis.

• Passive transport includes diffusion, osmosis, and facilitated diffusion, while active transport includes primary active transport and secondary active transport.

What are the roles of cell membrane proteins?

• Storing genetic information

• Regulating temperature within the cell

• Producing energy for the cell

• The roles of cell membrane proteins include transporting molecules, acting as receptors, and providing structural support.

Explain the concept of cell membrane receptors.

• Cell membrane receptors are made of carbohydrates

• Cell membrane receptors are proteins embedded in the cell membrane that bind to specific molecules, such as hormones or neurotransmitters, and initiate a cellular response.

• Cell membrane receptors only bind to water molecules

• Cell membrane receptors are located in the nucleus of the cell

How does the cell membrane maintain homeostasis?

• By controlling the movement of substances in and out of the cell

• By controlling the cell's shape

• By regulating the cell's temperature

• By producing energy for the cell

Discuss the importance of cholesterol in the cell membrane.

• Cholesterol is important in the cell membrane for maintaining fluidity, stability, and regulating permeability.

• Cholesterol has no impact on the cell membrane

• Cholesterol increases the permeability of the cell membrane

• Cholesterol causes instability in the cell membrane

Explain the process of endocytosis and exocytosis.

• Endocytosis is the process of expelling materials to the outside by fusing a vesicle with the cell membrane.

• Endocytosis is the process of taking in materials from the outside by engulfing them in a vesicle, while exocytosis is the process of expelling materials to the outside by fusing a vesicle with the cell membrane.

• Endocytosis and exocytosis are the same process.

• Exocytosis is the process of taking in materials from the outside by engulfing them in a vesicle.

What are the factors that affect the permeability of the cell membrane?

• amount of oxygen in the cell

• pH level of the surrounding environment

• Temperature, concentration of solutes, and the presence of specific proteins or channels

• size of the cell