Cell Membrane Functions and Structure

Mr. Anderson provides an overview of the cell membrane, explaining its function in regulating material entry and exit. He uses a muskox analogy to describe the amphipathic nature of phospholipids, which have hydrophilic heads and hydrophobic tails. The fluid mosaic model is introduced, highlighting the dynamic and diverse composition of cell membranes, primarily made of phospholipids and proteins. The video also covers the roles of glycoproteins, glycolipids, and cholesterol in maintaining membrane fluidity and facilitating transport. Various transport mechanisms, including diffusion and active transport, are discussed, emphasizing the role of proteins in these processes.

What is the primary function of the cell membrane?

• To store genetic information

• To regulate what enters and exits the cell

• To provide energy to the cell

• To produce proteins

How is the structure of a phospholipid described?

• It has a hydrophilic tail and a hydrophobic head

• It is completely hydrophobic

• It is completely hydrophilic

• It has a hydrophilic head and a hydrophobic tail

What does the term 'amphipathic' refer to in the context of phospholipids?

• Being completely hydrophobic

• Having both a hydrophilic and hydrophobic region

• Having no charge

• Being completely hydrophilic

What does the 'fluid' part of the fluid mosaic model refer to?

• The components of the membrane are in constant motion

• The membrane is static and unchanging

• The membrane is made of liquid

• The membrane is solid and rigid

Which two major components make up the cell membrane?

• Cholesterol and DNA

• Proteins and carbohydrates

• Lipids and nucleic acids

• Phospholipids and proteins

What role does cholesterol play in the cell membrane?

• It acts as a receptor for hormones

• It stores genetic information

• It helps maintain membrane fluidity

• It provides energy to the cell

What is the function of glycoproteins in the cell membrane?

• To produce proteins

• To act as receptors and provide structural support

• To facilitate movement of water

• To store energy

How do small uncharged molecules like oxygen move across the cell membrane?

• By simple diffusion

• By facilitated diffusion

• Through endocytosis

• Through active transport

What is the role of aquaporins in the cell membrane?

• To transport glucose

• To allow water to move quickly across the membrane

• To synthesize proteins

• To store ions

Which process requires energy to move substances across the cell membrane?

• Simple diffusion

• Active transport

• Osmosis

• Facilitated diffusion