Fluid mosaic model of the cell membrane

The video explores the structure and function of plasma membranes, emphasizing their role in maintaining cell organization and selective permeability. It covers the fluid mosaic model, detailing the components like proteins, lipids, and carbohydrates, and their arrangement in the membrane. The phospholipid bilayer's amphipathic nature is explained, along with the functions of membrane proteins. The video also discusses membrane fluidity, influenced by lipid composition and cholesterol, and outlines transport mechanisms, including passive and active transport, and osmosis.

What is the primary function of the plasma membrane in a cell?

• To provide energy to the cell

• To separate the cell from its surroundings

• To store genetic information

• To produce proteins

Which of the following is NOT a component of cell membranes?

• Proteins

• Nucleic acids

• Lipids

• Carbohydrates

What model describes the structure of the cell membrane?

• Static mosaic model

• Rigid framework model

• Fluid mosaic model

• Solid state model

What characteristic of phospholipids allows them to form bilayers?

• Their amphipathic nature

• Their rigid structure

• Their hydrophobic nature

• Their ability to conduct electricity

Which type of membrane protein is embedded within the lipid bilayer?

• Surface proteins

• Extrinsic proteins

• Integral proteins

• Peripheral proteins

What role do membrane proteins NOT play?

• Enzymatic activity

• Cell signaling

• Photosynthesis

• DNA replication

How does cholesterol affect membrane fluidity at high temperatures?

• Makes the membrane rigid

• Has no effect

• Decreases fluidity

• Increases fluidity

What is the main difference between passive and active transport?

• Passive transport requires energy, active transport does not

• Active transport requires energy, passive transport does not

• Both require energy

• Neither require energy

In osmosis, water moves from a _______ solution to a _______ solution.

• Isotonic; hypertonic

• Hypertonic; hypotonic

• Hypotonic; hypertonic

• Hypertonic; isotonic

Which of the following affects membrane fluidity?

• Length of phospholipid tails

• Cell size

• Presence of nucleic acids

• Amount of sunlight