Plasma Membrane Structure & Function

These flashcards cover key concepts related to the structure and function of the plasma membrane, types of cells, membrane transport mechanisms, and related biological processes.

What are the two main types of cells covered in the lecture?

Plant cells and animal cells.

What is a key structural difference between plant and animal cells?

Plant cells have a cell wall, chloroplasts, and a large central vacuole, whereas animal cells have a cell membrane and lysosomes.

What are the main functions of the plasma membrane?

Physical barrier, isolates, regulates transport/exchange, controls entry and exit, and communication.

What are the components of a phospholipid?

Hydrophilic head and hydrophobic tails.

What is the fluid mosaic model?

A model describing the structure of the plasma membrane as a mosaic of various components including lipids, proteins, and carbohydrates.

What are the three types of lipids in the fluid mosaic model?

Phospholipids, glycolipids, and cholesterol.

What is passive transport?

Movement of molecules across the cell membrane without energy, following the concentration gradient.

What is osmosis?

Diffusion of water through a selectively permeable membrane in response to solute concentrations.

What are isotonic, hypotonic, and hypertonic solutions?

Isotonic: equal solute concentration; Hypotonic: lower solute concentration outside; Hypertonic: higher solute concentration outside.

What is active transport?

The movement of materials against their concentration gradient, requiring energy (ATP) and proteins.

What is endocytosis?

The process where the membrane forms a pocket around a particle and pinches off to create a vesicle.

What function do receptor proteins serve in the membrane?

They notify the cell of the presence of other substances, facilitating communication.

What role does cholesterol play in the membrane?

It reinforces and solidifies the structure of the membrane.

What is facilitated diffusion?

A type of passive transport where membrane proteins help large or polar molecules cross the membrane.

What happens during phagocytosis?

The cell consumes solid particles by engulfing them with its membrane.

How does the concentration gradient affect diffusion?

Molecules move from areas of high concentration to areas of low concentration.