06 Cell Membrane and cell theory

Front

What are the main components of the cell membrane?

Back

The main components of the cell membrane are lipids (primarily phospholipids), proteins, and carbohydrates.

Front

What is the function of transport proteins in the cell membrane?

Back

Transport proteins facilitate the movement of substances across the cell membrane that cannot pass freely due to their size or polarity.

Front

Define the term 'hydrophobic' in the context of cell membranes.

Back

Hydrophobic refers to the 'water-fearing' nature of certain molecules, such as the fatty acid tails of phospholipids in the cell membrane, which do not interact with water.

Front

What is the role of receptor proteins in the cell membrane?

Back

Receptor proteins bind to specific molecules (ligands) outside the cell and initiate a response inside the cell, such as signaling pathways.

Front

What is cell theory?

Back

Cell theory states that: 1) All living things are composed of cells, 2) Cells are the basic unit of structure and function in living organisms, and 3) All cells arise from pre-existing cells.

Front

What type of molecules can pass through the cell membrane without assistance?

Back

Small nonpolar molecules, such as oxygen and carbon dioxide, can pass through the cell membrane without assistance.

Front

What is the significance of the fluid mosaic model of the cell membrane?

Back

The fluid mosaic model describes the cell membrane as a flexible structure with various proteins embedded in or attached to a bilayer of phospholipids, allowing for movement and interaction.

Front

What is the difference between passive and active transport?

Back

Passive transport does not require energy and moves substances down their concentration gradient, while active transport requires energy to move substances against their concentration gradient.

Front

What is osmosis?

Back

Osmosis is the diffusion of water across a selectively permeable membrane from an area of lower solute concentration to an area of higher solute concentration.

Front

What is the function of cholesterol in the cell membrane?

Back

Cholesterol helps to stabilize the fluidity of the cell membrane, making it less permeable to very small water-soluble molecules that might otherwise pass freely through.