Cell Membrane Structure, Transport Mechanisms, and Signaling in Biology

What are the main components of cell membranes?

Cell membranes contain both lipids and proteins.

What model describes the structure of cell membranes?

The 'Fluid Mosaic' Model describes cell membranes as fluid and selectively permeable.

What is selective permeability in cell membranes?

Selective permeability means that large, polar molecules cannot easily cross the membrane without assistance.

What type of molecules can easily pass through cell membranes?

Small, non-polar (hydrophobic) molecules can pass easily through membranes.

What is the role of phospholipids in cell membranes?

Phospholipids form a barrier when assembled, consisting of a polar head and two non-polar fatty acid chains.

What is the significance of solute concentration in relation to water balance in cells?

Solutes affect the concentration of water; cells require a proper solute balance for water balance.

What is simple diffusion?

Simple diffusion is the passive movement of molecules through the bilayer from higher to lower concentration without energy or special proteins.

What is osmosis?

Osmosis is the diffusion of water across a membrane, influenced by solute concentration.

What is facilitated diffusion?

Facilitated diffusion is a passive transport mechanism that involves carrier proteins and works along the concentration gradient.

What is active transport?

Active transport requires energy (ATP) and special transport proteins to move solutes against their concentration gradient.

What are the mechanisms of transport across cell membranes?

The mechanisms include simple diffusion, facilitated diffusion, and active transport.

What is the role of signaling in cell membranes?

Signaling involves receptors, initial signals, effectors, and second messengers to amplify the binding of a signal to its receptor.

What happens during equilibrium in simple diffusion?

Net movement occurs until there is no longer a difference in concentrations, achieving equilibrium.

What is the function of transport proteins in cell membranes?

Transport proteins assist large or polar molecules in crossing the membrane.

How do cells maintain solute concentrations?

Cells use mechanisms like passive and active transport to control solute concentrations across membranes.

What is the effect of solutes on water in cells?

Solutes attract water, affecting the overall water balance within the cell.

What is the importance of membrane fluidity?

Membrane fluidity allows for the movement of components and the functioning of transport mechanisms.

What are the characteristics of carrier proteins in facilitated diffusion?

Carrier proteins are very specific for the solute they transport.

What are the consequences of improper solute balance in cells?

Improper solute balance can disrupt water balance and cellular functions.