Cell transport

Fluid Mosaic Model

The Fluid Mosaic Model depicts the cell membrane as a dynamic structure composed of various proteins within a flexible phospholipid bilayer, allowing movement and change.

Phospholipid

A phospholipid is a fat molecule forming the cell membrane's structure, featuring a hydrophilic 'head' that attracts water and a hydrophobic 'tail' that repels it, regulating what enters and exits the cell.

Glycolipid

A glycolipid is a lipid with sugar molecules attached, crucial for cell membrane stability, recognition, and adhesion to other cells.

Cholesterol

Cholesterol is a fat molecule in the cell membrane that enhances stability and reduces permeability, protecting the cell from environmental changes.

Peripheral Protein

Peripheral proteins are attached to the cell membrane's surface and do not penetrate it, often involved in signaling and structural support.

Integral Protein

Integral proteins span the entire cell membrane and facilitate the transport of substances across it.

Channel Protein

A channel protein is an integral protein that forms pores in the membrane, enabling specific ions and molecules to pass through easily.

Carrier Protein

A carrier protein binds to specific molecules and alters its shape to transport them across the cell membrane.

Glycoprotein

Glycoproteins are proteins with sugar molecules attached, playing key roles in cell recognition and communication.

Diffusion

Diffusion is the natural movement of particles from high to low concentration areas without energy use.

Facilitated Diffusion

Facilitated diffusion allows specific molecules to pass through the cell membrane aided by proteins, moving from high to low concentration without energy.

Osmosis

Osmosis is the movement of water across a semi-permeable membrane from areas of high water (low solute) concentration to low water (high solute) concentration, without energy.

Tonicity

Tonicity describes how solute concentration in a solution affects water movement in and out of a cell, influencing the cell's shape.

Active Transport

Active transport uses energy to move molecules from low to high concentration, against their natural flow.

Primary Active Transport

Primary active transport directly uses ATP energy to move ions across the membrane against their gradient, like the sodium-potassium pump.

Secondary Active Transport

Secondary active transport relies on energy from the primary transport of one substance to move another substance, aiding glucose transport into the cell.

Endocytosis

Endocytosis is the process by which a cell engulfs substances, folding the membrane inward to take in materials.

Exocytosis

Exocytosis is when a cell expels substances by merging vesicles with the membrane, releasing contents outside.