Cell Membrane and Transport

Front

What is the structure of the cell membrane?

Back

The cell membrane is primarily composed of a phospholipid bilayer, which includes embedded proteins, cholesterol, and carbohydrate chains.

Front

What is a phospholipid?

Back

A phospholipid is a molecule that has a hydrophilic (water-attracting) 'head' and two hydrophobic (water-repelling) 'tails', forming the basic structure of the cell membrane.

Front

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

Back

Integral proteins span the membrane and are involved in transporting substances across the membrane, acting as channels or carriers.

Front

What role does cholesterol play 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.

Front

What is a carbohydrate chain in the context of the cell membrane?

Back

Carbohydrate chains are attached to proteins and lipids on the extracellular surface of the membrane, playing a key role in cell recognition and signaling.

Front

What happens to a cell in a hypertonic solution?

Back

In a hypertonic solution, water moves out of the cell, causing it to shrink.

Front

What is a hypotonic solution?

Back

A hypotonic solution has a lower concentration of solutes compared to the inside of the cell, leading to water moving into the cell, which may cause it to swell.

Front

What is an isotonic solution?

Back

An isotonic solution has an equal concentration of solutes inside and outside the cell, resulting in no net movement of water.

Front

What is passive transport?

Back

Passive transport is the movement of substances across the cell membrane without the use of energy, typically moving from an area of higher concentration to an area of lower concentration.

Front

What is active transport?

Back

Active transport is the movement of substances against their concentration gradient, requiring energy (ATP) to move molecules from an area of lower concentration to an area of higher concentration.