Cell Transport

Front

What is the main function of phospholipids in the cell membrane?

Back

Phospholipids form the basic structure of the cell membrane, creating a bilayer that acts as a barrier to protect the cell and regulate what enters and exits.

Front

Define semi-permeable membrane.

Back

A semi-permeable membrane allows certain molecules to pass through while blocking others, enabling selective transport.

Front

What role do transport proteins play in cell transport?

Back

Transport proteins facilitate the movement of large or polar molecules across the cell membrane that cannot pass through the lipid bilayer directly.

Front

What is the hydrophilic part of a phospholipid?

Back

The hydrophilic phosphate head, which is attracted to water.

Front

What is the hydrophobic part of a phospholipid?

Back

The hydrophobic lipid tail, which repels water.

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 the difference between isotonic, hypotonic, and hypertonic solutions?

Back

Isotonic solutions have equal concentrations of solute inside and outside the cell; hypotonic solutions have a lower concentration of solute outside the cell, causing it to swell; hypertonic solutions have a higher concentration of solute outside the cell, causing it to shrink.

Front

What is the function of cholesterol in the cell membrane?

Back

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

Front

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

Back

Receptor proteins bind to specific molecules (ligands) outside the cell, triggering a response inside the cell.

Front

Explain the term 'active transport'.

Back

Active transport is the movement of molecules across a cell membrane from a region of lower concentration to a region of higher concentration, using energy (ATP).