AP Bio - 2.5 Membrane Permeability

What passes through the cell membrane freely

Small non polar molecules, such as N₂, O₂, CO₂

What does not freely move across the cell membrane

hydrophilic substances such as large polar molecules and ions

How do hydrophilic substances move through the cell membrane

Through transport proteins such as channel proteins

Channel proteins

A hydrophilic tunnel spanning the membrane that allow specific target molecules to pass through

Carrier proteins

Spans the membrane and change shape to move a target molecule from one side of the membrane to the other

What can pass through the cell membrane in minimal amounts

Small polar molecules like H₂O

How is the cell wall a structural boundary

protects and maintains the shape of the cell, prevents against cellular rupture when internal water pressure is high, helps plants stand up against the force of gravity

How does the cell wall act as a permeable barrier

Through plasmodesmata

Plasmodesmata

Small holes between plant cells that allows the transfer of nutrients, waste, and ions

Which cell has cell walls

Plant cells, not animal cells

What complex carbohydrate does a plant have

Cellulose, a type of polysaccharide

What complex carbohydrate does a fungi have

Chitin, a type of polysaccharide

What complex carbohydrate does a prokaryote have

peptidoglycan, a polymer consisting of sugar and amino acids