AP Biology Cell Membrane Flashcard

Front

What does the fluid mosaic model of cell membranes describe?

Back

The fluid mosaic model describes the structure of cell membranes as a mosaic of various components (lipids, proteins, carbohydrates) that move laterally within the layer, allowing for flexibility and fluidity.

Front

What happens to a cell placed in a hypertonic solution?

Back

A cell in a hypertonic solution will lose water and shrink due to osmosis, as water moves out of the cell to balance solute concentrations.

Front

How do the membranes of eukaryotic cells differ from one another?

Back

The membranes of eukaryotic cells differ in their composition of proteins, which can be unique to each membrane, affecting their functions.

Front

What is osmosis?

Back

Osmosis is the movement of water molecules across a selectively permeable membrane from an area of lower solute concentration to an area of higher solute concentration.

Front

What is diffusion?

Back

Diffusion is the passive movement of molecules from an area of higher concentration to an area of lower concentration until equilibrium is reached.

Front

What role do phospholipids play in the cell membrane?

Back

Phospholipids form the basic structure of the cell membrane, creating a bilayer that is hydrophobic on the inside and hydrophilic on the outside, allowing for selective permeability.

Front

What is the significance of membrane proteins?

Back

Membrane proteins are crucial for various functions, including transport, signaling, and acting as enzymes, and they can be integral or peripheral to the membrane.

Front

What is the difference between passive and active transport?

Back

Passive transport does not require energy and moves substances down their concentration gradient, while active transport requires energy to move substances against their concentration gradient.

Front

What is a hypotonic solution?

Back

A hypotonic solution has a lower concentration of solutes compared to the inside of the cell, causing water to enter the cell and potentially leading to swelling or bursting.

Front

What is the function of cholesterol 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.