AP Biology Cell Membranes & Diffusion!

Front

What are biological membranes primarily composed of?

Back

Lipids and proteins.

Front

How do the plasma membranes of winter wheat remain fluid in extremely cold temperatures?

Back

By replacing saturated fatty acids with unsaturated fatty acids.

Front

What is the driving force for simple diffusion?

Back

Concentration gradient.

Front

What experimental technique is used to split the two sides of a membrane apart?

Back

Freeze-fracturing.

Front

What do the bumps observed on the interior of a freeze-fractured membrane bilayer likely represent?

Back

Integral membrane proteins.

Front

What does a concentration gradient of glucose across a membrane indicate?

Back

Glucose molecules are more crowded on one side of the membrane than on the other.

Front

What role do lipids play in biological membranes?

Back

They form the basic structure of the membrane, creating a bilayer.

Front

What is the function of integral membrane proteins?

Back

They assist in transport, act as receptors, and provide structural support.

Front

What is the significance of unsaturated fatty acids in membrane fluidity?

Back

They prevent tight packing of lipids, maintaining fluidity at lower temperatures.

Front

Define simple diffusion.

Back

The movement of molecules from an area of higher concentration to an area of lower concentration without the need for energy.