Membrane Structure and Diffusion

Front

What is the primary function of the plasma membrane?

Back

The primary function of the plasma membrane is to protect the cell and regulate what enters and exits the cell.

Front

Define selectively permeable in the context of the plasma membrane.

Back

Selectively permeable means that the plasma membrane allows certain substances to pass through while blocking others.

Front

What are phospholipids and their role in the plasma membrane?

Back

Phospholipids are molecules that make up the bilayer of the plasma membrane, consisting of hydrophilic (water-attracting) heads and hydrophobic (water-repelling) tails.

Front

What is homeostasis and how does the plasma membrane contribute to it?

Back

Homeostasis is the maintenance of a stable internal environment in a cell. The plasma membrane contributes to homeostasis by controlling the movement of substances in and out of the cell.

Front

What are membrane proteins and their functions?

Back

Membrane proteins are proteins embedded in the plasma membrane that assist in various functions such as transport, signaling, and structural support.

Front

Explain the significance of hydrophobic fatty acid tails in the plasma membrane.

Back

Hydrophobic fatty acid tails prevent water-soluble substances from easily passing through the membrane, contributing to its selective permeability.

Front

What is the fluid mosaic model of the plasma membrane?

Back

The fluid mosaic model describes the plasma membrane as a flexible structure with various proteins floating in or on the fluid lipid bilayer.

Front

How do cholesterol molecules affect the plasma membrane?

Back

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

Front

What role do carbohydrates play in the plasma membrane?

Back

Carbohydrates attached to proteins and lipids on the extracellular surface of the plasma membrane play a key role in cell recognition and signaling.

Front

What is diffusion and how does it relate to the plasma membrane?

Back

Diffusion is the movement of molecules from an area of higher concentration to an area of lower concentration. The plasma membrane regulates diffusion to maintain homeostasis.