Unit 2 Flashcard 2: Cell Size and Plasma Membranes

Front

What is the structure of a phospholipid?

Back

A phospholipid consists of a hydrophilic (water-attracting) 'head' and two hydrophobic (water-repelling) 'tails'. This structure allows them to form bilayers in cell membranes.

Front

What is the function of the plasma membrane?

Back

The plasma membrane regulates the movement of substances in and out of the cell, providing protection and structural support.

Front

How does cell size affect the surface area to volume ratio?

Back

As a cell increases in size, its volume increases faster than its surface area, leading to a decreased surface area to volume ratio.

Front

Why is a high surface area to volume ratio important for cells?

Back

A high surface area to volume ratio allows for more efficient exchange of materials (like oxygen and nutrients) with the environment.

Front

What role do proteins play in the plasma membrane?

Back

Proteins embedded in the plasma membrane assist in transport, act as receptors, and provide structural support.

Front

What is the significance 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.

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 osmosis?

Back

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

Front

What is the function of glycoproteins in the plasma membrane?

Back

Glycoproteins serve as recognition sites for cell signaling and communication, playing a key role in immune response.

Front

What is the fluid mosaic model?

Back

The fluid mosaic model describes the structure of the plasma membrane as a mosaic of various components (lipids, proteins, carbohydrates) that move freely within the layer.