AP Biology Unit 2 Review Qs

Front

What is the structure of a phospholipid and how does it contribute to membrane fluidity?

Back

A phospholipid consists of a hydrophilic (water-attracting) 'head' and two hydrophobic (water-repelling) fatty acid 'tails'. The presence of double bonds in the fatty acid tails creates kinks, preventing tight packing and increasing membrane fluidity.

Front

What occurs to the membrane of a vesicle after exocytosis?

Back

After exocytosis, the membrane of the vesicle fuses with the plasma membrane, becoming part of it.

Front

What is the difference in diffusion between monosaccharides and disaccharides through a dialysis membrane?

Back

Monosaccharides, like fructose, can diffuse through the dialysis membrane due to their smaller size, while disaccharides, like lactose, cannot diffuse through because of their larger size.

Front

What is the fluid mosaic model of the plasma membrane?

Back

The fluid mosaic model describes the plasma membrane as a flexible layer made of lipid molecules with embedded proteins, allowing for movement and a variety of functions.

Front

Why is membrane fluidity important for the plasma membrane?

Back

Membrane fluidity is important because it allows for the movement of proteins and lipids within the membrane, facilitating cell signaling, transport, and maintaining mechanical strength.

Front

What are isotonic solutions and why are they important in medicine?

Back

Isotonic solutions have the same solute concentration as the blood, which helps maintain equilibrium and prevents the net movement of water into or out of cells, avoiding cell damage.

Front

How do double bonds in fatty acid tails affect membrane properties?

Back

Double bonds create kinks in the fatty acid tails, preventing them from packing closely together, which increases the fluidity of the membrane.

Front

What role do proteins play in the fluid mosaic model?

Back

Proteins in the fluid mosaic model serve various functions, including transport, acting as enzymes, and facilitating communication between cells.

Front

What is the significance of the dialysis experiment with lactose and fructose?

Back

The experiment demonstrates selective permeability of the dialysis membrane, showing that smaller molecules like fructose can pass through while larger molecules like lactose cannot.

Front

How does the structure of the plasma membrane contribute to its function?

Back

The plasma membrane's structure, with its lipid bilayer and embedded proteins, allows it to be selectively permeable, facilitating communication and transport while protecting the cell.