Lec. 10 - Cell Transport

Question 1

Describe the composition of the lipid bilayer.

Answer 1

The lipid bilayer is broken down into 4 components, the phospholipids, cholesterol, proteins, and carbohydrates.

Question 2

Explain why the lipid bilayer is considered to be fluid.

Answer 2

It is considered to be fluid due to the dynamic nature of its components and their ability to move within the membrane.

Question 3

Compare osmosis and diffusion.

Answer 3

Diffusion is the passive movement of particles, it involves the movement of any type of particle, particles move against the concentration gradient, it can occur across any type of membrane, and it is driven by the movement of particles. Osmosis is the movement of molecules across a semiperable membrane from an area of lower solute concentration to an area of higher solute concentration.

Question 4

Describe how a concentration gradient determines the flow of molecules.

Answer 4

A concentration gradient is the difference in concentration of particles between to regions, so a concentration gradient is determined by the regions of higher and lower concentration, random motions, the rate of diffusion, and equilibrium.

Question 5

Describe the different types of passive transport.

Answer 5

Simple diffusion is where molecules move directly through the lipid bilayer of the cell membrane, facilitated diffusion involves the movement of larger or polar molecules that cannot pass through the lipid bilayer easily, osmosis is the transport involving the movement of water molecules.

Question 6

Describe the difference between a hypertonic, hypotonic, isotonic solution.

Answer 6

Hypertonic has a higher concentration of solutes compared to another, hypotonic has a lower concentration of solutes compared to another, and isotonic is when they are equal.