2B - Passive Transport

Question 1

Diffusion

Answer 1

The passive transport of molecules from an area of high concentration to an area of low concentration

Question 2

Why does simple diffusion not require energy

Answer 2

Due to the kinetic energy enabling the molecules to bound off each other

Question 3

What does the kinetic energy (rather the process of simple diffusion try to achieve)

Answer 3

An even dispersion of molecules in an area

Question 4

Features that enable molecules to freely diffuse across the plasma membrane

Answer 4

• Hydrophobic
• Non-polar
• Not charged
• Small

Question 5

Why specifically hydrophobic or non-polar molecules?

Answer 5

Because non-polar molecules tend to have an affinity for each other

Most of the plasma membrane is non-polar (hydrophobic) due to the fatty acid tails making up the majority of the plasma membrane

Question 6

Why can’t charged molecules cross the plasma membrane although they may be the perfect size

Answer 6

Because the charge of these ions prevents them from crossing the plasma membrane

Question 7

Ex. of these molecules that can freely diffuse across the plasma membrane

Answer 7

1. Proteins
2. Glucose
3. Amino Acids
4. Nucleic acid