Homework Part 2

Question 1

What are the four basic mechanisms by which solute molecules move across membranes?

Answer 1

1. Passive diffusion
2. Facilitated diffusion
3. Active transport
   4.Cotransport

These mechanisms include both energy-dependent and energy-independent processes.

Question 2

Define passive diffusion.

Answer 2

The movement of solute molecules across a membrane without the use of energy, down their concentration gradient.

This process relies on the inherent kinetic energy of molecules.

Question 3

What is facilitated diffusion?

Answer 3

The process of spontaneous passive transport of molecules across a membrane via specific transmembrane integral proteins.

Unlike passive diffusion, facilitated diffusion requires carrier proteins.

Question 4

What is active transport?

Answer 4

The movement of solute molecules across a membrane against their concentration gradient, requiring energy, typically in the form of ATP.

Active transport is crucial for maintaining concentration gradients in cells.

Question 5

What is bulk transport?

Answer 5

The movement of large quantities of substances across the membrane via vesicles.

This includes processes such as endocytosis and exocytosis.

Question 6

Fill in the blank: The movement of solute molecules across a membrane without the use of energy is called _______.

Answer 6

Passive diffusion

Question 7

True or False: Active transport does not require energy.

Answer 7

False

Question 8

Fill in the blank: The process of moving molecules against their concentration gradient is known as _______.

Answer 8

Active transport

Question 9

What role do carrier proteins play in facilitated diffusion?

Answer 9

They assist in the transport of specific molecules across the membrane without energy expenditure.

Carrier proteins change shape to help transport molecules.

Question 10

Name the two types of bulk transport.

Answer 10

1. Endocytosis
2. Exocytosis

Endocytosis involves intake of materials, while exocytosis involves expulsion.