Chapter 3

Question 1

List the general functions of the plasma membrane

Answer 1

• Physical isolation
• Regulation of exchange within the environment
• Sensitivity to the environment
• Structural support

Question 2

What components of the plasma allow it to perform its characteristic functions?

Answer 2

• Membrane Lipids
• Membrane Proteins
• Membrane Carbohydrates

Question 3

What component of the plasma membrane is responsible for the membrane’s ability to form a physical barrier between the cells’ internal and external environment?

Answer 3

The phospholipid bilayer

Question 4

What type of integral protein allows water and small ions to pass through the plasma membrane?

Answer 4

Channel protein

Question 5

Differentiate between the cytoplasm and the cytosol.

Answer 5

Cytoplasm is the material between the plasma membrane and the nuclear membrane; cytosol is the fluid portion of the cytoplasm

Question 6

What are the major differences between cytosol and ECF?

Answer 6

Cytosol has a higher concentration of potassium ions and suspended proteins, and a lower concentration of sodium ions.

Question 7

The non membranous organelles and their functions:

Answer 7

1) centriole- cell division
2) cilia- moving materials over cell surface
3) cytoskeleton- strength and support
4) microvilli- increases surface area for absorption
5) proteasomes- breakdown and recycling of intracellular proteins
6) ribosomes- protein synthesis

Question 8

Membranous organelles and functions

Answer 8

1) endoplasmic reticulum- synthesis of secretory products
2) smooth ER- lipid and carb synthesis
3) rough ER- protein
4) Golgi apparatus- storage, alteration, packaging of products and enzymes
5) lysosomes- intracellular removal
6) mitochondria- energy production
7) peroxisomes- neutralize toxic

Question 9

Contents and structure of nucleus

Answer 9

Organelle
RNA + DNA
Double membrane surrounds nucleus (envelope)
Pores for communication

Question 10

Gene

Answer 10

Portion of DNA that functions as hereditary unit