Chapter 3
The Cellular Level of Organization
Outline and Objectives
INTRODUCTION
1. Define a cell
2. Describe the connection between the chemical level of organization and cellular components.
3. Relate the essential importance of the cellular level of organization to all life forms.
A GENERALIZED VIEW OF THE CELL
4. Describe the three principal parts of a cell.
The Plasma Membrane
5. Describe how the “fluid mosaic model” concept appropriately describes the nature and structure of the plasma membrane.
The Lipid Bilayer
6. Explain how the chemical nature of the distinct regions of phospholipids
automatically produces a lipid bilayer in a water solution, with a range of
properties.
7. Describe the function of cholesterol and glycolipids in membranes.
Arrangement of Membrane Proteins
8. Distinguish between integral and peripheral proteins in cell membranes.
Functions of Membrane Proteins
9. Describe the chemistry and function of membrane proteins.
Membrane Fluidity
10. Discuss the fluidity of membranes and the mobility of membrane lipids and proteins.
11. Explain how cholesterol modifies membrane fluidity.
Membrane Permeability
12. Explain the mechanisms and factors involved in the selective movement of
materials across the cell membrane.
Gradients Across the Plasma Membrane
13. Define a chemical and electrical gradient and the predominant ions involved on opposite sides of the plasma membrane.
14. Explain how an electrical gradient leads to the membrane potential that exists
in cells of the body.
Transport Across the Plasma Membrane
15. Distinguish between passive and active transport, including direction of particle
movement and energy requirements.
16. Distinguish between nonmediated and mediated transport.
17. Discuss the role of transporter proteins in mediated transport.
18. Discuss the basis of vesicular transport.
Principles of Diffusion
19. Explain the concept of diffusion based on the kinetic energy of random motion in terms of concentration differences, net movement, and the properties of substances and conditions.
20. List and explain the factors that influence the diffusion rate of substances in solution.
Osmosis
21. Explain the process of osmosis as the net movement of a solvent through a
selectively permeable membrane.
22. Discuss the roles of hydrostatic pressure and osmotic pressure in regulating osmosis.
23. Show the relation of osmotic pressure to tonicity by the effect on red blood
cells of different concentrations of solute in a surrounding solution.
Diffusion Through the Lipid Bilayer
24. Describe the movement and importance of nonpolar, hydrophobic molecules
through the lipid bilayer of the plasma membrane.
Diffusion Through Membrane Channels
25. Describe the process of small, inorganic ion movement across the plasma membrane.
Facilitated Diffusion
26. Detail the facilitated diffusion characteristics and process where transporter
proteins move glucose molecules along their concentration gradients.
Active Transport
27. Define active transport and list two energy sources used to drive the process.
Primary Active Transport
28. Describe the process of primary active transport and relate it to the sodium pump.
Secondary Active Transport
29. Describe the process of secondary active transport and the role of symporters and antiporters.
30. Discuss the effect of digitalis on the sodium pump.
Vesicular Transport
31. Describe the two main types of vesicular transport between a cell and its
extracellular fluid.
Endocytosis
32. Describe the process of endocytosis.
Receptor-Mediated Endocytosis
33. Define ligand and discuss the function of ligands.
34. List and explain the steps involved in receptor-mediated endocytosis.
35. Describe how some viruses can use receptor-mediated endocytosis to infect body cells.
Phagocytosis
36. Define phagocytosis and explain its importance.
Pinocytosis
37. Define pinocytosis and explain its importance.
Exocytosis
38. Describe the process of exocytosis.
CYTOPLASM
39. List the two components of the cytoplasm.
Cytosol
40. Describe the elements of the cytosol and how it is different from the plasma membrane.
ORGANELLES
41. Describe the basic structural features and functions of organelles.
42. Distinguish between membranous and nonmembranous organelles.
The Cytoskeleton
43. Distinguish the characteristics and functions of microfilaments, microtubules, and intermediate filaments.
Centrosome
44. Show the relationship of cytoskeletal elements to centrioles and the
centrosome and note their purpose in dividing and nondividing cells.
Cilia and Flagella
45. Describe the arrangement of microtubules in flagella and cilia that allow these
projections to perform the different types of transport movements.
Ribosomes
46. Indicate the origin and components of ribosomes that allow them to produce
proteins, and their association with other organelles in this process.
Endoplasmic Reticulum
47. Specify how the interconnected form of the ER membranous labyrinth is
related to its various synthetic purposes and molecular distribution within the
cell.
Golgi Complex
48. Describe how the Golgi apparatus conducts the processing and directing of
newly synthesized molecules.
49. Convey how the faulty operation of the Golgi complex is related to cystic fibrosis.
Lysosomes
50. Delineate the role of lysosomal enzymes in protection, digestion, and recycling
of external and internal substances.
51. Describe how faulty lysosomes are related to Tay-Sachs disease.
Peroxisomes
52. Describe the enzymes and reactants peroxisomes use to deactivate potentially
toxic molecules.
Mitochondria
53. Indicate how the two membrane layers of the mitochondrion are associated
with the enzymes that produce the energy-storage molecule ATP.
54. Describe the role of DNA in mitochondrial replication.
Nucleus
55. Discuss the morphology and function of the nuclear envelope, nucleoli, and
hierarchical levels of chromatin.
Protein Synthesis
56. Accentuate that DNA acts by coding for structural and functional (enzyme)
proteins,and those proteins form all the structures and perform almost all the
metabolic reactions to generate and maintain an organism.
Transcription
57. Describe the steps of transcription and nucleotides of the DNA sequence that
are used to synthesize complementary sequences of RNA nucleotides of three
types.
58. Define the process and functions of the gene splicing of mRNA.
Translation
59. Provide the identity and function of all the molecules involved in the
translation process.
60. Illustrate the relation between the codes of the DNA nucleotide triplet, the
mRNA codon, and the rRNA anticodon that specifies an amino acid in the
protein sequence.
61. Go through the steps in which the molecular components of this process
interact to translate the mRNA sequence into a successive coupling of amino
acids in a protein.
62. Discuss the techniques of genetic engineering and recombinant DNA.
Normal Cell Division
63. Define cell division
64. Distinguish between somatic and reproductive cell division.
The Cell Cycle in Somatic Cells
65. Describe the purpose and activities of the DNA and cell components in each
phase of the interphase cell cycle.
Interphase
66. Indicate the objectives and activities of the DNA and cell components in each
phase of the interphase cell cycle.
Mitotic Phase
67. List the events of mitosis.
Nuclear Division: Mitosis
68. Describe the physical events of each phase occurring with the chromatids/
centromeres in relation to the spindle apparatus, and show the concomitant
development of other cell parts that allow the process.
Cytoplasmic Division: Cytokinesis
69. Explain what is happening to the cytoplasm, organelles, and plasma membrane
during cytokinesis, and why.
Control of Cell Destiny
70. List and describe the three possible destinies of a cell.
71. Describe the role of tumor-suppressor genes in the cell cycle.
Cells and Aging
72. Explain how the three main theories of aging (genetic programming, free
radical reactions, and excess immune response) lead to the signs of aging.
Cellular Diversity
73. Discuss the concept of cellular diversity.
Disorders: Homeostatic Imbalances
74. Describe cancer (CA) as a homeostatic imbalance of cells with different
characteristics for benign versus malignant tumors.
Types of Cancer
75. Distinguish the origins and properties of the different types of tumors.
Growth and Spread of Cancer
76. Describe the effects of hyperplasia, metastasis, and secondary site development
on normal tissue.
Causes of Cancer
77. Explain the nature of the numerous carcinogens and viruses and with which
cell growth control genes they may interact.
Carcinogenesis: A Multistep Process
78. Describe the features and progression of steps that lead a normal cell to
develop into a malignancy.
Treatment of Cancer
79. Discuss how it is that the multiple personalities of the cells within a tumor
make the differing drug therapies difficult or ineffective.
Medical Terminology
80. Define medical terminology associated with cells.