2. OBJECTIVES
1. Identify and discuss the basic structure and function of the three major components of a cell.
2. List and briefly discuss the functions of the primary cellular organelles.
3. Compare the major passive and active transport processes that act to move substances through cell membranes.
4. Compare and discuss DNA and RNA and their function in protein synthesis.
5. Discuss the stages of mitosis and explain the importance of cellular reproduction.
6. Explain how epithelial tissue is grouped according to shape and arrangement of cells.
7. List and briefly discuss the major types of connective and muscle tissue.
8. List the three structural components of a neuron.

3. OUTLINE CELLS MOVEMENT OF SUBSTANCES THROUGH CELL MEMBRANES
Size and Shape
Composition
Parts of the Cell
Relationship of Cell Structure and Function
MOVEMENT OF SUBSTANCES THROUGH CELL MEMBRANES
Passive Transport Processes
Active Transport Processes
Cell Transport and Disease
CELL REPRODUCTION AND HEREDITY
DNA Molecule and Genetic information
Cells, Genetics, and Disease
Cell Division
Changes in Cell Growth and Reproduction
TISSUES
Epithelial Tissue
Connective Tissue
Muscle Tissue
Nervous Tissue
Tissue Repair

4. CELLS A. Size and shape B. Composition
1. Human cells vary considerably in size
2. All are microscopic
3. Cells differ notably in shape
B. Composition
1. Cytoplasm containing specialized organelles surrounded by a plasma membrane
2. Organization of cytoplasmic substances important for life
Page(s) 42-43

5. CELLS C. Structural parts Plasma membrane (Figure 3-1)
a. Forms outer boundary of cell
b. Thin, two-layered membrane of phospholipids containing proteins
c. Is selectively permeable
Page(s) 42-43

6. CELLS C. Structural parts 2. Cytoplasm (Figure 3-2) a. Organelles
(1) Ribosomes
(a) May attach to rough ER or lie free in cytoplasm
(b) Manufacture proteins
(c) Often called protein factories
Page(s) 43-45

7. CELLS C. Structural parts 2. Cytoplasm (Figure 3-2) a. Organelles
(2) Endoplasmic reticulum (ER)
(a) Network of connecting sacs and canals
(b) Carry substances through cytoplasm
(c) Types are rough and smooth
(d) Rough ER collects and transports proteins made by ribosomes
(e) Smooth ER synthesizes chemicals; makes new membrane
Page(s) 44, 46

8. CELLS 2. Cytoplasm (Figure 3-2) a. Organelles Page(s) 44, 46
(3) Golgi apparatus
(a) Group of flattened sacs near nucleus
(b) Collect chemicals that move from the smooth ER in vesicles
(c) Called the chemical processing and packaging center
Page(s) 44, 46

9. CELLS 2. Cytoplasm (Figure 3-2) a. Organelles Page(s) 44, 46
(4) Mitochondria
(a) Composed of inner and outer membranes
(b) Involved with energy-releasing chemical reactions
(c) Often called power plants of the cell
(d) Contains one DNA molecule
Page(s) 44, 46

10. CELLS 2. Cytoplasm (Figure 3-2) a. Organelles Page(s) 44, 46
(5) Lysosomes
(a) Membranous—walled organelles
(b) Contain digestive enzymes
(c) Have protective function (eat microbes)
(d) Formerly thought to be responsible for apoptosis (programmed cell death)
Page(s) 44, 46

11. CELLS C. Structural parts 2. Cytoplasm (Figure 3-2) a. Organelles
(6) Centrioles
(a) Paired organelles
(b) Lie at right angles to each other near nucleus
(c) Function in cell reproduction
Page(s) 44, 46

12. CELLS C. Structural parts 2. Cytoplasm (Figure 3-2) a. Organelles
(7) Microvilli
(a) Small, finger-like extensions of the plasma membrane
(b) Increase absorptive surface area of the cell
Page(s) 44, 47

13. CELLS C. Structural parts 2. Cytoplasm (Figure 3-2) a. Organelles
(8) Cilia
(a) Fine, hairlike extensions found on free or exposed surfaces of some cells
(b) Capable of moving in unison in a wavelike fashion
Page(s) 44, 47

14. CELLS C. Structural parts 2. Cytoplasm (Figure 3-2) Organelles
(9) Flagella
(a) Single projections extending from cell surfaces
(b) Much larger than cilia
(c) "Tails" of sperm cells only example of flagella in humans
Page(s) 44, 47

15. Page(s) 44

16. Page(s) 45

17. CELLS C. Structural parts 3. Nucleus
a. Controls cell because it contains the genetic code—instructions for making proteins, which in turn determine cell structure and function
b. Component structures include nuclear envelope, nucleoplasm, nucleolus, and chromatin granules
c. 46 chromosomes contain DNA, which contains the genetic code
Page(s) 47-48

18. CELLS D. Relationship of cell structure and function
1. Regulation of life processes
2. Survival of species through reproduction of the individual
3. Relationship of structure to function apparent in number and type of organelles seen in different cells
a. Heart muscle cells contain many mitochondria required to produce adequate energy needed for continued contractions
b. Flagellum of sperm cell gives motility, allowing movement of sperm through female reproductive tract, thus increasing chances for fertilization (Figure 3-3)
Page(s) 49

19. Page(s) 47

20. MOVEMENTS OF SUBSTANCES THROUGH CELL MEMBRANES
A. Passive transport processes do not require added energy and result in movement "down a concentration gradient"
1. Diffusion (Figure 3-4)
a. Substances scatter themselves evenly throughout an available space
b. It is unnecessary to add energy to the system
c. Movement is from high to low concentration
d. Osmosis and dialysis are specialized examples of diffusion across a selectively permeable membrane
e. Osmosis is diffusion of water (when some solutes cannot cross the membrane)
f. Dialysis is diffusion of solutes
Page(s) 49-50

21. Page(s) 51

22. MOVEMENTS OF SUBSTANCES THROUGH CELL MEMBRANES
A. Passive transport processes do not require added energy and result in movement "down a concentration gradient"
2. Filtration
a. Movement of water and solutes caused by hydrostatic pressure on one side of membrane
b. Responsible for urine formation
Page(s) 51

23. Page(s) 50

24. MOVEMENTS OF SUBSTANCES THROUGH CELL MEMBRANES
B. Active transport processes occur only in living cells; movement of substances is "up the concentration gradient"; requires energy from ATP
1. Ion pumps
a. An ion pump is protein complex in cell membrane
b. Ion pumps use energy from ATP to move substances across cell membranes against their concentration gradients
c. Examples: sodium-potassium pump (Figure 3-5), calcium pump
d. Some ion pumps work with other carriers so that glucose or amino acids are transported along with ions
Page(s) 51-52

25. Page(s) 53

26. MOVEMENTS OF SUBSTANCES THROUGH CELL MEMBRANES
B. Active transport processes occur only in living cells; movement of substances is "up the concentration gradient"; requires energy from ATP
2. Phagocytosis and pinocytosis
a. Both are active transport mechanisms because they require cell energy
b. Phagocytosis is a protective mechanism often used to destroy bacteria (Figure 3-6)
c. Pinocytosis is used to incorporate fluids or dissolved substances into cells
Page(s) 53-54

27. Page(s) 52

28. Page(s) 53

29. MOVEMENTS OF SUBSTANCES THROUGH CELL MEMBRANES
C. Several severe diseases result from damage to cell transport processes
1. Cystic fibrosis, characterized by abnormally thick secretions in the airways and digestive ducts, results from improper Cls transport (Figure 3-7)
2. Cholera is a bacterial infection that causes Cls and water to leak from cells lining the intestines, resulting in severe diarrhea and water loss
Page(s) 54-55

30. Page(s) 55

31. CELL REPRODUCTION
A. DNA structure—large molecule shaped like a spiral staircase; sugar (deoxyribose), and phosphate units compose sides of the molecule; base pairs (adenine-thymine or guanine-cytosine) compose "steps"; base pairs always the same but sequence of base pairs differs in different DNA molecules; a gene is a specific sequence of base pairs within a DNA molecule; genes dictate formation of enzymes and other proteins by ribosomes, thereby indirectly determining a cell’s structure and functions; in short, genes are heredity determinants (Figure 3-8)
Page(s) 55-56

32. CELL REPRODUCTION
Page(s) 56

33. CELL REPRODUCTION B. Genetic code
1. Genetic information—stored in base-pair sequences on genes—expressed through protein synthesis
2. RNA molecules and protein synthesis
a. DNA—contained in cell nucleus
b. Protein synthesis—occurs in cytoplasm, thus genetic information must pass from the nucleus to the cytoplasm
c. Process of transferring genetic information from nucleus to cytoplasm where proteins are produced requires completion of transcription and translation (Figure 3-8)
Page(s) 56-57

34. CELL REPRODUCTION
Page(s) 56

35. CELL REPRODUCTION B. Genetic code 3. Transcription 4. Translation
a. Double—stranded DNA separates to form messenger RNA (mRNA)
b. Each strand of mRNA duplicates a particular gene (base-pair sequence) from a segment of DNA
c. mRNA molecules pass from the nucleus to the cytoplasm, where they direct protein synthesis in ribosomes and ER
4. Translation
a. Involves synthesis of proteins in cytoplasm by ribosomes
b. Requires use of information contained in mRNA
Page(s) 57

36. CELL REPRODUCTION
C. Abnormal DNA that is inherited, or that results from damage from viruses or other factors, is often the basis of disease
D. Cell division—reproduction of cell involving division of the nucleus (mitosis) and the cytoplasm; period when the cell is not actively dividing is called interphase
E. DNA replication—process by which each half of a DNA molecule becomes a whole molecule identical to the original DNA molecule; precedes mitosis
F. Mitosis—process in cell division that distributes identical chromosomes (DNA molecules) to each new cell formed when the original cell divides; enables cells to reproduce their own kind; makes heredity possible
Page(s) 57-58

37. CELL REPRODUCTION G. Stages of mitosis (Figure 3-9)
1. Prophase—first stage
a. Chromatin granules become organized
b. Chromosomes (pairs of linked chromatids) appear
c. Centrioles move away from nucleus
d. Nuclear envelope disappears, freeing genetic material
e. Spindle fibers appear
Page(s) 58-59

38. Page(s) 59

39. CELL REPRODUCTION G. Stages of mitosis (Figure 3-9) Page(s) 59-60
2. Metaphase—second stage
a. Chromosomes align across center of cell
b. Spindle fibers attach themselves to each chromatid
3. Anaphase—third stage
a. Centromeres break apart
b. Separated chromatids now called chromosomes
c. Chromosomes are pulled to opposite ends of cell
d. Cleavage furrow develops at end of anaphase
4. Telophase—fourth stage
a. Cell division is completed
b. Nuclei appear in daughter cells
c. Nuclear envelope and nucleoli appear
d. Cytoplasm is divided (cytokinesis)
e. Daughter cells become fully functional
Page(s) 59-60

40. Page(s) 59

41. Page(s) 58

42. CELL REPRODUCTION H. Changes in cell growth and reproduction
1. Changes in growth of individual cells
a. Hypertrophy—increase in size of individual cells, increasing size of tissue
b. Atrophy—decrease in size of individual cells, decreasing size of tissue
2. Changes in cell reproduction
a. Hyperplasia—increase in cell reproduction, increasing size of tissue
b. Anaplasia—production of abnormal, undifferentiated cells
c. Uncontrolled cell reproduction results in formation of a benign or malignant neoplasm (tumor) (Figure 3-10)
Page(s) 60-61

43. Page(s) 61

44. Page(s) 60

45. Page(s) 62

46. TISSUES (TABLES 3-7 THROUGH 3-9)
A. Epithelial tissue
1. Covers body and lines body cavities
2. Cells packed closely together with little matrix
3. Classified by shape of cells (Figure 3-11)
a. Squamous
b. Cuboidal
c. Columnar
d. Transitional
Page(s) 62-63

47. Page(s) 63

48. TISSUES (TABLES 3-7 THROUGH 3-9)
A. Epithelial tissue
4. Classified by arrangement of cells
a. Simple
b. Stratified
5. Simple squamous epithelium (Figure 3-12)
a. Single layer of scalelike cells
b. Transport (e.g., absorption) is function
6. Stratified squamous epithelium (Figure 3-13)
a. Several layers of closely packed cells
b. Protection is primary function
Page(s) 64-65

49. Page(s) 64-65

50. TISSUES (TABLES 3-7 THROUGH 3-9)
A. Epithelial tissue
7. Simple columnar epithelium (Figure 3-14)
a. Columnar cells arranged in a single layer
b. Line stomach and intestines
c. Contain mucus-producing goblet cells
d. Specialized for absorption
8. Stratified transitional epithelium (Figure 3-15)
a. Found in body areas, such as urinary bladder, that stretch
b. Up to 10 layers of roughly cuboidal shaped cells that distort to squamous shape when stretched
9. Pseudostratified epithelium
a. Each cell touches basement membrane
b. Lines the trachea
Page(s) 64-65

51. Page(s) 66

52. TISSUES (TABLES 3-7 THROUGH 3-9)
A. Epithelial tissue
10. Simple cuboidal epithelium (Figure 3-16)
a. Often specialized for secretory activity
b. Cuboidal cells may be grouped into glands
c. May secrete into ducts, directly into blood, and on body surface
d. Examples of secretions include saliva, digestive juice, and hormones
e. Cuboidal epithelium also forms the urine—producing tubules of the kidney
Page(s) 65, 67

53. Page(s) 68

54. TISSUES (TABLES 3-7 THROUGH 3-9)
B. Connective tissue
1. Most abundant tissue in body
2. Most widely distributed tissue in body
3. Multiple types, appearances, and functions
4. Relatively few cells in intercellular matrix
5. Types
a. Areolar—glue that holds organs together
b. Adipose (fat)—lipid storage is primary function (Figure 3-17)
Page(s) 67-68

55. Page(s) 72

56. TISSUES (TABLES 3-7 THROUGH 3-9)
B. Connective tissue
5. Types
c. Fibrous—strong fibers; example is tendon (Figure 3-18)
Page(s) 68-69

57. TISSUES (TABLES 3-7 THROUGH 3-9)
B. Connective tissue
5. Types
d. Bone—matrix is calcified; function is support and protection (Figure 3-19)
Page(s) 69

58. TISSUES (TABLES 3-7 THROUGH 3-9)
B. Connective tissue
5. Types
e. Cartilage—chondrocyte is cell type (Figure 3-20)
Page(s) 69

59. TISSUES (TABLES 3-7 THROUGH 3-9)
B. Connective tissue
5. Types
f. Blood—matrix is fluid; function is transportation (Figure 3-21)
Page(s) 69-70

60. Page(s) 73

61. TISSUES (TABLES 3-7 THROUGH 3-9)
C. Muscle tissue (Figures 3-22 to 3-24)
1. Types
a. Skeletal—attaches to bones; also called striated or voluntary; control is voluntary; striations apparent when viewed under a microscope (Figure 3-22)
Page(s) 71

62. TISSUES (TABLES 3-7 THROUGH 3-9)
C. Muscle tissue (Figures 3-22 to 3-24)
1. Types
b. Cardiac—also called striateal involuntary; composes heart wall; ordinarily cannot control contractions (Figure 3-23)
Page(s) 71

63. TISSUES (TABLES 3-7 THROUGH 3-9)
C. Muscle tissue (Figures 3-22 to 3-24)
1. Types
c. Smooth—also called nonstriated (visceral) or involuntary; no cross striations; found in blood vessels and other tube—shaped organs (Figure 3-24)
Page(s) 71-72

64. TISSUES (TABLES 3-7 THROUGH 3-9)
D. Nervous tissue (Figure 3-25)
1. Cell types
a. Neurons—conducting cells
b. Glia (neuroglia)—supportive and connecting cells
2. Neurons
a. Cell components
(1) Cell body
(2) Axon (one) carries nerve impulse away from cell body
(3) Dendrites (one or more) carry nerve impulse toward the cell body
3. Function—rapid communication between body structures and control of body functions
Page(s) 72, 74

65. TISSUES (TABLES 3-7 THROUGH 3-9)
E. Tissue repair—usually accomplished by means of regeneration of tissue
1. Epithelial and connective tissues regenerate easily
2. Muscle and nervous tissues have very limited abilities to repair themselves
Page(s) 73-74

66. Credits
All photos and references are taken from:
Thibodeau, Gary, & Patton, Kevin. (2005). The Human body in health & disease. Mosby. ISBN: