CH. 4 - CELL STRUCTURE
I. CELL THEORY
A. CELL = basic unit of life - ALL LIFE COMPOSED OF CELLS
B. ARISE from pre-existing cells - HEREDITARY INFO IN CELLS - passed on
(Viruses?) (1st cell?)
II. AUTOTROPHS & HETEROTROPHS
A. AUTOTROPHS- Self feeding, plants.
B. HETEROTROPHS - Other feeding, animals, fungi, etc.
III. CELLS - 2 TYPES
A. PROKARYOTES - Before (no) nucleus. (p. 63-65)
1. No membrane-bound organelles.
2. "Naked" DNA, no histone proteins
B. EUKARYOTES - True nucleus. (p. 66-67)
1. Have membrane-bound organelles.
2. Has DNA + histone proteins.
IV. MICROSCOPES - because cells are small (p. 62)
A. LIGHT - color, live, easy prep, quick, 1200X, slides
B. ELECTRON - B & W, dead, tough prep, time-consuming
1. Transmission E.M. - see internal of specimen if it is cut thinly enough.
1,000,000x. Great resolution.
2. Scanning E.M. - surface detail (like radar).
V. ULTRASTRUCTURE = Membrane + Nucleus + cytoplasm & organelles + cytoskeleton
* * * KNOW TABLE 4.2, p. 78
A. MEMBRANE - surrounds cell, Ch. 5
B. NUCLEUS - cell "brain" (p. 68)
- heredity & stores information.
- controls cell physiology
1. Nuclear envelope. double membrane, pores
2. Nucleolus - manufactures ribosome parts (rRNA)
3. Chromatin = DNA + histone proteins
a. Normally, thread-like, loosely coiled fibers
b. Chromosomes- tightly coiled, visible during cell division.
C. ORGANELLES: - "division of labor"
1. Vacuoles - water storage & support
2. Vesicles - smaller, transport in or out.
3. Ribosomes - "Protein factory" (small). No membranes. (p. 69)
a. Free - proteins for the cell use
b. Attached (to E.R.) - proteins for export/external use
4. Endoplasmic reticulum - network of tubes for transport
and communication (p. 70)
a. Smooth E.R. - S.E.R.- Lipid factories, detox, modification
b. Rough E.R. - R.E.R. - ribosomes, proteins for export
5. Golgi complex - Looks like a stack of flattened sacs.
Processing, packaging & distribution of vesicles. (p. 70)
6. Lysosome stomach of the cell, contains powerful enzymes (p. 72)
7. Microbodies - isolate specific chemical rxns from cell
8. Mitochondria cell Power house, makes ATP, respiration
9. Chloroplasts - photosynthesis
D. CYTOSKELETON - in cytoplasm, (p. 76)
1. Microfilaments = Actin, solid, smallest, support & intracellular movement.
Actin and Myosin, muscle contraction. Permanent.
2. Microtubules - hollow & large, transient or permanent, 9+2
a. Cilia - Small, numerous, moves things outside cell
b. Flagella - longer, fewer, cell motility.
c. Spindle - cell division, transient
3. Intermediate filaments - solid, fewest, middle-sized.
lots of them in skin. Permanent.
4. Centrioles animal, associated with nucleus, cell division, produce spindle,
MTOC.
VI. PLANT vs. ANIMAL CELLS - *KNOW* (Tab. 4-3, p. 81)