N2060 2020
Patho: Chapters 1, 2, 3 Study Objectives
CHAPTER 1
1. Compare and contrast the two major classes of living cells.
2. Prokaryotes:
... [Show More]
a. Structure:
i. Lack of distinct nucleus
ii. Nuclear material is not encased by a nuclear membrane
iii. No organelles
iv. Examples: fungi, protozoa, most algae; cyanobacteria (blue-green algae), bacteria, Rickettsiae
b. Chemical Composition and Biochemical Activity:
i. Nuclei carry genetic information in a single circular chromosome
ii. Lack histones (class of proteins)
iii. Protein production differs due to structural differences in RNA protein complexes
iv. Differences in mechanisms of transport
v. Differences in enzyme content
3. Eukaryotes:
a. Structure:
i. Larger
ii. Well defined nucleus
iii. Characteristic set of membrane bound organelles
iv. Complex cellular organization
v. Examples: Higher animals and plants, fungi, protozoa
b. Chemical Composition and Biochemical Activity:
i. Have several chromosomes
ii. Histones in eukaryotic cells bind with DNA (loops and coiling of DNA are important for many diseases)
iii. Protein production differs due to structural differences in RNA protein complexes
iv. Differences in mechanisms of transport
v. Differences in enzyme content
1. Describe and provide examples of the eight major cellular functions: movement, conductivity, absorption, secretion, excretion, respiration, reproduction, and communication.
Cells become specialized through the process of differentiation or maturation
1. Movement: Muscle cells can generate forces that produce motion. Muscles that are attached to bones produce limb movements, whereas those that enclose hollow tubes or cavities move or empty contents when they contract.
○ Example: The contraction of smooth muscle cells surrounding blood vessels changes the diameter of the vessels; the contraction of muscles in the walls of the urinary bladder expels urine.
2. Conductivity: Conduction as a response to a stimulus is manifested by a wave of excitation, an electrical potential that passes along the surface of the cell to reach its other parts. Conductivity is the chief function of nerve cells.
3. Metabolic absorption: All cells take in and use nutrients and other substances from their surroundings. Cells of the intestine and the kidney are specialized to carry out absorption. Cells of the kidney tubules reabsorb fluids and synthesize proteins. Intestinal epithelial cells reabsorb fluids and synthesize protein enzymes. [Show Less]