Exam 1 Objectives Flashcards
Describe the composition of the cell membrane.
Phospholipid bilayer with a hydrophilic heads on the outside and the hydrophobic tails on the inside.
there are proteins that are embedded within the membrane.
State at least three functions of the cell membrane.
The plasma membrane functions as a selective barrier that allows passage of enough oxygen, nutrients, and wastes to serve the entire cell.
Protects the cell from its surroundings.
Explain the function of the mitochondria.
Organelle where cellular respiration occurs and most ATP is generated.
There is mitochondrial DNA, most of which is from the mother.
Explain the function of the Lysosome.
Digestive organelle where macromolecules are hydrolyzed
Explain the function of the nucleus.
Contains most of the genes; contains a nuclear envelope, nucleolus, and chromatin.
Nuclear envelope: double membrane enclosing the nucleus; perforated by pores; continuous with the ER
Nucleolus: non-membranous structure involved in production of ribosomes; a nucleus has one or more nucleoli
Chromatin: material consisting of DNA and proteins; visible in a diving cell as individual condensed chromosomes
Explain the function of the endoplasmic reticulum
Network of membranous sacs and tubes; activate in membrane synthesis and other synthetic and metabolic processes; has rough (ribosome-studded) and smooth regions.
Explain the function of the Golgi complex.
Organelle active in synthesis, modification, sorting, and secretion of cell products
Explain the function of the Peroxisome.
Organelle with various specialized metabolic functions; produces hydrogen peroxides as a by-product, then converts it to water
Explain the function of microtubules.
Hollow rods that can grow in length by adding tubulin dimers to it; they shape and support the cell and also serve as tracks along which organelles equipped with motor proteins that can move; involved in the separation of chromosomes during cell division.
Explain the function of microfilaments.
Solid rods; built from molecules of actin; help support the cells shape and bear tension.
Explain the function of ribosomes.
Complexes that make proteins; free in cytosol or bound to rough ER or nuclear envelope.
Define the term etiology.
Cause of the disease (the pathogen)
Virus, bacteria, genetics, etc.
Define the term pathogenesis.
How the disease develops.
Progression of the illness.
What are some of the ways that a normal cell or tissue can adapt to stress.
Cells can undergo hypertrophy, hyperplasia, atrophy, metaplasia, dysplasia, and hypoplasia.
What is hypertrophy
Increased cell (organ) size in response to stress. Increased work load on cells that can't divide.
What is hyperplasia.
Increase in the number of cells.
Cells are capable of division.
What is atrophy.
Cells shrink by loss of cell substance.
May lose enough cells to effect the whole organ.
Shrunken cells: diminished function - not dead.
What is metaplasia.
Reversible change - one cell type is replaced by another.
Good thing in stress.
Improves function in light stress.
Increases risks.
What is dysplasia.
1
What is hypoplasia.
1
Discuss homeostasis.
Homeostasis is a physiological balance a steady state.
Biological systems try to maintain a steady state while adjusting to changes in the environment so that they can survive.
List the major causes of cell injury.
Hypoxia, chemical damage, genetic problems, physical damage, irradiation, infection, immune system reactions, nutritional causes of disease, aging.
Describe how hypoxia causes cell injury.
Oxygen deficiency.
Possible causes include ischemia, inadequate blood oxygenation, lower blood oxygen carrying capacity (not enough hemoglobin; CO2 binds to hemoglobin better than O2)
Describe how chemical damage can cause cell injury.
Substances cause damage to cells, often through membrane damage.
Possible causes include too much of a good thing (glucose, salt, water), potions, ethanol, air pollutants, asbestos
