Exam 1 Objectives

Question 1

Describe the composition of the cell membrane.

Answer 1

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.

Question 2

State at least three functions of the cell membrane.

Answer 2

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.

Question 3

Explain the function of the mitochondria.

Answer 3

Organelle where cellular respiration occurs and most ATP is generated.
There is mitochondrial DNA, most of which is from the mother.

Question 4

Explain the function of the Lysosome.

Answer 4

Digestive organelle where macromolecules are hydrolyzed

Question 5

Explain the function of the nucleus.

Answer 5

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

Question 6

Explain the function of the endoplasmic reticulum

Answer 6

Network of membranous sacs and tubes; activate in membrane synthesis and other synthetic and metabolic processes; has rough (ribosome-studded) and smooth regions.

Question 7

Explain the function of the Golgi complex.

Answer 7

Organelle active in synthesis, modification, sorting, and secretion of cell products

Question 8

Explain the function of the Peroxisome.

Answer 8

Organelle with various specialized metabolic functions; produces hydrogen peroxides as a by-product, then converts it to water

Question 9

Explain the function of microtubules.

Answer 9

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.

Question 10

Explain the function of microfilaments.

Answer 10

Solid rods; built from molecules of actin; help support the cells shape and bear tension.

Question 11

Explain the function of ribosomes.

Answer 11

Complexes that make proteins; free in cytosol or bound to rough ER or nuclear envelope.

Question 12

Define the term etiology.

Answer 12

Cause of the disease (the pathogen)

Virus, bacteria, genetics, etc.

Question 13

Define the term pathogenesis.

Answer 13

How the disease develops.

Progression of the illness.

Question 14

What are some of the ways that a normal cell or tissue can adapt to stress.

Answer 14

Cells can undergo hypertrophy, hyperplasia, atrophy, metaplasia, dysplasia, and hypoplasia.

Question 15

What is hypertrophy

Answer 15

Increased cell (organ) size in response to stress.
Increased work load on cells that can't divide.

Question 16

What is hyperplasia.

Answer 16

Increase in the number of cells.

Cells are capable of division.

Question 17

What is atrophy.

Answer 17

Cells shrink by loss of cell substance.
May lose enough cells to effect the whole organ.
Shrunken cells: diminished function - not dead.

Question 18

What is metaplasia.

Answer 18

Reversible change - one cell type is replaced by another.
Good thing in stress.
Improves function in light stress.
Increases risks.

Question 19

What is dysplasia.

Answer 19

1

Question 20

What is hypoplasia.

Answer 20

1

Question 21

Discuss homeostasis.

Answer 21

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.

Question 22

List the major causes of cell injury.

Answer 22

Hypoxia, chemical damage, genetic problems, physical damage, irradiation, infection, immune system reactions, nutritional causes of disease, aging.

Question 23

Describe how hypoxia causes cell injury.

Answer 23

Oxygen deficiency.
Possible causes include ischemia, inadequate blood oxygenation, lower blood oxygen carrying capacity (not enough hemoglobin; CO2 binds to hemoglobin better than O2)

Question 24

Describe how chemical damage can cause cell injury.

Answer 24

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

Question 25

Describe how genetic problems can cause cell injury.

Answer 25

Congenital or later mutations.

Possible causes include inherited defects and accumulation of damaged DNA or proteins.

Question 26

Describe how physical damage can cause cell injury.

Answer 26

Outside action by the physical world.
Possible causes include temperature (burns), mechanical damage, electric shock, barometer pressure (scuba diving), and radiation (UV light)

Question 27

Describe how irradiation can cause cell injury.

Answer 27

Categorized with physical damage.
Electromagnetic or particulate.
Danger from radiation is based on strength of dose and duration of dose and what part of the body is exposed.
Exposed radiation all day every day (0.001 rad average daily - this is normal and okay, need to be exposed to a lot to cause damage)

Question 28

Describe how infection can cause cell damage.

Answer 28

Infection could be caused by a virus, fungi, protozoa, other parasites, and bacteria cause various type of damage.
Toxins are especially likely culprits with cellular injury from bacteria.

Question 29

Describe how immune system reactions can cause cell damage.

Answer 29

Can be caused by autoimmunity, allergy, and chronic inflammation

Question 30

Describe how nutritional causes of disease can cause cell damage.

Answer 30

Can be caused by calorie deficiency, specific vitamin deficiency, obesity, and improper nutrition.

Question 31

Describe how aging can cause cell damage.

Answer 31

Overall, aging or senescence results in cells which are less able to respond to damage. It takes longer to recover.