Understanding Disease at the Cellular Level

Question 1

Cell

Answer 1

The basic unit of all living things.

Question 2

Nucleus

Answer 2

The central portion of the cell that contains organelles and other components.

Question 3

Organelles

Answer 3

Structures within the nucleus that carry out necessary biological processes.

Question 4

Prokaryotic Cells

Answer 4

Do not contain a nucleus.

Question 5

Eukaryotic Cells

Answer 5

Contain a nucleus and organelles.

Question 6

Plasma Membrane

Answer 6

The membrane that surrounds a cell.

Question 7

Lipid Bilayer

Answer 7

The two layers of phospholipids (hydrophobic tail and hydrophilic head) that form the cell membrane.

Question 8

Cell Membrane

Answer 8

(Plasma membrane); the outer covering of a cell.

Question 9

Cytoplasm

Answer 9

(Cytosol); Fluid inside a cell that consists of water, salts, organic molecules, and many enzymes that catalyze numerous biochemical reactions.

Question 10

Integral Proteins

Answer 10

Span the entire lipid bilayer of the cellular membrane.

Question 11

Peripheral Membrane Proteins

Answer 11

Embedded on the membrane surface.

Question 12

What four roles does the plasma membrane play?

Answer 12

1. Ability of cells to adhere to one another using linkers called Cell Adhesion Molecules (CAMs) that extend out and help in movement, tissue development, and healing.
2. Cell-cell recognition using glycoproteins.
3. Communication between cells.
4. Regulates movement of substances into and out of the cell.

Question 13

Simple Diffusion

Answer 13

Random movement from region of high to region of low concentration.

Question 14

Facilitated Diffusion

Answer 14

Movement from region of high to region of low concentration with the aid of a carrier or channel protein.

Question 15

Osmosis

Answer 15

Movement of water from a region of high water concentration (low solute concentration) to a region of low water concentration (high solute concentration).

Question 16

Active Transport

Answer 16

Movement from region of high to region of low concentration with the aid of a carrier or channel protein, usually ATP.

Question 17

Endositosis

Answer 17

Materials engulfed by the plasma membrane and drawn into the cell in a vesicle.

Question 18

Exositosis

Answer 18

Membrane-bound vesicle from inside the cell fuses with plasma membrane and spills contents outside the cell.

Question 19

Concentration Gradient

Answer 19

The difference in number of molecules or ions of the substance on one side of the membrane from the number of molecules on the other. The greater the concentration gradient, the more rapid the rate of diffusion.

Question 20

Osmotic Gradient

Answer 20

Applies specifically to the movement of water across as semipermeable membrane.

Question 21

What is the universal solvent needed for many biochemical reactions?

Answer 21

Water.

Question 22

Isotonic

Answer 22

When the concentrations of solutions on both sides of a semipermeable membrane are equal.

Question 23

Hypertonic

Answer 23

When a solution on one side of the membrane is more concentrated than the solution on the other side.

Question 24

Hypotonic

Answer 24

When a solution on one side of the membrane is less concentrated than the solution on the other side.

Question 25

Osmotic Pressure

Answer 25

The pressure exerted by the concentration of solutes on one side of a membrane that, if hypertonic, tends to "pull" water (cause osmosis) from the other side of the membrane.

Question 26

Osmolarity

Answer 26

The concentration of solute particles in a solution.

Question 27

Osmolality

Answer 27

A measurement used to measure the concentration of particles in body fluids such as plasma and urine.

Question 28

Which particles cannot move through the plasma membrane by simple diffusion?

Answer 28

Water-soluble and ionized molecules.

Question 29

Carrier Proteins

Answer 29

(Transporters); bind a specific type of solute and are induced to undergo a series of conformational changes that effectively carries the solute to the other side of the membrane.

Question 30

Ion Channels

Answer 30

Hydrophilic pores through the membrane that open and allow certain types of solutes, usually inorganic ions, to pass through.

Question 31

Which type of active transport is faster: carrier proteins or ion channels?

Answer 31

Ion channels.

Question 32

Ligand

Answer 32

A molecule that will bind to a site.

Question 33

What are the two types of ion channels?

Answer 33

Voltage-gated and Ligand-gated.

Question 34

Sodium-Potassium Pump

Answer 34

Transports sodium ions out of the cell and potassium ions into the cell, against the concentration gradient. It is an enzyme (Na+-K+-ATPase) in the plasma membrane and it is powered by ATP. Three sodium ions go out, two potassium ions come in.

Question 35

Phagocytosis

Answer 35

The process whereby the cell engulfs large particles or bacteria.

Question 36

Pinocytosis

Answer 36

The process by which the cell engulfs droplets of fluid carrying dissolved substances.

Question 37

What percentage of body weight does water account for?

Answer 37

Approximately 60%.

Question 38

Total Body Water (TBW)

Answer 38

The total amount of water in the body at any given time.

Question 39

What is the largest water compartment in the body?

Answer 39

Intracellular compartment. Accounts for approximately 70% of all body water.

Question 40

Intravascular Fluid

Answer 40

Extracellular fluid found in the circulatory system. Accounts for 5% of body water.

Question 41

Interstitial Fluid

Answer 41

Extracellular fluid outside of the circulatory system. Accounts for 25% of body water.

Question 42

Dehydration

Answer 42

An abnormal decrease in TBW.

Question 43

What are the five main causes of dehydration?

Answer 43

Gastrointestinal losses, increased insensible losses, increased sweating, internal losses, and plasma losses.

Question 44

What are the signs of dehydration?

Answer 44

Initial signs include dry mucous membranes, poor skin turgor, and increased thirst. Next will be an increase in pulse, decreased blood pressure, and orthostatic hypotention.

Question 45

What are the four major elements?

Answer 45

Hydrogen (H), Oxygen (O), Carbon (C), and Nitrogen (N).

Question 46

What are the nine trace elements?

Answer 46

Calcium (Ca), Chlorine (Cl), Iodine (I), Iron (Fe), Magnesium (Mg), Phosphorus (Ph), Potassium (K), Sodium (Na), and Sulfur (S).

Question 47

Electrolytes

Answer 47

Substances that dissociate into electrically charged particles when placed into water.

Question 48

Name four cations.

Answer 48

Sodium (Na+), Potassium (K+), Calcium (Ca++), and Magnesium (Mg++).

Question 49

Name three anions.

Answer 49

Chlorine (Cl-), Bicarbonate, and Phosphate.

Question 50

Oncotic Force

Answer 50

(Colloid osmotic pressure); a form of osmotic pressure exerted by the large proteins present in blood plasma. In capillaries, plasma colloids tend to pull water from the interstitial space across the capillary membrane into the capillary.

Question 51

Hydrostatic Pressure

Answer 51

Blood pressure; the force exerted against the walls of the blood vessels, created by contractions of the heart.

Question 52

Filtration

Answer 52

Movement of water out of the plasma, across the capillary membrane, into the interstitial space; movement of molecules across a membrane from an area of higher pressure to an area of lower pressure.

Question 53

Net Filtration

Answer 53

(Starlings Hypothesis) Net Filtration = (forces favoring filtration)-(forces opposing filtration); hydrostatic pressure forces water out of the capillaries, into the interstitial space. The higher concentration of plasma proteins pulls the water back using osmosis. Therefore, water is retained in the intravascular space.

Question 54

Antidiuretic Hormone (ADH)

Answer 54

(Vasopressin); the cheif water retention and distribution regulator.

Question 55

Where are osmoreceptors located?

Answer 55

In the anterior hypothalamus. They release ADH to increase fluid retention if osmolality increases by 1-2 percent.

Question 56

Where are baroreceptors located?

Answer 56

In the carotid sinus, aortic arch, and kidney. They detect changes in pressure and send signals to the hypothalamus to release ADH.

Question 57

Edema

Answer 57

The accumulation of water in the interstitial space, caused by a decrease in plasma oncotic force, an increase in hydrostatic pressure, increased permeability of the capillary membrane, and lymph obstruction.