Mcat: The Eukaryotic Cell; The Nervous System

Front 1

Nucleus

Back 1

Contains DNA of animal cell.

Front 2

Nuclear Envelope

Back 2

Double phospholipid bilayer outside nucleus contains nuclear pores for RNA to exit.

Front 3

Nucleolus

Back 3

Site where rRNA trancribed and ribosomes are assembled.

Front 4

Endocytosis

Back 4

Method for aquiring substances from the extracellular environment.

Front 5

Phagocytosis

Back 5

The cell membrane protrudes outward to envelope and engulf particulate matter. The matter is recognized by specific proteins.

Front 6

Pinocytosis

Back 6

Extracellular fluid is engulfed by small invaginations of the cell membrane.

Front 7

Exocytosis

Back 7

Removal of particles from the cell.

Front 8

Rough Endoplasmic Reticulum

Back 8

Is where ribosomes attach and make proteins that are to be transported outside the cell. The proteins are translated into the lumen of the ER.

Front 9

Smooth Endoplasmic Reticulum

Back 9

Lipid sythesis and detoxification of some drugs.

Front 10

Golgi Appartus

Back 10

Modifies and packages proteins for use in other parts of the cell and outside the cell.

Front 11

Secretory Vesicles

Back 11

Contain enzymes, growth factors, or extracellular matrix components. Release cotnents through exocytosis and because of this incorporates into cell membranes and can be used to supply cell membrane with its integral proteins and lipids and membrane expansion.

Front 12

Lysosomes

Back 12

Contain hydrolytic enzymes that digest substances taken in by endocytosis. Lysosomes come from the Golgi. The hyrdolytic enzymes of lysosomes are activated by a low pH achieved by pumping protons into the interior.

Front 13

Peroxisomes

Back 13

Vesicles in the cytosol that inactivate toxic substances, regulate oxygen concentration, breakdown lipids, and metabolism of nitrogenous bases and carbohydrates.

Front 14

Cytoskeletan

Back 14

Moves components within cell and moves cell itself.

Front 15

Microtubules

Back 15

Tubulin, Flagella and Cilia; have a 9 + 2 arrangement.

Front 16

Microfilaments

Back 16

Actin; produce the contracting force in muscle as well as being active in cytoplasmic streaming, phagocytosis, and microilli movement.

Front 17

Tight Junction

Back 17

Attachment between cells that prevents the movement of fluid around cells. Example bladder, intestines, kidney

Front 18

Desmosome

Back 18

Attachment between cells that join two cells together at a single point and attach directly to the cytoskeleton of each cell. Example Skin

Front 19

Gap Junction

Back 19

Attachment between cells that allows exchange of small molecules. Example: Cardiac Muscle

Front 20

Mitochondria

Back 20

May have evolved according to the symbiotic relationship between prokaryotes and eukaryotes (endosymbiotic theory), contain own genetic information, and are involved in respiration for energy.

Front 21

Neuronal Communication

Back 21

Rapid, Direct, and Specific.

Front 22

Hormonal Communication

Back 22

Slower, Spread throughout the body, and affect many cells and tissues in many different ways.

Front 23

Interstitial Fluid

Back 23

Fluid between cells.

Front 24

Neuron

Back 24

Highly specialized cell capable of transmitting an electrical signal from one cell to another via electrical or chemical means. Uses glucose for energy and is not dependant on insulin for transport of glucose. Contain dendrites (receive signal), cell body, axon (send signal).

Front 25

Axon Hillock

Back 25

If stimulus received from dendrite is strong enough generates action potential in all directions including down the axon.

Front 26

Action Potential

Back 26

Is a disturbance in the elecric field across the membrane of a neuron.

Front 27

Resting Potential

Back 27

established mainly by an equilibrium between passive diffusion of ions and the Na+/K+ pump. A negative charge is established inside the cell and a positive charge outside this makes the potential difference.

Front 28

Na+/K+ Pump

Back 28

Moves three positively charged sodium ions out of the cell while bringing in two positively charged potassium ions into the cell.

Front 29

Voltage Gated Sodium Channels

Back 29

Proteins change configuration when the voltage across the membrane is disturbed. Allow for Sodium to pass to the inside of the cell.

Front 30

Depolarization

Back 30

The net influx of sodium because of the voltage gated channels causes an increase the polarity so that it becomes positive.

Front 31

Voltage Gated Potassium Channels

Back 31

Less sensitive to voltage change and take longer to open. By the time they begin to open sodium channels begin to close.

Front 32

Repolarization

Back 32

K+ flows out of the cell making the cell more negative.

Front 33

Hyperpolariztion

Back 33

Because potassium channels are slow to close therefore the inside membrane is a little more negative than at resting potential.

Front 34

All or Nothing Principle

Back 34

The membrance completely depolarizes or no action potential is genereated. The stiumulus must be greater than the threshold stimulus.

Front 35

Synapse

Back 35

Where neural impulses are transmitted from one cell to another chemically or electrically.

Front 36

Electrical Synapse

Back 36

Fast, gap junctions, cardiac muscle, visceral smooth muscle.

Front 37

Chemical Synapse

Back 37

Unidirectional, contain vesicles with neurotransmitters, activated when Ca+ attaches.

Front 38

Synaptic Cleft

Back 38

Space between pre-synaptic and post-synaptic neurons.

Front 39

Brownian Motion

Back 39

Random motion of molecules.