The Cell

Front 1

theory of endosymbiosis

Back 1

eukaryotic cells emerged when mitochondria and chloroplasts, once free-living prokaryotes, took up permanent residence inside other larger cells

Front 2

Schleiden and Schwann

Back 2

states that all organisms are composed of cells

Front 3

Virchow

Back 3

states that all cells arise from preexisting cells

Front 4

cell theory

Back 4

1) all living things are composed of cells
2) cells are the basic unit of all organisms
3) all cells arise from preexisting cells

Front 5

all bacteria are

Back 5

prokaryotes

Front 6

prokaryotes

Back 6

1) no internal membranes (nuclear, ER, mitochondria, vacuoles, or other organelles)
2) circular, naked DNA
3) ribosomes are SMALL
4) metabolism is anaerobic or aerobic
5) no cytoskeleton
6) unicellular
7) cells are SMALL

Front 7

eukaryotes

Back 7

1) has distinct organelles
2) DNA wrapped with histone proteins into chromosomes
3) ribosomes are LARGE
4) cytoskeleton present
5) multicellular
6) LARGE cells

Front 8

nucleus of a prokaryote is called a

Back 8

nucleoid

Front 9

the first microscope was developed by

Back 9

Leeuwenhoek

Front 10

studied cork cells and developed a microscope that enabled him to study them

Back 10

Robert Hooke

Front 11

light microscopes

Back 11

use light, passing through a living or dead specimen, to form an image

Front 12

electron microscope

Back 12

use electrons passing through a DEAD specimen to form an image

Front 13

transmission electron microscopes

Back 13

used for studying the INTERIOR of cells
-images appear flat and 2 dimensional

Front 14

scanning electron microscope

Back 14

used for studying the SURFACE of cells
-images appear 3 dimensional
-specimen coated with heavy metal

Front 15

phase contrast microscopes

Back 15

used to examine UNSTAINED, LIVING CELLS

Front 16

FUCTION DICTATES FORM
-give examples involving cells

Back 16

1) nerve cell, whose purpose is to send electrical impulses, is LONG AND SPINDLY
2) cells that store fat are ROUNDED, LARGE, and DISTENDED
3) cells that make up a tough peach pit resemble square building blocks

Front 17

pores

Back 17

contained in the nuclear memrane
-allow for the transport of molecules, which might be too large to diffuse through the envelope

Front 18

ribosomes are synthesized in the

Back 18

nucleolus

Front 19

ribosomes are the sites of

Back 19

protein synthesis

Front 20

plants and algae have cell walls made of___

Back 20

cellulose

Front 21

the cell walls of fungi are made of_____

Back 21

chitin

Front 22

the primary cell wall

Back 22

immediately outside the plamsa membrane

Front 23

secondary cell wall

Back 23

outside the primary cell wall

Front 24

middle lamella

Back 24

a thin gluey layer that forms between the 2 new cells when a plant cell divides

Front 25

plasma membrane

Back 25

selectively permeable

Front 26

S.J. Singer

Back 26

famous for his description of the cell membrane
-FLUID MOSAIC MODEL

Front 27

the cell membrane is able to move fluidly and not rigidly because

Back 27

of the saturated hydrocarbon tails which allow the molecules to pack close together
-unsaturated hydrocarbons have kinks in them

Front 28

amphipathic

Back 28

(phospholipids are amphipathic)
-has both a hydrophobic and hydrophilic region

Front 29

integral proteins

Back 29

have nonpolar regions that completely span the hydrophobic interior of the membrane

Front 30

choesterol molecules

Back 30

embedded in the interior of the bilayer to stabilize the membrane

Front 31

glycocalyx

Back 31

formed from carbohydrates
-important for cell-to-cell recognition
-embedded on the external surface of the phospholipid bilayer

Front 32

contractile vacuoles

Back 32

pump excess water out of a cell

Front 33

peroxisomes

Back 33

contain enzymes that transfer hydrogen from various substrates to oxygen, producing hydrogen peroxide as a by-product

Front 34

mictrotubules

Back 34

-thickest of the three types of cytoskeleton
-made up of tubulin
-maintains cell shape
-helps in cell motility

Front 35

microfilaments

Back 35

thinnest of the types of cytoskeleton
-made of actin
-muscle contraction

Front 36

intermediate filaments

Back 36

-anchorage of nucleus and other organelles

Front 37

microtubule organizing center

Back 37

centrosome

Front 38

plasmodesmata

Back 38

channels within plant cell walls

Front 39

tight junctions

Back 39

-membranes of neighboring cells are very tightly pressed together
-prevent leakage of extracellular fluids

Front 40

desmosomes

Back 40

-fasten cells together into strong sheets
-anchors filaments

Front 41

gap junctions

Back 41

-provide cytoplasmic channels from one cell to an adjacent cell
-necessary for communication between cells

Front 42

active transport

Back 42

requries ATP

Front 43

passive transport

Back 43

does not requre ATP
-movement of molecules down its concentration gradient
-high to low

Front 44

simple diffusion

Back 44

-passive transport
-does not involve protein channels

Front 45

faciliated diffusion

Back 45

-passive transport
-involves protein channels
-requires a hydrophilic protein channel

Front 46

countercurrent exchange

Back 46

-simple diffusion
-flow of adjacent fluids in opposite directions that maximizes the rate of simple diffusion (fish gills)
--blood flows toward the head in the gills, while water flows over the gills in the opposite direction

Front 47

osmosis

Back 47

-passive transport
-diffusion of water across a membrane

Front 48

solvent

Back 48

the substance that does the dissolving

Front 49

solute

Back 49

the substance that dissolves

Front 50

hypertonic

Back 50

having greater concentration of solute than another solution

Front 51

hypotonic

Back 51

having lesser concentration of solute than another solution

Front 52

isotonic

Back 52

two solutions containing equal concentrations of solutes

Front 53

water potential

Back 53

the tendency of water to move across a permeable membrane into a solution

Front 54

turgid

Back 54

when a cell swells

Front 55

plasmolysis

Back 55

when a cell shrinks

Front 56

aquaporins

Back 56

special water channel proteins that facilitate the diffusion of massive amounts of water across a cell membrane

Front 57

sodium potassium pump

Back 57

-active transport
-pumps Na+ out and K+ in

Front 58

pumps 2 K+, for every ____Na+

Back 58

3

Front 59

electron transport chain

Back 59

in mitochondria
-consists of proteins that pump proteins across the cristae membrane

Front 60

exocytosis

Back 60

occurs in nerve cells when vesicles release neurotransmitters into a synapse

Front 61

pinocytosis

Back 61

the uptake of large, dissolved particles

Front 62

phagocytosis

Back 62

the engulfing of large particles or small cells

Front 63

receptor mediated endocytosis

Back 63

enables a cell to take up large quantities of very specific substrates

Front 64

ligand

Back 64

the general name for any molecule that binds specifically to a receptor site of another molecule

Front 65

how do cells take in cholesterol from the blood

Back 65

by receptor-mediated endocytosis

Front 66

bulk flow

Back 66

the general term for the overall movement of a fluid in one direction in an organism

Front 67

bulk flow movement is always from _____to_____

Back 67

source (where it originates)
to sink (where it is used)

Front 68

the urinary bladder uses______junctions to prevent the urine from leaking out of the bladder

Back 68

tight junctions

Front 69

desmosomes are found in tissues that are often subjected to____

Back 69

severe mechanical stress (skin that must expand, example: childbirth)

Front 70

signal transduction pathway

Back 70

1) in reception, the signal molecule, commonly a protein that does not enter the cell, binds to a specific receptor on the cell surface, causing the receptor molecule to undergo a change in conformation
2) this change in conformation leads to a transduction, a change in signal form, where the receptor relays a message to a secondary messenger.
3) secondary messenger induces a response within a cell

Front 71

cell to cell recognition

Back 71

the cell's ability to distinguish one type of neighboring cell from another and is crucial to the functioning of a multicelled organism

Front 72

contact inhibition

Back 72

the normal trait of cells to stop dividing when they become too crowded

Front 73

this breaks down the by-product of cell respiration

Back 73

peroxisomes

Front 74

this detoxifies alcohol in liver cells

Back 74

smooth endoplasmic reticulum