2. Anatomy of the cell

Question 1

which cells have the most water

Answer 1

embryonic

Question 2

what determines that shape and fluidity of a cell

Answer 2

the cytoskeleton

Question 3

other structures within the membrane which may or may not be bound by membrane are called

Answer 3

inclusions

Question 4

what does the plasma membrane do

Answer 4

separates the cytoplasm from the outside environment

Question 5

the plasma membrane is a bimolecular layer of what type of phospholipid molecules

Answer 5

amphipathic

Question 6

the plasma membrane contains which type of proteins

Answer 6

integral

Question 7

what integral proteins contain/be

Answer 7

receptors/channels/transporters/enzymes/cell attachment proteins

Question 8

the cell has the ability to transport material in and out through the cell membrane. In and Out have terms called…

Answer 8

exocytose and endocytose

Question 9

the cell membrane is selectively permeable and allows what through it?

Answer 9

Water and oxygen

Question 10

the cell membrane is selectively permeable and does not allow what through it?

Answer 10

Impermeable charged ions such as Na+

Question 11

membrane proteins can diffuse ………in the cell membrane

Answer 11

Laterally

Question 12

Many proteins are not distributed equally within the cell membrane. why.

Answer 12

because some proteins are anchored

Question 13

The Plasmalemma (plasma membrane) has what type of appearance

Answer 13

trilaminar

Question 14

inclusions are dispensable and may only be present as

Answer 14

transients

Question 15

what do inclusions represent

Answer 15

components that have been synthesized by the cell itself of taken up from the extracellular environment (endocytotic vesicle)

Question 16

the cytoskeleton definition

Answer 16

filamentous cytosolic proteins

Question 17

How many classes of filaments are there

Answer 17

3

Question 18

name the 3 classes of filaments

Answer 18

microfilaments, intermediate filaments and microtubules

Question 19

microfilaments are how big

Answer 19

7 nanometers in diameter

Question 20

what are microfilaments composed of

Answer 20

the protein actin

Question 21

what can the actin molecules do in microfilaments

Answer 21

they can assemble into filaments and later dissociate

Question 22

how big are intermediate filaments

Answer 22

greater than 10 nanometers in diameter

Question 23

what are intermediate filaments composed of

Answer 23

6 main proteins which differ in the different cell types

Question 24

what do intermediate filaments do

Answer 24

bind intracellular elements together and to the plasma membrane

Question 25

how big are microtubules

Answer 25

25 nanometers in diameter

Question 26

what are microtubules composed of

Answer 26

hollow tubules made of 2 types tubulin proteins

Question 27

what are the 2 types of tubulin

Answer 27

alpha and beta alternatives

Question 28

where do microtubules aka tubulin originate from

Answer 28

the centrosome

Question 29

can microtubules/tubulin assemble or de-assembe

Answer 29

both

Question 30

what do microtubules also contain

Answer 30

stabilizing proteins called microtubules associated proteins (MAPs)

Question 31

what else do microtubules serve as

Answer 31

a 'motorway'

Question 32

what 2 proteins attach to the microtubules

Answer 32

Dynein and Kinesin

Question 33

Dynein is an ATPase that moves which direction?

Answer 33

toward the cell center

Question 34

Kinesin is an ATPase that moves which direction?

Answer 34

away from the cell center

Question 35

what are Intracellular junctions

Answer 35

specialized membrane structures which link individual cells together into a functional unit

Question 36

where are intracellular junctions the most prominent

Answer 36

epithelial cells

Question 37

how many types of intracellular junctions are there

Answer 37

3

Question 38

name the 3 types of intracellular junctions there are

Answer 38

Occluding, anchoring and communicating junctions

Question 39

what do occluding junctions do

Answer 39

link cells to form a diffusion barrier

Question 40

occluding junctions are also known as

Answer 40

tight junctions or zonula occludens

Question 41

anchoring junctions provide and do what

Answer 41

provide mechanical strength and link submembrane actin bundles of adjacent cells

Question 42

anchoring junctions are also called

Answer 42

zonula adherens

Question 43

anchoring junctions have transmembrane molecules that bind to each other in the extracellular space and to actin of the cytoskeleton. what is this molecule called?

Answer 43

Cadherin

Question 44

there are also anchoring junctions called desmosomes which...?

Answer 44

link submembrane intermediate filaments of adjacent cells

Question 45

anchoring junctions desmosomes are also called

Answer 45

macula adherens

Question 46

Communicating Junctions allow what

Answer 46

selective diffusion of molecules between adjacent cells

Question 47

Communicating Junctions are also called

Answer 47

Gap junctions

Question 48

in Communicating Junctions each junction is a circular patch studded with.....

Answer 48

hundreds of pores

Question 49

pores of Communicating Junctions are produced by what protein

Answer 49

connexon proteins

Question 50

Communicating Junctions are found in the epithelia but also

Answer 50

smooth muscle and cardiac muscle

Question 51

close association of several types of junctions found in certain types of epithelial tissue are called

Answer 51

Junctional Complex