2. Anatomy of the cell Flashcards
which cells have the most water
embryonic
what determines that shape and fluidity of a cell
the cytoskeleton
other structures within the membrane which may or may not be bound by membrane are called
inclusions
what does the plasma membrane do
separates the cytoplasm from the outside environment
the plasma membrane is a bimolecular layer of what type of phospholipid molecules
amphipathic
the plasma membrane contains which type of proteins
integral
what integral proteins contain/be
receptors/channels/transporters/enzymes/cell attachment proteins
the cell has the ability to transport material in and out through the cell membrane. In and Out have terms called…
exocytose and endocytose
the cell membrane is selectively permeable and allows what through it?
Water and oxygen
the cell membrane is selectively permeable and does not allow what through it?
Impermeable charged ions such as Na+
membrane proteins can diffuse ………in the cell membrane
Laterally
Many proteins are not distributed equally within the cell membrane. why.
because some proteins are anchored
The Plasmalemma (plasma membrane) has what type of appearance
trilaminar
inclusions are dispensable and may only be present as
transients
what do inclusions represent
components that have been synthesized by the cell itself of taken up from the extracellular environment (endocytotic vesicle)
the cytoskeleton definition
filamentous cytosolic proteins
How many classes of filaments are there
3
name the 3 classes of filaments
microfilaments, intermediate filaments and microtubules
microfilaments are how big
7 nanometers in diameter
what are microfilaments composed of
the protein actin
what can the actin molecules do in microfilaments
they can assemble into filaments and later dissociate
how big are intermediate filaments
greater than 10 nanometers in diameter
what are intermediate filaments composed of
6 main proteins which differ in the different cell types
what do intermediate filaments do
bind intracellular elements together and to the plasma membrane
how big are microtubules
25 nanometers in diameter
what are microtubules composed of
hollow tubules made of 2 types tubulin proteins
what are the 2 types of tubulin
alpha and beta alternatives
where do microtubules aka tubulin originate from
the centrosome
can microtubules/tubulin assemble or de-assembe
both
what do microtubules also contain
stabilizing proteins called microtubules associated proteins (MAPs)
what else do microtubules serve as
a ‘motorway’
what 2 proteins attach to the microtubules
Dynein and Kinesin
Dynein is an ATPase that moves which direction?
toward the cell center
Kinesin is an ATPase that moves which direction?
away from the cell center
what are Intracellular junctions
specialized membrane structures which link individual cells together into a functional unit
where are intracellular junctions the most prominent
epithelial cells
how many types of intracellular junctions are there
3
name the 3 types of intracellular junctions there are
Occluding, anchoring and communicating junctions
what do occluding junctions do
link cells to form a diffusion barrier
occluding junctions are also known as
tight junctions or zonula occludens
anchoring junctions provide and do what
provide mechanical strength and link submembrane actin bundles of adjacent cells
anchoring junctions are also called
zonula adherens
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?
Cadherin
there are also anchoring junctions called desmosomes which…?
link submembrane intermediate filaments of adjacent cells
anchoring junctions desmosomes are also called
macula adherens
Communicating Junctions allow what
selective diffusion of molecules between adjacent cells
Communicating Junctions are also called
Gap junctions
in Communicating Junctions each junction is a circular patch studded with…..
hundreds of pores
pores of Communicating Junctions are produced by what protein
connexon proteins
Communicating Junctions are found in the epithelia but also
smooth muscle and cardiac muscle
close association of several types of junctions found in certain types of epithelial tissue are called
Junctional Complex
