Biology Quiz #2 Flashcards
what is the cell membrane sometimes referred to as
the phospholipid bilayer
what does the cell membrane consist of
a double layer of lipids that each has a phosphate group attached
what does hydrophilic mean
they love water and are attracted to it
what does hydrophobic mean
they do not like water and avoid it
what is the cell membrane
protective layer that allows things to transfer in and out of the cell
where are the hydrophilic heads located
at the top of the cell membrane, closest to the surface or outside portion
where are the hydrophobic heads located
at the bottom of the cell membrane, closest to the inside portion of the cell
where are integral proteins located
throughout the whole cell membrane
where are peripheral proteins located
more on the side of the cell membrane
what do carbohydrates do in the cell membrane
they act as a physical barrier and signal the cell to what’s good or bad
what does cholesterol do
regulate how everything flows
what organelle is responsible for transport
the cells membrane
whats stated in the particle model of matter
all matter is made up of particles, particles of matter constantly moving, particles are attracted to each other, particles have spaces between them
what is concentration
the amount of a specific particle
what is the concentration gradient
the movement of particles from a high concentration to a low concentration
whats diffusion
natural movement of particles from an area of high concentration to an area of lower concentration
what is the result of diffusion
state of equilibrium
how can the rate of diffusion be increased
by adding energy and/or increasing molecular movement
when does diffusion occur in cells
when there is a difference between the concentrations of solutes on either side of the membrane or within the cytoplasm
why is the cell membrane considered selectively permeable
allows certain particles to pass through it but not all particles
what are the 3 determinants of what passes through the cell membrane
its size, charge, and solubility in lipids
what is osmosis
the diffusion of water
whats a hypertonic solution
solution that has a higher concentration of solute than that in the cell
what happens if a cell is put into a hypertonic solution
water will leave the cell and the cell will dry out
whats a hypotonic solution
a solution that has a lower concentration of solutes than that in a cell
what happens if a cell is put in a hypotonic solution
water will enter the cell, causing it to swell and eventually explode
whats an isotonic solution
solution that has the same concentration of solutes as that in the cell
what happens if a cell is put into an isotonic solution
there will be no net movement of water molecules
what state are cells the happiest and healthiest in
isotonic
what is osmoregulation
control of water balance and the tendency of water to move into the plant cell to create pressure that supports the plant’s structure
what is the process of losing water and shrinking in animal cells called
crenation
why is cytolysis
the swelling and bursting of animal cells
what is plasmolysis
when the cell membrane of a plant cell shrinks away from the cell wall from being placed in a hypertonic environment
what is deplasmolysis
rehydration of a plant cell due to it being placed in a hypotonic environment
whats facilitated diffusion
diffusion of water-soluble molecules through a channel in the membrane
what do channel proteins do
create channels through which small water-soluble particles are able to move in response to the concentration gradient
what do carrier proteins do
attach large molecules unable to diffuse across the membrane then change shape to physically move the molecule across the membrane
what is active transport used for
to move particles from a high concentration to a low concentration
what is active transport
transport that requires energy input
where and how is the energy for active transport produced
in the mitochondria through the process of cellular respiration
where do you get energy for active transport from
adenosine triphosphate or ATP
what happens in endocytosis
vesicle forms around the particles and the cell membrane pinches off around it, putting the vesicle inside the cell
what does phagocytosis deal with
bigger particles
what does pinocytosis deal with
smaller particles
when are endocytosis and exocytosis used in transport
when a bigger particle needs to get in or out of the cell
whats exocytosis
vesicle containing the material is brought to the surface of the cell membrane and it is released outside of the cell
what do recognition proteins do?
allow cells to recognize each other
what do receptor proteins do?
bind specifically with certain molecules to bring then bring the cell through endocytosis
what does insulin do
binds to receptor proteins of tissue cells through facilitated diffusion using carrier protein
what is desalination
the process of removing salt from seq water
what is reverse osmosis
moving water from a low concentration to a high water concentration
why are small cells better
if they are bigger stuff cant transport into them in the time it needs
what is the benefit of an increased surface area
possibility for more transport
what happens if the cell becomes to large
volume increases and the distance any molecule has to travel from the cell surface will increase
what must happen for efficient transport at a cell surface
cell must have a large surface area in relation to its volume
what does it mean when there is a higher SA to V ratio
cell has more efficient transport
