cell membrane & transport Flashcards
the ______ ________ model is used to describe the structure of the cell membrane
fluid mosaic
a form of endocytosis where smaller substances are brought into the cell by forming vesicles at the cell membrane
pinocytosis
______ transport via proteins requires no energy
facilitated
the _____ gland requires the active transport of iodine out of the blood and into its cells
thyroid
a membrane is said to be _____ permeable if it lets some things pass through it, but does not allow other things to pass
selectively
the movement of a vacuole out of the cell
exocytosis
a homogeneous mixture where one substance is dissolved into another
solution
a type of endocytosis where larger substances are brought into the cell by forming vacuoles at the cell membrane
phagocytosis
receptor-_____ endocytosis occurs when a substance binds to a receptor protein and causes another substance to be taken into the cell via vesicle formation
mediated
if a plant cell is placed in a hypertonic solution, ______ may occur
plasmolysis
if an animal cell is placed in a hypertonic solution, ______ may occur
crenation
when an animal cell is placed in a hypotonic solution, ______ may occur
lysis
the sodium / potassium pump is found in large numbers in these kind of cells
nerve and muscle cells
carrier proteins are _______, meaning they only carry one type of particle
specific
refers to a solution that is less concentrated when compared to another solution
hypotonic
the substance that does the dissolving in a solution
solvent
_______ sized molecules tend to produce a higher rate diffusion
smaller
_______ proteins catalyze chemical reactions on the cell membrane
enzymatic
_______ proteins cause a change to the cell membrane when a specifically shaped molecule binds its binding site
receptor
the diffusion rate can be increased by raising the _________, which in turn increases the speed at which particles are moving
temperature
active transport is able to move molecules ______ the concentration gradient
against
when solutions on either side of a membrane are the same concentration, there is ______ net movement of water or solute across the membrane
no
turgor pressure is important to plant cells because as their cells start to lose turgor pressure the plant will start to
wilt
the substance that is being dissolved in a solution
solute
a ______ protein uses ATP to change shape to move molecules across the cell membrane
carrier
this is a special type of diffusion where water is the substance that is moving
osmosis
“water fearing” - molecules which do not mix well with charged or polar molecules
hydrophobic
refers to a solution that is the same concentration when compared to another solution
isotonic
a _______ protein only passes part way through the lipid bilayer of the cell membrane
peripheral
this type of protein transport requires ATP as an energy source
active
a carbohydrate chain attached to a lipid molecule in the cell membrane
glycolipid
“water loving” - molecules which mix well with charged or polar molecules
hydrophilic
the rate of diffusion can be increased by increasing the ________ gradient
concentration
this occurs when there is a concentration gradient across a membrane and only water is able to pass through the membrane
osmotic pressure
a cell ________ protein has glycoproteins attached to it which are unique to each organism and aid in immune system research
recognition
this molecule is the energy currency of the cell
ATP
movement of molecules along a concentration gradient
diffusion
a carbohydrate chain attached to a protein in the cell membrane
glycoprotein
the movement of a vacuole into the cell
endocytosis
an ______ protein passes all the way through the lipid bilayer of the cell membrane
integral
refers to a solution that is more concentrated when compared to another solution
hypertonic
when movement of molecules does not require additional energy input, it is called ______
passive
if a plant cell is placed in a hypotonic solution, an increase in _____ pressure will develop
turgor
a ______ protein allows a particular ion or molecule to pass through it with the concentration gradient and without the use of ATP
channel
can carrier proteins go against the concentration gradient?
yes
can channel proteins go against the concentration gradient?
no
what is the purpose of a glycoprotein?
they are used for signalling, allowing a cell to recognize another cell
which substances can easily pass through the cell membrane?
non-charged substances such as CO2, O2, as well as steroids and alcohol
which substances need channel proteins to pass through the cell membrane?
charged molecules such as Na+, K+, sugars, amino acids
which cells need a vesicle to pass through the cell membrane?
big molecules such as proteins or viruses
why does diffusion happen?
because of the movement of molecules, particles move randomly from place to place, always moving from an area of higher concentration to an area of lower concentration
what factors can increase the rate of diffusion?
increasing the temperature (it increases the kinetic energy), increasing the concentration gradient, or decreasing the size of the diffusing molecules
what produces ATP?
the mitochondria
Why can only some molecules pass through the dialysis tubing?
it has a semipermeable membrane. small molecules like iodine, glucose, and water are able to pass through, where as starch cannot.
what molecules are moved by facilitated transport?
lipid-insoluble molecules such as glucose and amino acids, also charged molecules like Na+ and K+
what is the job of the cell membrane
- it separates the internal environment of the cell from the external environment
- it regulates what enters and exits the cell
- helps the cell maintain homeostasis
what do glycolipids and glycoproteins do?
they play an important role in cellular identification
how does your body recognize it’s own cells
from cell recognition proteins, such as glycoproteins. This is often why your body rejects organ transplants
what is an example of the job of a receptor protein?
the liver stores glucose after it is signalled to do so by insulin
after a solution reaches equilibrium, do the molecules continue moving?
yes, they are still moving but there’s no net movement
what does the sodium-potassium pump do?
it carries sodium ions to the outside of the cell and potassium ions to the inside of the cell
what is exocytosis important for?
secretion and excretion in cells
