Biochemistry, Microbiology, and Immunology Week 7 Flashcards
What are phospholipids
major component of cell membrane
what is amphipathic
phosphlipid bilayer
hydrophobic tail
hydrophiliic head
the cell membrane is called a
fluid mosaic
what are the components of the cell membrane
phospholipid bilayer
integral proteins/glycoproteins
peripheral proteins
cholesterol
what is the lipid bilayer consist of
phosophlipids
cholesterol
glycolipids
what is glycocalyx
outer sugary coat
glycoporteins and glycolipids
what kinds of proteins are in the lipid bilayer
peripheral
integral or transmembrane
what does the hydrophobic core do
allows small, non polar, uncharged molecules to pass through the membrane easily
examples of what passes through the membrane easily
O2 and Co2
What are transmembrane proteins
large molecules, ions, and hydrophilic molecules
very selective
large sized, hydrophilic, ionic molecules need transport via
integral proteins
____ soluble molecules diffuse through the plasma membrane
lipid soluble
large molecules that cannot diffuse through lipids cannot cross the plasma membrane unless they are transported by a
carrier mechanism
diffusion
movement of particles from an area of high concentration to an area of low concentration
the rate at which molecules diffuse across the membrane depends on
solubility and size
hydrophobic molecule diffusion
diffuse across the membrane easily
small molecules diffuse across more ____ than large molecules
quickly
Simple diffusion
random process: molecules move around on their own until they are spread out
movement of solute
is simple diffusion active or passive
passive
rate of simple diffusion dependent on
concentration gradient
electrical gradient
simple diffusion occurs for what kind of molecules
O2, CO2, steroids
osmosis
water will move from its own high to its own low concentration
or from the side with low solute concentration to the side with high solute concetration
what has the highest priority for diffusion
water
osmosis is movement through a ____ membrane
semi-permeable
in osmosis the membrane is
permeable to solvent
not permeable to solute
hypotonic solution
lower solute concentration than another
cells gain water and burst
hypertonic solution
higher solute concentration than another solution
cells lose water and shrivel
isotonic solution
equal concentration to another solution
cell stays the same
what kind of materials can’t get through the cell membrane on their own
large molecules
polar molecules
glucose
ions
how do the material that can’t get through the cell membrane on their own diffuse?
facilitaed diffusion
transport proteins help molecules through membranes
requirements for facilitated diffusion
carrier protein or channel protein
there must be a concentration gradient
passive process
trasport proteins
channel proteins
carrier proteins
what are channel proteins
tiny hydrophilic pores
what are carrier proteins
bind and transport/change shape
like glucose
what is the driving force for simple and facilitated diffusion
concentration gradient
passive needs what kind of energy
no energy
what is active transport
the movement of solute molecules across a membrane with the use of cellular energy
why is energy needed in active transport
because the direction of movement is against the concentration gradient
what is required for an active transport
carrier protein
what are the three kinds of passive transport
diffusion through the lipid bilayer
diffusion through a channel
facilitated diffusion
what kind of transport is the sodium/potassium pump
active transport
endocytosis
materials move into the cell in a vesicle formed by the plasma membrane
exocytosis
materials move out of the cell by the fusion of vesicles with the plasma membrane
endocytosis and exocytosis require
energy
what is phagocytosis
a type of endocytosis
material take in is large
the membrane engulfs it
a vesicle is formed by specialized cells
what is pinocytosis
a type of endocytosis
a tiny drop of extracellular fluid is engulfed by the membrane
vesicle is tiny
most cells can do this
what type of diffusion is receptor mediated
endocytosis
characteristics of exocytosis
all cells do this
especially important in secretory cells and nerve cells
diffusion allows cells to
obtain or release a variety of important materials such as oxygen
diffusion is effective in situations where materials must be moved down a
concentration gradient
facilitated diffusion is essential in moving
charged or large solute molecules
facilitated diffusion gradient si from
high to love
is energy needed for facilitated diffusion?
no
osmos regualtes ___ inside cells
pressure
osmosis is active or passive?
passive
active transport cells may required _____
nutrients to be maintained at different concentrations inside the cell than is normally rpesent outside of the cell
active transport requires or does not require energy?
requires
what is receptor mediated endocytosis
important substances needed by the body
vitamins, anti-bodies, LDLs, transferrin, hormones
what are the types of active transports
active transport endocytosis exocytosis receptor mediated endocytosis phagocytosis pinocytosis
what are the passive transports
osmosis
diffusion
facilitated diffusion
a red blood cell placed in a hypertonic solution gains or loses water
gains
the movement of molecules form an area of low to high concentration requires
cellular energy
integral proteins
the movement of sodium ions out of a cell from an area of low solute sodium ion concentration to an area of higher sodium ion concetrations would be a process called
active transport
pinocytosis is an example of
active transport
