cellular Flashcards
the cell can divided into how many parts and what are they called
3 parts
plasma (Cell) membrane, or plasmalemma
cytoplasm - cytosol and organelles
nucleus - chromosomes and genes
what is the plasma membrane
The plasma membrane (plasmalemma) is a flexible yet sturdy
barrier that surrounds and contains the cytoplasm of the cell
what are the 2 types of membrane proteins
Integral (also called transmembrane) proteins
2. Peripheral proteins
list the membrane proteins and their type
ion channel - integral
carrier - integral
receptor - integral
enzyme - integral and peripheral
linker - integral and peripheral
cell identity marker - glycoprotein
are membranes fluid structures and why
yes because most of the lipids and the proteins move easily in the bilayer
Membrane lipids and proteins are mobile in their own
half of the bilayer
what does cholesterol do in the membrane
Cholesterol serves to stabilize the membrane and
reduce membrane fluidity
what is permeability of the membrane
selective
what is the plasma membrane permeable to
The lipid bilayer is always permeable to small,
nonpolar, uncharged molecules
what increases the permeability of the membrane
Transmembrane proteins that act as channels or
transporters
how can macromolecules pass through the plasma membrane
vesicular transport
what is a concentration gradient
the difference in the
concentration of a chemical between one side of the
plasma membrane and the other
what kind of gradient is the difference in concentration of
ions between one side of the plasma membrane and the
other
electrical gradient
what are the 2 gradients make up
electrochemical gradient
what are the transport processes that move substances across the cell membrane
Passive processes
o Simple diffusion
o Facilitated diffusion
o Osmosis
Active processes
o Primary and secondary transport
o Vesicular transport
passive transport processes always move chemicals where
down their concentration gradient
active transport uses what and moves chemicals where
energy in ATP molecules to move chemicals up their concentration gradients
what can diffuse through the phospholipid bilayer and why
gases and some molecules can diffuse because they are small or non-polar (eg. O2 CO2 H2O)
how can ions diffuse through
they go through membrane pores or gated channels via membrane proteins
are pores always open?
yes
what determines more ions to diffuse
more pores allow more ions
are gated channels always open?
no
how is glucose diffused and what type of diffusion
faciliatated diffusion and diffuses with a transporter protein
what increases glucose diffusion
insulin because it increases transporters which means more glucose to pass through
how does water pass through membrane and which way does it go in terms of concentration
osmosis and it moves down its concentration gradient from a high concentration to a low concentration
more ions results in what water concentration in a solution
lower water concentration
less ions results in what water concentration in a solution
higher water concentration
what happens to water osmosis when there is an isotonic solution which is an equal amount of ions in both solutions
water moves in equal amounts in both directions
hypertonic is what and where will water go
has a lower concentration of water so water will from outside to inside
hypotonic is what and where will water go
has a high concentration of water so water will from inside to outside
in a hypotonic solution, where is the solute concentration higher?
where is the water concentration higher?
so what would happen to the cell
inside the cell
outside the cell
it may burst cause of water going in
in a hypertonic solution, where is the solute concentration higher?
where is the water concentration higher?
so what would happen to the cell
outside the cell
inside the cell
shrink
which way do molecules go with primary active transport and how
molecules move against their concentration gradient via pumps energized by the hydrolysis of ATP
how does the cell maintain water balance
actively transporting ions