Chapter 5-PowerPoint Lectures Flashcards
Difference between integral and peripheral proteins?
integral proteins go through the bilayer membrane while peripheral proteins do not
What do biological membranes consist of?
lipids and proteins
What is glycerol?
3-carbon polyalcohol
What is the structure of cholesterol?
3 benzene rings, 1 pentane ring, hydrophobic tail attached to the pentane ring, and a hydroxyl group on the benzene ring end (hydrophilic)
What is the function of cholesterol?
helps in membrane fluidity (only in certain concentrations)
Why is it called fluid mosaic model?
phospholipids and proteins are freely moving around
Which move around at a great rate phospholipids or proteins?
phospholipids
What does “Mosaic” refer to?
membrane proteins—not uniform all around the surface
What are the purpose of membrane protien?
transport, recognition, receptors, cell adhesion
What helps keep membranes fluid at low temperatures?
unsaturated fatty acids
How does cholesterol help with membrane fluidty?
prevents hydrocarbon tails from stiffening
What does cholesterol do at higher temperatures?
stabilizes membranes and decreases fluidity
How do eukaryotic organisms adapt to colder temps?
changing membrane lipids—hibernation
Double bonds (increases unsat. fatty acids to improve fluidity) and cholesterol increase
Do membrane proteins move around in the bilayer?
Frye and Edidin’s experiment, they found it did b/c the chimera cell had the human and mouse cell proteins mixed together
What do antibodies do?
proteins that specifically recognizes the protein of interest
What is chimera?
mixing of two cells (ex. mixing a mouse and human cell)
What can integral membrane proteins also be called?
transmembrane proteins
Which (nonpolar/polar) move through the membrane easily? (selective permeability)
nonpolar hydrophobic molecules
Which (nonpolar/polar) move through the membrane harder? (selective permeability)
polar hydrophilic molecules
need a membrane protein to get across
Do charges atoms and molecules blocked by membrane?
yes they are blocked by the hydrophobic core
What are types of passive transport?
simple diffusion, facilitated diffusion, osmosis
Where do passive transport get its energy from?
concentration gradient
What are the forms of active transport?
primary and secondary
Where does primary active transport get its energy from?
ATP
Where does secondary active transport get its energy from?
other energy forms other than ATP
What does it mean when active transport moves against the gradient?
moving from low to high concentration—need energy!
What is another name for secondary active transport?
coupled transports
What does simple diffusion transport?
non polar inorganic gases such O2,N2, CO2 and organic molecules
What is transported with facilitated diffusion?
polar and charged molecules that need transport proteins such as water, amino acids , sugars, and ions
What is the difference between facilitated and simple diffusion?
facilitated diffusion need a transport protein to go across the membrane
What are channel proteins?
integral membrane proteins that allow water and ions to pass
What do auqaporins transport?
water—type of channel protein
Are ion channels open usually?
No they are gated
What states are gated channels?
open, closed, or intermediate
What proteins are involved in facilitated diffusion?
channel and carrier proteins
What does it mean when the carrier protein can become saturated?
too many solute molecules to transport or not enough carrier proteins
What does it mean when the carrier protein can become saturated?
too many solute molecules to transport or not enough carrier proteins
What does change in conformation mean?
change of shape of the protein
What does simple diffusion depend on?
molecular size and lipid solubility
Which are permeable to the cell membrane?
gases, small uncharged polar molecules
What are not permeable to the cell membrane?
large uncharged polar molecules, ions, charged polar molecules
What is osmosis?
passive water transport
What does osmosis depend on?
concentration gradients
high to low
What are the physical effects of osmosis?
cells will swell, burst, shrink, and shrivel up
What is used as a counteraction to the movement of osmosis?
energy by animal cells
Osmosis of solutes concentration gradient?
low to high concentration of solutes
What is osmotic pressure?
force needed to stop osmotic flow
Cells in hypotonic solution reacts like?
water moves into cell causing cell to swell
What type of solution should animal cells be kept in?
isotonic
What is tonicity?
property of a solution with respect to a membrane
Cells in a hypertonic solution react like?
shrink as water leaves the cell
What type of solution should plant cells be kept in?
hypotonic
What is a plant cell in an isotonic cells called?
flaccid cell
What happens to plant cells in a hypertonic cells?
cell body shrinks away from the cell wall
What happens to plant cells in a hypertonic cells?
cell body shrinks away from the cell wall
How do organisms maintain osmotic balance?
contractile vacuoles (eject water) and plants use turgor pressure to keep cell rigid
What are the 3 main functions of active transport?
taking up essential nutrients even when it goes against the concentration gradient, removal of waster against the concentration gradient, maintain of intracellular ion concentration (H,Na,K,Ca)
What is membrane potentail?
electrical charge (voltage) different across the plasma membrane
What do the active transport ions contribute to?
membrane potential
What are some applications of membrane potentail?
neurons and muscle cells
Which bond is broken in ATP during primary active transport?
the first phosphate bond
What is secondary active transport indirectly driven by?
ATP hydrolysis….use favorable concentration gradient created by primary active transport
What type of protein do primary active transport use?
carrier
What ions are moved in a sodium-potassium pump?
moves 3 Na ions out and brings 2 K into the cell
What type of transport is a sodium-potassium pump?
primary active transport
What type of transport is a sodium-potassium pump?
primary active transport
What is the bilayer slightly permeable to?
water and urea
When is a cell isotonic?
concentration of solutes is equal inside and outside of the cell
What ion do animal cell need to actively transport across the membrane to keep it in an isotonic state?
Na+
Where do the positive charges accumulate on the cell during primary active transport?
outside the membrane
Where do the negative charges accumulate on the cell during primary active transport?
inside the membrane
What is membrane potential difference in primary active transport?
-50 to -200 mV
What type of gradient does primary active transport create?
electrochemical gradient—-form of potential energy
What type of protein does a sodium potassium pump use?
carrier
What does inward facing conformation mean?
facing inside the cell
In a sodium potassium pump what is broken down and what binds to the pump
ATP broken into phosphate and ADP, phosphate group binds to pump
Do the sodium and potassium bind to the same place in the pump?
No, they have different binding sites
What is the release of phosphate called?
dephospholayte
what is the sequence of a sodium potassium pump?
Binding of sodium ions, ATP binds, ATP hydrolysis, phosphate binds to pump, conformation is outward facing, sodium ions are released, potassium ions binds, phosphate is removed (dephosporalyation, pump faces inwards (change in conformation), release potassium, binding of sodium ions
Does secondary active transport use an already existing concentration gradient?
yes, gradient formed by primary active transport
What two molecules are moving in secondary active transport?
ion and solute
When the ion and solute move in the same direction during secondary active transport called?
symport
When the ion and solute move in different directions during secondary active transport called?
anitport
What do type of protein does symport and anitport need?
carrier
Is a symporter or anitporter used in coupled transport?
symporter
What happens in glucose-Na symporter?
sodium is driving ion, and glucose is the transported against a concentrated gradient
Does the transport ion always move with or against the gradient?
against
What are the 2 types of endocytosis?
non-specific endocytosis and specific endocytosisi
What can non-specific endocytosis also be called?
bulk endocytosis
Which type of endocytosis does pinocytosis fall under?
non-specific endocytosis
What can specific endocytosis also be called?
receptor -mediated endocytosis
What type of vesicles are involved in endocytosis
endocyticvesicles
Where do endocytic vesicles go after entering the cell?
lysosome, to be broken down
In receptor-meditate endocytosis what is the depression in the plasma membrane that holds the target molecules called?
coated pit
In receptor-meditate endocytosis, what is the protein coat that reinforces the cytoplasmic side called?
clathrin
What happens in receptor-meditate endocytosis?
target molecules are bound to receptors (integral proteins) and brought into the cell
What can perform phagocytosis on large protist such as amoeba, or whole cells
phagocytes
What does mutations in the aquaporin gene result in?
cannot make concentrated urine
What type of protein in a Human Aquaporin-1 gene?
channel protein
What affinity does the inward facing phosphorylation have?
Na
What affinity does the outward facing phosphorylation have?
K
What affinity does the outward facing dephosphorylation have?
K
What affinity does the inward facing dephosphorylation have?
Na
Does the driving ion always move with or against the gradient?
with
