Membranes in Motion
What type of molecules pass through the plasma membrane most easily, and without help?
Small, nonpolar molecules
This organelle produces ATP and has its own DNA.
Mitochondria
The term (tonicity) for:
a) Solutions with high amounts of solute
b) Solutions with low amounts of solute
c) Solutions with an equal amount of solute as the cell
a) Hypertonic
b) Hypotonic
c) Isotonic
Where does a protein for secretion go AFTER the rough ER?
Golgi apparatus
Which type of cell has a bigger SA:V ratio, a cell with 2mm radius or 10mm radius?
2 mm radius cell
Which membrane protein helps water cross quickly?
Aquaporins
Organelle that modifies, packages, tags, and ships out proteins into vesicles?
Golgi apparatus
In a hypertonic solution, what happens to:
a) An animal cell?
b) A plant cell?
a) Shrivels
b) Plasmolysis
The Golgi Body has directionality. What side of the golgi
a) Receives proteins or other molecules?
b) Do vesicles leave the Golgi after processing?
a) Cis face
b) Trans face
What helps increase the surface area in eukaryotic organelles?
Folding of membranes
a) What part of the membrane most affects permeability?
b) Why can ions such as Na+ not pass through the membrane via simple diffusion?
a) The hydrophobic properties of the phospholipid tails.
b) Because they are charged, they require assistance of proteins to come through.
Organelle that synthesizes lipids, stores calcium, and helps with detoxification?
Smooth ER
a) Water moves from areas of ___ to ___ water potential.
b) Water moves from areas of ____ to ____ solute potential.
a) high to low
b) low to high
What's the correct path for a secreted protein?
a) What type of solution allows a plant cell to remain turgid?
b) What organelle is responsible for maintaining that turgor pressure?
a) Hypotonic
b) Central vacuole
What type of transport requires:
a) The use of carrier or channel proteins to allow molecules to move DOWN their gradient?
b) The use of pumps to move molecules AGAINST their gradient?
a) Facilitated diffusion (a form of passive transport)
b) Active transport
Organelle that makes proteins for export.
Ribosomes at the Rough ER
Water flows out of the bag (cells) and into the solution.
If a bunch of materials need to be moved IN to the cell at once,
a) Is ATP required?
b) What is it called if the main uptake is fluids & dissolved minerals?
c) What is it called if the main uptake is a great amount of one specific substance?
a) Yes
b) Pinocytosis
c) Receptor mediated endocytosis
Name at least two structures found in ALL cells (prokaryotic and eukaryotic).
Cell membrane
Cytosol
DNA/Chromosomes
Ribosomes
The phospholipids allow the membrane to have fluidity.
What two structures within the bilayer allow for the regulation of its fluidity?
Cholesterol AND the fatty acid tails - whether they are saturated or unsaturated.
What are the three types of fibers found in the cytoskeleton?
Microtubules, microfilaments, intermediate filaments
A cell has Ψs = –0.3 MPa and Ψp = 0 MPa. What’s the total water potential, and will water move in or out if placed in pure water?
a) Total water potential is -0.3 MPa
b) Water will move into the cell.
An important protein that helps maintain membrane potential in animal cells is called the Sodium/Potassium pump.
a) Which ions and how many are pumped OUT of the cell?
b) Which ions and how many are brought INTO the cell?
a) 3 Na+ pumped out
b) 2 K+ let in
A student places a plant cell in a sucrose solution. The solution has a sucrose concentration of 0.3 M, and the temperature of the room is 22°C.
Calculate the solute potential in bars.
-7.36 bars