ch. 5 launchpad
a bacterial cell, a plant cell, and an animal cell have which of the following structures in common?
cytoplasm
The random movement of molecules from areas of high concentration to low concentration is referred to as:
diffusion.
the interior region of a phospholipid bilayer is characterized as
hydrophobic
In the figure below, the cell is _____ to the solution. If the membrane is permeable to water, but not to solutes, net movement of water will be _____ the cell. (Note that the units mM represent the total concentration of solute in the solution.) http://www.macmillanhighered.com/brainhoney/Resource/9493420,8,0,5,0/Assets/resources/chapter_39/39_105.jpg
hypotonic; out of
Which of the following molecules does NOT easily diffuse across a plasma membrane?
large polar molecules
which eukaryotic organelle is associated with the breakdown of macromolecules?
lysosome
which one of the following is NOT a component of an animal cell's plasma membrane
nucleic acid
a protein that is temporarily associated with a biological membrane is a
peripheral membrane protein
The lipid components of cellular membranes often include:
phospholipids and cholesterol
During osmosis, water moves from a region of _____ to a region of _____.
Both "high solvent concentration; low solvent concentration" AND "low solute concentration; high solute concentration" are correct answers.
Why does active transport require ATP?
An input of energy is needed to allow the movement of molecules from an area of low concentration to one of higher concentration.
Which one of the following molecules would MOST likely require a transport protein to cross the plasma membrane of a red blood cell?
C6H12O6
The concentration of Waste molecules is ________ inside the cell compared to the outside.
Lower
The beaker in the illustration below contains two solutions of salt with different concentrations (measured by molarity, M). The two solutions are separated by a membrane that is permeable to both salt and water. http://www.macmillanhighered.com/brainhoney/Resource/9493420,8,0,5,0/Assets/resources/chapter_5/5_64.jpg
Net diffusion of water from A to B and of salt from B to A.
The diagram below shows a cell with three different membrane transport proteins. The Na+/K+ Pump is a primary active transporter and the Na+/Waste Co-transporter is a secondary active transporter. Arrows show the direction of net movement of molecules through the Pump and Co-transporter. The Na+ Channel can exist in either a closed state (no Na+ can pass through) or an open state (Na+ can pass through). Use this diagram to answer the questions below. http://www.macmillanhighered.com/brainhoney/Resource/9493420,8,0,5,0/Assets/MembraneTransportDiagram.png
Net movement of Waste out of the cell will continue for some time and then all net movement of Waste in or out of the cell will stop
The beaker in the illustration below contains two solutions of salt with different concentrations (measured by molarity, M). The two solutions are separated by a membrane that is permeable to both salt and water. http://www.macmillanhighered.com/brainhoney/Resource/9493420,8,0,5,0/Assets/OsmosisBeaker.jpg
No net diffusion of water or salt across the membrane.
A beaker contains two solutions of salt dissolved in water. The two solutions have different concentrations (measured by molarity, M) and are separated by a membrane that is permeable to both salt and water. http://www.macmillanhighered.com/brainhoney/Resource/9493420,8,0,5,0/Assets/resources/chapter_5/5_91.jpg
Side A is hypotonic relative to side B.
Why does a phospholipid on the cytoplasmic side of the cell membrane rarely flip to the extracellular side if both environments are polar?
The polar head group cannot pass through the nonpolar interior.
Compared to when the Na+ channel is closed, how will the transport of Waste molecules change when the Na+ channel is open?
The rate of Waste transport out of the cell will decrease
A beaker contains two solutions of salt dissolved in water. The two solutions have different concentrations (measured by molarity, M) and are separated by a membrane that is permeable to salt. http://www.macmillanhighered.com/brainhoney/Resource/9493420,8,0,5,0/Assets/resources/chapter_5/5_84.jpg
There will be a net movement of salt from side B to side A
What will happen when the Na+ channel is open?
There will be net movement of Na+ into the cell through the channel
The plasma membranes of some plant cells use transport proteins to move protons out of the cell against their concentration gradient (from areas of low proton concentration to areas of high proton concentration). This is an example of:
active transport.
how do eukaryotic plant and animal cells differ from one another?
animal cells don't have chloroplasts and cell walls, and plant cells do
all cells have:
genetic information
Some plant cells take advantage of the high concentration of protons outside the cell to move solutes, such as sucrose, across the plasma membrane into the cell where the sucrose concentration is already relatively high. This type of transport is an example of:
secondary active transport.
which of the following eukaryotic cell structures plays a role in protein trafficking and sorting?
the golgi apparatus
Phospholipase is an enzyme that cleaves the phosphate head group off a phospholipid molecule. The plasma membrane is not, however, permeable to the enzyme. Imagine a cell where phospholipid A is present in the layer of phospholipids facing the exterior of the cell, and phospholipid B is present in the layer of phospholipids facing the interior of the cell. After adding phospholipase to the medium in which the cell is growing, what would you expect to find in the fluid surrounding the cell?
the phosphate head group from phospholipid A only
If cells had single-layer membranes like micelles, how would the structures of transmembrane proteins be affected?
transmembrane proteins would possess a hydrophobic region in the cell interior and a hydrophilic region in the extracellular space
