Quizzes for Exam 1 Flashcards
(30 cards)
If a single layer of phospholipids coats the water in a beaker (NOT A BILAYER), which parts of the molecules will face up into the air?
the hydrocarbon tails
The movement of tagged proteins in hybrid cells formed form the fusion of a mice and human plasma membranes best illustrates
support for the fluid-mosaic model
Glycoproteins and glycolipids are important for
cell-cell recognition
Which of the following is an organelle found in a prokaryotic cell?
none, prokaryotes do not have organelles.
Autotrophs use which of the following to power cellular work
ATP
basic components of cell theory?
- All cells arise from other cells
- Cells are the most basic unit of life.
- All living organisms are composed of cells.
Which of the following can be found in a bacterial chromosome?
DNA
The fluidity of membranes in a plant in cold weather may be maintained by increasing the
number of phospholipids with unsaturated hydrocarbon tails.
Facilitated diffusion of ions across a cellular membrane requires _________; and the ions move ___________.
channel proteins; down their electrochemical gradient
Which of the following is TRUE about osmosis?
- water moves into the cell from a hypotonic solution
- it can occur rapidly though channel proteins call aquaporins
- there is no net osmosis when cells are in an isotonic solution.
Some regions of the plasma membrane, called lipid rafts, have a higher concentration of cholesterol molecules. As a result, these lipid rafts
are more rigid than the surrounding membrane.
In a eukaryotic paramecium, cell surface integral membrane proteins are synthesized
by ribosomes bound to the rough endoplasmic reticulum.
Mammalian blood contains the equivalent of 0.15 M NaCl. Seawater contains the equivalent of 0.45 M NaCl. What will happen if red blood cells are transferred to seawater?
Water will leave the cells, causing them to shrivel and collapse.
Which of the following is one of the ways that the membranes of winter wheat are able to remain fluid when it is extremely cold?
by increasing the percentage of unsaturated phospholipids in the membrane
Which of the following membrane activities require energy from ATP hydrolysis?
Na+ ions moving out of a mammalian cell to reestablish the resting potential of the cell.
Proton pumps are used in various ways by members of every domain of organisms: Bacteria, Archaea, and Eukarya. What does this most probably mean?
Proton gradients across a membrane were used by cells that were the common ancestor of all three domains of life.
The phosphate transport system in bacteria imports phosphate into the cell even when the concentration of phosphate outside the cell is much lower than the cytoplasmic phosphate concentration. Phosphate import depends on a pH gradient across the membrane–more acidic outside the cell than inside the cell. Phosphate transport is an example of
cotransport.
Five dialysis bags, constructed from a semipermeable membrane that is impermeable to sucrose, were filled with various concentrations of sucrose and then placed in separate beakers containing an initial concentration of 0.6 M sucrose solution. At 10-minute intervals, the bags were massed (weighed) and the percent change in mass of each bag was graphed.Which line in the graph represents the bag that contained a solution isotonic to the 0.6 M solution at the beginning of the experiment?
C
Five dialysis bags, constructed from a semipermeable membrane that is impermeable to sucrose, were filled with various concentrations of sucrose and then placed in separate beakers containing an initial concentration of 0.6 M sucrose solution. At 10-minute intervals, the bags were massed (weighed) and the percent change in mass of each bag was graphed.Which line in the graph represents the bag with the highest initial concentration of sucrose?
A
Five dialysis bags, constructed from a semipermeable membrane that is impermeable to sucrose, were filled with various concentrations of sucrose and then placed in separate beakers containing an initial concentration of 0.6 M sucrose solution. At 10-minute intervals, the bags were massed (weighed) and the percent change in mass of each bag was graphed.Which line or lines in the graph represent(s) bags that contain a solution that is hypertonic at 50 minutes?
A and B
Why does the oxidation of organic compounds by molecular oxygen to produce CO2 and water release free energy?
Electrons are being moved from atoms that have a lower affinity for electrons (such as C) to atoms with a higher affinity for electrons (such as O).
The ATP made during glycolysis is generated by
the action of a kinase enzyme
Which of the following is the most correct interpretation of the figure? (ATP cycle)
ATP is a molecule that acts as an intermediary to store energy for cellular work.
The primary role of oxygen in cellular respiration is to
act as an acceptor for electrons and hydrogen, forming water.
