comomon assement
The sodium-potassium pump regulates the amount of sodium and potassium inside of cells, particularly nerve and muscle cells. In this process, an ATP is burned, causing three sodium ions to be pumped out and exchanged for two potassium ions, which are pumped in by a membrane protein. Both ions go against their concentration gradients.
Active transport
The graph illustrates the relative activity levels of three common digestive enzymes, where 0 represents no activity and 12 represents the highest level of activity. Which enzyme is most active at a neutral pH of 7?(
Amylase
Which suspension, when viewed under a microscope, would contain red blood cells that appear to be in homeostasis with their environment?
C red blood cells + distilled warter
Consider the graph above, noting the rate of transpiration as atmospheric humidity increases. Compare this process of osmosis of water from plant cells themselves.
Increasing humidity leads to reduced transpiration due to decreased concentration gradient between leaf and atmosphere. Similarly, osmosis increases as the concentration gradient reaches equilibrium within the cell.
A lab technician needs to determine whether cells in a test tube are prokaryotic or eukaryotic. The technician has several dyes she could use to stain the cells. Four of the dyes are described in the table below.
Nile blue
The structural formula of cellulose is shown. Which phrase correctly describes cellulose?
Polymer made of glucose
In both cells, the organelles labeled D are the sites of
Protein synthesis
Viral activity is represented in the diagram shown. Invading the host cell enables the virus to
Reproduce
To study osmosis, a student placed a thin potato slice in a salt solution. The slice became soft and shriveled. Then, he placed the shriveled slice in water. The slice regained its original shape. Based on the observations, which of these statements is correct?
The potato slice shriveled because water moved out of the slice into the salt solution.
A person with swollen gums rinses his mouth with warm salt water, and the swelling decreases. Which of the following has occurred?
The water in the gums has moved from a high to a low concentration of water.
Substances that enter the cell without the expense of cellular ATP, but are too large to directly pass through the membrane, use ________________________ in order to gain access to the inside of the cell.
Transport proteins
Examine the images below. Image "A" shows the solute concentration. Image "B" shows the end result. Which type of solution do these images illustrate? (2C1)WHITE AREA = WATER
a hypotonic solution in which the water travels into the cell.
A protein pump, which "pumps" molecules from an area of lower concentration to an area of higher concentration, is an example of
active transport
Red blood cells contain a higher concentration of potassium than the surrounding blood plasma does. This higher concentration is maintained by the process of
active transport
Since cyanide is a poison that limits a cell's ability to manufacture ATP, a cell containing cyanide is least likely to carry on the process of
active transport
The movement of molecules in which of the following processes requires energy in the form of ATP?
active transport
The diagram shows a section of a cell membrane that includes a transport protein used for facilitated diffusion. The function of this protein is to
allow certain substances to enter or leave the cell
In prokaryotic and eukaryotic cells, the amount of water in the cell is kept at a steady state. The organelles through which water passes into and out of cell is the
cell membrane
Within the human body, many substances are made in one place and used elsewhere. One example of this is the pancreas that produces insulin, a large protein. Which process would most likely be used to release insulin from pancreatic cells?
exocytosis
Pickles are cucumbers preserved in a brine solution containing dill, alum, and salt. Cucumbers shrink to a fraction of their normal size in the pickle jar. This is the result of the cucumbers being in a
hypertonic
The solution outside of the cell is ____ compared to the solution inside of the cell
hypertonic
If the molecular concentration of a substance is the same across a membrane, the substance
is in equilibrium
Homeostasis is
maintaining a relatively constant internal environment
When a raw, shell-less egg was placed in sugar solution, the egg shrank. The egg was brought back to its original size by placing it in water. Which process does the experiment demonstrate?
osmosis
The movement of oxygen molecules over time from one side of the semipermeable membrane to the other side is known as
osmosis.
Refer to the figure. At the beginning of the experiment,
side A is hypotonic to side B.
A student filled a bag of dialysis tubing with a milky-white starch solution and placed the bag in a beaker of iodine-water as shown in the diagram. An hour later, the student observed that the starch solution had turned blue-black (positive test for starch). What is the most probable explanation for the change?
the iodine diffused into the bag
The membrane is permeable to
water only
Use the diagram to answer the question below. The box to the right represents a cell with a semi permeable membrane that is impermeable to the solute. The small dots represent molecules of water, and the larger dots represent the solute sugar. What will happen to the substances in this diagram to bring the concentration closer to equilibrium?
water will flow into the cell from the surrounding environment
In the above example, water
will move out of the cell
