Chapter 5 BIOPORTAL Flashcards
Any cell’s response to a signal molecule takes place in three sequential steps. What are these steps in their proper order?
- The signal binds to a receptor protein. 2. The binding of the signal causes a message to be conveyed to the inside of the cell and amplified. 3. The cell changes its activity in response to the signal.
Which of the following is catalyzed by a protein kinase?
transfer of a phosphate group from ATP to another molecule
When the G protein is activated, _______ is displaced by ______.
GDP; GTP
Which of the following is a correct description of how exocytosis functions in transporting molecules across the cellular membrane?
Vesicles are filled with molecules in the interior of the cell and then fuse with the membrane to deposit the molecules outside of the cell.
You measure the concentration of a large polar molecule inside and outside of a cell. You find that the concentration outside the cell is on average the same as the inside of the cell but that the concentration outside the cell shows a gradient character that seems to indicate that molecules are interacting with the membrane. Your best hypothesis for the process that is occurring would be?
endocytosis
To absorb large particles, cells engulf them within their plasma membrane in a process called
endocytosis.
In terms of the receiving cell’s reaction, what are the three stages of cell signaling?
signal reception, signal transduction, and cellular response
Which of the following describes an autocrine signal?
A signal that diffuses to and affects the cells that produced them.
A sequence of events that leads to a cell’s signal response is called:
a signal transduction pathway.
Which of the following describes the first step that takes place when a cell responds to a signal molecule?
The signal binds to a receptor in or on the cell.
Hydrophobic molecules can pass freely though the membrane, but ions and polar molecules are impeded by the membrane’s hydrophobic core, thus membranes are said to be:
selectively permeable.
The primary function of molecular membranes is the transport of ions and molecules in and out of cells—transport is directional and selective. The moving of molecules from areas of high concentration to that of low concentration to gain energy is best described as:
passive transport.
In terms of the receiving cell’s reaction, what are the three stages of cell signaling?
signal reception, signal transduction, and cellular response
If a cell is put into a solution with a higher concentration of solute than is present inside the cell, the solution is ____________. The cell will __________. If a cell is put into a solution with a lower concentration of solute than is present inside the cell, the solution is _____________. The cell will _________.
hypertonic; shrink; hypotonic; swell
A hormone is a signal that operates in which of the following ways?
It travels through the circulatory system and binds to receptors on far away cells.
