Cellular Transport--QUESTIONS Flashcards
What example correctly illustrates the process of osmosis?
A. Water leaves the tubules of the kidney in response to the hypertonic fluid surrounding the tubules.
B. Digestive enzymes are excreted into the small intestine.
C. White blood cells travel through the blood to the site of the infection.
D. Calcium is pumped inside the muscle cell after the muscle completes its contraction.
A. Water leaves the tubules of the kidney in response to the hypertonic fluid surrounding the tubules.
What is phagocytosis used for?
uptake of large particles by specialized cells after activation of cell-surface receptors
What is an example of phagocytosis?
a neutrophil, which is a type of white blood cell that engulfs pathogens via phagocytosis
What is pinocytosis?
used for uptake of small particles by almost all eukaryotic cells and occurs constantly
What is the mechanism for pinocytosis?
involves clathrin-coated pits, which invaginate from the plasma membrane and subsequently fuse with endosomes
What is exocytosis?
the process by which cells transport, substances form the inside of the cell to either the plasma membrane or outside of the cell
What is transcytosis?
the process by which an endocytosed receptor is sent back to the plasma membrane but to a different domain from which it came.
Two cells in the body are touching, but they are separated by plasma membranes that only allow water to flow between the cells. Cell 1 has an osmolarity of 1.6 osm/L. Cell 2 has an osmolarity of 1.9 osm/L.
What will happen?
A. Solute will flow from cell 1 to cell 2 until equilibrium is reached.
B. Solute will flow from cell 2 to cell 1 until equilibrium is reached.
C. Water will flow from cell 1 to cell 2 until equilibrium is reached.
D. Water will flow from cell 2 to cell 1 until equilibrium is reached.
C. Water will flow from cell 1 to cell 2 until equilibrium is reached.
What leaves the nucleus and associates with ribosomes?
A. DNA
B. Endoplasmic reticulum
C. mitochondria
D. mRNA
D. mRNA
The concentration of potassium on the intracellular side of a membrane is 60 mM. On the extracellular side of the membrane, the concentration of potassium is 4 mM.
A. ATP-powered pump B. Channel protein C. Receptor protein D. Uniporter transport protein Correct
A. ATP-powered pump
The cell membrane consists of a phospholipid bilayer with ____ head groups and ____ tails.
A. Hydrophilic; hydrophobic B. Hydrophobic; hydrophilic C. Lipophilic; lipophobic D. Acidic; basic E. Basic; acidic
A. Hydrophilic; hydrophobic
What part of the cell makes the most ATP?
A. Golgi apparatus
B. Mitochondria
C. Nucleus
D. Ribosome
B. Mitochondria
You have isolated a group of cells containing the Na+/K+ pump in their cell membranes
If you added a non-hydrolyzable analog of ATP to the solution outside the cell membrane, what effect would you expect to observe?
A. Cytoplasmic pH would fall due to the increased production of lactic acid.
B. K would accumulate outside the cell, and Na would accumulate inside the cell.
C. Na would accumulate outside the cell and K would accumulate inside the cell.
D. Transport of Na and K would cease because the Na/K pump would be inhibited.
C. Na would accumulate outside the cell and K would accumulate inside the cell.
The Na/K pump transports ______ ions out of the cells while simultaneously importing ________ ions.
Na; potassium
Ligands are signaling molecules that bind to receptors either on the cell surface or inside the cell. Which of the following statements is true of ligands?
A. Ligands bind to receptors with a high degree of specificity.
B. Ligands permanently bind to corresponding receptor sites, creating a ligand-receptor complex.
C. The higher the concentration of ligands present, the fewer active ligand-receptor complexes.
D. Ligands are primarily hydrophilic
A. Ligands bind to receptors with a high degree of specificity.
