The Cell-Size Challenge
This type of surrounding solution causes no sustained change in a cell’s volume.
What is an isotonic solution?
This molecule directly supplies energy to the sodium–potassium pump.
What is ATP?
Coupled transport of two substances in the same direction has this name.
What is symport?
This general process brings extracellular material into a cell inside a membrane-bound vesicle.
What is endocytosis?
After a meal, this hormone increases the number of GLUT4 transporters at muscle and fat cell surfaces.
What is insulin?
A red blood cell swells after placement in this type of solution.
What is a hypotonic solution?
Transport that directly couples ATP breakdown to uphill movement belongs to this category.
What is primary active transport?
Coupled transport of two substances in opposite directions has this name.
What is antiport?
A macrophage surrounds and engulfs a bacterium using this process.
What is phagocytosis?
Glucose enters a muscle cell through GLUT4 down its concentration gradient using this mechanism.
What is facilitated diffusion?
A red blood cell loses water and shrinks after placement in this type of solution.
What is a hypertonic solution?
For each ATP used, the sodium–potassium pump moves these numbers of sodium and potassium ions in these directions.
What are three Na⁺ out and two K⁺ in?
Secondary active transport immediately draws its energy from this source rather than directly hydrolyzing ATP.
What is another substance’s electrochemical gradient?
Sometimes called “cell drinking,” this process takes in extracellular fluid and its dissolved substances.
What is pinocytosis?
During hemodialysis, small waste molecules move down their concentration gradients across the dialysis membrane by this process.
What is diffusion?
A red blood cell takes in so much water that it ruptures. This is the name of that event.
What is hemolysis?
Each sodium–potassium pump cycle transfers this net charge in this direction.
What is one positive charge outward?
This apical intestinal transporter couples sodium entry to glucose uptake.
What is SGLT1?
LDL binds a specific surface receptor before entering a cell by this selective uptake process.
What is receptor-mediated endocytosis?
Correctly prepared oral rehydration solution promotes sodium and glucose absorption. Water then follows by this process.
What is osmosis?
A cell contains 300 mOsm/L of nonpenetrating particles, while its surroundings contain 200 mOsm/L. With equal initial pressure and a water-permeable membrane, these changes occur.
What are water entering the cell and the cell swelling?
This calcium pump moves calcium from the cytosol into the sarcoplasmic reticulum, helping muscles relax.
What is SERCA?
In the sodium–hydrogen exchanger, sodium enters the cell while this ion leaves, helping regulate intracellular pH.
What is H⁺?
A rise in cytosolic calcium triggers a stored vesicle to release neurotransmitter. This is the specific type of exocytosis involved.
What is regulated exocytosis?
An intestinal cell takes glucose in through apical SGLT1. This basolateral transporter then allows glucose to leave toward the blood by facilitated diffusion.
What is GLUT2?