Unit 2.8 - Tonicity and Osmoregulation Flashcards
What are aquaporins?
Aquaporins are proteins embedded in cell membranes that facilitate the transport of water molecules in and out of cells.
What is the cell membrane?
The cell membrane is a thin, flexible envelope that surrounds the cell. It controls what enters and leaves the cell and protects the internal environment of the cell.
What is the cell wall?
The cell wall is a rigid layer of polysaccharides lying outside the plasma membrane of the cells of plants, fungi, and bacteria. In algae and higher plants, it consists mainly of cellulose.
What is a concentration gradient?
A concentration gradient occurs when there is a difference in concentration of a particular substance between two regions. Substances will naturally move from areas of high concentration to areas of low concentration until equilibrium is reached.
What is homeostasis?
Homeostasis is the process by which organisms maintain a relatively stable internal environment despite changes in external conditions.
What is a hypertonic solution?
A hypertonic solution is one that has a higher concentration of solutes outside the cell than inside the cell. This causes water to move out of the cell, leading to shrinkage or crenation.
What is a hypotonic solution?
A hypotonic solution has less solute and more water than another solution. When cells are in such an environment, they tend to absorb water from outside until equilibrium is reached or the cell bursts.
What is the ionization constant?
The ionization constant, or acid dissociation constant (Ka), measures the strength of an acid in solution. It is the equilibrium constant for the chemical reaction known as dissociation in the context of acid-base reactions.
What is an isotonic solution?
An isotonic solution is one where the concentration of solutes is equal both inside and outside the cell. This results in no net movement of water across the cell membrane.
What is molar concentration?
Molar concentration, also known as molarity, is the amount of a solute (in moles) divided by the volume of the solution (in liters).
What is osmoregulation?
Osmoregulation is the process by which organisms regulate their body’s osmotic pressure in order to maintain homeostasis or balance within their cells.
What is osmosis?
Osmosis is the movement of water from an area of low solute concentration to an area of high solute concentration across a semi-permeable membrane.
What is the pressure constant?
The pressure constant, often denoted as ‘R’ in scientific equations, is a physical constant that appears in the ideal gas law equation. It relates the energy scale to the temperature scale that occurs in thermodynamics.
What is solute potential?
Solute potential, also known as osmotic potential, is the tendency of water to move by osmosis in response to differences in solute concentrations.
What is temperature in Kelvin?
The Kelvin scale is an absolute temperature scale starting at absolute zero, the theoretical lowest possible temperature where all molecular motion ceases. One Kelvin unit equals one degree Celsius.
