What is the relationship between diffusion and concentration gradient? | Socratic
What do diffusion and equilibrium have to do with cell membranes? . What is the difference between phagocytosis and pinocytosis? 6. Critical. MAIn IDeAS. Diffusion and osmosis are types of passive transport. difference in the concentration of a substance from one location to another. This means the molecules have reached a dynamic equilibrium. 4b investigate and explain. The equilibrium constant, Keq, is defined as: The rate of the reaction is given by.
Therefore, a net movement of molecules across a cell membrane will occur only if there is a higher concentration of the particular molecules on one side than on the other side. This movement does not require the use of the cell's energy. Lesson in High School Biology Active Transport As powerful as diffusion is, cells sometimes must move materials in the opposite direction—against a concentration difference.
This is accomplished by a process known as active transport.
What is the relationship between diffusion and concentration gradient?
As its name implies, active transport requires energy. Larger molecules and clumps of material can also be actively transported across the cell membrane by processes known as endocytosis and exocytosis. The transport of these larger materials sometimes involves changes in the shape of the cell membrane.
Molecular Transport Small molecules and ions are carried across membranes by proteins in the membrane that act like energy-requiring pumps. Many cells use such proteins to move calcium, potassium, and sodium ions across cell membranes.
When is equilibrium reached in diffusion?
Changes in protein shape, as shown in the figure at right, seem to play an important role in the pumping process. A considerable portion of the energy used by cells in their daily activities is devoted to providing the energy to keep this form of active transport working.
The use of energy in these systems enables cells to concentrate substances in a particular location, even when the forces of diffusion might tend to move these substances in the opposite direction. Endocytosis and Exocytosis Larger molecules and even solid clumps of material may be transported by movements of the cell membrane.
One of these movements is called endocytosis en-doh-sy-TOH-sis. Endocytosis is the process of taking material into the cell by means of infoldings, or pockets, of the cell membrane.
The pocket that results breaks loose from the outer portion of the cell membrane and forms a vacuole within the cytoplasm. Large molecules, clumps of food, and even whole cells can be taken up in this way. The cell then engulfs it.
- How does diffusion affect dynamic equilibrium?
- Molecular diffusion
- High School Biology/Lessons/Lesson 3
Amoebas use this method of taking in food. For more information, please read Measuring Reaction Rates. An example of a fast reaction would be fire burning combustion of oxygen and an example of a slow reaction is iron rusting oxidation of a metal.
Reactions do not only proceed forward; reactions often occur in a mixture of forward and reverse, the more prevalent being the observed course of the reaction. In this scenario, there is a point where the two components are acting at equal rates; this is referred to as equilibrium. At equilibrium, the reaction rates of the forward and reverse reactions are equal. There are two different types of equilibrium: Dynamic Equilibrium At dynamic equilibrium, reactants are converted to products and products are converted to reactants at an equal and constant rate.
Reactions do not necessarily—and most often do not—end up with equal concentrations. Equilibrium is the state of equal, opposite rates, not equal concentrations. Static Equilibrium Static equilibrium, also called mechanical equilibrium, occurs when all particles in the reaction are at rest and there is no motion between reactants and products.
Static equilibrium can also be seen as a steady-state system in a physics-based view.
How does diffusion affect dynamic equilibrium? | Socratic
Dynamic forces are not acting on the potential energies of the reverse and forward reactions. An example of static equilibrium is graphite turning into diamond, shown below.
This reaction is considered at static equilibrium after it occurs because there are no more forces acting upon the reactants graphite and products diamond. Before the reaction of C to D occurs Figure 4: