Which one of the following is against concentration gradient?
Which one of the following is against concentration gradient?
Which one of the following is against concentration gradient?
However, in the case of osmosis, it is opposite. In that case, the solvent molecule moves from the lower concentration to higher concentration. Hence, from the above, the discussion osmosis process occurs against a concentration gradient of solute. Therefore, the correct answer is option B.
What are three ways for materials to move in and out of cells?
- Answer: Diffusion, Osmosis and Active Transport.
- Explanation:
- The processes of transport between the cell and the external environment can be grouped into groups: Passive Processes – occur through the plasma membrane, without energy expenditure to the cell, to equalize cell concentration with the external medium.
Which of the following factors is important in creating a resting membrane potential of 70mv?
The resting membrane potential is dependent upon two important factors: 1) differences in sodium and potassium concentrations across the membrane (electrochemical gradients) and 2) differences in sodium and potassium membrane permeability. – The concentration of K+ is higher inside than outside the cell.
What contributes to the resting membrane potential?
What generates the resting membrane potential is the K+ that leaks from the inside of the cell to the outside via leak K+ channels and generates a negative charge in the inside of the membrane vs the outside. At rest the membrane is impermeable to Na+, as all of the Na+ channels are closed.
What is a concentration gradient and what role does it play in cellular environments?
One of its most important functions is to maintain a healthy environment within the cell. This requires controlling the intracellular concentrations of various molecules, such as ions, dissolved gases and biochemicals. A concentration gradient is a difference in the concentration of a substance across a region.
What are the factors that affect diffusion?
Many factors can affect the rate of diffusion, including, but not limited to, concentration gradient, size of the particles that are diffusing, and temperature of the system. In living systems, diffusion of substances in and out of cells is mediated by the plasma membrane.
How do environmental factors alter diffusion rates?
What environmental factors affect kinetic energy and diffusion? If distance is increased, diffusion rate is decreased. An increase in pressure will cause molecules to move more quickly, increasing molecular collisions. Molecular size and mass affect diffusion rates.
What causes the fluid movement to decrease with time?
What causes the fluid movement to decrease with time? A decrease in the concentration gradient.
What processes are responsible for chemicals moving into throughout and out of cells?
Dissolved or gaseous substances have to pass through the cell membrane to get into or out of a cell. Diffusion is one of the processes that allows this to happen. Diffusion occurs when particles spread.
What is meant by a concentration gradient?
The difference in the concentration of a substance between two areas is called the concentration gradient . The bigger the difference, the steeper the concentration gradient and the faster the molecules of a substance will diffuse.
What three factors affect the concentration gradient?
Several factors affect the rate of diffusion of a solute including the mass of the solute, the temperature of the environment, the solvent density, and the distance traveled.
What must happen when a concentration gradient is eliminated?
it is the random motion of the molecules that causes them to move from an area of high concentration to an area with a lower concentration. Diffusion will continue until the concentration gradient has been eliminated.
How substances move in and out of cells?
In facilitated diffusion, substances move into or out of cells down their concentration gradient through protein channels in the cell membrane. Simple diffusion and facilitated diffusion are similar in that both involve movement down the concentration gradient.
How is a concentration gradient maintained?
Concentration gradients are generated and maintained across biological membranes by ion pump enzymes that transport ionic solutes such as sodium, potassium, hydrogen ions, and calcium across the membrane. Energy is required to produce a gradient, so the gradient is a form of stored energy.
What is an example of concentration gradient?
For example, a few drops of food dye in a glass of water diffuse along the concentration gradient, from where the dye exists in its highest concentration (for instance, the brightest blue or red) to where it occurs in its lowest concentration (the water is still clear).
Which of the following contributes to the maintenance of a resting membrane potential?
Cards
Front | Back |
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Which of the following contributes to the maintenance of a resting membrane potential? | lower plasma permeability to Na+ than to K+ |
Graded potentials: | arise when ion movement causes a minor change in the resting membrane potential. |
What are two active transport examples?
Here are some examples of active transport in animals and humans:
- Sodium-potassium pump (exchange of sodium and potassium ions across cell walls)
- Amino acids moving along the human intestinal tract.
- Calcium ions moving from cardiac muscle cells.
- Glucose moving in or out of a cell.
- A macrophage ingesting a bacterial cell.
Why do ions have a difficult time getting through the membrane?
Why do ions have a difficult time getting through plasma membranes despite their small size? Ions are charged, and consequently, they are hydrophilic and cannot associate with the lipid portion of the membrane. Ions must be transported by carrier proteins or ion channels.
How will a person know if the transport mechanism is not working?
Answer: when he/she has no longer strenght to release when he/she/’s riding a bike or when he wants to carry something like things or groceries.
Which of the following statements is most accurate concerning the plasma membrane of neurons?
The most accurate about the plasma membrane of excitable cells is “The resting membrane potential of neurons is explained by the electrogenic nature of the sodium-potassium ATPase” since there are two potassium ions and three sodium ions in the cells to maintain the negatively-charged membrane inside the cell that …
How does temperature affect active transport?
The higher the oxygen concentration the more energy is released and therefore the rate of active transport is increased. Increase in temperature up to optimum levels increases rate of chemical reactions that release energy in the cell. Increase in energy increases the rate of active transport.
What is the most famous example of active transport?
Examples of Active Transport One of the most important active transport proteins in animals is the sodium-potassium pump.
Why can’t charged molecules pass through the membrane?
Charged atoms or molecules of any size cannot cross the cell membrane via simple diffusion as the charges are repelled by the hydrophobic tails in the interior of the phospholipid bilayer.
What causes a concentration gradient?
A concentration gradient occurs when the concentration of particles is higher in one area than another. In passive transport, particles will diffuse down a concentration gradient, from areas of higher concentration to areas of lower concentration, until they are evenly spaced.
What is concentration gradient and why is it important?
The concentration gradient is an important process for understanding how particles and ions move in random motion in a solution or gas. It is the process used for particles moving from an area of higher concentration in a solution to an area of lower concentration.
Why do substances move from high to low concentration?
Diffusion is the net movement of substances from an area of higher concentration to an area of lower concentration. This movement occurs as a result of the random and constant motion characteristic of all molecules, atoms, or ions (due to kinetic energy) and is independent from the motion of other molecules.
Why do shorter tails make membranes more fluid?
The length of the fatty acid tail This is because the intermolecular interactions between the phospholipid tails add rigidity to the membrane. As a result, the longer the phospholipid tails, the more interactions between the tails are possible and the less fluid the membrane will be.
What do you call the movement of water across a membrane?
Osmosis is the net movement of water across a selectively permeable membrane driven by a difference in solute concentrations on the two sides of the membrane.
What statement best describes active transport?
During active transport, substances move against the concentration gradient, from an area of low concentration to an area of high concentration. This process is “active” because it requires the use of energy (usually in the form of ATP).