Active and passive transport in the kidneys
9.2.3.2.5 distinguish between passive and active transport and relate these to processes occurring in the mammalian kidney
Passive transport requires no expenditure of energy. This is because molecules have the tendency to move from areas of high concentration to areas of low concentration. This can be through a partially permeable membrane.
An example of this is when toast begins to burn and the smoke moves throughout the house and can be smelt strongly. The smoke moves from the toaster which has a high concentration throughout the house which has a low concentration of smoke particles.
Passive transport occurs in the kidney as the small blood capillaries called glomerulus have their waste products removed from the blood. The concentration of nitrogenous waste products in the Bowman's capsule is low and therefore the wastes in the glomerulus diffuse through the glomerular filtration membrane. This occurs without any energy being used up.
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On the other hand, active transport uses energy to pump or transport substances across a membrane. Active transport is used against the concentration gradient of solutes, which means when low concentrations move to high concentrations instead of the other way around. This occurs within the body because most cells require a high concentration of certain materials like glucose and amino acids.
Active transport in cells is undertaken with specific carrier proteins that lie within the membrane. The carrier proteins binds with the molecule that needs to be transported and then changes its shape (with the help of ATP) to move the substance to the other side of the membrane.
Endocytosis is another way of active transport, where the membrane surrounds the substance and then engulfs it into the cell.
Active transport can be seen in the kidneys, at the reabsorption stage in the nephrons. Along the nephron, a large network of capillaries surround the tubules that carry the waste. Substances that the body needs from the waste that can be re-used are reabsorbed into the blood stream. These substances are usually glucose, amino acids, vitamins, water and more. This reabsorption usually happens in the proximal and distal convoluted tubules and the loop of Henle.
For a fun, interesting explanation of passive and active transport, please watch this BrainPOP video by clicking the button below:
Passive transport requires no expenditure of energy. This is because molecules have the tendency to move from areas of high concentration to areas of low concentration. This can be through a partially permeable membrane.
An example of this is when toast begins to burn and the smoke moves throughout the house and can be smelt strongly. The smoke moves from the toaster which has a high concentration throughout the house which has a low concentration of smoke particles.
Passive transport occurs in the kidney as the small blood capillaries called glomerulus have their waste products removed from the blood. The concentration of nitrogenous waste products in the Bowman's capsule is low and therefore the wastes in the glomerulus diffuse through the glomerular filtration membrane. This occurs without any energy being used up.
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On the other hand, active transport uses energy to pump or transport substances across a membrane. Active transport is used against the concentration gradient of solutes, which means when low concentrations move to high concentrations instead of the other way around. This occurs within the body because most cells require a high concentration of certain materials like glucose and amino acids.
Active transport in cells is undertaken with specific carrier proteins that lie within the membrane. The carrier proteins binds with the molecule that needs to be transported and then changes its shape (with the help of ATP) to move the substance to the other side of the membrane.
Endocytosis is another way of active transport, where the membrane surrounds the substance and then engulfs it into the cell.
Active transport can be seen in the kidneys, at the reabsorption stage in the nephrons. Along the nephron, a large network of capillaries surround the tubules that carry the waste. Substances that the body needs from the waste that can be re-used are reabsorbed into the blood stream. These substances are usually glucose, amino acids, vitamins, water and more. This reabsorption usually happens in the proximal and distal convoluted tubules and the loop of Henle.
For a fun, interesting explanation of passive and active transport, please watch this BrainPOP video by clicking the button below: