When something needs to be transported against its concentration gradient, or a molecule is too big to simply diffuse through a membrane, active transport has to be used. So active transport requires energy (ATP).
Examples:
1. Antiport pumps: transport one substance in one direction while transporting another substance the other way. An example of this is the sodium-potassium pump.
2. Symport pumps - uses a substance that wants to move from an area of high concentration to low concentration and carries another substance against its concentration gradient. An example of this is the sodium-glucose transport protein
3. Endocytosis - large amounts of extra cellular fluid can be taken into a cell - needs ATP to bind proteins in the cell membrane and causes them to change their shape...which eventually causes the surrounding of the fluid to be brought in (a vesicle).
4.exocytosis - opposite of above
Answer: Amino acids are organic compounds (molecules) that contain amine (–NH2) and carboxyl (–COOH) functional groups, along with a side chain (R group) specific to each amino acid.
Explanation: The variation seen in naturally occurring amino acids arises from differences in this side chain.
Summary of Differences Between DNA and RNA<span>DNA contains the sugar deoxyribose, while RNA contains the sugar ribose. The only difference between ribose and deoxyribose is that ribose has one more -OH group than deoxyribose, which has -H attached to the second (2') carbon in the ring.DNA is a double stranded molecule while RNA is a single stranded molecule.DNA is stable under alkaline conditions while RNA is not stable.<span>DNA and RNA perform different functions in humans. DNA is responsible for storing and transferring genetic information while RNA directly codes for amino acids and as acts as a messenger between DNA and ribosomes to make proteins.</span></span>
The answer is D. You really have to think about this one :)) I hope you get it right
The proximal tubule is the segment of the nephron in kidneys which begins from the renal pole of the Bowman's capsule to the beginning of loop of Henle. The glomerulus is the site in the nephron where fluid and solutes are filtered out of the blood to form a glomerular filtrate. The proximal and distal tubules, the loop of Henle, and the collecting ducts are sites for the reabsorption of water and ions. Fluid and small solutes are forced under pressure to flow from the glomerulus into the capsular space of the glomerular capsule.
Reabsorption as this filtrate passes through the tubules, specific substances are reabsorbed back into the blood of the peritubular capillaries. Bowman's capsule surrounds the glomerular capillary loops and participates in the filtration of blood from the glomerular capillaries.
To learn more about glomerular filtrate ,here
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