The fact that the two strands of DNA are complementary <span />
A baby using a fork to eat
Answer:
Human cells can readily absorb folic acid; bacteria cells cannot.
Explanation:
Bacterial cells cannot absorb folic acid and synthesize it. On the other hand, humans do not synthesize folic acid in their cells. They rather obtain it from the diet. Sulfa drugs, for example, sulfanilamide resemble p-aminobenzoate (PABA). PABA is a molecule that is used as a substrate in the synthesis of the coenzyme folic acid. The sulfa drugs serve as competitive inhibitors and compete with PABA for the catalytic site of an enzyme involved in the folic acid synthesis. This prevents the synthesis of folic acid in bacterial cells and thereby, inhibits bacterial growth.
One of the most poplar examples of commensalism is the relationship between cattle egrets and livestock. The cattle egret is a common species of heron that is found in most regions of the world, and is mostly seen moving along with herds of cattle. This bird moves about in pastures, and follows livestock such as cattle and horses.
Depolarization is initiated when there is an influx of sodium inside the cell as opposed to repolarization, where potassium exits the cell (occurring after Na+ gates close). Remember that for every 3 Na+ in, there is 2 K+ out. This imbalance helps to stabilize the membrane.
