Answer:
d. Fluoride becomes incorporated into the crystalline structure of teeth, making them less susceptible to decay
Explanation:
Dental caries results when cariogenic (caries-causing) bacteria metabolize carbohydrates or sugars present in the mouth for their energy needs, producing organic acids as byproducts, thus lowering the pH of the plaque biofilm.
The hydroxyapatite of tooth enamel is composed mainly of phosphate ions (PO₄³⁻) and calcium ions (Ca⁺). Under normal conditions, there is a stable equilibrium between the calcium and phosphate ions in saliva and the crystalline hydroxyapatite. At low pH (acidic conditions), there is a shift in equilibrium resulting in the dissolution of hydroxyapatite from tooth enamel, a process known as demineralization. A reverse process called remineralization (the process of incorporation of minerals in tooth enamel) occurs when the saliva, acting as a buffer elevates pH. When equilibrium is shifted to favor continued demineralization, dental caries results.
However, when fluoride is present in saliva, fluorapatite, rather than hydroxyapatite, forms during the remineralization process as fluoride ions replace hydroxyl groups in the formation of the apatite crystal lattice.
Fluorapatite is less soluble than hydroxyapatite making it more resistant to demineralization, even under conditions of low pH. Thus, fluoride acts as an effective anticaries agent.
An amniote are animals in that lay eggs on land or retain the fertilized egg within the mother. amniotes can be mammals, birds or reptiles
Answer:
D. A positive charge, because of a covalent bond with oxygen
Explanation:
A water molecule contain both hydrogen and oxygen atom. Water is a polar molecule because it has positive electric charge in one of it's poles and negative charge on the other. The hydrogen is positively charged and the oxygen is negatively charged which are bonded by covalent bond. Hydrogen is positively charged because it cannot attract electrons strongly like oxygen which is positively charged. There is unequal sharing of electrons in water molecules and this is why oxygen is slightly negative and hydrogen is slightly positive.
Protease enzymes are doing most of the work during the process of Maxwell's digestion. These enzymes breakdown peptide bonds of proteins which make food digestible. Chicken breasts mostly contain protein nutrients that are broken down by the enzyme and then absorbed well within the body hours after the intake.
Answer and Explanation:A) the heart must move and it is not possible to make an organ that moves.
