Correct Answer: (1) enzymes that clot blood
Enzymes refer to a class of proteins that serve as catalysts, chemical agents that change the rate of reaction without being consumed during the reaction. In the body processes, there are various enzymes used however, when the pH of the blood is not normal (must be near 7.4) then the reaction would not take place as expected. The Le Chatellier's Principle best explains this condition, which states that "if a chemical system at equilibrium experiences a change in concentration, temperature, volume, or partial pressure, then the equilibrium shifts to counteract the imposed change and a new equilibrium is established.
The clotting mechanism usually starts with the release of clotting factors from platelets and involves a complex chain of reactions that ultimately transforms fibrinogen to fibrin. So if the pH is not in equilibrium, the reactions in blood clotting mechanism would be disrupted.
(2) red blood cells that make antibodies
pH can affect the formation of antibodies, however it is not the red blood cells that form antibodies. Antibodies are antigen-binding immunoglobulin, produced by B cells, which is a type of white blood cell that functions as the effector of immune response. On the other hand, red blood cells function for the delivery of oxygen to various parts of the body.
(3) chlorophyll that carries oxygen in the blood
Chlorophyll is a green pigment located within the chloroplasts of plants, while blood is a specialized fluid that transports nutrients, oxygen, and other substances within the body of animals. Blood is absent in plants. Red blood cells, a portion of the blood, serve as a buffer for blood pH.
(4) DNA that controls starch digestion in the blood
DNA or deoxyribonucleic acid is a double-stranded nucleic acid molecule that has the ability to replicate and determine the inherited structure of a cell's proteins. Its activity may be affected by the pH in the blood, however, it does not directly control the digestion of starch. Starch, a complex carbohydrate, is digested in the digestive system and then converted into glucose molecules which are absorbed into the blood. Some of it goes to the liver for storage or converted into energy for the activities of the body.