The dark brown color of a penny is most likely oxidation, which occurs when the copper in the penny comes in contact with oxygen.<span> </span>
1. The correct answer is pH.
The activity of the enzymes might be affected by environmental changes such as change in pH. Each enzyme has the point when it is the most active and this value is known as the optimum pH. Extremely high or low pH values can lead to loss of enzyme activity and stability.
Phosphofructokinase is sensitive to acidity, meaning that it is inhibited by low pH levels.
2. The correct answer is temperature.
Enzyme is sensitive to the environmental conditions such as temperature changes.
Temperature is a factor that usually increases the rate of enzyme-catalyzed reactions by increasing the activity of enzymes. But, after reaching the optimum temperature, reaction rate abruptly declines. This happens because enzymes are deactivated or denatured at a certain temperature (above 40° C).
Answer:
Adaptive immune defense system consists of lymphocytes like B-lymphocytes and T- lymphocytes. B-lymphocytes provides humoral immunity while T- lymphocytes provide cell-mediated immunity to the body.
99% of lymphocytes circulate freely in the blood and lymph. B lymphocytes differentiate into plasma B cells and B memory cells when interact with antigen presented by T helper cells.
Then plasma cells secrete antibodies in the circulation which binds to extracellular antigens through antigen-binding site. Then the bounded antigen is recognized by receptors present on phagocytic cells. This receptor binds the Fc region of antigen bounded antibody and destroy the antigen by phagocytosis.
