Circulatory -
Brings oxygen and nutrients where it is needed, removes toxic chemicals, maintains a stable body temperature
Digestive -
Food and nutrients are absorbed in the small intestine. These nutrients are necessary for other body systems to maintain homeostasis.
Excretory -
Removes all waste from the body, kidneys filter chemicals, liver filters toxins
Answer:
D) They can increase the reaction rate for a given reaction by a thousand-fold or more.
Explanation:
Enzymes are like catalysts with the only difference that they are bio-molecules. Biochemical/chemical reactions are slow because of 'transition state barriers' which require a lot of energy to overcome so enzymes rather than overcoming transition state barrier provide an alternate pathway for biochemical reactions which require comparatively less energy. Thus presence of an enzyme leads to an increase in reaction rate because alternate pathway which requires less energy makes the rate of chemical reaction rapid by a thousand-fold or more.
During the transfer of energy from one tropic level to the next tropic level around 90% of the total energy is lost in the metabolic processes in the form of heat. Hence only about 10% of the total energy can only be transferred from one tropic level to the next tropic level.
