How do enzymes lower activation energy? a. by linking to the substrate and causing a chemical reaction b. by linking to the substrate permanently, creating a very large molecule c. by changing the temperature and ph of the substrate's environment d. by undergoing a chemical change and reacting with the substrate

D, by undergoing a chemical change and reacting with the substrate .

the answer is tropical areas. the tropical areas obtain more

radiant energy from the sun than they lose to space through terrestrial

radiation, and vice versa for polar areas. earth has an energy remaining in the

tropics and an energy scarcity for the polar areas.

explanation:

hey, i believe your answer would be d. sugar ribose and the base uracil. i believe this is the answer, because rna consists of sugar ribose, adenine, guanine, cytosine, and uracil.

your first option is incorrect, because that's dna. where it consists of sugar deoxyribose, adenine, guanine, cytosine and thymine.

your second option is also incorrect, this is because sugar deoxyribose is in dna, and uracil is in rna. these two do not make sense together.

your third option being incorrect, because sugar ribose is in rna, but not the base of thymine. rna consists of uracil, not thymine.

lastly your fourth option being correct! this answer is correct, because both sugar ribose, and the base uracil are in rna! ~

answer is d. sugar ribose and the base uracil.