Which electron carrier is used in the redox reactions in cellular respiration?

The right answer is NAD+ (NADH).

NAD (Nicotinamide-adenine-dinucleotide) is a coenzyme found in cells. It is a dinucleotide, insofar as the molecule consists of a first nucleotide, whose nucleic base is adenine, united to a second nucleotide, the base of which is nicotinamide. NAD exists in an oxidized form, denoted NAD+, and a reduced form, denoted NADH.

the correct answer is(the type of energy described here is potential energy.)

explanation: now if the person holding the bow and arrow has now let go. the arrow shoots forward toward its target. the   type of energy then becomes

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.