The answer is all of the above
The heart cells must be able to continue aerobic metabolism when skeletal muscle cannot. Aerobic metabolism is a part of cellular respiration and involves body cells making energy through glycolysis, the citric acid cycle, and the electron transport/oxidative. It is done in the heart at a rate below 85% of maximum heart rate and does not use vigorous muscle contraction. fatty acids , ketone bodies and carbohydrates are the primary substrates of the heart metabolized to generate ATP. The metabolic demands of the heart are the largest than any other organ in the body, and normal cardiac metabolism is required to fuel contractile function and viability.
<span>Compare: both RNA and DNA have 3 nitrogenous bases: Adenine Cytosine and Guanine. Also b</span>oth have a phosphate groups in their nucleotides<span>
Contrast: </span>RNA is a polymer with a ribose AND a phosphate backbone. It has four different nitrogenous bases: adenine, guanine, cytosine, and uracil.
DNA<span> is a long polymer with deoxyriboses AND phosphate backbone. It also has four </span>different<span> nitrogenous bases: adenine, guanine, cytosine and thymine.
</span>
Hope this helps
Producers are primary consumers and it gets 10 %