<span>Enzyme and substrate bind using a lock-and-key mechanism. </span>
Animal cells do not have chloroplasts because animals get sugar from the food they eat, they do not need chloroplasts: just mitochondria.
and plant cell need chloroplast because plants don't get their sugar from eating food, so they need to make sugar from sunlight so they have chloroplast
Answer:
carbohydrates
Explanation:
this is because even though the person hasn't eaten he or she still has an amount of carbohydrates in the body that can be broken down and its end product glucose will be obtained
