So, first question:
When we run, we sweat, which means we're getting hotter and hotter and our bodies need to cool down, which they do through transpiration (sweating). If we need to cool down, we need to release the heat that is in our bodies.
To run, we also need to move our muscles, which requires a specific type of energy, called mechanical or kinetic energy, which is the "energy of movement". In our bodies, we don't store that type of energy though, so we have to convert chemical energy to mechanical energy.
Answers: First option and third option.
Second question:
We know that to move we need energy, and that an amazing source of energy is sugar. In this case, the biomolecule mainly used by cells to obtain energy, is glucose, which is a type of sugar.
Answer: B.
Third question:
NAD+ stands for Nicotinamide adenine dinucleotide +, an it has many functions, such as an oxidiser. In this case, in fermentation, it's related to glycolysis.
Glycolysis is a process of energy transformation used by cells, where they convert sugars to biochemical energy. The function of NAD in this case, is "housing" electrons for the process to function normally. Note that during the process, when NAD accepts electrons, it gains 1 proton which converts it to NADH.
Answer: C.
Hope it helped,
BioTeacher101
