??? ??? ??? calorie the amount of energy needed to raise the temperature of 1 gram of water 1 degree celcius ??? ??? ??? glycolysis the process in which a glucose molecule is split in half ??? ??? ??? pyruvic acid, a 3 carbon compound what is the product of glycolysis ??? ??? ??? cellular respiration process that releases energy by breaking down glucose and other food molecules in the presence of