nuclease - general term for enzymes that catalyze the hydrolysis of nucleic acid by cleaving chains of nucleotides into smaller units. 1  endonuclease - a nuclease that cleaves nucleic acids at interior bonds and so produces fragments of various sizes. exonuclease - a nuclease that releases one nucleotide at a time (serially) beginning at one of a nucleic acid. enzyme - any of several complex proteins that are produced by cells and act as catalysts in specific biochemical reactions.
1 gram of fat = 9 calories. Each gram of fat contains 9 calories. In general carbs are 4 cal per gram, as is protein and fat is 9 cal per gram. 16 people found this useful.
The calories in food come from carbohydrates, proteins, and fats. A gram of carbohydrate contains 4 calories. A gram of protein also contains 4 calories. A gram of fat, though, contains 9 calories â more than twice the amount of the other two. That's why one food with the same serving size as another may have far more calories. A high-fat food has many more calories than a food that's low in fat and higher in protein or carbohydrates.