Answer:
A). 315 Kcal
B). 108 KCal
Explanation:
The reason we eat is to obtain energy, which is the same reason Anna ate dinner yesterday. Food consists of different classes but the three major ones that acts as sources of energy are Carbohydrates, fats and protein. The energy in the food we ingest is measured in Kilocalories (Kcal) which is a thousand calories.
However, the different classes of food mentioned above contains different quantities of energy per gram i.e.
1 gram of carbohydrate = 4 Kcal
1 gram of protein= 4 Kcal
1 gram of fat = 9 Kcal
Hence, to calculate the total energy value (Kcal) present in the dinner Anne ate, we multipy the grams of each class of food by it's corresponding energy value in Kcal. Thus, we have;
For 7 grams of fat, 7 × 9 Kcal/g = 63 Kcal
For 36 grams of carbohydrates, 36 × 4 Kcal/g = 144 Kcal
For 27 grams of protein, 27 × 4 Kcal/g = 108 Kcal
Hence, the total energy value contained in the food is:
63 + 108 + 144
= 315 Kcal
For question B, based on the above explanation, 27 grams of protein was present in the food eaten. Hence, 27 × 4 Kcal/g = 108 Kcal
108 Kcal of protein contributed to Anna's total Kcal present in the food.
