Nutrition and Energy Production

Free Response

What are essential nutrients?

Hint:

Essential nutrients are those nutrients that must be obtained from the diet because they cannot be produced by the body. Vitamins and minerals are examples of essential nutrients.

What is the role of minerals in maintaining good health?

Hint:

Minerals—such as potassium, sodium, and calcium—are required for the functioning of many cellular processes, including muscle contraction and nerve conduction. While minerals are required in trace amounts, not having minerals in the diet can be potentially harmful.

Discuss why obesity is a growing epidemic.

Hint:

In the United States, obesity, particularly childhood obesity, is a growing concern. Some of the contributors to this situation include sedentary lifestyles and consuming more processed foods and less fruits and vegetables. As a result, even young children who are obese can face health concerns.

There are several nations where malnourishment is a common occurrence. What may be some of the health challenges posed by malnutrition?

Hint:

Malnutrition, often in the form of not getting enough calories or not enough of the essential nutrients, can have severe consequences. Many malnourished children have vision and dental problems, and over the years may develop many serious health problems.

Generally describe how a piece of bread can power your legs as you walk up a flight of stairs.

Hint:

A piece of bread is eaten and converted into chemical energy. The bread is broken down in the mouth by mastication and salivary enzymes, then transferred to the stomach for further digestion. After digestion by the acid and digestive enzymes in the stomach, the macromolecules that made up the bread move into the small intestine. In the small intestine, the carbohydrates from the bread are absorbed through the microvilli into the bloodstream. In muscle cells in the legs, the carbohydrates can be broken down into glucose, and then used for cellular respiration to create ATP. The muscles in the leg then use the ATP to perform the mechanical work needed to climb a flight of stairs.

In the 1990s fat-free foods became popular among people trying to lose weight. However, many dieticians now conclude that the fat-free trend made people less healthy and heavier. Describe how this could occur.

Hint:

Fats are an essential component of a healthy diet, and needed by the body to function. Fats are essential for many processes, including the absorption of fat-soluble vitamins and production of some hormones. Fats also send a satiation signal to the brain that regulates hunger. Without fats in their diets many people may have actually consumed more calories, which would have resulted in weight gain.