food and nutrients

why we need food

Did you ever hear the old saying, An apple a day keeps the doctor away? Do apples really prevent you from getting sick? Probably not, but eating apples and other fresh fruits can help keep you healthy. Do you eat your vegetables? Maybe you do, but you may have friends who wont touch a piece of broccoli or asparagus. Should you eat these foods and food like them? The girls pictured in the Figure 1.1 are eating salads. Why do you need foods like these for good health? What role does food play in the body? Your body needs food for three reasons: 1. Food gives your body energy. You need energy for everything you do. Remember that cellular respiration converts the glucose in the food you eat into ATP, or cellular energy. Which has more glucose, a salad or a piece of meat? Do you remember what types of foods produce glucose? Recall that glucose is the product of photosynthesis. These girls are eating leafy green vegetables. Fresh vegetables such as these are excellent food choices for good health. 2. Food provides building materials for your body. Your body needs building materials so it can grow and repair itself. Specifically, it needs these materials to produce more cells and its components. 3. Food contains substances that help control body processes. Your body processes must be kept in balance for good health. For all these reasons, you must have a regular supply of nutrients. Nutrients are chemicals in food that your body needs. There are five types of nutrients. 1. 2. 3. 4. 5. Carbohydrates Proteins Lipids Vitamins Minerals Carbohydrates, proteins, and lipids are categories of organic compounds. They give your body energy, though carbohydrates are the main source of energy. Proteins provide building materials, such as amino acids to build your own proteins. Proteins, vitamins, and minerals also help control body processes. Carbohydrates include sugars such as the glucose made by photosynthesis. Often glucose is stored in large molecules such as starch. Proteins are found in foods like meats and nuts. Lipids includes fats and oils. Though you should stay away from many types of fats, others are needed by your body. Important vitamins include vitamins A, B (multiple types) C, D, and E. Important minerals include calcium and potassium. What should you drink to get calcium? Milk is a good source.


instructional diagrams

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there are more carbohydrates in a salad than in a steak.

-->  a. true

b. false

the four types of nutrients are carbohydrates, lipids, proteins and nucleic acids.

a. true

-->  b. false

what is the main source of energy for your body?

a) lipids

b) proteins

-->  c) carbohydrates

d) nucleic acids

which of the following are proteins built from amino acids?

-->  a) enzymes, antibodies, and muscle fibers

b) dna and rna

c) glucose and starch

d) olive oil

what type of food provides lipids?

a) pizza

b) broccoli

-->  c) peanut oil

d) hot dog

what process turns glucose into usable energy?

-->  a) cellular respiration

b) photosynthesis

c) digestion

d) metabolism

why does your body need food?

a) food provides building materials for your body.

b) food contains substances that help control body processes.

c) food gives your body energy.

-->  d) all of the above

diagram questions

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