Knowledge Points

1. Nutrient Functions

Provide energy: Sugars, fats, and proteins can be oxidized and decomposed for energy.

The order of their energy supply: sugars, fats, proteins

Proteins are the main raw materials for building and repairing tissues

Provide building and repairing substances: sugars and lipids are an important part of the cell membranes and nerve tissues

Ga, Mg,,, and P are the main components of the skeleton

Enzymes and some hormones are proteins

Provide regulatory substances iodine is the main component of thyroid hormones

2, malnutrition:

Insufficient supply of protein, affecting the development and resistance

Insufficient supply of nutrients lack of calcium affects the development of the bone

Lack of vitamin A can cause night blindness

Lack of vitamin C can cause scurvy

Excessive nutrients: such as Excessive energy can lead to obesity

The type, quantity and proportion of nutrients consumed are in line with the actual needs

Reasonable processing of food can reduce the loss of nutrients and increase the utilization rate

3. Reasonable Diet: Foods that are not poisonous to the human body and meet the requirements of food hygiene

Establishment of good dietary habits and reasonable dietary systems

Examples to comprehend

Example 1, the following belong to the human body to build and repair the body's tissues, a group of substances:

① water ② lipids ③ sugars ④ proteins ⑤ cellulose ⑥ inorganic salts ⑦ vitamins

A ① ③ ④ ⑤ ⑦ B ① ③ ④ ⑥ ⑦ C ① ② ③ ④ ⑥ D ① ② ③ ④ ⑥ ⑦

Ans: The substances involved in the construction and repair of human tissues are mainly water, Proteins, lipids, sugars and inorganic salts. Cellulose is the main component of the cell wall of the plant body; cellulose is an important substance to regulate the physiological function of the body. Answer: C

Example 2, the following items are not adults to eat a certain amount of protein every day is:

A, protein can not be stored in the body.

B. Protein cannot be converted all by sugar and fat in the body.

C, Proteins provide most of the energy needed for life activities.

D. Proteins in the body have to be broken down some in small amounts and replaced with new ones every day.

Ans: Protein as an indispensable and important biological material, although it can be used as an energy material, but not the main, the order of the body's energy supply of substances in the order of sugars, fats, proteins.

Answer: C

Self-assessment

Multiple Choice Questions:

1, the following statement about human nutrition, is incorrect: ()

A, because protein can participate in various life activities, so the daily food to protein content is appropriate.

B, washing rice should not be done too many times to prevent the loss of vitamin B1.

C. Vegetables should be washed and cut first, and stir-fried over high heat to prevent the loss of vitamin C. The first thing you need to do is to cut and wash the vegetables.

D, food processing to prevent both biological pollution, but also preservatives and other excessive chemical pollution.

2, human blood is not possible ()

A, cellulose B, red blood cells C, protein D, hormones

3, someone due to malnutrition, the body swollen, its therapeutic dietary remedies are: ()

A, eat more vegetables B, eat more steamed bread C, drink more soybean milk D, drink more water

4, 1 gram of sugar, fat and Protein in the body complete oxidative decomposition of the energy released are 17. 15 kilojoules, 38. 91 kilojoules and 17. 15 kilojoules, from which it can be concluded that: ()

A, all three can be used as an energy source

B, protein is the main energy source.

C. Sugar is the main energy substance

D. Fat is the main energy substance

5. Which of the following groups of diseases is caused by malnutrition:()

A. Foot fungus and scurvy B. Night blindness and gigantism

C. Diabetes mellitus and chondromalacia D. Rickets and heart disease

6. A healthy man If he eats more sugar and salt, then the amount of glucose and salt contained in his excreted urine:()

A, salt increased, sugar did not increase B, sugar increased, salt did not increase

C, both increased D, both did not increase