A. lysine
B. phenylalanine
C. cysteine
D. tyrosine
2. What disease is it easy to get by eating polished rice and refined noodles for a long time?
A. Night blindness
B. beriberi
C. furuncle
Despicable
3. For children and adolescents with normal development, the relationship between nitrogen intake and nitrogen excretion is:
A.I=(U+F+S)
B. I & lt(U+F+S)
C. I & gt(U+F+S)
D. irrelevant
4. The foods that should be eaten to treat iron deficiency are:
A. Fish, eggs, vegetables and fruits
B. lean meat, animal whole blood and eggs
C. Yogurt, milk and dental floss
D. Soybean and its products
5. Vitamins related to night blindness are:
A. vitamin a
B. vitamin b
C. vitamin C.
D. calcified alcohol
6. Nutrients that neither participate in body composition nor provide energy are:
A. protein
B. Fat
C. carbohydrates
D. vitamins
Reference answer and analysis
1. Reference answer C. Analysis: Conditionally necessary amino acids are cysteine and tyrosine, which are transformed from methionine and phenylalanine respectively in vivo. If cysteine and tyrosine can be provided directly in the diet, the demand for methionine and phenylalanine can be reduced by 30% and 50% respectively. Cysteine changes from methionine, that is, cysteine can save methionine. Therefore, this question chooses C.
2. reference answer B. analysis: refined rice flour lacks vitamin B 1, and it is easy to get athlete's foot after eating refined rice flour for a long time; Night blindness lacks vitamin a; Leprosy lacks vitamin B3; Scurvy lacks vitamin C, therefore, choose B in this question.
3. Reference answer C. Analysis: Nitrogen balance reflects the relationship between nitrogen intake and nitrogen excretion. Relationship: B=I-(U+F+S), b: nitrogen balance; I: nitrogen intake; U: urine nitrogen; F: fecal nitrogen; Loss of nitrogen from the skin. Healthy adults generally maintain zero nitrogen balance, that is, nitrogen intake equals nitrogen excretion; Children in the growth and development stage, pregnant women, people who need to gain muscle during exercise and labor, generally maintain a positive nitrogen balance, that is, nitrogen intake is greater than nitrogen excretion; People with chronic wasting diseases, the elderly, tissue trauma and hunger generally maintain negative nitrogen balance, that is, nitrogen intake is less than nitrogen excretion. Therefore, this question chooses C.
4. Reference answer B. Analysis: Good sources of iron are animal liver, whole blood, meat, fish and eggs. Therefore, choose B in this question.
5. Reference answer A. Analysis: Vitamin A can maintain normal vision, promote the synthesis and regeneration of rhodopsin in cells, and maintain normal dark adaptation ability, thus maintaining normal vision. Vitamin A deficiency will reduce the dark adaptation ability of the body in the early stage, and serious deficiency will lead to night blindness or even blindness. Therefore, choose a in this question.
6. Reference answer D. Analysis: protein, fat and carbohydrate are the three major nutrients of the human body. Vitamins are a kind of trace organic compounds with low molecular weight, which are necessary to maintain the life activities of the body. They do not participate in the body composition or provide energy physiologically, but play an important role in the process of material and energy metabolism. Therefore, choose D in this question.