Section 49.1.2 (Exam 4) Food Flashcards
Food Provides Energy As Well As Materials for Biosynthesis
Why must proteins be broken down into amino acids before being used by the body?
Proteins are large and not readily absorbed by the gut
Protein structure and function vary by species
The immune system would attack protein molecules entering directly from the gut
What is one example of an essential fatty acid that humans require in their diet? What could happen if these needs are not met?
Linoleic acid is one that helps synthesize other unsaturated fatty acids, including signaling molecules and membrane phospholipids
Deficiency can lead to –impaired fertility and lactation problems
Minerals are also required in the human diet. Explain the two types of minerals required in the diet.
Mineral macronutrients: elements required in large amounts, such as calcium
Mineral micronutrients: elements required in tiny amounts (<100mg/day), such as iron
Describe iron deficiency.
Insufficient iron leads to anemia and is the most common mineral deficiency in the world today
What are vitamins?
carbon compounds required for growth and metabolism that can’t be synthesized
What is the function of vitamins, and which ones are required in diet?
Most function as coenzymes or parts of coenzymes
Required vitamins vary with species (e.g., primates can’t make vitamin C but other mammals can)
How many vitamins do humans require? How many of each type?
Humans require 13 vitamins.
Water-soluble vitamins – 9: eliminated in urine if there is an excess (e.g., vitamin C)
Fat-soluble vitamins – 4: can accumulate to toxic levels in body fat and the liver. (e.g. Vitamins D, E, K, and A)
What happens if there is an excess of water-soluble vitamins?
It can be removed through the urine, an excess is not toxic
What happens if there is an excess of fat-soluble vitamins?
It can accumulate in toxic levels in body fat and the liver
Why is vitamin D (calciferol) special?
It is synthesized by the skin when the skin is exposed to UV rays
What can nutrient deficiency lead to?
malnutrition
What can chronic malnutrition lead to? What are three examples?
Deficiency diseases:
Scurvy—lack of vitamin C
Beriberi—lack of thiamin (vitamin B1); this disease led to the discovery of vitamins
Deficiency of folic acid during pregnancy can lead to neural tube defects in the baby
What can deficiency diseases be caused by? What is one example of this?
Inability to absorb or process a nutrient
In pernicious anemia, vitamin B12 is not absorbed in the stomach (damage to stomach lining)
What are 2 diseases caused by mineral deficiencies?
Iodine deficiency leads to hypothyroidism and goiter
Iron deficiency leads to anemia
