Chapter 8 - Minerals

Question 1

What 4 elements are living matter composed of - building blocks of life?

Answer 1

• hydrogen
• carbon
• nitrogen
• oxygen

Question 2

Of the 118 elements on the periodic table, how many are essential to human life

Answer 2

25

Question 3

element

Answer 3

single type of atom

• of 118 elements, 94 occur naturally on earth
• cannot be broken down into smaller substances

Question 4

major minerals

Answer 4

group of minerals that are required by the body in amount of more than 100 mg/day
- calcium, phosphorus, sodium, potassium, chloride, magnesium, sulfur

Question 5

key concepts

Answer 5

human body requires a variety of minerals to perform its numbers metabolic tasks

• mixed diet of varied foods and adequate energy value is the best source of minerals necessary for health
• of total amount of minerals that a person consumes, only a relatively limited amount is available to the body

Question 6

trace minerals

Answer 6

group of elements that are required by the body in amounts of less than 100 mg/day
- iron, iodine, zinc, selenium, fluoride, copper, manganese, chromium, molybdenum, cobalt, boron, vanadium, nickel

Question 7

mineral metabolism

Answer 7

controlled either at the point of intestinal absorption or at the point of tissue uptake

Question 8

mineral digestion

Answer 8

absorbed and used in the body in their ionic forms

• carries either a positive or negative electric charge
• do not require a great deal of mechanical or chemical digestion before absorption occurs

Question 9

mineral absorption

Answer 9

• influencing factors: food form (animal sources more readily absorbed), body need (more absorbed if body if deficient), tissue health (is intestinal surface is diseases, absorptive capacity is diminished)
• presence of fiber, phytate, or oxalate can bind certain minerals in the GI tract and inhibit or limit their absorption

Question 10

mineral transport

Answer 10

enter the portal blood circulation and travel throughout the body bound to plasma proteins or mineral specific transport proteins (ex: iron binds to transferrin in the circulation)

Question 11

mineral tissue uptake

Answer 11

controlled by hormones

- excess excreted into the urine

Question 12

thyroid-stimulating hormone (TSH)

Answer 12

controls the uptake of iodine from the blood by the thyroid gland

• dependent on the amount that the thyroid gland needs to make the hormone thyroxine
• when more is thyroxine is needed, TSH stimulates thyroid gland to take up indie and the kidney to excrete less iodine in the urine
• less TSH is released from the anterior pituitary gland when thyroxine concentration is normal

Question 13

mineral occurence in the body

Answer 13

• free ions in body fluids (sodium in tissue fluids which influence water balance)
• covalently bound minerals that may combine with other minerals (calcium and phosphorus in hydroxyapatite) or organic substances (iron bound to heme and global to form organic compound hemoglobin)

Question 14

Calcium

Answer 14

2% of total body weight is calcium (most are bones & teeth = 99% / 1% body weight)