Chapter 24
Nutrition, Metabolism, and Body Temperature Regulation
915
24
Table 24.3
Mineral Requirements of Humans
MINERAL
MAJOR DIETARY SOURCES
MAJOR FUNCTIONS IN THE BODY
SYMPTOMS OF DEFICIENCY*
Greater Than 200 mg per Day Required
Calcium (Ca)
Dairy products, dark green
vegetables, legumes
Bone and tooth formation, blood
clotting, nerve and muscle function
Retarded growth, possibly loss of
bone mass
Phosphorus (P)
Dairy products, meats, grains
Bone and tooth formation, acid-
base balance, nucleotide synthesis
Weakness, loss of minerals from
bone, calcium loss
Sulfur (S)
Proteins from many sources
Component of certain amino acids
Symptoms of protein deficiency
Potassium (K)
Meats, dairy products, many
fruits and vegetables, grains
Acid-base balance, water balance,
nerve function
Muscular weakness, paralysis,
nausea, heart failure
Chlorine (Cl)
Table salt
Acid-base balance, formation
of gastric juice, nerve function,
osmotic balance
Muscle cramps, reduced appetite
Sodium (Na)
Table salt
Acid-base balance, water balance,
nerve function
Muscle cramps, reduced appetite
Magnesium (Mg)
Whole grains, green leafy
vegetables
Cofactor; ATP bioenergetics
Nervous system disturbances
Trace Amounts Required
Iron (Fe)
Meats, eggs, legumes, whole
grains, green leafy vegetables
Component of hemoglobin and
of electron carriers in energy
metabolism; enzyme cofactor
Iron-deficiency anemia, weakness,
impaired immunity
Fluorine (F)
Drinking water, tea, seafood
Maintenance of tooth (and
probably bone) structure
Higher frequency of tooth decay
Zinc (Zn)
Meats, seafood, grains
Component of certain digestive
enzymes and other proteins
Growth failure, skin abnormalities,
reproductive failure, impaired
immunity
Copper (Cu)
Seafood, nuts, legumes, organ
meats
Enzyme cofactor in iron
metabolism, melanin synthesis,
electron transport
Anemia, cardiovascular
abnormalities
Manganese (Mn)
Nuts, grains, vegetables, fruits,
tea
Enzyme cofactor
Abnormal bone and cartilage
Iodine (I)
Seafood, dairy products, iodized
salt
Component of thyroid hormones
Goiter (enlarged thyroid)
Cobalt (Co)
Meats and dairy products
Component of vitamin B
12
None, except as B
12
deficiency
Selenium (Se)
Seafood, meats, whole grains
Enzyme cofactor; antioxidant
functioning in close association
with vitamin E
Muscle pain, possibly heart muscle
deterioration
Chromium (Cr)
Brewer’s yeast, liver, seafood,
meats, some vegetables
Involved in glucose and energy
metabolism
Impaired glucose metabolism
Molybdenum (Mo)
Legumes, grains, some
vegetables
Enzyme cofactor
Disorder in excretion of nitrogen-
containing compounds
*All of these minerals are also harmful when consumed in excess.
Source:
From Jane B. Reece, CAMPBELL BIOLOGY, 9th Edition, © 2011. Reprinted by permission of Pearson Education, Inc., Upper Saddle River, N. J.
Later it was discovered that oxidation also occurs when hy-
drogen atoms are
removed
from compounds, so the definition
was expanded to its current form:
Oxidation is the gain of oxy-
gen or the loss of hydrogen.
As explained in Chapter 2, whichever
way oxidation occurs, the oxidized substance always
loses
(or
nearly loses) electrons as they move to (or toward) a substance
that more strongly attracts them.
To explain this loss of electrons, let’s review the consequences
of different electron-attracting abilities of atoms (see pp. 31–35).
Consider a molecule made up of a hydrogen atom plus some
other kinds of atoms. Hydrogen is very electropositive, so its
lone electron usually spends more time orbiting the other at-
oms of the molecule. But when a hydrogen
atom
is removed,
its electron goes with it, and the molecule as a whole loses that
electron. Conversely, oxygen is very electron-hungry (electro-
negative), so when oxygen binds with other atoms the shared
electrons spend more time in oxygen’s vicinity. Again, the mol-
ecule as a whole loses electrons.
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