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Biology 2122
Study Guide and Notes
Nutrition – Chapter 24
Topic
Introduction
Notes
1. The major nutrients are carbohydrates, lipids and proteins. Water is also
considered a major nutrient. Vitamins and minerals are needed in lower
amounts.
2. Nutrients are needed by the body to build proteins, and other
macromolecules. Simple sugars are needed by the cells to produce ATP
during cell respiration.
3. What are essential nutrients? These are nutrients that the body cannot
make fast enough through interconversion. Must get these in the diet.
Carbohydrates
4. Carbohydrates are found in the diet as starch from plants or indigestible
cellulose in plant walls. Glucose is the simple sugar most used to
produce ATP in cells. Other monosaccharides can be used but they are
usually converted into glucose.
5. The RDA for carbohydrates is 130 g/d. Complex carbs such as whole
grains and wheat do not alter blood sugar levels as much as simple
carbohydrates. It is recommended that you consume around 40-60% of
carbohydrates for your total caloric intake.
Lipids
6. Yes we need to consume lipids! It is advisable to take in
polyunsaturated and unsaturated fats as much as possible. Examples
would be seeds, nuts, olive oils, vegetable oils, etc.
7. The liver is unable to convert one fatty acid to an important fatty acid
called linoleic acid. This is considered to be an essential fatty acid that
must be taken in via the diet. It is an omega-6 fatty acid.
8. Lipids are used throughout the body. Phospholipids make up a great
part of the cell membrane. Adipose tissue surrounds and protects
organs. It also insulates organs. It is a source for fuel during times when
the body is depleted of all other energy sources. Cholesterol is also an
important component in the cell membrane.
9. Fat intake should be less than 30% of total calories. Saturated fats less
than 10%. Cholesterol intake should be limited to less than 300 mg/day.
Proteins
10. The best protein comes from animal sources. They contain the greatest
amount of essential amino acids that must be consumed in the diet. You
can see the essential amino acids on 947. Complete proteins meet all the
body’s amino acid needs (eggs, milk, fish, meats). Interestingly beans
and other legumes are good sources of proteins but are missing some
amino acids.
11. Uses of proteins. Amino acids are used to make proteins. They function
as enzymes, protein carriers in cell membranes, hormones, in skin such
as keratin or collagen, elastin and amino acids and proteins can be
oxidized for energy.
12. Dietary Requirements. You should intake 0.8 g per kilogram of body
weight.
Vitamins
13. Are organic compounds needed in small amounts for growth. They are
not used for energy! They are not monomers for larger compounds.
14. Many vitamins are considered to be coenzymes. They combine with an
enzyme to serve a function. Two B-vitamin coenzymes NAD and FADH
serve as coenzymes in metabolism.
15. Most vitamins are not made in the body. Some are such as vitamin D in
the skin, vitamin D and K in the large intestine. Most must be ingested
as a part of a diet. Some vitamins are converted from other vitamins.
Beta-carotene may be converted to vitamin A.
16. Vitamins are also classified as fat-soluble (A, D, E) and some watersoluble (B, C). Water soluble vitamins are absorbed with water from the
GI tract and are not stored. Fat soluble vitamins are stored and can
become toxic if too high of levels are consumed. You will need to know
some of the important characteristics of some vitamins (provided in the
table at the end of this table).
Minerals
17. There are seven major minerals your body needs in fairly moderate
amounts. They include Ca, P, K, S, Na, Cl, Mg. Trace minerals are
needed in very small amounts (F, Co, Cu, I, Fe, Mn, Se, Zn)
18. Minerals are not used for building blocks or fuels for the cells. They
work with other substances to provide consistent body functions.
19. Minerals such as Ca, P and Mg harden teeth and bone. Fe is essential in
the structure of hemoglobin.
Vitamin and Mineral Study Notes (next page)
Vitamins: You will only be responsible for the following vitamins.
Fat-Soluble
Vitamins
A
D
Characteristics / Functions
1.
2.
3.
4.
10.
11.
Called retinol. 90% stored in the liver.
Formed from beta-carotene in the intestine, kidneys and liver.
Found in green leafy veggies, fish, oils egg yolk, milk.
Functions: required to make photoreceptor pigments for the eyes; bne and
tooth development; antioxidant properties.
Classified as sterols. Concentrated mostly in the liver and some in the spleen
and kidneys.
Produced from a cholesterol precursor (7-dehydrocholesterol) via UV light in
the skin.
Main function is hormonal. Increases calcium blood levels by enhancing
absorption of calcium. With the PTH also allows for calcium to be released
from bone.
Find in egg yolk, milk
Called tocopherols which are chemically related to sex hormones. Stored in
adipose and muscle tissues.
Antioxidant properties and protects cell membranes.
Found in vegetable oils, nuts, whole grains, green leafy vegetables.
12.
13.
14.
15.
Know as Quinones. Small amounts stored in the liver.
Most synthesized by bacteria in the large intestine.
Find in leafy green vegetables, broccoli, cabbage, pork, liver
Essential for blood clotting.
5.
6.
7.
E
K
Water-Soluble
Vitamins
C
B1
B2
B3
8.
9.
1. Called Ascorbic acid. Derived from glucose (6-carbon crystalline structure).
Destroyed by heat and light. Very little stored in adrenal gland, retina,
intestine.
2. Antioxidant properties; converts cholesterol to bile salts; enhances iron
absorption
3. Found in fruits and vegetables. Citrus fruits are high in vitamin C.
4. Thiamin. Destroyed by heat. Very little stored in the body.
5. Functions as a part of a coenzyme called cocarboxylase which functions
carbohydrate metabolism; helps to convert pyruvic acid to acetyl CoA;
oxidation of alcohol.
6. Found in liver, fish, eggs, leafy green veggies and legumes.
7. Riboflavin. Similar to ribose sugar. Decomposed by UV light. Very little stored.
8. Present in coenzyme FAD which functions in cell metabolism.
9. Found in egg, liver, whole grains, meat, poultry, fish, legumes, milk.
10. Niacin. Very stable. Not affected by heat, acids, light very much. Limited
amount stored.
11. Part of NAD coenzyme involved in cell metabolism; cell repair of DNA; inhibits
B6
B12
Folic Acid
cholesterol synthesis; vascular dilator
12. Found in most protein foods. Amino acid tryptophan is converted to B3.
13. Pyridoxine. Stable to heat and acids. Destroyed by alkalines and light.
14. Functions as a coenzyme; required for tryptophan conversion to niacin;
glycogenolysis, antibody formation and hemoglobin.
15. Found in meat, poultry fish, bananas
16. Complex vitamin. Contains cobalt. Inactivated by light but stable to heat.
17. Requires intrinsic factor for absorption.
18. Functions include coenzymes in GI tract, nervous system and bone marrow;
needed by erythrocytes to develop normally and divide properly.
19. Found in liver, meat, fish, dairy foods.
20. Bright-yellow crystalline formation; stable to heat and oxidized in light.
21. Essential for red blood cell formation; normal neural tube development
Minerals
Mineral
Calcium
Chlorine
Sulfur
Potassium
Sodium
Magnesium
Phosphorus
Characteristics and Functions
1. Stored in salt of bones; blood levels regulated by PTH and calcitonin.
2. Required for hardness of bones and teeth; normal membrane permeability;
transmission of impulses; muscle contraction, heart rhythm, activation of
enzymes
3. Found in milk, leafy green veggies, egg yolk
4. Exists mostly as chloride ion.
5. Maintains osmotic pressure; pH of extracellular fluids; HCl formation in
parietal cells of stomach; activates salivary amylase; transport of carbon
dioxide.
6. Found in table salt.
7. Abundant in hair, nails.
8. Part of insulin protein; some vitamins and found in cartilage and tendons.
9. Found in meat, milk, eggs, legumes.
10. Principal intracellular ion.
11. Maintains intracellular osmotic pressure; normal nerve transmission, muscle
contraction, protein synthesis.
12. Found in most foods especially avocados, meat, fish, cereals
13. Found in extracellular fluids, and bone salts.
14. Most abundant extracellular ion; osmotic pressure; acid-base balance; part of
glucose pumps.
15. Table salt
16. Abundant in bones.
17. Part of many coenzymes; ATP to ADP conversion; normal nerve and muscle
irritability.
18. Found in milk, dairy products, cereals, nuts, legumes, leafy green veggies.
19. Found in bones, teeth and other body tissues.
20. Functions in keeping teeth strong; found in DNA; ATP; energy storage; muscle
and nerve activity and cell permeability.
21. Found in milk, eggs, meat, fish, poultry.
YOU WILL ONLY NEED TO STUDY THE FOLLOWING TRACE MINERALS:
1.
2.
3.
4.
Fluorine
Iodine
Iron
Zinc