Lecture Notes-11 Biology 1004

North Arkansas College

Topic:  Macromolecules

1. Organic compounds containing carbon, hydrogen and oxygen.
2. Carbohydrates may be:

1. triose - 3 carbons
2. tetrose - 4 carbons
3. pentose - 5 carbons
4. hexose - 6 carbons
5. heptose - 7 carbons

Most common are pentose (DNA, RNA) and heptose (starch, cellulose, etc.).

3. Most carbohydrates have an –ose ending. They are aldose (aldehyde) or ketose (ketos such as fructose).

1. Glucose (6 carbon) is the most common nutrient used to energy production.
2. Fructose (6 carbon) is fruit sugar.
3. Ribose and deoxyribose (5 carbon) are found in DNA/RNA.

                 

1. Sucrose - glucose and fructose (table sugar).
2. Lactose - glucose and galactose (milk sugar).
3. Maltose - glucose and glucose.

(Chains of Sugar @ 4-5,000)

Starch - chains of glucose linked α 1,4. Alpha linkage - O is in down position on carbon involved in the bond (#1C).

The storage nutrient in roots and stems of plants. It has a fibril nature that makes it very good as a storage molecule.

1. The enzyme that breaks down starch is amylase (breaks the α 1,4 bonds) to produce maltose. Straight chains of starch with no branches are called amylose. Starch with some minor branching is called amylopectin.
2. Glycogen is the storage form of polysaccharides in humans and most animals (animal starch). Blood is @ 0.1% glycogen that is broken down into glucose.
3. Cellulose is made of chains of glucose with β 1,4 link. Beta linkage is one in which the "O" is in the up position on the carbon involved in the bond (#1 for cellulose). Amylase cannot break down cellulose due to the difference in the types of linkage. Cellulase breaks down the β 1,4 linkage of cellulose. Most animals do not produce cellulase, so they cannot use cellulose as a nutrient. Cellulose acts as a fiber and increases mucous production in the system to increase the release of waste of the body. Some animals can produce cellulase and can use cellulose as a nutrient. These animals are called ruminants and have four stomachs. Some examples are cattle, sheep, goats, deer, bison, etc. This allows them to eat and digest woody substances. They contain microorganisms that produce cellulase. Similar organisms in the gut of termites allow them to digest cellulose (woody tissue).
4. Cellulose is the #1 worldwide economic crop. Over 3 billion tons are produced annually. In recent years, processes have been developed to industrially convert cellulose to a usable nutrient. On average, we can convert 100 lbs of newspaper into @ 60 lbs of usable "edible" proteins (using strong base such as sodium hydroxide) and/or microbial enzymes.
5. Cellulose has a structure that is conducive to cell structure and it makes up the structure of plant cell walls.
6. Chitin is made of chains of glucose with an attached NH₂ group. Chitin makes up the outer coating of insects, shellfish, etc. New processes allow us to use chitin to produce sutures, etc.

A healthy 21 year old male has approximately 17 lbs of fat. A healthy 21 year old female has approximately 22 lbs of fat.

1. Composed of fatty acids and glycerol.
2. These are triglycerides (usually 3 fatty acids).
3. Neutral means non-polar. They do not dissolve in water. Some fatty acids are saturated and some are unsaturated. Saturated fats have a maximum number of H, etc. Unsaturated fats have double or triple bonds. Saturated fats are animal fats, and they tend to form deposits in artery walls. They can lead to heart problems such as arteriosclerosis.
4. Unsaturated lipids occur in vegetable oils. Plants grown in warmer climates tend to have more natural unsaturated fatty acids (e.g. cotton/peanuts from Georgia, etc.) versus corn grown in Iowa.
5. Unsaturated fats form less deposits in artery walls.
6. Saturated lipids are solid even at room temperature, while unsaturated lipids remain solid even in refrigeration. Saturated fatty acids become solids because the molecules become tightly packed.
7. Unsaturated fatty acids form "kinks" in molecules, so they do not pack as tightly and remain a liquid.
8. Is margarine which starts as a vegetable solid (an unsaturated product) better for your health than animal fat lipids such as lard? Margarine, etc. have hydrogenated double or triple bonds to become mostly saturated. They are not much better than animal fats. However, they still contain many unsaturated bonds, and are slightly better.
9. Lipids contain more potential energy on a weight-to-weight ratio than do carbohydrates or proteins. On a gram-to-gram basis, lipids have twice as much as others. On a molecule-to-molecule basis, there is 6 times as much.
10. Whales store fat as "blubber". Humans store fat as a spare tire, etc.
11. Approximately 0.15% g of fat is accumulated daily per gram of body weight. Glucose - fat - C0₂, H20, ATP.

1. Long chains of fatty acids with alcohol attached.
2. Found in ear canal to prevent dust or microbes from entering ear canal.
3. In honey bees, it is stored under abdomen and is used to produce the hive (honey).
4. Coating on leaves of plants to prevent water loss and in animal fur to provide water proofing, feet of penguins, etc.

1. Has a phosphate attached to glycerol and fatty acids.
2. Composed of head region (polar and hydrophilic) and a tail portion (non-polar and hydrophobic).
3. Phospholipid placed in water produces a lipid bilayer that separates the liquid on each side.
4. In the bilayer, heads point outward on each side and tails come together to form a hydrophobic region between the polar heads.
5. Proteins imbedded in the bilayer make up the basis structure of all cell membranes. This is called the fluid mosaic design.

1. Composed of a backbone structure of lipids arranged as 4 fused rings.
2. Testosterone, etc. are sex hormones. Cholesterol is found in cell membranes. Aldosterone absorbs calcium out of blood.
3. Athletes/body builders frequently take steroids to increase muscle mass. These mimic sex hormones. Their use can use sterility, live and kidney damage, heat disease, blindness, etc. Diethystilbesterone used to be placed into livestock feed to increase production.

Some important proteins are spider webs, hair, nails, horns, hooves, antibodies, enzymes, etc. In the human body:

1. Actin and myosin cause muscle contractions.
2. Hormones such as insulin absorb sugar from blood.
3. Collagen fibers support many organs.
4. Enzymes are important in cellular functions.

1. Macromolecules made up from amino acids.
2. There are 20 naturally occurring amino acids (23 are found in proteins).
3. Amino acids are held together by peptide bonds to form polypeptides.

Amino Acid   National Human Genome Research Institute (NHGRI)   http://www.nhgri.nih.gov/DIR/VIP/     by artist Darryl Leja

                          

Proteins occur in living system in 4 basic configurations.

1. Primary - straight chain polypeptides.
2. Secondary - polypeptides are folded into either alpha helix or beta (e.g. keratin).

1. Alpha helix - this provides stability to proteins.
2. Beta sheets - cross links also occur between sheets.

3. Tertiary - the chains already present in an alpha helix or beta sheets are going to fold on themselves many times forming additional cross-links with every fold (e.g. enzymes, antibodies, etc.).
4. Quaternary - Hemoglobin transports O₂ in blood. Forms four different polypeptides, each with iron or Fe (heme) portion attached. Each polypeptide winds/folds around other polypeptides to form a complex structure. All plants are deficient in 1-3 amino acids (lysine, tryptophan and methionine). How do we get complete proteins from eating or consuming plants? We must combine various vegetables or from supplements.

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