Food ChemistryUnit 11

The study of the chemistry of living things.Organism:80% water20% mostly organic molecules (carbon based)

Earth’s Crust vs. Human

Biochemistry

Earth Human

Oxygen 46% Oxygen 65%

Silicon 28% Carbon 18.5%

Aluminum 8.0%

Hydrogen 9.5%

Iron 6% Nitrogen 3%

Magnesium 4% Calcium 1.5%

Calcium 2.4% Phosphorus 1%

Potassium 2.3%

Potassium .4%

4 TypesProtein Carbohydrates

Lipids Nucleic Acids

Macromolecules

A polymer formed from amino acids linked together by amide groups.

Amino Acids: 20 different amino acids make all proteins. Contain carbon, nitrogen, oxygen,

hydrogen, and sulfur.

Protein

Condensation reaction creating a peptide bond.

A chain of amino acids is called a polypeptide chain.

Proteins can be made of one or more polypeptide chains.

Making Proteins

About half of the proteins in your body function as catalysts in cell reactions.◦ Lactase(splits lactose into glucose and galactose)

Structural proteins provide strength and give your body its shape.◦ Collagen(ligaments, tendons, and cartilage)◦ Keratin(hair, fingernails ,hooves , and skin)

Other proteins function as transport substances.◦ Hemoglobin(makes up red blood cells/transport O)◦ Fibrin (blood clotting)

Role of Protein

Have 3D structure because of polypeptide folding.

Geometric shape extremely important because it determines chemical interactions.◦ Antibodies: Protect body from invaders, antibodies

recognize foreign bodies by specific bonding.

Protein Shape

3D shape is broken and protein unfolds. Causes include high temperatures, pH

extremes, agitation, and chemical treatments.

Eggs:◦ Whipping◦ Cooking

Hot springs:◦ Bacteria

Denaturation

Enzymes (proteins acting as catalysts)

A biomolecule that contains the elements carbon, hydrogen, and oxygen, in a ratio of 1:2:1.

Monosaccharides are smallest carbohydrates also known as simple sugars. Glucose Fructose Galactose

Carbohydrates

Two monosaccharides linked together in a condensation reaction. Sucrose: table sugar Lactose: milk sugar Maltose: malt sugar

Disaccharides

Large carbohydrates containing a long chain of monosaccharides. Starch:store energy in plants, slightly

branched Glycogen: found in muscle of animals,

highly branched Cellulose: structural molecule in plants,

linear, cannot be digested by humans

Polysaccharides

Polysaccharides

The large carbohydrates in pasta, bread, and fruit are broken down into glucose which is the main source of energy in our body.

Also play a structural role in some organisms.◦ Cellulose (strength and support in plants)◦ Chitin (forms exoskeleton of insects and

arthropods)

Role of Carbohydrates

A biomolecule that contains a large proportion of C-H bonds and less oxygen than a carbohydrate.

Fatty acids are long carbon chains with a carboxylic acid at the end. (most 12 to 26 carbons)Ex: oleic acid (major component of olive oil)

Lipids

Saturated fat: Only single bonds attaching each carbon.

Monounsaturated fat: Has one carbon/carbon double bond.

Polyunsaturated: Two or more double bonds

Saturated vs Unsaturated

When an organism takes in more food than needed the excess energy is stored by atoms bonding into a lipid molecule.

Lipids also form membranes that surround

cells as barriers. Include cholesterol and phospholipids.

Role of Lipids

A lipid what has a specific four-ring structure; all steroids are based off of the same basic four rings.

Steroids

Cholesterol (Structural)Sex Hormones (testosterone, estrogen, etc.)Vitamin D:• Reduce chances of heart disease• Dramatically reduce chances of cancer• Extremely helpful against osteoporosis• Very good for the immune system• Helps fight depression• Reduces acne• Helps reduce chances of getting Alzheimers• May also help with weight loss• Help prevent pathological muscle weakness• Combat type II diabetes and the metabolic syndrome

Important Steroids

Diets high in saturated fats have been linked to cardiovascular problem such as heart disease.High cholesterol levels are associated with the thickening and stiffening of blood vessels.

Lipids and Health

A large polymer containing carbon, hydrogen, oxygen, nitrogen, and phosphorus.

Two types: DNA (deoxyribose nucleic acid) RNA (ribose nucleic acid)

Nucleic Acids

Not essential to the human diet. The body can form them from proteins and

carbohydrates. Regulate the cells by controlling the

synthesis of new proteins.

Role of Nucleic Acids

Organic molecules that are required in small amounts in the diet.

Two major classes: Water-soluble (Vitamin-B series, Vitamin C) Fat-soluble ( Vitamin A, D, E , and K)

Vitamins

These vitamins are not stored in the body. They are eliminated in urine. Due to the elimination we need a continuous supply in our diet.

Deficiencies:◦ Vitamin C: Scurvy, bleeding gums◦ Vitamin B1: Mental confusion, impaired growth

Water-Soluble Vitamins

These vitamins are stored for long periods of time and if consumed in large quantities can lead to toxicity.

Should not be taken as supplements in mega doses.

Overconsumption:◦ Vitamin A: nausea, loss of hair, liver enlargement◦ Vitamin D: mental retardation, movement of

calcium from bones to soft tissue◦ Vitamin E: Digestive tract disorder

Fat-Soluble Vitamins