Biochemistry Review

InorganicsNo Carbon

Water

• High heat capacity

• Polarity/Solvent properties

• Chemical reactivity

• Cushioning

High heat capacity

• Absorbs and releases heat before its temperature changes

• Helps body get rid of excess heat• Helps regulate body temperature by carrying

heat through out body in the blood• Helps prevent excessive changes in

homeostasis due to external temperatures

Polarity/Solvent Properties• Universal solvent• Salts, Acids, and Bases

dissolve readily in water• Transports nutrients,

gases, and wastes throughout the body

• Molecules that lubricate the body use water as their base

Reactivity

• Reactant in metabolic reactions• Hydrolysis– Adding water to larger molecule

Cushioning

• Acts to protect by filling spaces around organs– Brain– Fetus

Salts – Yum!

• Most common contain Calcium and Phosphorus

• Ionic compounds• Dissociation to

form ions• Ions important in

nerve impulses and as part of the hemoglobin molecule

• Electrolytes – conduct electrical currant in solution

Acids and Bases• Electrolytes• Based on pH scale • pH of 7 is neutral, below is acidic, above is

basic or alkaline• Buffers• Blood pH – 7.35 to 7.45 – Depletion of oxygen to body if blood pH strays

by just tenths• Cells sensitive to change in body fluid pH– Regulated by kidneys, lungs and buffers found

through the body and tissue fluids

OrganicsContains carbon

Carbohydrates

• Sugars and starches

• Contain carbon, hydrogen, oxygen

• Monosaccharides, disaccharides, and polysaccharides

• Energy for necessary metabolic reactions

Monosaccharides• Most important in body– Glucose, universal energy– Fructose and Galactose, broken down by

cells to glucose– Ribose and Deoxyribose, part of nucleic

acids

Disaccharides

• Built with two monosaccharides• Important disaccharides– Sucrose (glucose + fructose), cane sugar– Lactose (glucose + galactose), found in

milk–Maltose (glucose + glucose), malt sugar

• Dehydration and Hydrolysis– Dehydration builds disaccharides– Hydrolysis breaks down disaccharides

Polysaccharides• Complex branching chains of simple sugars• Excellent storage product• Not sweet or are they?• Important to the body, Starch and Glycogen– Starch from plants for energy– Glycogen stored energy in animal tissues (muscles

and liver)

• Cellular respiration

Lipids

• Enter the body in Yummy things we eat!• Most abundant in body• More Carbon and Hydrogen than

oxygen• Insoluble in water so must be dissolved

by solvents – alcohol and acetone• Types– Neutral Fats– Phospholipids– Steroids

Neutral Fats• Triglycerides– Composed of fatty acids and glycerol– Saturated: solid animal fats, single

bonds for carbons– Unsaturated: plant oils, double or triple

bonds– Body’s most abundant and

concentrated source of usable energy

Phospholipids

• Polar due to phosphorus “heads”• Found in cell membranes, selective

permeability

SteroidsCholesterol• Cell membranes and more concentrated in the brain• Raw material for vitamin D• Sex hormones• Bile Salts

Proteins• 50% of the organic matter in the body• Built by Amino Acids connected by peptide

bonds - Polypeptides• Fibrous proteins are structural proteins– Collagen; support– Keratin; strength

• Globular proteins are functional proteins– Enzymes (catalysts)– Antibodies– Hormones– Transport proteins

Nucleic Acids

• DNA and RNA• Nucleotides• Genetic

information

Adenosine Triphosphate

• Usable form of energy for body cells• Modified Nucleotide• Energy captured in high energy bond

of 3rd phosphate from breakdown of glucose

ATP