Chapter 2
Organic Compounds
Biochemistry: Essentials for LifeBiochemistry: Essentials for Life
1. Organic compounds
• Contain carbon with hydrogen and oxygen
• Most are covalently bonded
• Example: C6H12O6 (glucose)
2. Inorganic compounds
• Lack carbon w/ H & O
• Tend to be simpler compounds
• Example: H2O (water), CO2
Important Inorganic CompoundsImportant Inorganic Compounds
1. Water
• Most abundant inorganic compounds
• Vital properties
• High heat capacity
• Polarity/solvent properties
• Chemical reactivity
• Cushioning
Important Inorganic CompoundsImportant Inorganic Compounds2. Salts
• Easily dissociate into ions in the presence of water
• Vital to many body functions
• Include electrolytes which conduct electrical currents
Important Inorganic CompoundsImportant Inorganic Compounds3. Acids
• Can release detectable hydrogen ions
4. Bases
• Proton acceptors
pHpH
• Measures relative concentration of hydrogen ions
• pH 7 = neutral
• pH below 7 = acidic
• pH above 7 = basic
• Buffers
• Chemicals that can regulate pH change
Important Organic CompoundsImportant Organic Compounds
• Carbohydrates
• Lipids
• Proteins
• Nucleic Acids
• ATP
1. Carbohydrates
• Contain carbon, hydrogen, and oxygen
• Include sugars and starches
• Classified according to size
• Monosaccharides – simple sugars
• Disaccharides – two simple sugars joined by dehydration synthesis
• Polysaccharides – long branching chains of linked simple sugars
CarbohydratesCarbohydrates
Figure 2.12a, b
2. Lipids
• Contain carbon+, hydrogen+, and oxygen
• C and H outnumber O
• Insoluble in water
Common lipids in the human body
a. Neutral fats (triglycerides)- Found in fat deposits- Composed of fatty acids & glycerol- Source of stored energy
b. Phospholipids- Form cell membranes
c. Steroids - cholesterol, bile salts, vitamin D, & some
hormones
LipidsLipids
CholesterolCholesterol
3. Proteins
• Made of amino acids
• Contain C, O, H, N, and sometimes sulfur
• over ½ of body’s organic matter
• Structural (fibrous) proteins
Ex. keratin
• Functional (globular) proteins
Ex. enzymes, hormones, & antibodies
Enzymes (Functional Proteins)Enzymes (Functional Proteins)
• Act as biological catalysts
• Increase the rate of chemical reactions
4. Nucleic Acids
• Provide blueprint of life
• Nucleotide bases
• A = Adenine
• G = Guanine
• C = Cytosine
• T = Thymine
• U = Uracil
• Make DNA and RNA
5. Adenosine triphosphate (ATP)
• Chemical energy used by all cells
• Energy is released by breaking high energy phosphate bond
• ATP is replenished by oxidation of food fuels
How ATP Drives Cellular WorkHow ATP Drives Cellular Work