Chapter 6.4: The Building Blocks of Life

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Organic Chemistry

• The element carbon is a component of almost all biological molecules

• Life on Earth is considered carbon-based • Organic chemistry – study of compounds

containing carbon

Macromolecules

• Small carbon compounds serve as building blocks for large molecules

• Macromolecules are large molecules formed by joining smaller molecules

• These large molecules are also called polymers – Polymers are made up of repeating, smaller units

called monomers – Polymer = monomer + monomer + monomer + …

4 Types of Macromolecules

• Carbohydrates• Lipids• Proteins• Nucleic Acids

Carbohydrates

• Composed of carbon, hydrogen, and oxygen • Sugars (glucose, monosaccharides, disaccharides,

polysaccharides) • Bread, pasta, sugar • Function: – Energy source (short term)– Provide structural support in plant cell walls (cellulose)– Main component in the hard outer shell of insects and

shell fish (called chitin)

Lipids/Fats

• Composed of elements carbon and hydrogen• Waxes, fats, oils • Composed of fatty acids and glycerol (called a

triglyceride) • Main function: long term energy storage• Other examples: phospholipids (cell

membrane structure), steroids

Proteins

• Composed of small monomers called amino acids • Amino acids are made of carbon, nitrogen,

oxygen, hydrogen, and sulfur • Function: – Muscles, skin, hair are all made of proteins– Structural support, transport substances– Communicate signals within cells– Speed up chemical reactions (enzymes)– Control cell growth

Nucleic Acids

• Store and transmit genetic information • Made of small monomers called nucleotides – Carbon, hydrogen, nitrogen, oxygen, and

phosphorous • Two types: DNA and RNA

Review

• If an unknown substance found on a meteorite is determined to contain no trace of carbon, can scientists conclude that there is life at the meteorite’s origin?

• A polymer is made up of smaller units called …• Another word for a polymer is … • List the elements that are found in

carbohydrates