Carbon and the Molecular Diversity of Life

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Carbon and the Molecular Diversity of Life

• AP Biology Chapter 4

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The Importance of Carbon

• There are about 90 naturally occurring elements
• Four make up over 96 of the human body C, N, O,
  and H
• Two major groups of chemicals
• 1) organic and 2) inorganic

3
Inorganic Chemistry

• Inorganic Compounds
• usually, those chemicals that do not contain the
  element carbon
• carbon dioxide is an exception
• others water, calcium phosphate, salts, minerals
  in soil and sand

4
Organic Chemistry

• Organic Compounds
• carbon-containing compounds
• more than 2 million of them. Why?
• Carbon forms covalent bonds that are strong and
  stable.
• Can form 4 bonds- with itself as well as other
  elements

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Versatility of Carbon

• Simplest organic compound is methane, CH4
  (natural gas)
• carbon can form long chains by bonding with other
  carbons
• single- double- and triple-bonds are possible
  also rings
• No other element can do this.

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Diversity of Organic Molecules

• Carbon forms the backbone of organic molecules.
• Carbon skeletons can be straight, branched, or in
  rings.
• Hydrocarbons are molecules that contain carbon
  and hydrogen.
• Isomers are compounds that have the same
  molecular formula, but different structures.

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Isomers Continued

• Structural isomers differ in the covalent
  arrangement of their atoms.
• Geometric Isomers have same covalent
  partnerships, but differ in their spatial
  arrangement.
• Enantiomers are mirror-image molecules.

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Functional Groups

• While carbon skeletons form the backbone of
  organic molecules, functional groups are
  attachments that undergo chemical reactions.
• Each functional group has properties that are the
  same, no matter what the carbon skeleton is.
• There are 6 major functional groups that are
  important in the chemistry of life.

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Hydroxyl

• - OH

• Hydrogen bonded to an Oxygen that is bonded to
  the carbon skeleton of an organic molecule.
• Alcohols
• Hydrophilic, polar
• Example- ethanol

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Carbonyl

• Carbon joined to an oxygen by double bond.
• IF at end aldehyde otherwise it is a ketone.

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Carboxyl

• An oxygen atom is double-bonded to a carbon atom
  that is bonded to a hydroxyl.
• Carboxylic Acids

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Amino

• Amino groups contain a nitrogen atom bonded to
  two hydrogen atoms and to the carbon skeleton.
• Amines
• Acts as a base.

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Sulfhydryl

• Sulfur bonded to hydrogen.
• Thiols
• Stabilize protein structure.

• -SH

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Phosphate

• Anion with 2 negative charges.
• Phosphate ion covalently bonded by one of its
  oxygen atoms to the carbon skeleton.
• Function in energy transfer.