Carbon and the Molecular Diversity of Life

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Chapter 4

• Carbon and the Molecular Diversity of Life

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Why Study Carbon?

• All living things are made of cells
• Cells
• 72 water
• 3 Salts (Na, Cl, K)
• 25 carbon compounds
• lipids, carbohydrates, proteins, nucleic acids

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Chemistry of Life

• Organic Chemistry - study of carbon compounds
• C atoms are versatile Building blocks
• 4 stable covalent bonds

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Complex Molecules assembled like Tinker Toys

• Like sugars
• C6H12O6
• Can be arranged in different ways
• Glucose
• Galactose
• Dextrose

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Hydrocarbons

• Simplest Carbon molecules
• Combinations of C and H
• Simplest HC molecules Methane
• 1 C bound to 4 Hydrogen Atoms
• Nonpolar
• Not soluble in water
• Hydrophobic
• Stable
• Little attraction between molecules
• Gas at room temperature

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Hydro Carbons Can Grow

• Adding C-C bonds
• Straightline
• Ethane, hexane
• Branching
• isohexane
• Ring
• cyclohexane

Ethane
Hexane
Isohexane
Cyclohexane
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Diversity of Organic Molecules
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Isomers

• Molecules with same molecular formula but
  different structures
• Different chemical properties

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Structural Isomers

• Molecules differ in structural arrangement of
  atoms

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Geometric Isomers

• Molecules differ in arrangement around CC double
  bond
• Same covalent partnerships

CC CC
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Enantiomer (stereo) isomers

• Molecules which are mirror
• images of each other
• Carbon bonded to 4 different
• atoms or groups (assymetric)
• Left Handed or Right
• Handed
• L versions are biologically
• active

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Form affects Function

• Structural differences create important
• functional significance
• Amino acid alanine
• L alanine used in proteins
• but not D-alanine
• Medicines
• L version active
• but not D-version
• Sometimes with tragic results

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Form affects function

• Thalidomide
• Prescribed to pregnant women in the 50s and 60s
• Reduced morning Sickness but
• Stereoisomer caused severe birth defects

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Diversity of Molecules

• Substitute other atoms or groups around the C
• Ethane vs. ethanol
• Hydrogen replaced by a hydroxyl group
• Nonpolar vs. polar
• Gas vs. liquid
• Biological Effects

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Functional Groups

• Groupings of atoms
• Reoccur time and time again in many different
  molecules
• Have important roles in the reactions the
  molecule can participate in.
• Give organic molecules distinctive properties
• Ex. Male and Female Hormones

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Viva la difference!

• Basic structure of male female hormones is
  identical
• identical C skeleton
• different functional groups
• interact with different targets in the body

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Types of functional groups

• 6 functional groups most important to chemistry
  of life
• Affect reactivity
• Hydrophilic
• Increase solubility in water

• Hydroxyl
• Carbonyl
• Carboxyl
• Amino
• Sulfhydral
• Phosphate

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Why study functional groups?

• These are the building blocks for biological
  molecules
• . and that comes NEXT!

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Your turn!!

• Use the chart in your book.
• Make flashcards of each functional group
• You should have
• The name of the functional group
• Structure of functional group
• Name of compounds
• Examples
• Functional Properties
• This is serious business! You MUST know these!!