The Chemical Building Blocks The Chemical Building Blocks of Living Systemsof Living Systems

•• There are four major classes of chemical compounds found There are four major classes of chemical compounds found in living organisms: in living organisms:

-Carbohydrates-Carbohydrates

-Nucleic Acids-Nucleic Acids

-Proteins-Proteins

-Fats and Lipids-Fats and Lipids

•• Carbon is the predominant element in living systems.Carbon is the predominant element in living systems.

•• Carbon can form covalent bonds with up to four atoms.Carbon can form covalent bonds with up to four atoms.

•• All carbon-containing compounds in living organisms are All carbon-containing compounds in living organisms are called organic compounds.called organic compounds.

Examples of Carbon-containing MoleculesExamples of Carbon-containing Molecules

Important Functional GroupsImportant Functional Groups

•• Groups of covalently Groups of covalently linked atoms that linked atoms that have specific have specific chemical properties chemical properties wherever they are wherever they are found.found.

Complex Structures From Smaller ComponentsComplex Structures From Smaller Components

•• Small carbon-containing Small carbon-containing molecules can either remain molecules can either remain as individual molecules or as individual molecules or bond with other small bond with other small molecules to form larger molecules to form larger structures called structures called macromolecules.macromolecules.

•• Monomers are individual Monomers are individual small molecules with 20 or small molecules with 20 or fewer atoms.fewer atoms.

•• A polymer is a collection of A polymer is a collection of hundreds of monomers.hundreds of monomers.

Dehydration Synthesis and HydrolysisDehydration Synthesis and Hydrolysis

•• Dehydration synthesis (condensation reaction):Dehydration synthesis (condensation reaction):Simple molecules are joined together to form larger Simple molecules are joined together to form larger molecules by the removal of water.molecules by the removal of water.

Energy is stored in the bond created between the Energy is stored in the bond created between the simple molecules.simple molecules.

•• Hydrolysis:Hydrolysis:Larger molecules are separated into simple Larger molecules are separated into simple molecules by the addition of water.molecules by the addition of water.

Energy is released by breaking the bond between Energy is released by breaking the bond between the simple molecules.the simple molecules.

Dehydration Synthesis (Condensation Reaction)Dehydration Synthesis (Condensation Reaction)

More examples at:More examples at:http://science.nhmccd.edu/biol/dehydrate/dehydrate.htmlhttp://science.nhmccd.edu/biol/dehydrate/dehydrate.html

CarbohydratesCarbohydrates

Examples:Examples:

Sugars and starchesSugars and starches

Made up of Carbon, Hydrogen, and OxygenMade up of Carbon, Hydrogen, and Oxygen

C:H:O = 1:2:1C:H:O = 1:2:1

Building blocks:Building blocks:

Monosaccharides (simple sugars).Monosaccharides (simple sugars).

Function:Function:

Primary source and storage of energy.Primary source and storage of energy.

CarbohydratesCarbohydrates

DissacharidesDissacharides are made up of two monosaccharides joined together and have the chemical are made up of two monosaccharides joined together and have the chemical formula formula C12H22O11.Examples: Maltose = Glucose + Glucose

Sucrose = Glucose + Fructose

Lactose = Glucose + Galactose

2 Monosaccharides 1 Disaccharide

Monosaccharides have the chemical formula C6H12O6.

Examples: Glucose, Galactose and Fructose.

CarbohydratesCarbohydrates

Polysaccharides:Polysaccharides:

Made of a chain of Made of a chain of monosaccharides.monosaccharides.

Examples: Examples:

• Cellulose forms strong Cellulose forms strong parallel fibers that parallel fibers that help support the leaves help support the leaves and stems of plants.and stems of plants.

• Starch stores energy in Starch stores energy in plants.plants.

• Glycogen stores energy Glycogen stores energy in the liver and in the liver and muscles of animals.muscles of animals.

Sweet Facts

NucleotidesNucleotides

Examples:Examples:DNA and RNADNA and RNA

Consist of linked rings of atoms (C, H, O, P and N).Consist of linked rings of atoms (C, H, O, P and N).

Building blocks:Building blocks:• Nitrogen containing base (adenine, cytosine, guanine, Nitrogen containing base (adenine, cytosine, guanine,

thymine, and uracilthymine, and uracil• Sugar ring (deoxyribose in DNA and ribose in RNA)Sugar ring (deoxyribose in DNA and ribose in RNA)• Phosphate group (1, 2 or 3 can bond to the sugar)Phosphate group (1, 2 or 3 can bond to the sugar)

Function:Function:Stores genetic information for every cell in an organism.Stores genetic information for every cell in an organism.Involved with energy transfer (ex. ATP)Involved with energy transfer (ex. ATP)

Nucleotides – Store and Transfer InformationNucleotides – Store and Transfer Information

Nucleotides join together to form the rungs of a Nucleotides join together to form the rungs of a twisted ladder shape called a twisted ladder shape called a double helixdouble helix..

In DNAIn DNA

A bonds to TA bonds to T

G bonds to CG bonds to CThe bases bases The bases bases

also bond to also bond to deoxyribosedeoxyribose

In RNAIn RNA

A bonds to UA bonds to U

G bonds to CG bonds to CThe bases also The bases also

bond to ribosebond to ribose

Nucleotides – Store and Transfer EnergyNucleotides – Store and Transfer Energy

ATP is made up ATP is made up of an adenine of an adenine base, a ribose base, a ribose sugar and 3 sugar and 3 phosphate phosphate groups.groups.

Energy is stored in the covalent bonds that link its 3 Energy is stored in the covalent bonds that link its 3 phosphate groups together.phosphate groups together.

The breaking of the bond between the second and third The breaking of the bond between the second and third phosphates releases energy, which can be used to phosphates releases energy, which can be used to drive other chemical reactions.drive other chemical reactions.

Amino Acids are the Building Blocks of ProteinsAmino Acids are the Building Blocks of Proteins

There are 20 different There are 20 different amino acids.amino acids.

Each has an amino group, Each has an amino group, a carboxyl group and a a carboxyl group and a different side chain (R different side chain (R group) bonded to a group) bonded to a central carbon.central carbon.

Amino Acids are the Building Blocks of ProteinsAmino Acids are the Building Blocks of Proteins

T form proteins, chains of T form proteins, chains of amino acids link amino acids link together by covalent together by covalent bonds between the bonds between the amino group of one amino group of one amino acid and the amino acid and the carboxyl group of carboxyl group of another.another.

Each protein folds into a Each protein folds into a unique 3-D structure unique 3-D structure largely determined by largely determined by the interaction of the R the interaction of the R groups of the protein.groups of the protein.

Nonpolar or uncharged and are repelled by water.

R Groups Give Each Amino Acid Specific Chemical Properties

R Groups Give Each Amino Acid Specific Chemical Properties

Polar or charged and can interact with water.

Unique chemical properties

The Importance of Proteins

Proteins That Can Take the HeatProteins That Can Take the Heat

• When heated, most proteins unfold.When heated, most proteins unfold.

• Proteins from thermophilic bacteria have given scientists clues Proteins from thermophilic bacteria have given scientists clues about what makes a protein thermostable.about what makes a protein thermostable.

• Understanding how the chemical properties of amino acids Understanding how the chemical properties of amino acids define protein shapes has allowed biologists to engineer define protein shapes has allowed biologists to engineer proteins that are more stable.proteins that are more stable.

Fatty Acids Store Energy and Form MembranesFatty Acids Store Energy and Form Membranes

• Composed primarily of long chains of C and H called Composed primarily of long chains of C and H called hydrocarbons and end with a carboxyl group.hydrocarbons and end with a carboxyl group.

• Key components of fats and lipids.Key components of fats and lipids.

• Functions:Functions:

FatsFats Long-term energy storage. Long-term energy storage.

Lipids Lipids Main component of biological membranes. Main component of biological membranes.

Fatty AcidsFatty Acids

SaturatedSaturatedAll the carbon All the carbon atoms are atoms are linked linked together by together by single single covalent covalent bonds.bonds.

Can pack Can pack tightly tightly together and together and tend to form tend to form solids.solids.

Examples:Examples:fats & waxesfats & waxes

UnsaturatedUnsaturatedOne or more of One or more of the carbon the carbon atoms are atoms are linked together linked together by double by double covalent bonds.covalent bonds.

Do not pack Do not pack tightly together tightly together and tend to and tend to form liquids.form liquids.

Example:Example:

oilsoils

Three Fatty Acids Bond to GlycerolThree Fatty Acids Bond to Glycerol

A single molecule of A single molecule of glycerol can be glycerol can be covalently linked to 3 covalently linked to 3 fatty acids to form a fat fatty acids to form a fat molecule.molecule.

Glycerol tristearate is the Glycerol tristearate is the most common fat most common fat storage molecule.storage molecule.

Fats contain significantly Fats contain significantly more energy than an more energy than an equal amount of equal amount of glucose.glucose.

– Steroids are very different from fats in structure and function.

• The carbon skeleton is bent to form four fused rings.

– Cholesterol is the “base steroid” from which your body produces other steroids.

• Example: sex hormones

Steroids

Phospholipids Form Bilayer Membranes in WaterPhospholipids Form Bilayer Membranes in Water