What is a Biomolecule?

Organic molecule
made by living
organisms

Consist mostly of
carbon (C),
hydrogen (H), and
oxygen (O)
But wait…What is an Organic
Molecule?

Organic Molecules:
 Contain carbon
 Considered the “chemicals of life”

Inorganic Molecules:
 Do not contain carbon
Monomers vs. Polymers

Monomers:
 Molecules that may react with similar molecules
to form a chain

Polymers:
 A chain of many monomers that are chemically
bonded together
Formation of Polymers

Animation

How are polymers formed?
 Dehydration Synthesis (Condensation): Two
hydrogen atoms and one oxygen atom are
removed from the monomers to form water,
and the two monomers are joined together.
Breakdown of Polymers

Animation

How are polymers broken down?
 Hydrolysis—the reverse of dehydration
synthesis (condensation)
 Water added to the polymer, un-linking the
chain and breaking it back down to its
original monomer units
Carbohydrates

What are they?
 Group of organic molecules that includes sugars,
starches and cellulose.
Carbohydrates

Structure:
 Carbon, hydrogen and oxygen in a 1:2:1




ratio
(CH2O)n – n is an integer such as 5
(C5H10O5)
Subunits: Monosaccharides, such as
glucose or fructose
Most often in a ring shape
Subunits are connected with covalent bonds
Monosaccharide Example
Disaccharide Example
Polysaccharide Example
Carbohydrates

Function:
 Energy
 Structural Support
 Cell Wall
 Cell Membrane Marker
Lipids

What are they?
 Organic molecule group including fats and
phospholipids
Lipids

Structure:
 Subunits:
○ Glycerol and fatty acids
○ Glycerol and fatty acids plus phosphate group
 Insoluble in water
 Do not form large polymers (2 or 3 fatty acids
with glycerol)
○ Examples: diglyceride and triglyceride
Triglyceride Example
Phospholipid Example
Lipids

Function:
 Energy storage
 Insulation
 Part of cell membrane (phospholipids)
 Hormones
Proteins

What are proteins?
 Group of organic molecules that provides
structure and facilitates chemical reactions.
Proteins

Structure:
 Subunits: Amino acids
 Amino acids connect via peptide bonds
 Very large molecules
 Globular or structural
Amino Acid
Proteins

Function:
 Lots of functions!
 Enzymes (speed rate of chemical reactions)
 Structural components in cells
 Mechanical functions in muscles and
cytoskeleton (internal cell framework)
 Cell signaling
 Immune response
Nucleic Acids

What are Nucleic
Acids?
 Group of organic
molecules
including DNA
and RNA
Nucleic Acids

Structure:
 Subunits are nucleotides—5-Carbon sugar,
Nitrogen base and one or more Phosphate
groups
Nucleic Acids

Function:
 Storage and retrieval of information:
○ Encode genes
○ Gene expression