BIological Macromolecules

Elements in Living Things Bond Together to Form Macromolecules

Macromolecules (large molecules) are large molecules found in all living things

  • Carbohydrates

  • Lipids (Fats)*

  • Proteins

  • Nucleic Acids



Only Carbohydrates, Proteins, and Nucleic Acids can also be defined as polymers.

  • Polymers are large molecules made up of repeating units called monomers.


Water is used to make and break biological macromolecules

Dehydration Synthesis - Removing water to form a macromolecule.

Hydrolysis - Adding water to break apart a macromolecule.

Carbohydrates - CHO 

  • Made up of carbon, hydrogen, and oxygen in a ratio of 1:2:1

  • Name ends in -ose 



  • Monomer: Monosaccharide (Simple)

    • Function: Short-term energy storage


Carbohydrates - CHO 

Polymer: Disaccharide (Simple)

  • Function: Short-term energy storage

Polymer: Polysaccharides (Complex)

  • Function: Long-term energy storage


Lipids (Fats) - CHO 

Function: Long-term energy storage



There are many structures of fats, but all are non-polar (hydrophobic) and do not dissolve in water.


Lipids (Fats) - CHO 

Phospholipids - Major component of the cell membrane.

Waxes - Form natural coatings for fruits, leaves, and insects.

Steroids - Include cholesterol and female and male sex hormones.


Proteins - CHON 

  • Monomer: Amino Acid

  • Polymer: Polypeptide (protein)



  • Function: Raw material for growth and repair of structures like skin and muscle, hair, nails, enzymes (-ase)


Proteins fold and twist into 3D shapes



Different shapes = Different jobs


Nucleic Acids - CHONP 

  • Monomer: Nucleotide 

  • Polymer: Nucleic Acid



  • Function: Stores genetic information (blueprint for proteins)



  • Examples: DNA (deoxyribonucleic acid) + RNA (ribonucleic acid)


Enzymes are proteins that catalyze (speed up) chemical reactions by decreasing activation energy (Ea).

Enzymes end in -ase

  • Maltase binds to maltose

  • Lactase binds to lactose

  • Lipase breaks down fats



Enzymes are specific

  • One type of enzyme can only bind to one type of substrate

    • Ex. Maltase can only bind to maltose

  • In the presence of a substrate, the active site will change shape to allow a better fit; this is called induced fit



Enzymes are catalysts 

  • Speeds up chemical reactions without being physically altered (not reactants)

  • Enzymes can be used over and over again


Enzymes can be denatured

Denaturation occurs when the enzymes physical shape is altered due to high heat or extreme changes in pH


Temperature and Enzyme

At low temperatures enzymes and substrates are moving slowly and are not likely to find and bind to one another

As the temperature increases enzymes find substrates more quickly and the reaction rate increases

If the temperature increases too much the enzyme becomes denatured and the substrate will no longer bind to the active site


pH and Enzyme

Every enzyme will work best at its own optimal pH 

The further away from the optimal pH the more enzymes will become denatured and no longer bind to substrates


Inhibitors and Co-Factors/Co-Enzymes

Inhibitors are molecules that bind to an enzyme that prevent the substrate from binding to the active site

Co-factors and Co-enzymes are molecules that bind to an enzyme that allow the substrate to bind to the active site