My AP Biology Thoughts  Episode #41

Welcome to My AP Biology Thoughts podcast, my name is Arthur and I am your host for episode 41 called Unit 1: Monomers and Polymers of the Macromolecules. Today we will be discussing dehydration and hydrolysis reactions in regards to macromolecules.

Segment 1: Introduction to Monomers and Polymers of the Macromolecules

• The formation and breaking of macromolecules are essential for complex life to function. We will be discussing the chemical mechanisms by which macromolecules both form and break down.  
• Monomers: The unit components of the larger macromolecules.
• Polymers: What is formed when the monomers bond together, which are known as macromolecules.
• Dehydration synthesis: A water molecule being ejected in order to allow for a monomer to covalently bond to another monomer or polymer.
• Hydrolysis: A polymer splitting apart after reacting with a water molecule.  
• Activation energy: An energy threshold, which must be met in order for a reaction to proceed.  

Segment 2: Example of Monomers and Polymers of the Macromolecules

• Monosaccharides are the monomers of carbohydrates. In the presence of the necessary enzyme, a hydroxyl group is ripped off one of the monosaccharides and a hydrogen off the hydroxyl group of the other. This results in the two monosaccharides bonding together via an ether (glycosidic) bond as well as the formation of a water molecule. Conversely, this reaction can happen in reverse via hydrolysis.  
• The formation of triglycerides involves dehydration synthesis. An ester linkage is created between a fatty acid and a glycerol and a water molecule is released. A hydrogen is ripped of the carboxylic acid from the fatty acid and the hydroxyl is ripped off the glycerol.
• Polypeptide chains form via dehydration synthesis between two amino acids. An OH is ripped off the carboxylic acid and a hydrogen is ripped off the amine group, allowing the amino acids to covalently bond as well as allowing the formation of a water molecule. This occurs many times allowing for long polypeptide chains to form, which eventually leads to proteins.  

Segment 3: Digging Deeper Monomers and Polymers of the Macromolecules

• The creation of macromolecules from monomers gives complex life its structure (ex. Cellulose). Additionally, the breaking down of macromolecules is essential for metabolism and the operations of cells (ex. Breaking down polysaccharides down to glucose for cellular respiration).  

Thank you for listening to this episode of My AP Biology Thoughts. For more student-ran podcasts and digital content, make sure that you visit www.hvspn.com. See you next time!

Music Credits:

• “Ice Flow” Kevin MacLeod (incompetech.com)
• Licensed under Creative Commons: By Attribution 4.0 License