Overview
This lecture covers the four main biomolecules essential for life: carbohydrates, lipids, proteins, and nucleic acids. It explains their monomers, functions, examples, and elemental composition.
Introduction to Biomolecules
- Biomolecules are large molecules necessary for life, found in the foods we eat.
- The four primary biomolecules are carbohydrates, lipids, proteins, and nucleic acids.
- These molecules are the building components of all living things.
Monomers: The Building Blocks
- A monomer is a small molecule that serves as a building block for larger biomolecules.
- Understanding monomers helps explain what each biomolecule is made of and how they function.
- Monomers are like building blocks that join together to form complex structures.
Carbohydrates
- Carbohydrates (carbs) are a major source of quick energy for the body.
- Foods high in carbohydrates include pasta and bread.
- Carbohydrates are especially important for activities requiring fast energy, such as running a marathon (e.g., "pasta loading").
- The monomer of carbohydrates is the monosaccharide.
- Carbohydrates are often discussed in the context of diets, with people choosing to increase or decrease their intake.
Lipids
- Lipids, also known as fats, serve as long-term energy storage and provide insulation.
- Lipids are made from two types of building blocks: fatty acids and glycerol.
- Examples of lipids include butter, oil, and cholesterol.
- Lipids are important for insulating animals (e.g., blubber in seals) and storing energy for extended periods, such as during long swims.
- Lipids are key components of cell membranes, making them essential for all living cells.
- While necessary, excessive lipid intake can be harmful, so moderation is important.
Proteins
- Proteins are crucial for muscle building, immune system function, and as enzymes that speed up chemical reactions.
- Foods rich in protein include meats and many types of beans.
- The monomers of proteins are amino acids.
- Proteins are not only important for muscles but also for other body functions, such as acting in the immune system and as enzymes.
- DNA contains the instructions for making proteins, which are vital for the structure and function of the body.
Nucleic Acids
- Nucleic acids, including DNA and RNA, store and transmit genetic information.
- The monomer of nucleic acids is the nucleotide.
- DNA and RNA are involved in coding for traits and directing cell activities.
- All living things, including plants and animals, contain DNA in their cells.
- When you eat foods from living things, such as strawberries, you also consume their DNA.
- Nucleic acids are essential for life because they control genetic information and cell functions.
Elemental Composition Mnemonic
- Carbohydrates and lipids are made of carbon (C), hydrogen (H), and oxygen (O) — "CHO".
- Proteins contain carbon, hydrogen, oxygen, and nitrogen — "CHON".
- Nucleic acids contain carbon, hydrogen, oxygen, nitrogen, and phosphorus — "CHONP".
- The arrangement of these elements (such as rings or chains) differs among biomolecules and affects their properties and functions.
- Remember the order and elements with the mnemonic: CHO, CHO, CHON, CHONP.
Key Terms & Definitions
- Biomolecule: A large molecule essential for life.
- Monomer: A small building block molecule that forms larger biomolecules.
- Monosaccharide: The simple sugar monomer of carbohydrates.
- Fatty acid & Glycerol: The building blocks of lipids.
- Amino acid: The monomer of proteins.
- Nucleotide: The monomer of nucleic acids.
- Enzyme: A protein that speeds up chemical reactions in the body.
Action Items / Next Steps
- Search for and review illustrations of biomolecule arrangements to better understand how their structures differ and how structure relates to function.
- Explore how the arrangement of elements in biomolecules impacts their properties and roles in living organisms.