Biological Macromolecules for the TEAS Exam

Introduction to Macroolelecules and Living Chemistry

Definition of Macroolelecules: Macroolelecules are the chemicals that constitute all living things, including plants, animals, and bacteria. While the official TEAS preparatory materials provide complex definitions, they are essentially the building blocks of life.
The Building Analogy: * Just as diverse buildings (houses, factories, skyscrapers, airports) are made from a few basic materials like wood, metal, stone, brick, and glass, all living things are constructed from four primary types of chemicals. * Though the proportions vary—for instance, a cow contains a high concentration of protein (meat), while wheat or corn contains high concentrations of carbohydrates—every living organism utilizes the same four categories of materials.
Scale and Atomic Composition: * All matter is made of atoms. Groups of atoms bonded together form molecules. * "Macro" signifies "big." Standard molecules like water ( $H_2O$ ) contain only three atoms. Glucose ( $C_6H_{12}O_6$ ) contains $24$ atoms. * Macroolelecules are massive in comparison, consisting of hundreds, thousands, or even millions of atoms clumped together. For example, a single full string of DNA contains millions of atoms.

Fundamental Structural Concepts: Monomers and Polymers

Polymers: A polymer is a large molecule made of individual units connected together. * Metaphors: A polymer is comparable to a train made of individual cars or a necklace made of beads on a string.
Monomers: Monomers are the individual pieces (the "beads" or "cars") that are connected to build the polymer chain.
Nature of Construction: For every category of macroolelecule, specific types of monomers are linked to form characteristic polymers.

Metabolic Processes: Anabolism and Catabolism

Anabolism: This is the process of building large, complex molecules by connecting smaller pieces (monomers) together. * Mnemonic: Anabolic steroids are used by individuals to build muscle tissue; therefore, anabolism equals building.
Catabolism: This is the process of taking a large molecule and chopping it down into smaller constituent monomers. * Mnemonic: Catabolism equals breaking things down.
Relationship to Polymers: * Monomers $\rightarrow$ Polymers = Anabolism. * Polymers $\rightarrow$ Monomers = Catabolism.

The Four Main Categories of Macroolelecules

The four chemicals that make up essentially all parts of living things are: 1. Carbohydrates 2. Lipids 3. Proteins 4. Nucleic Acids

Carbohydrates: Structures and Functions

Composition: Carbohydrates are polymers made from monomers called monossaccharides, which are also known as simple sugars.
Primary Roles: 1. Energy Storage: Providing fuel for the organism. 2. Structure: Providing physical support and rigid barriers.
Identification Tip: Names ending in $-OSE$ (e.g., glucose, fructose, sucrose, cellulose) are a "tip off" that the molecule is a carbohydrate.
Key Examples of Carbohydrates: * Glucose: A monossaccharide (monomer) also known as blood sugar. It is the most famous individual monomer. * Sucrosse (Table Sugar): A disaccharide made of one glucose monomer connected to one fructose monomer. Because it has only two simple sugars, it is not a full polymer. * Glycogen: A long polymer (chain) of thousands of glucose monomers. It is used to store energy in the liver and muscles of animals. * Starch: A long polymer of glucose used for energy storage specifically in plants. * Cellulose: A long string of glucose monossaccharides that makes up wood and the thick cell walls of plants. Human bodies cannot digest it, though termites can, thanks to specialized bacteria in their stomachs. * Kiten (Chitin): A structural carbohydrate that forms the hard, crunchy outer shells of insects.

Chemical Bonding: Dehydration Synthesis

Dehydration Synthesis: The specific chemical method nature uses to connect monomers during anabolism. * Monomers have hydrogen ( $H$ ) and oxygen ( $O$ ) on their sides. * Nature removes a hydrogen ( $H$ ) from one monomer and a hydroxyl group ( $OH$ ) from another to create a water molecule ( $H_2O$ ). * "Dehydration" refers to the removal of water; "synthesis" refers to making or building. This loss of water allows the monomers to bond together.

Lipids: Fats, Oils, and Waxes

General Characteristics: Lipids are non-polar molecules primarily composed of carbon ( $C$ ) and hydrogen ( $H$ ) chains.
Solubility and Hydrophobicity: * Lipids do not dissolve in water (they are insoluble). * Hydrophobic: From the Greek "hydro" (water) and "phobic" (hating/fearing). Lipids "hate" water and will not mingle with it.
Triglycerides: A common lipid structure consisting of one glycerol molecule attached to three fatty acids (long strings of carbon and hydrogen).
Roles of Lipids: 1. Energy Storage: Lipids store significantly more energy than carbohydrates but are slower to digest and release that energy. 2. Insulation and Cushioning: Providing thermal protection and physical padding in animals. 3. Cellular Structure: Phospholipids are specialized lipids used to build the cell membrane. 4. Chemical Messaging: Steroid hormones (chemical messengers) are lipids. Examples include cholesterol, testosterone, estrogen, cortisol, and eldoststerone.

Proteins: The Workhorses of the Cell

Monomers: Proteins are polymers made of amino acids.
Peptide Bonds: These are the specific covalent bonds (the "glue") that connect amino acids together to form proteins. The TEAS frequently asks about this specific bond.
Primary Roles of Proteins: 1. Enzymes (Catalysts): Proteins that speed up chemical reactions by increasing the reaction rate. Without them, vital reactions would occur too slowly to sustain life. 2. Structure: Building physical components of the body.
Identification Tip: Many enzyme names end in $-ASE$ .
Key Examples of Proteins: * Pepsin: An enzyme that breaks down other proteins. * Trison (Trypsin): Another enzyme responsible for protein breakdown. * Amaase (Amylase): An enzyme found in saliva that digests starch (carbohydrates) into simpler sugar monomers. * Keratin: A structural protein that builds hair and nails. * Collagen: A structural protein also involved in building hair and nails.

Nucleic Acids: Genetic Information

Monomers: Nucleic acids are polymers made of monomers called nucleotides.
Primary Role: Carrying genetic, hereditary, or trait-related information passed from parent to child.
Two Main Types: 1. DNA (Deoxxyribboucleic acid): The master blueprint of genetic information. 2. RNA (Ribboucleic acid): Involved in the translation and transmission of genetic data.

Summary: Carbohydrates vs. Lipids Energy Storage

Carbohydrates: Provide less energy storage but allow for fast energy access.
Lipids: Provide more energy storage but requires slower digestion and results in slower energy release.

Questions & Discussion

Question: "How soon will you be adding the anatomy and physiology videos?"
Response: I am working on them as quickly as possible. I will continue doing live streams over the next couple of weeks and will refine those into formal course materials for the website.
Question: "What is the difference between anabolism and catabolism regarding monomers and polymers?"
Response: Anabolism builds polymers from monomers (building muscle). Catabolism breaks polymers down into monomers (digesting food or muscle wasting during starvation).
Question: "Is cellulose a carbohydrate?"
Response: Yes, it is a structural carbohydrate that makes up wood. It is a long polymer of glucose that humans cannot digest.
Question: "What bond holds amino acids together?"
Response: Peptide bonds, which are a type of covalent bond.
Critique/Feedback: The speaker notes they have "thick skin" and welcome all feedback, whether students feel the pace is too slow, too fast, or if the material is boring. The primary goal is to improve the quality of TEAS preparation, which the speaker believes is currently poorly served by existing books and videos.