Chem & Macromolecules

• Cell is the basic unit of life
• Element is the purest form of a substance that cannot be broken down into simpler forms by ordinary means
• Atom is the basic unit of matter
• 4 Major Elements of the Body: C, H, O (most abundant), N
• 9 Minerals in the body: Na, Mg, K, Ca, Fe, P, S, Cl, I
• 13 Trace Minerals in the body: B, F, Al, Si, V, Cr, Mn, Co, Cu, Zn, Se, Sn, Mo
• Compounds are formed when 2 or more atoms from 1 or more elements are chemically combined to form another substance (molecule – smallest unit)
• H2O is the most abundant compound in the body (60%)
• Functions of Water in the Body:

  1. Lubricant, moistening and protective agent

  2. Body temperature regulation

  3. Carrier of nutrients, gases, and wastes
• Hydrophilic compounds are water-loving, while hydrophobic compounds are water-fearing
• Mixtures can be homogenous (solutions) or heterogenous (have distinct visible parts)
• Types of Mixtures:

  1. Solution – solute is dissolved in solvent (homogenous: tears, sweat)

  2. Suspension – solute is dispersed in solvent (heterogenous: circulating whole blood)

  3. Colloid – solute is evenly dispersed in solvent (heterogenous dispersion: plasma of blood)
• Tyndall Effect is the scattering of visible light by colloidal particles
• 2 Types of Compounds based on how they are formed:

  1. Ionic Compounds – Ionic Bonding – involves transferring of electrons

  2. Covalent Compounds – Covalent Bonding – involves sharing of electrons (stronger)
• pH of Body Fluids:

  • Stomach pH: Highly Acidic (1.5 pH)
  • Vaginal pH: Mildly Acidic (5.5 pH)
  • Blood pH: Mildly Alkali (7.4 pH)
  • Urine pH: Variable
  • Sweat pH: Mildly Acidic (5.5 – 6 pH)
• Acids act as proton or H+ ion donors, while bases act as proton or H+ ion acceptors
• Buffers are substances that resist drastic changes in pH
• Blood is acidic at pH < 7.35 (acidosis), basic at pH > 7.45 (alkalosis), and normal at pH 7.35 to 7.45
• Macromolecules:

  1. Carbohydrate > monosaccharides

  2. Lipids > fatty acids

  3. Protein > amino acids

  4. Nucleic Acid > nucleotides
• Carbohydrates are the main source of body energy and supply carbon atoms for the synthesis of other macromolecules
• Lipids include fats, oils
• Lipids include fats, oils, cholesterol, and phospholipids, with main elements being CHO and building blocks being Fatty Acids
• Lipids have a common property of water insolubility due to a non-polar chain (hydrophobic)
• Two types of lipids are dietary fats (animal and plant fats) and body fats produced by the body as lipids
• Saturated fats (dietary fats) mostly come from animal fats, have no double bonds between carbon atoms, are solid at room temperature, and include examples like butter and lard
• Unsaturated fats (dietary oils) mostly come from plants, have at least one double bond (mono) or more (poly), are liquid at room temperature, and include examples like olive oil and canola oil
• Trans fats are saturated on opposite sides of the double bond and are unhealthy, found in fried food, pasta, and desserts
• Hydrogenated oils have hydrogen atoms added to unsaturated fats, making them more saturated and also unhealthy
• Body fats include simple fats (triglycerides) made of glycerol and fatty acids, and compound fats like cholesterols and phospholipids
• Cholesterols are "fat-like" compounds with a sterol ring, while phospholipids have a phosphate group and function as structural components of membranes and emulsifiers
• Functions of lipids include being an alternative energy source, cell structure component, body insulation, organ support, protection, lubrication, hormone precursors, and carriers of fat-soluble vitamins
• Proteins are made up of polypeptides, with main elements being CHO plus Nitrogen, and building blocks being amino acids
• Essential amino acids are needed, cannot be synthesized by the body, and must be sourced from the diet
• A mnemonic for remembering the 10 essential amino acids is "PVT. TIM HALL": Phenylalanine, Valine, Tryptophan, Threonine, Isoleucine, Methionine, Histidine, Arginine, Lysine, Leucine
• Proteins from amino acids are the building blocks, peptides are 2 amino acids joined by peptide bonds, polypeptides are chains of 2 or more peptides, and proteins are long or multiple chains of polypeptides
• Body proteins include globular proteins with functional roles like enzymes, fibrous proteins with structural roles like collagen, keratin, and cytoskeleton, and membrane proteins with roles in transport, cell signaling, recognition
• Functions of body proteins include building, repair, maintenance, some hormones, catalysts (enzymes), transport, storage, blood clotting, immunity, muscle contractility, and alternative energy source
• Enzymes are proteins essential to metabolism, functioning as catalysts, requiring vitamins and minerals to function, and having names that usually end in -ase
• Nucleic acids include DNA and RNA, with DNA serving as genetic material and RNA having various functions