LW

Chapter 1-8 Lecture Notes: Biology Vocabulary Review

Overview: Key ideas you’ll need for the exam

  • Oxidation-reduction basics (redox): loss of electrons = oxidation; gain of electrons = reduction.
  • Memory tricks for redox: oil rig mnemonic (Oxidation Is Loss; Reduction Is Gain). A playful personal cue was shared: “leiosis” as another reminder.
  • Blood pH maintenance and buffers: normal blood pH is 7.35–7.45.
  • Buffer system in plasma: carbon dioxide and water form carbonic acid, which interconverts with bicarbonate; major buffering in blood.
  • Acid-base disorders: acidosis (too acidic) and alkalosis (too alkaline).
  • Body fluid compartments: plasma (extracellular, within vessels) vs interstitial fluid (extracellular, in tissues) vs intracellular fluid (inside cells).
  • Organic vs inorganic molecules: organic contain carbon and hydrogen; examples include carbohydrates, lipids, proteins, nucleic acids. CO₂ is inorganic because it lacks hydrogen.
  • Focus of course content: learn the monomer/building blocks, how the body uses each molecule, where they’re found, and a few specific examples.
  • Practical context: practice quizzes may cover broader material; use PowerPoint depth as the guide for exam topics.
  • Cell membrane and transport topics previewed: phospholipid bilayer, membrane proteins, glycocalyx, transport mechanisms (diffusion, facilitated diffusion, osmosis, active transport).

Oxidation-reduction (redox) and buffers in physiology

  • Oxidation: loss of electrons; often associated with gain of oxygen or loss of hydrogen.
  • Reduction: gain of electrons.
  • Memory aids:
    • “Oil Rig”: Oil = Oxidation, Rig = Reduction; oil rig mnemonic helps recall
    • “Loss = Oxidation; Gain = Reduction.”
  • pH regulation in blood:
    • Target range: 7.35
      ightarrow 7.45
    • Buffer system: carbon dioxide + water ⇌ carbonic acid (H₂CO₃) ⇌ bicarbonate (HCO₃⁻) + H⁺
    • Major buffering role of CO₂ in plasma; interconversion maintains tight pH range.
  • Clinical note:
    • Acidosis: blood too acidic.
    • Alkalosis: blood too basic.

Fluid compartments and plasma basics

  • Plasma is extracellular fluid within blood vessels.
  • Extracellular fluid has two components:
    • Plasma (within vessels)
    • Interstitial fluid (in tissues)
  • Intracellular fluid (inside cells).
  • Summary:
    • Intracellular fluid = inside cells.
    • Extracellular fluid = outside cells; includes plasma and interstitial fluid.

Organic versus inorganic molecules; what makes something organic

  • Organic molecules contain both carbon and hydrogen.
  • Some carbon-containing substances aren’t organic (e.g., CO₂) because they lack hydrogen.
  • Organic molecules covered here: carbohydrates, lipids, proteins, nucleic acids.

Carbohydrates: monomers, functions, and examples

  • Monomer: monosaccharides (simple sugars). Disaccharides can also be building blocks for some pathways.
  • Polysaccharides: long chains of monosaccharides (starch, glycogen, cellulose).
  • Primary roles:
    • Quick energy source
    • Some components of cell membranes
  • Common examples:
    • Glucose, fructose, galactose (monosaccharides)
    • Lactose (glucose + galactose) – disaccharide; lactose intolerance results from lactase enzyme deficiency, leading to gas, indigestion, pain.
    • Maltose (two glucose units) – disaccharide
    • Glycogen – storage form of glucose in liver and muscles
    • Starch – storage form in plants (analogous to glycogen in animals)
    • Cellulose – fiber (in plants)
  • Enzymes and carbohydrates:
    • Enzymes lower activation energy, speeding reactions (e.g., digesting lactose requires lactase).

Lipids: monomers, types, and functions

  • Monomer: fatty acids (plus glycerol backbone forms the building blocks of many lipids).
  • Key lipid structures:
    • Triglycerides: glycerol + 3 fatty acids. Formation involves dehydration synthesis (removal of water):
    • Reaction: ext{Glycerol} + 3 ext{ Fatty Acids}
      ightarrow ext{Triglyceride} + 3 H_2O
    • Saturated fats: every carbon has maximum hydrogens (no double bonds); straight chains.
    • Unsaturated fats: contain one or more C=C double bonds, causing kinks/bends in the chain.
    • Phospholipids: glycerol backbone with two fatty acid tails and a phosphate-containing head; amphipathic (hydrophilic head, hydrophobic tails).
    • Steroids: cholesterol and steroid hormones; cholesterol essential in balanced amounts; excess linked to problems if not regulated.
    • Prostaglandins: lipid-derived signaling molecules involved in inflammation and other immune responses.
  • Role of lipids:
    • Energy storage (long-term, especially when glycogen depleted)
    • Structural components (membranes, lipoproteins)
    • Precursors for signaling molecules (steroids, prostaglandins)

Proteins: monomers, structure, and functions

  • Monomer: amino acids.
  • General structure of amino acids:
    • Central carbon (alpha carbon) with:
    • Amino group (NH₂)
    • Carboxyl group (COOH)
    • Hydrogen atom (H)
    • Side chain (R group) – variable among amino acids
  • Peptide bonds: bonds between amino acids formed during protein synthesis; dehydration synthesis forms the bond and releases a water molecule.
  • Degrees of protein structure:
    • Primary: unique sequence of amino acids (polymer chain).
    • Secondary: local folding patterns—alpha-helix (α-helix) or beta-pleated sheet (β-sheet).
    • Tertiary: overall 3D folding driven by interactions (polarities, hydrophobic/hydrophilic effects, disulfide bonds, etc.). Results in globular or fibrous shapes.
    • Quaternary: assembly of multiple tertiary structures into a larger functional unit (hemoglobin is a classic example).
  • Function follows structure: Form determines function; DNA guides the order of amino acids to achieve the correct protein shape.
  • Protein categories and roles:
    • Structural proteins (support, movement, connective tissues)
    • Transport proteins (move substances across membranes, e.g., channels, carriers)
    • Enzymes (catalysts lowering activation energy)
    • Antibodies (immune defense)
    • Buffers (pH stabilization)
  • Denaturation: loss of native 3D structure due to heat or pH changes; impacts function; cooking and digestion examples discussed.
  • Enzymes: biological catalysts; do not change the product, but speed the reaction and lower activation energy; substrates fit into active sites forming an enzyme-substrate complex.
  • Practical note on learning depth: focus on definitions, key terms (peptide bonds, primary/secondary/tertiary/quaternary), and examples; you do not need exhaustive memorization of every amino acid or detailed mechanism at this level.

Nucleic Acids: DNA and RNA basics

  • Monomers: nucleotides (composed of sugar, phosphate, and base).
  • Sugars:
    • Deoxyribose (DNA)
    • Ribose (RNA)
  • Bases (general):
    • DNA: Adenine (A), Thymine (T), Cytosine (C), Guanine (G)
    • RNA: A, Uracil (U), C, G
  • Nucleic acids roles: store and transmit genetic information; RNA plays roles in protein synthesis and regulation.
  • Note: The course touches on the idea of nucleic acids as informational and functional molecules; specifics on base-pairing and sequencing are built in later courses.

Nucleotides and energy carriers

  • Adenosine triphosphate (ATP): energy currency of the cell.
    • ATP structure: adenosine + three phosphate groups.
    • Energy release via hydrolysis: ext{ATP}
      ightarrow ext{ADP} + ext{P}_i + ext{energy}
    • ADP: adenosine diphosphate (two phosphates).
    • AMP: adenosine monophosphate (one phosphate).
    • Interconversion cycle: ATP ⇄ ADP ⇄ AMP; phosphate groups are recycled.
    • Cyclic AMP (cAMP): a cyclic form of AMP used in signaling pathways.
  • Key equations to remember:
    • ext{ATP}
      ightarrow ext{ADP} + ext{P}_i + ext{energy}
    • ext{ADP}
      ightarrow ext{AMP} + ext{P}_i
    • ext{cAMP} = ext{cyclic adenosine monophosphate}

The cell membrane: structure and components

  • Core structure: phospholipid bilayer – amphipathic (phosphate head is hydrophilic; fatty acid tails are hydrophobic).
  • Fluid mosaic model: membrane is fluid; lipids and proteins move laterally.
  • Key components:
    • Integral (transmembrane) proteins: span the membrane; essential for transport and signaling.
    • Peripheral proteins: on one side of the membrane; may act as enzymes or receptors.
    • Channel proteins: create passageways for non-fat-soluble substances; enable diffusion across the membrane.
    • Cholesterol: embedded in the membrane; influences fluidity and flexibility at different temperatures.
    • Glycocalyx: formed by glycoproteins and glycolipids on the cell surface; serves as identity markers (self vs non-self) for immune surveillance.
    • Glycoproteins and glycolipids contribute to cell recognition and signaling.
  • Lipid-based identity and signaling:
    • Receptors on the extracellular side bind ligands (signal molecules) and trigger intracellular responses.
    • Ligand = molecule that binds to a receptor.

Transport across the cell membrane

  • Passive transport: diffusion and facilitated diffusion (no ATP required).
    • Simple diffusion: small or nonpolar molecules can cross directly.
    • Facilitated diffusion: requires a carrier or channel protein for passage of larger or charged solutes.
    • Osmosis: diffusion of water across a selectively permeable membrane; water movement toward higher solute concentration.
  • Active transport: requires ATP; moves substances against their concentration gradient.
  • Diffusion concepts:
    • Isotonic: inside and outside have the same solute concentration; no net water movement. Example: isotonic saline roughly 0.9 ext{% NaCl}.
    • Hypertonic: outside has higher solute concentration; water moves out; cell shrinks (crenation).
    • Hypotonic: outside has lower solute concentration; water moves in; cell swells and may rupture.
  • Real-world example highlights:
    • Severe dehydration and fluid balance concerns; hypotonic hydration can be dangerous; medical care might involve sodium administration to correct imbalance.
    • A cautionary real-world anecdote was shared about a radio contest involving excessive water intake; illustrates risks of rapid fluid intake and electrolyte imbalance.

Practical and conceptual takeaways for exam readiness

  • For each organic molecule, you should know:
    • The monomer/building block (e.g., monosaccharides for carbohydrates; amino acids for proteins; fatty acids for lipids; nucleotides for nucleic acids).
    • The major body uses (energy, structure, signaling, genetic information, etc.).
    • Where they’re found in the body (e.g., carbohydrates as glycogen in liver/m muscles; plasma vs blood cell contents; membranes).
    • A few specific examples (e.g., lactose intolerance as failure to digest lactose; starch/glycogen storage; cellulose as dietary fiber).
  • Protein structure and function:
    • Be able to identify primary, secondary (α-helix and β-sheet), tertiary, and quaternary structures and why structure dictates function.
    • Understand peptide bonds and the concept of denaturation affecting function and digestibility.
  • Enzymes:
    • They lower activation energy and do not fundamentally alter the chemical identity of substrates; they speed up reactions and are essential for metabolic pace.
  • Nucleic acids:
    • Distinguish DNA vs RNA sugars (deoxyribose vs ribose) and DNA bases (A, T, C, G) vs RNA bases (A, U, C, G).
  • Cell membrane topics:
    • Amphipathic nature of phospholipids; role of cholesterol in membrane flexibility; importance of membrane proteins for transport and signaling; glycocalyx in cell recognition.
  • Fluid balance and the calculator of tonicity:
    • Isotonic, hypertonic, hypotonic concepts; 0.9% NaCl as a common isotonic solution.
  • Practice guidance:
    • Quizzes may cover broader chapter content; focus on the core topics presented in the PowerPoint: monomers, uses, basic structures, and terms like peptide bonds, enzyme, receptor, ligand, channel, and glycocalyx.

Quick reference: key formulas and terms (LaTeX-ready)

  • Blood pH range: 7.35 \le pH \le 7.45
  • Carbonic acid–bicarbonate buffer system: ext{CO}2 + ext{H}2 ext{O} \\rightleftharpoons \text{H}2 ext{CO}3 \\rightleftharpoons \text{H}^+ + ext{HCO}_3^-
  • Dehydration synthesis (formation of triglyceride):
    ext{Glycerol} + 3 ext{ Fatty Acids}
    ightarrow ext{Triglyceride} + 3 ext{H}_2 ext{O}
  • ATP cycle basics:
    • ext{ATP}
      ightarrow ext{ADP} + ext{P}_i + ext{energy}
    • ext{ADP}
      ightarrow ext{AMP} + ext{P}_i
    • ext{cAMP} = ext{cyclic adenosine monophosphate}
  • Protein structure terminology (peptide bonds):
    • Peptide bond forms between the carboxyl group of one amino acid and the amino group of the next: - ext{CO}- ext{NH}-
  • Isotonic solution reference: 0.9 ext{% NaCl}

Note on exam approach

  • Focus on the depth outlined in the PowerPoint: definitions, uses, and simple examples for each organic molecule, plus the structural levels of proteins and the basics of enzyme function.
  • Don’t overemphasize memorizing chemical structures or all amino acids; prioritize understanding concepts, terms, and how these molecules support body function.
  • Be prepared for practice quizzes that may extend beyond this lecture; use them to test comprehension, not to panic about material not covered in depth here.

Quick glossary (in case you skim)

  • Buffer, pH, homeostasis, isotonic, hypertonic, hypotonic
  • Monomer, polymer, dehydration synthesis, peptide bond
  • Monosaccharide, disaccharide, polysaccharide
  • Fatty acid, glycerol, triglyceride, phospholipid, cholesterol, prostaglandin
  • Amino acid, peptide bond, primary/secondary/tertiary/quaternary structure
  • DNA, RNA, ATP, ADP, AMP, cAMP
  • Integral protein, peripheral protein, channel protein, glycocalyx
  • Diffusion, facilitated diffusion, osmosis, active transport
  • Isotonic saline, dehydration risks, electrolyte balance