Pt. 1

Overview of Cell Structure and Function

  • Fundamental unit of life: Cells

  • Organized into 3 Domains:

    • Bacteria

    • Archaea

    • Eukarya

DNA and Its Functions

  • DNA

    • Watson and Crick: Discoverers of the double helix structure.

    • Functions of DNA:

    • Reproduction: Ensures genetic continuity.

    • Protein Synthesis: Codes for proteins, which perform various functions in cells.

    • Transport Substances: Facilitates movement of molecules in and out of cells.

    • Food Processing: Metabolism of nutrients for energy.

    • Homeostasis: Maintenance of stable internal conditions.

Cytology: Study of Cells

  • Cytology: The branch of biology that studies cells.

    • Hooke’s Observations: All organisms are composed of cells; all cells originate from pre-existing cells.

    • Similar molecules catalyze essential cellular processes across different organisms.

Types of Organisms

  • Protists: Primarily unicellular organisms that are classified within Eukarya.

Microscopy Techniques

  • Leeuwenhoek: Noted for early observations using microscopes.

  • Types of Microscopes:

    • Light Microscope: Uses light to magnify specimens.

    • Electron Microscope: Provides higher magnification and resolution.

  • Key concepts:

    • High Magnification: Ability to enlarge images of small specimens.

    • High Resolution: Ability to discern fine detail in the observed specimen.

Genetics Fundamentals

  • Gregor Mendel: Often referred to as the father of genetics.

  • Classification of living organisms:

    • Prokaryotes:

    • Characteristics:

      • Unicellular

      • Lack a nucleus

      • Comprise only ribosomes

      • Generally smaller (ex: bacteria, archaea)

    • Eukaryotes:

    • Characteristics:

      • Can be unicellular or multicellular

      • Possess a nucleus

      • Contains all organelles; tend to be larger (ex: plants, animals, fungi)

Protein Structure and Function

  • Protein Functionality Requirement: Proteins must fold into specific structures to function.

    • Protein Folding Levels:

    1. Primary Level: Sequence of amino acids; no bonds formed yet.

    2. Secondary Level: Formation of structures such as alpha helices and beta sheets held by hydrogen bonds.

    3. Tertiary Level: Further folding leads to a functional state (native conformation).

    4. Quaternary Level: Multiple polypeptides combine to form a complex (ex: Insulin, Hemoglobin).

  • Denaturation: Loss of structure due to environmental changes.

  • Anfinsen Dogma: The sequence of a protein determines its structure and function.

  • X-Ray Crystallography: Technique for determining molecular structure of proteins.

  • Types of Proteins:

    • Keratin: Structural component in hair and nails.

    • Collagen: Primary protein in connective tissues.

    • Myosin: Motor protein in muscle cells.

Fundamentals of Energy in Biology

  • Energy: Capacity to do work.

    • Potential Energy: Stored energy.

    • Kinetic Energy: Energy in motion.

  • Metabolism: All chemical reactions in living organisms, balancing anabolism and catabolism.

    • Catabolism: Breakdown of complex molecules to release energy.

    • Exergonic Reactions: Energy is released; Gibbs Free Energy (ext{ΔG} < 0); spontaneous reaction.

    • Anabolism: Building up processes that require energy input.

    • Endergonic Reactions: Energy is absorbed; Gibbs Free Energy (ext{ΔG} > 0); non-spontaneous reaction.

  • Laws of Thermodynamics:

    • 1st Law: Energy cannot be created or destroyed, only transformed.

    • 2nd Law: In any energy transfer, entropy (disorder) tends to increase; energy tends to spread out.

Acids, Bases, and pH

  • Acids Examples:

    • Lemon juice

    • Vinegar

    • Gastric juice (ex: acetic acid)

  • Bases Examples:

    • Bleach

    • Ammonia

    • Oven cleaner

    • Soap

  • pH Scale: A measure of H$^+$ concentration in an aqueous solution.

    • pH 7: Neutral (ex: water)

    • pH < 7: Acidic

    • pH > 7: Basic

  • Buffers: Substances that resist changes in pH, maintaining homeostasis in biological systems.

Solution Chemistry

  • Solvent: Substance in which solutes are dissolved (ex: water).

  • Solution: Mixture of substances.

  • Solute: The substance that gets dissolved (ex: salt).

Functional Groups in Organic Chemistry

  • Functional Groups:

    • Carboxyl Group (COOH): Acidic properties.

    • Hydroxyl Group (OH): Alcohol properties; usually basic.

    • Amino Group (NH₂): Basic properties.

  • Organic Compounds: Must contain both carbon (C) and hydrogen (H); inorganic compounds include everything else.

Water Properties

  • Dissociation of Water:

    • Water can dissociate to form hydrogen ions and hydroxyl ions.

    • Water's structural formula: $ ext{H}_2 ext{O}
      ightleftharpoons ext{H}^+ + ext{OH}^-$.

    • Water exhibits high heat of vaporization and cohesion properties contributing to its surface tension.

Introduction to Atomic Structure

  • Atoms: The fundamental units of matter, comprised of:

    • Protons: Positively charged, located in the nucleus.

    • Neutrons: Neutral charge, also located in the nucleus.

    • Electrons: Negatively charged, orbiting the nucleus.

  • Atomic Mass: The total number of protons and neutrons.

  • Atomic Number: The number of protons in the nucleus ( ext{p}+ ext{n}).

  • Ions: Atoms that gain or lose electrons, resulting in a charge.

  • Octet Rule: Atoms tend to bond in a way that gives them eight electrons in their outermost shell, leading to stability.

  • Isotopes: Variants of the same element that have different atomic masses due to varying numbers of neutrons. For instance, Carbon 6 12, Carbon 6 14