Microbiology Chapter 2 Flashcards

Subatomic Particles and Atoms

• Electrons: Negatively charged particles that orbit the nucleus.
• Nucleus: Comprises neutrons (neutral particles) and protons (positively charged particles).
• Atoms: The smallest units of matter, forming the basic building blocks of elements.
• Matter: Any substance that has mass and occupies space.

Atomic Structure

• Atomic Number: Represents the number of protons in the nucleus, defining the element.
• Atomic Weight: The combined mass of protons, neutrons, and electrons in an atom.
• Isotopes: Variants of elements that differ in their neutron count, affecting stability.

Chemical Bonds

• Chemical Bonds: Formed when atoms share or transfer valence electrons, leading to molecule formation.
• Covalent Bonds: Occur when two atoms share pairs of electrons.
• Ionic Bonds: Form when atoms with significant differences in electronegativity transfer electrons to each other.
• Hydrogen Bonds: Weak attractions between a partially positive hydrogen atom and a partial negative charge in another atom.

Types of Reactions

• Metabolism: Encompasses all chemical reactions within an organism, involving synthesis and breakdown processes.
• Types of Reactions:
  • Synthesis: Formation of complex molecules from simpler ones.
  • Decomposition: Breakdown of larger molecules into smaller units.
  • Exchange: Involves both breaking and forming bonds.

Characteristics of Water

• Water exhibits cohesion and acts as an effective solvent.
• Remains liquid over a wide range of temperatures and can absorb energy without significant temperature change.
• Participates in numerous chemical reactions in biological systems.

Electrolytes and pH

• Electrolytes: Ionic compounds like salts that dissociate into cations and anions, maintaining electrical balance in cells.
• Acids and Bases: Acids release H+ in solution, whereas bases bind with H+; both are crucial for metabolic balance.
• Buffers: Substances that prevent drastic pH changes, ensuring stability in biological systems.

Macromolecules

• Four main categories: lipids, carbohydrates, proteins, nucleic acids.
• Monomers: Basic building blocks of macromolecules, such as amino acids in proteins.
• Lipids: Include fats, phospholipids, waxes, and steroids with specific functions in energy storage and membrane structure.

Proteins

• Made up of amino acids, which are composed of carbon, hydrogen, oxygen, nitrogen, and sometimes sulfur.
• Perform vital functions, including enzymatic activity, structural support, and transport.

Nucleic Acids

• Composed of nucleotides, which include a phosphate, a pentose sugar, and nitrogenous bases (adenine, guanine, cytosine, thymine, uracil).
• DNA serves as genetic material, existing predominantly as double-stranded molecules, while RNA plays a crucial role in protein synthesis.

Functional Groups and Interaction

• Functional Groups: Specific groups of atoms within molecules that determine their chemical properties and reactions.
• Hydrophobic: Describes substances that do not dissolve in water, important for structure and functionality of biological membranes.

Use these concise notes for a clear and organized overview of essential microbiological concepts regarding atomic structure, chemical bonds, metabolic processes, and biomolecular functions.