Biology 1111 Exam Study Guide

Properties of Life

  • Order, sensitivity to stimuli, reproduction, adaptation, growth and development, regulation/homeostasis, energy processing
  • Phototaxis (light), chemotaxis (chemicals), thigmotaxis (touch)

Reproduction

  • Prokaryotic cells: binary fission
  • Eukaryotic cells: sexual or asexual (parthenogenesis, fragmentation, budding, cutting, gemmules)

Levels of Organization

  • Atom, molecule, macromolecule, organelle, cell, tissue, organ, organ system, organism, population, community, ecosystem, biosphere
  • Atom: Smallest unit retaining element properties
  • Cell: Smallest unit of living organisms

Domains of Life

  • Bacteria, archaea (prokaryotes), and eukaryotes

Taxonomy

  • Carl Linnaeus: Binomial naming system
  • Hierarchy: domain, kingdom, phylum, class, order, family, genus, species
  • Biological species concept: interbreed and produce fertile offspring
    • Drawbacks: Doesn't apply to all, e.g., non-sexual species or fossils

Scientific Method

  • Sir Francis Bacon: Documented the method
  • Hypothesis: Testable, falsifiable explanation
  • Deductive reasoning: Logic in hypothesis testing
  • Null-hypothesis: No relationship between phenomenon and explanation

Variables in Experiments

  • Independent variable: Adjusted variable
  • Dependent variable: Measured variable
  • Standardized/Controlled variables: Kept constant

Control

  • Control subject: No treatment, used for comparison

Peer Review

  • Articles reviewed by experts before publication

Chemistry

  • Organic molecule: Contains carbon
  • Atomic number: Number of protons
  • Isotopes: Same protons, different neutrons (e.g., carbon-12, carbon-14)
  • Ions: Unequal electrons and protons; cations (+), anions (-)

Chemical Bonds

  • Covalent: Strong, electrons shared
  • Ionic: Strong, between oppositely charged ions
  • Hydrogen: Weak, between hydrogen and oxygen or nitrogen
  • Van der Waals: Weak attractions between molecules

Properties of Water

  • Polar, temperature stabilizer, cohesive, excellent solvent

pH Scale

  • Inverse logarithmic scale of H+ concentration (0-14)
  • pH<7pH < 7: Acidic, pH>7pH > 7: Basic, pH=7pH = 7: Neutral
  • Acids increase H+ concentration (HX); bases decrease H+ concentration (XOH)

Buffers

  • Resist pH change

Organic Compounds

  • Carbohydrates, lipids, proteins, nucleic acids

Carbohydrates

  • Simple sugars (glucose, fructose, ribose, galactose; -ose suffix)
  • Polysaccharides (starch, glycogen, cellulose, chitin)

Proteins

  • Polymers of amino acids (20 types)
  • Amino acids: Carboxylic acid (-COOH), amino group (-NH3), R group
  • Structures: Primary, secondary, tertiary, quaternary

Nucleic Acids

  • DNA: Polymer of nucleotides (phosphate, ribose, base)
  • Bases: Adenine, guanine (purines); cytosine, thymine (pyrimidines)

Lipids

  • Fats (triglycerides), phospholipids, steroids, waxes
  • Hydrophobic, not polymers
  • Triglycerides: Glycerol + 3 fatty acids
  • Fatty acids: Saturated (no double bonds), monounsaturated (one double bond), polyunsaturated (multiple double bonds)

Cell Theory

  • All living things have cells.
  • All cells come from other cells.
  • The cell is the basic unit of life.

Cell Structure

  • All cells have: plasma membrane, ribosomes, DNA, cytoplasm
  • Eukaryotic cells: Nucleus, organelles, linear chromosomes
  • Prokaryotic cells: Nucleoid, no organelles, circular chromosome

Cell Membrane

  • Fluid mosaic model: Proteins, carbohydrates, cholesterol in phospholipid bilayer

Cytoskeleton

  • Microfilaments, intermediate filaments, microtubules

Endomembrane System

  • Nucleus, ER, Golgi, lysosomes, vesicles, vacuoles

Golgi Apparatus

  • Processes and packages proteins
  • Cis-face (entry), trans-face (exit)

Lysosomes

  • Digestive enzymes, acidic
  • Merge with phagosomes for digestion

Endoplasmic Reticulum

  • Rough ER:modifies proteins, makes phospholipids
  • Smooth ER:carbs, lipids, steroids, detoxification

Vesicles and Vacuoles

  • Vesicles: transport, can fuse with membranes
  • Vacuoles: storage, do not fuse with membranes

Ribosomes

  • Protein synthesis (rRNA and proteins)

Mitochondria

  • ATP production (cellular respiration)
  • Double membrane, cristae (inner membrane folds), matrix (DNA and ribosomes)

Chloroplasts

  • Photosynthesis
  • Double membrane, stroma, thylakoids (grana stacks), chlorophyll, DNA, ribosomes

Intercellular Junctions

  • Animal cells: tight, desmosomes, gap
  • Plant cells: plasmodesmata

Cell Differences

  • Plant: cell wall, chloroplasts, vacuole, plasmodesmata
  • Animal: lysosomes, centrosomes, gap junctions

Diffusion

  • Molecules move from high to low concentration

Osmosis

  • Water moves from low to high solute concentration
  • Isotonic: Same concentration
  • Hypertonic: Higher concentration (cell shrinks)
  • Hypotonic: Lower concentration (cell bloats)

Concentration Gradient

  • Unequal solute concentration across a membrane

Electrochemical Gradient

  • Combination of concentration and electrical gradients

Membrane Transport

  • Passive transport: No energy needed
  • Facilitated transport: Passive with transmembrane protein
  • Active transport: Against gradient, requires energy

Endocytosis and Exocytosis

  • Endocytosis: Taking in matter (phagocytosis, pinocytosis, receptor-mediated)
  • Exocytosis: Expelling matter

Thermodynamics

  • 1st Law: Energy cannot be created or destroyed, only converted
  • 2nd Law: Energy transfers lose some energy as unusable form; entropy increases

Energy Forms

  • Heat, radiant, potential, chemical, kinetic, electrical

Free Energy

  • Energy available to do work
  • Endergonic: Absorbs energy (products > reactants)
  • Exergonic: Releases energy (products < reactants)

ATP

  • Primary energy carrier

Cellular Respiration

  • Aerobic: Oxygen consumed, glucose to CO2 and water, produces ATP
  • Reactants: Oxygen and glucose; products: CO2 and water

Cellular Respiration Stages

  1. Glycolysis: Glucose to pyruvate (2 ATP net), in cytoplasm
  2. Citric Acid Cycle: Pyruvate to CO2, NADH, FADH2, GTP, in mitochondrial matrix
  3. Electron Transport Chain: Electrons passed between complexes, H+ gradient, ATP synthase makes ATP, oxygen is final electron acceptor, in inner mitochondrial membrane

Enzymes

  • Proteins that speed up reactions, not consumed
  • Substrate binds to active site

Enzyme Inhibition and Activation

  • Competitive inhibition: Inhibitor binds to active site
  • Non-competitive/Allosteric inhibition: Inhibitor binds to allosteric site, changes active site
  • Allosteric activation: Activator binds to allosteric site, improves substrate binding
  • Feedback inhibition: Product inhibits upstream enzyme

Anaerobic Respiration

  • No oxygen needed (lactic acid fermentation, alcohol fermentation, methanogenesis)
  • Lactic acid fermentation: Glucose to lactic acid and CO2
  • Alcohol fermentation: Glucose to ethanol and CO2
  • Facultative anaerobes: Can do both
  • Obligate anaerobes: Only anaerobic, oxygen is poisonous