213 STUDY GUIDE: EXAM 1
Theory vs. Law: Theory – explains why; Law – describes what
SLIDE SET 1 PRINCIPLES OF BIOLOGY
happens.
Principles of Biology, Biological Organization: Basic concepts of life
Source of Life: Theories of life’s origin (abiogenesis, RNA world
and its structure.
hypothesis).
Homeostasis: Maintaining stable internal conditions.
SLIDE SET 2 CHEMICAL BASIS OF LIFE
Hierarchy of Life: Atom → Molecule → Organelle → Cell → Tissue
Atoms, protons, neutrons, electrons: Atoms are the smallest units of
→ Organ → Organism → Population → Community → Ecosystem
matter; protons (+) and neutrons (neutral) are in the nucleus,
→ Biosphere.
electrons (-) orbit around.
Evolutionary History: Tracing life’s development over time.
Electron/energy shells, octet rule: Electrons occupy shells; the octet
Evolutionary Change: Genetic adaptation across generations.
rule states atoms gain, lose, or share electrons to fill their outermost
Miller & Urey: Experiment simulating early Earth’s conditions to form
shell (8 electrons).
organic molecules.
Atomic mass, atomic number, isotopes: Atomic number = protons,
RNA Ribozyme, Protobiont: Self-replicating RNA and early cell-like
atomic mass = protons + neutrons, isotopes = same element,
structures.
different neutron count.
Horizontal & Vertical Gene Transfer; Tree of Life, Web of Life:
Periodic table, columns, rows: Columns (groups) have similar
Horizontal – genes shared across species, Vertical – genes passed
properties; rows (periods) indicate increasing atomic number.
from parent to offspring; Tree of Life – single ancestor model, Web of
Electronegativity, anion, cation: Electronegativity is an atom’s ability
Life – interconnected evolution.
to attract electrons; anion (negative ion, gains electrons), cation
Taxonomy, Domains of Life: Three domains – Bacteria, Archaea,
(positive ion, loses electrons).
Eukarya.
CHON carbon, hydrogen, oxygen, nitrogen: Four most abundant
Classification, Taxonomy, Binomial Nomenclature: Naming and
elements in living organisms.
grouping organisms (Genus + Species, e.g., Homo sapiens).
Types of bonds: HIC hydrogen, ionic, covalent: Hydrogen bonds =
Discovery-Based Science, Hypothesis Testing: Observations leading
weak attractions, ionic bonds = electron transfer, covalent bonds =
to conclusions vs. making and testing predictions.
electron sharing.
Scientific Method: Observation → Question → Hypothesis →
Polar covalent bonds, nonpolar covalent bonds: Polar = unequal
Experiment → Data → Conclusion.
electron sharing (water), nonpolar = equal sharing (oxygen gas).
Independent vs. Dependent Variables: Independent – changed
Chemical reactions: Reactants form products by breaking and
factor; Dependent – measured outcome.
forming bonds; obeys conservation of mass.
Control Variable, Controlled Environment: Constant factors; stable
Water properties, hydrophobic, hydrophilic, amphipathic molecules:
experimental conditions.
Hydrophobic = water-repelling (oil), hydrophilic = water-loving
(salt), amphipathic = both (soap).
Micelle formation: Amphipathic molecules (like soap) form spheres in
Mono-, di-, oligo-, poly-saccharide: Mono (one sugar), Di (two
water with hydrophobic tails inward, hydrophilic heads outward.
sugars), Oligo (3-10 sugars), Poly (many sugars, e.g., starch,
Colligative properties of water, freezing point, boiling point:
cellulose).
Colligative properties depend on solute amount, freezing point
Lipid properties, Saturated vs unsaturated fat; ester linkages: Lipids
lowers, boiling point increases with solutes.
are hydrophobic; saturated fats (no double bonds, solid),
Acid, base, pH of solution, buffer, examples: Acid (H⁺ donor, pH <
unsaturated fats (double bonds, liquid); ester linkages join fatty
7), Base (H⁺ acceptor, pH > 7), Buffer resists pH change (e.g., blood
acids to glycerol.
bicarbonate system).
Trans fat, omega-3 fatty acids: Trans fats are artificially
CH 3 ORGANIC MOLECULES
hydrogenated, omega-3s are essential for brain/heart health.
Properties of carbon and organic molecules: Carbon forms four
Lipid CH bond, examples/steroids/waxes etc, glycerol, fatty acids:
covalent bonds, making it the backbone of organic molecules.
Lipids have C-H bonds for energy; steroids (cholesterol), waxes
Dehydration, condensation, hydrolysis reactions:
(beeswax), glycerol + fatty acids form triglycerides.
Dehydration/condensation joins monomers by removing water;
Properties of phospholipid bilayers, amphipathic, lipoproteins:
hydrolysis breaks polymers by adding water.
Phospholipids are amphipathic (hydrophilic heads, hydrophobic
Functional groups, R group interactions: Functional groups (e.g.,
tails), forming membranes; lipoproteins transport fats in the body.
hydroxyl, carboxyl) determine molecule properties; R groups affect
Fluid mosaic model of the membrane: Membrane is flexible (fluid)
protein folding.
with embedded proteins and lipids (mosaic) allowing movement
Monomers, polymers, bonds, tests: Monomers (single units) form
and function.
polymers via covalent bonds; tests detect macromolecules (e.g.,
Protein properties: CHON, amino acids, nitrogen, examples:
Benedict’s for sugars).
Proteins contain C, H, O, N, built from amino acids (e.g., enzymes,
MACROS: carbohydrates, lipids, proteins, nucleic acids: Four main
hemoglobin).
biological macromolecules, essential for energy, structure, and
Interaction of R groups: R groups influence protein folding
function.
(hydrophobic, hydrophilic, charged interactions).
Carb Properties: mono- di-saccharide, glycosidic bonds:
Positive/Negatively charged hydrophilic amino acid side chains:
Monosaccharides (glucose), disaccharides (sucrose), joined by
Positively charged (lysine, arginine), negatively charged
glycosidic bonds.
(aspartate, glutamate) interact with water.
Chemical structures of carbs, Chemical formula of a carb: General
Polar uncharged amino acid side chains: Hydrophilic but neutral
formula (CH₂O)n; structures include linear or ring forms (e.g.,
(serine, threonine, asparagine, glutamine).
glucose, fructose).
Nonpolar hydrophobic side chains: Avoid water, found in
membranes (leucine, valine, phenylalanine).
Special cases of amino acids (Cysteine, Glycine, Proline): Cysteine
(disulfide bonds), Glycine (smallest, flexible), Proline (rigid, disrupts
structure).
Polypeptide formation, Oligopeptide: Polypeptides form by peptide
bonds between amino acids; oligopeptide = short chain (2-20
amino acids).
5 factors of protein folding & stability: Hydrogen bonds, ionic
bonds, hydrophobic interactions, van der Waals forces,
disulfide bonds.
Protein structure: primary, secondary, tertiary, quaternary structure:
Primary (amino acid sequence), Secondary (alpha-helix, betasheet), Tertiary (3D folding), Quaternary (multiple polypeptides).
Conditions affecting secondary/tertiary structure; denature: Heat, pH,
chemicals disrupt folding, causing loss of function (denaturation).
Nucleic acid properties: nucleotides, phosphate, sugar, base:
Nucleotides contain phosphate, sugar (ribose or deoxyribose),
nitrogenous base (A, T, G, C, U).
DNA vs RNA Table: DNA (double-stranded, thymine, deoxyribose),
RNA (single-stranded, uracil, ribose).
Comparison of DNA strand vs RNA strand properties: DNA stores
genetic info, RNA transmits it for protein synthesis.
Phosphodiester bond vs hydrogen bond: Phosphodiester bonds
join nucleotides (sugar-phosphate backbone), hydrogen bonds hold
DNA strands together (A-T, G-C).
Nucleotides of DNA vs RNA: DNA (A, T, G, C), RNA (A, U, G, C).
Sugar backbone of DNA vs RNA: DNA has deoxyribose, RNA has
ribose (extra oxygen).