General Biology Study Guide: Core Concepts, Cell Structure, Biochemistry, and Ecology

Unit 1: The Study of Life and Biological Organization

1.1 Seven Properties Common to All Life

• Order: Living things are made of cells, the basic unit of life.

• Growth and Development: Organisms grow and develop according to specific instructions coded for by their genes.

• Response to Stimuli: All living things respond to environmental changes.

• Regulation (Homeostasis): Maintenance of internal balance (e.g., temperature, pH).

• Reproduction: Ability to produce offspring, passing genetic material to the next generation.

• Energy Processing (Metabolism): Obtain and use energy for survival.

• Evolutionary Adaptation: Populations evolve over generations through adaptations.

1.4 Qualitative vs. Quantitative Data

• Qualitative Data: Descriptive characteristics (e.g., color, texture).

• Quantitative Data: Numerical measurements (e.g., height, weight).

1.4 Interpreting Data in Graphs and Tables

• Ability to read and analyze graphical and tabular data is essential for scientific understanding.

1.4 Hypotheses, Theories, and Experimental Design

• Hypothesis: A testable explanation for an observation.

• Theory: A broad explanation supported by evidence.

• Control Group: Used for comparison; does not receive the experimental treatment.

• Experimental Group: Receives the treatment or variable being tested.

1.5 Variables in Controlled Experiments

• Independent Variable: The factor that is changed or manipulated.

• Dependent Variable: The factor that is measured.

1.5 Taxonomy and Classification

• Taxonomy: The science of classifying organisms.

• Hierarchical Classification: Kingdom, Phylum, Class, Order, Family, Genus, Species.

Level	Example
Kingdom	Animalia
Phylum	Chordata
Class	Mammalia
Order	Primates
Family	Hominidae
Genus	Homo
Species	Homo sapiens

1.14 Binomial Nomenclature

• Scientific names use Genus species format (e.g., Homo sapiens).

1.14 Abiotic vs. Biotic Factors

• Abiotic: Non-living components (e.g., sunlight, water, soil).

• Biotic: Living components (e.g., plants, animals).

1.14 Community Ecology

• Study of interactions among species in a community.

17.2 Interspecific Competition

• Occurs when two species compete for the same resources.

17.3 Ecological Niche

• The role and space an organism fills in an ecosystem.

Unit 2: The Chemical Basis of Life

2.1 Matter, Elements, and Compounds

• Matter: Anything that occupies space and has mass.

• Element: Substance that cannot be broken down chemically into simpler substances.

• Compound: Substance consisting of two or more elements in a fixed ratio.

2.3 Subatomic Particles

• Proton: Positive charge, found in nucleus.

• Neutron: No charge, found in nucleus.

• Electron: Negative charge, orbits nucleus.

2.3 Atomic Number, Mass Number, and Isotopes

• Atomic Number: Number of protons in an atom.

• Mass Number: Protons + neutrons.

• Isotopes: Atoms of the same element with different numbers of neutrons.

2.5 Electron Arrangement and Chemical Behavior

• Electron configuration determines how atoms interact and bond.

2.6-2.8 Covalent and Ionic Bonds

• Covalent Bond: Atoms share electrons (can be polar or nonpolar).

• Ionic Bond: Transfer of electrons from one atom to another.

• Hydrogen Bond: Weak attraction between a hydrogen atom and another electronegative atom.

2.6-2.8 Intramolecular vs. Intermolecular Bonds

• Intramolecular: Bonds within a molecule (e.g., covalent bonds).

• Intermolecular: Bonds between molecules (e.g., hydrogen bonds).

2.10-2.13 Properties of Water

• Cohesion: Water molecules stick together.

• Adhesion: Water molecules stick to other substances.

• High Specific Heat: Water resists temperature changes.

• Evaporative Cooling: Removes heat from surfaces.

• Solvent Properties: Water dissolves many substances.

2.11 Sweating and Cooling

• Evaporation of sweat removes heat, cooling the body.

2.13 Solutions, Solutes, and Solvents

• Solution: Homogeneous mixture.

• Solute: Substance dissolved.

• Solvent: Substance doing the dissolving (often water).

2.13 Solubility and Conductivity

• Substances that dissolve into ions (electrolytes) conduct electricity.

2.13 Electrolytes in Biology

• Electrolytes are essential for nerve function and muscle contraction (e.g., Na+, K+, Ca2+).

2.14 pH and Buffers

• pH: Measure of hydrogen ion concentration.

• Buffers help maintain stable pH in cells and body fluids.

Unit 3: The Molecules of Cells

3.1 Carbon's Versatility

• Carbon can form four covalent bonds, allowing for a diversity of organic molecules.

3.1 Organic Compounds and Functional Groups

• Organic compounds contain carbon skeletons and functional groups (e.g., hydroxyl, carboxyl, amino, phosphate).

3.1 Elements in Biomolecules

• CHNOPS: Carbon, Hydrogen, Nitrogen, Oxygen, Phosphorus, Sulfur are most common in living things.

3.3 Monomers and Polymers

• Monomer: Small building block molecule.

• Polymer: Large molecule made of repeating monomers.

3.3 Dehydration Synthesis and Hydrolysis

• Dehydration Synthesis: Joins monomers by removing water.

• Hydrolysis: Breaks polymers into monomers by adding water.

3.4-3.7 Carbohydrates

• Monosaccharides (simple sugars), disaccharides, polysaccharides (e.g., starch, glycogen, cellulose).

• Functions: Energy storage, structural support.

3.8-3.11 Lipids

• Fats, phospholipids, steroids.

• Functions: Energy storage, insulation, cell membranes.

3.10 Phospholipids

• Form bilayers in cell membranes due to hydrophilic heads and hydrophobic tails.

3.11 Steroids

• Cholesterol and hormones (e.g., testosterone, estrogen).

Unit 4: A Tour of the Cell

4.1 Cell Theory

• All living things are composed of cells.

• All cells come from pre-existing cells.

4.2 Plasma Membrane Structure and Function

• Phospholipid bilayer with embedded proteins; controls movement of substances in and out of the cell.

4.3-4.4 Prokaryotic vs. Eukaryotic Cells

• Prokaryotes: No nucleus, circular DNA, smaller (e.g., bacteria, archaea).

• Eukaryotes: Nucleus, linear DNA, larger (e.g., plants, animals, fungi, protists).

4.4 Plant vs. Animal Cells

• Plant cells have cell walls, chloroplasts, and large central vacuoles; animal cells do not.

4.5 Ribosomes

• Sites of protein synthesis; found in all cells.

4.7-4.12 Endomembrane System

• Includes nucleus, endoplasmic reticulum, Golgi apparatus, lysosomes, vacuoles, and plasma membrane.

4.13-4.14 Mitochondria and Chloroplasts

• Sites of cellular respiration and photosynthesis, respectively.

• Both have their own DNA and may have evolved via endosymbiosis.

Unit 5: The Working Cell

5.1-5.2 Membrane Structure and Function

• Phospholipid bilayer allows selective permeability.

• Hydrophobic tails and hydrophilic heads drive membrane formation.

5.3 Diffusion and Facilitated Diffusion

• Diffusion: Movement of particles from high to low concentration.

• Facilitated Diffusion: Uses transport proteins; no energy required.

5.4 Osmosis

• Diffusion of water across a selectively permeable membrane.

5.5 Tonicity

• Hypertonic Solution: Higher solute concentration outside cell; cell loses water.

• Hypotonic Solution: Lower solute concentration outside cell; cell gains water.

• Isotonic Solution: Equal solute concentration; no net water movement.

5.6 Active Transport

• Movement of substances against concentration gradient; requires energy (ATP).

5.7-5.8 Bulk Transport

• Exocytosis: Export of materials out of the cell.

• Endocytosis: Import of materials into the cell (includes phagocytosis, pinocytosis, receptor-mediated endocytosis).

Unit 6: How Cells Harvest Chemical Energy

5.12 ATP as Energy Shuttle

• ATP stores and transfers energy for cellular work.

5.13-5.15 Enzymes

• Enzyme: Protein catalyst that speeds up chemical reactions.

• Activation Energy: Energy required to start a reaction.

• Enzyme-Substrate Interaction: Substrate binds to enzyme's active site.

• Competitive Inhibition: Inhibitor binds to active site.

• Noncompetitive Inhibition: Inhibitor binds elsewhere, changing enzyme shape.

• Feedback Inhibition: End product inhibits an earlier step in the pathway.

Unit 34-38: Ecology and the Biosphere

Biogeochemical Cycles

• Movement of elements (e.g., carbon, nitrogen) through living and nonliving systems.

Food Chains and Food Webs

• Food Chain: Linear sequence of energy transfer.

• Food Web: Interconnected food chains in an ecosystem.

Energy Flow in Ecosystems

• Energy decreases at each trophic level; only a fraction is transferred upward.

Carbon Cycle

• Carbon moves between atmosphere, biosphere, hydrosphere, and lithosphere.

• Burning fossil fuels increases atmospheric CO2, contributing to global warming.

Global Warming and Climate Change

• Increased greenhouse gases (e.g., CO2) trap heat, raising Earth's temperature.

• Human activities (e.g., deforestation, burning fossil fuels) accelerate climate change.

Key Terms & Vocabulary

Term	Definition
Biogeochemical	Refers to interactions and cycles involving biological, geological, and chemical reactions
Hydrophilic	Substances that are attracted to and soluble in water
Hydrophobic	Substances that are not able to dissolve in water
Electrolyte	Substance that dissolves into positive and negative ions, allows for conductivity
Aqueous	Has a neutral pH; water is the solvent
Ocean Acidification	CO2 dissolving in seawater lowers the pH of the ocean
Tonicity	Ability to cause water to move in and out of cell by osmosis

Additional info: Some reference sheets and diagrams are mentioned but not included; students should consult their course materials for these visuals. This guide expands on brief points with academic context for clarity and completeness.