General Biology Exam 1 Study Guide: Key Concepts and Terminology

Module 1: Foundations of Biology

Terminology

• Adaptive trait: A heritable characteristic that increases an organism's ability to survive and reproduce in a particular environment.

• Clinical trial: A research study conducted with human participants to evaluate the effects of medical, surgical, or behavioral interventions.

• Community: All the populations of different species that live and interact in a particular area.

• Confounding variable: An external factor that may affect the outcome of an experiment, making it difficult to determine the true relationship between variables.

• Control group: The group in an experiment that does not receive the experimental treatment and is used as a benchmark.

• Critical thinking: The objective analysis and evaluation of an issue to form a judgment.

• Deductive reasoning: Reasoning from general principles to specific cases.

• Double-blind experiment: An experiment in which neither the participants nor the experimenters know who is receiving a particular treatment.

• Ecosystem: A community of living organisms and their physical environment interacting as a system.

• Epidemiological study: Research investigating the patterns, causes, and effects of health and disease conditions in defined populations.

• Eukaryote: An organism whose cells contain a nucleus and other organelles enclosed within membranes.

• Experimental group: The group in an experiment that receives the variable being tested.

• Homeostasis: The maintenance of a stable internal environment despite changes in external conditions.

• Hypothesis: A testable statement or prediction about the natural world.

• Inductive reasoning: Reasoning from specific observations to broader generalizations.

• Information literacy: The ability to identify, locate, evaluate, and use information effectively.

• Informed consent agreement: A process by which a participant voluntarily confirms their willingness to participate in a study after being informed of all relevant aspects.

• Metabolism: The sum of all chemical reactions that occur within a living organism to maintain life.

• Placebo: A substance with no therapeutic effect, used as a control in testing new drugs.

• Population: A group of individuals of the same species living in a specific area.

• Prokaryote: An organism whose cells lack a nucleus and other membrane-bound organelles.

• Theory: A well-substantiated explanation of some aspect of the natural world based on a body of evidence.

Concepts

1. Characteristics of living things: Living organisms share traits such as organization, metabolism, homeostasis, growth, reproduction, response to stimuli, and adaptation.

2. Levels of organization: Biological organization ranges from atoms to molecules, cells, tissues, organs, organ systems, organisms, populations, communities, ecosystems, and the biosphere.

3. Clinical trial phases: Clinical trials are conducted in phases I (safety), II (efficacy), and III (comparison to current standard).

4. Correlation vs. causation: Correlation is a relationship between two variables, while causation indicates that one variable directly affects the other.

5. Classification of life: Life is classified into three domains: Bacteria, Archaea, and Eukarya. Eukarya is further divided into kingdoms such as Plantae, Animalia, Fungi, and Protista.

6. Scientific method: Steps include observation, hypothesis formation, experimentation, data collection, analysis, and conclusion.

Module 2: Chemistry of Life

Terminology

• Amino acids: Building blocks of proteins, each containing an amino group, carboxyl group, and a unique side chain.

• Base: A substance that decreases the hydrogen ion concentration in a solution.

• Buffer: A solution that resists changes in pH when acids or bases are added.

• Carbohydrates: Organic molecules composed of carbon, hydrogen, and oxygen; serve as energy sources and structural components.

• Covalent bond: A chemical bond formed by the sharing of electron pairs between atoms.

• Denaturation: The process in which proteins or nucleic acids lose their structure due to external stress or compounds.

• Electronegativity: The tendency of an atom to attract electrons in a chemical bond.

• Element: A substance that cannot be broken down into simpler substances by chemical means.

• Hydrogen bond: A weak bond between two molecules resulting from an electrostatic attraction between a proton and an electronegative atom.

• Ion: An atom or molecule with a net electric charge due to the loss or gain of electrons.

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

• Lipid: A group of organic compounds including fats, oils, and steroids, insoluble in water.

• Monomer: A small molecule that can join with others to form a polymer.

• Nucleotide: The building block of nucleic acids, consisting of a sugar, phosphate group, and nitrogenous base.

• Phospholipid: A lipid containing a phosphate group, a major component of cell membranes.

• Polysaccharide: A carbohydrate whose molecules consist of a number of sugar molecules bonded together.

• Protein: A molecule composed of amino acids linked by peptide bonds, performing a variety of functions in organisms.

• Saturated/unsaturated fatty acid: Saturated fatty acids have no double bonds between carbon atoms; unsaturated fatty acids have one or more double bonds.

• Solvent: The substance in which a solute dissolves to form a solution.

• Starch: A polysaccharide that functions as a carbohydrate storage molecule in plants.

• Tertiary structure: The overall three-dimensional structure of a polypeptide.

• Triglycerides: A type of fat found in the blood, composed of glycerol and three fatty acids.

Concepts

1. Atoms and elements: Atoms are the smallest units of matter; elements are pure substances consisting of one type of atom.

2. Atomic structure: Atoms consist of protons, neutrons, and electrons. The atomic number is the number of protons; the mass number is the sum of protons and neutrons.

3. Isotopes: Atoms of the same element with different numbers of neutrons. Some are radioactive and used in medical imaging.

4. Chemical bonds: Atoms form molecules via ionic, covalent, and hydrogen bonds.

5. Macromolecules: Carbohydrates, lipids, proteins, and nucleic acids are the four major classes of biological macromolecules.

6. Protein structure: Proteins have primary, secondary, tertiary, and quaternary structures.

7. DNA and ATP: DNA stores genetic information; ATP is the primary energy carrier in cells.

8. Skin cancer types: Basal cell carcinoma, squamous cell carcinoma, and melanoma differ in origin and severity.

Bond Type	Description	Example
Ionic	Transfer of electrons	NaCl
Covalent	Sharing of electrons	H2O
Hydrogen	Attraction between polar molecules	Between water molecules

Key Equations

• Atomic number: $\text{Atomic number} = \text{Number of protons}$

• Mass number: $\text{Mass number} = \text{Number of protons} + \text{Number of neutrons}$

• Charge of ion: $\text{Charge} = \text{Number of protons} - \text{Number of electrons}$

Module 3: The Cell

Terminology

• 9 + 2 pattern of microtubules: The arrangement of microtubules in cilia and flagella (nine pairs surrounding two central microtubules).

• Actin: A protein that forms microfilaments and is involved in cell movement and structure.

• ATP: Adenosine triphosphate, the main energy currency of the cell.

• Chloroplast: Organelle in plant cells where photosynthesis occurs.

• Cytoskeleton: A network of protein filaments that gives shape and support to cells.

• Endocytosis/exocytosis: Processes by which cells take in (endocytosis) or expel (exocytosis) materials.

• Facilitated diffusion: Movement of molecules across cell membranes through protein channels.

• Glycolysis: The breakdown of glucose to pyruvate, producing ATP.

• Lysosome: Organelle containing digestive enzymes.

• Mitochondria: Organelles that produce ATP through cellular respiration.

• Osmosis: Diffusion of water across a selectively permeable membrane.

• Phagocytosis/pinocytosis: Types of endocytosis; phagocytosis is "cell eating," pinocytosis is "cell drinking."

• Plasma membrane: The cell's outer membrane, composed of a phospholipid bilayer with embedded proteins.

• Ribosome: Organelle that synthesizes proteins.

• Rough/smooth endoplasmic reticulum: Rough ER has ribosomes and synthesizes proteins; smooth ER synthesizes lipids.

• Surface-to-volume ratio: The ratio of a cell's surface area to its volume, affecting the rate of diffusion.

Concepts

1. Plasma membrane structure: Composed of a phospholipid bilayer with embedded proteins, cholesterol, and glycoproteins; regulates entry and exit of substances.

2. Membrane-bound organelles: Eukaryotic cells contain organelles such as the nucleus, mitochondria, and Golgi apparatus, each with specialized functions.

3. Osmosis and tonicity: Cells can be hypertonic, hypotonic, or isotonic relative to their environment, affecting water movement.

4. Prokaryotic vs. eukaryotic cells: Prokaryotes lack a nucleus and membrane-bound organelles; eukaryotes have both.

5. Cellular respiration: Includes glycolysis, citric acid cycle, and electron transport chain; produces ATP.

6. Cell structure and function: The structure of a cell is closely related to its function (e.g., muscle cells have many mitochondria for energy).

Cell Type	Nucleus	Membrane-bound Organelles	Example
Prokaryote	No	No	Bacteria
Eukaryote	Yes	Yes	Plant, animal cells

Module 4: Tissues and the Integumentary System

Terminology

• Adipose tissue: Connective tissue that stores fat.

• Basement membrane: A thin layer of extracellular material underlying epithelial tissue.

• Connective tissue: Tissue that supports, binds, or separates other tissues and organs.

• Dermis: The thick layer of living tissue below the epidermis.

• Epidermis: The outermost layer of skin.

• Epithelial tissue: Tissue that covers body surfaces and lines cavities.

• Glands (endocrine/exocrine): Endocrine glands secrete hormones into the bloodstream; exocrine glands secrete substances through ducts.

• Homeostasis: The maintenance of stable internal conditions.

• Keratin: A protein that provides strength and waterproofing to skin, hair, and nails.

• Melanin: A pigment that gives skin its color and protects against UV radiation.

• Negative/positive feedback: Mechanisms that regulate physiological processes; negative feedback reverses a change, positive feedback amplifies it.

• Serous/mucous/synovial membranes: Serous membranes line body cavities; mucous membranes line passages open to the exterior; synovial membranes line joint cavities.

• Vitamin D: A vitamin produced in the skin in response to sunlight; important for calcium absorption.

Concepts

1. Organ systems: The human body is organized into systems (e.g., integumentary, muscular, nervous) with specific functions.

2. Organization: Cells form tissues, tissues form organs, organs form organ systems.

3. Types of epithelial and connective tissue: Epithelial tissue types include squamous, cuboidal, columnar (simple and stratified); connective tissue includes bone, cartilage, adipose, blood.

4. Skin structure: The skin consists of the epidermis, dermis, and subcutaneous layer; each has distinct functions.

5. Skin cancer: Basal cell carcinoma, squamous cell carcinoma, and melanoma differ in origin, appearance, and severity.

6. Acne: Caused by blocked hair follicles and sebaceous glands; types include whiteheads, blackheads, and cystic acne.

7. Membranes: Cutaneous (skin), mucous, serous, and synovial membranes have different locations and functions.

8. Nutrient delivery: Nutrients reach the epidermis by diffusion from blood vessels in the dermis.

9. Negative feedback in temperature regulation: Sensors detect temperature changes, the control center (hypothalamus) processes information, and effectors (sweat glands, blood vessels) respond to restore balance.

10. Cell types in skin: Squamous, cuboidal, columnar, stratified squamous, stratified cuboidal, stratified columnar cells have specific locations and functions.

11. Functions of the skin: Protection, temperature regulation, sensation, vitamin D synthesis, excretion.

Skin Layer	Main Components	Functions
Epidermis	Keratinocytes, melanocytes	Protection, waterproofing, UV defense
Dermis	Connective tissue, blood vessels, nerves	Support, nutrient supply, sensation
Subcutaneous	Adipose tissue	Insulation, energy storage