biology exam

Chemical evolution — Formation of organic molecules from nonliving chemicals.

Chemical selection — Certain molecules became more stable and common in early Earth.

RNA world — Hypothesis that RNA was first genetic material before DNA.

Liposomes — Small membrane-bound spheres formed from lipids.

Ribozymes — RNA molecules that act as enzymes.

Endosymbiosis theory — Mitochondria and chloroplasts evolved from engulfed bacteria.

Binary fission — Asexual reproduction method of prokaryotes.

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II. Microscopy

Microscope — Tool used to view small objects.

Micrograph — Image taken through a microscope.

Magnification — Makes objects appear larger.

Resolution — Ability to distinguish two objects as separate.

Contrast — Difference in light to see structures clearly.

Transmission electron microscopy (TEM) — Shows internal cell structure.

Scanning electron microscopy (SEM) — Shows surface structure in 3D.

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III. Basic Cell Types

Cell theory —

1. All organisms are made of cells

2. Cells are the basic unit of life

3. Cells come from pre-existing cells

Prokaryotic cells — Cells without nucleus (Bacteria, Archaea).

Bacteria — Domain of simple prokaryotic organisms.

Archaea — Prokaryotes distinct from bacteria.

Eukaryotes — Organisms with nucleus and membrane-bound organelles.

Genome — Complete genetic material of an organism.

Nuclear genome — DNA inside nucleus.

Mitochondrial genome — DNA in mitochondria.

Chloroplast genome — DNA in chloroplasts.

Proteome — All proteins expressed by a cell.

Differential gene regulation — Different genes expressed in different cells.

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IV. Prokaryotic Cell Structures

Plasma membrane — Selective barrier around cell.

Cytoplasm — Interior contents of cell.

Cytosol — Fluid inside cell.

Ribosomes — Protein synthesis.

Cell wall — Rigid outer layer.

Glycocalyx — Sticky outer coating.

Pili — Hair-like structures for attachment.

Flagella — Long tail for movement.

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V. Eukaryotic Cell Organization

Organelle — Membrane-bound structure with specific function.

Compartmentalization — Separation of cellular processes into organelles.

Liquid-liquid phase separation — Formation of membrane-less compartments.

Droplet organelles — Temporary membrane-less organelles.

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VI. Cytoskeleton & Movement

Cytoskeleton — Network of protein fibers for shape and movement.

Microtubules — Largest cytoskeletal fibers.

Intermediate filaments — Provide strength.

Actin filaments (microfilaments) — Smallest fibers; movement.

Dynamic instability — Rapid growth and shrinking of microtubules.

Microtubule organizing center (MTOC) — Region where microtubules form.

Centrosome — Main MTOC in animal cells.

Centrioles — Structures inside centrosome.

Motor proteins — Proteins that move along cytoskeleton.

Axoneme — Internal structure of cilia and flagella.

Basal bodies — Anchor cilia and flagella.

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VII. Nucleus

Nucleus — Stores DNA.

Nuclear envelope — Double membrane around nucleus.

Nuclear pores — Openings allowing transport.

Chromosomes — DNA molecules carrying genes.

Chromatin — DNA + protein complex.

Chromosome territories — Specific nuclear regions for chromosomes.

Nucleolus — Makes ribosomal RNA.

Nuclear matrix — Structural framework in nucleus.

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VIII. Endomembrane System

Endomembrane system — Network including ER, Golgi, vesicles.

Vesicles — Membrane-bound transport sacs.

Cisternae — Flattened membrane sacs in ER and Golgi.

Endoplasmic reticulum (ER) — Membrane network for synthesis.

ER lumen — Interior space of ER.

Rough ER — Has ribosomes; makes proteins.

Smooth ER — Makes lipids; detoxifies.

Golgi apparatus — Modifies and sorts proteins.

Protein sorting — Directing proteins to correct location.

Sorting signals — Amino acid sequences guiding proteins.

Cotranslational sorting — Sorting during protein synthesis.

Post-translational sorting — Sorting after synthesis.

Secretory pathway — Path proteins take for secretion.

Secretory vesicles — Vesicles carrying proteins out of cell.

Secretion — Release of substances from cell.

Proteases — Enzymes that break down proteins.

Lysosomes — Digestive organelles.

Acid hydrolysis — Breakdown using acidic conditions.

Vacuoles — Storage organelles.

Central vacuole — Large vacuole in plants.

Contractile vacuoles — Pump excess water out.

Peroxisomes — Break down fatty acids and toxins.

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IX. Energy Organelles

Mitochondrion — Produces ATP through cellular respiration.

ATP — Cell’s energy currency.

Chloroplast — Site of photosynthesis.

Photosynthesis — Converts light energy to chemical energy.

Thylakoid membrane — Membrane inside chloroplast where light reactions occur.

Granum — Stack of thylakoids.

Stroma (you wrote “Storma”) — Fluid inside chloroplast.

Plastids — Plant organelles (chloroplasts are one type).

Proplastids — Precursors to plastids.

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X. Extracellular Structures

Extracellular matrix (ECM) — Network outside animal cells for support.

Collagen — Structural protein in ECM.

Elastin — Provides elasticity.

Adhesive proteins — Help cells stick together.

Structural proteins — Provide support.

Glycosaminoglycan — Long carbohydrate chains in ECM.

Proteoglycan — Protein + carbohydrate complex in ECM.

Cell wall — Rigid layer outside plasma membrane.

Primary cell wall — Flexible plant cell wall.

Secondary cell wall — Thick rigid layer inside primary wall.

Cellulose — Main structural polysaccharide in plants.

Hemicellulose — Supports cellulose fibers.

Pectins — Help bind plant cells.

Chitin — Structural polysaccharide in fungi.

Glycan — Carbohydrate chain.

Polysaccharides — Long chains of sugars.

Biochemistry — Study of the chemistry of living organisms.

Organic molecules — Molecules that contain carbon.

Carbon — Element with 4 valence electrons; forms 4 covalent bonds and builds life’s backbone.

Carbon atoms — Can bond in chains, branches, and rings.

Hydrocarbon — Molecule made only of carbon and hydrogen.

Functional groups — Groups of atoms attached to carbon that determine molecule behavior.

Macromolecules — Large biological molecules made from smaller units.

Monomers — Small building blocks.

Polymers — Large molecules made of repeating monomers.

Condensation reaction — Reaction that joins molecules together.

Dehydration reaction — Builds polymers by removing water.

Hydrolysis reaction — Breaks polymers by adding water.

Carbohydrates — Sugars and sugar polymers used for energy and structure.

Monosaccharides — Single sugar units (glucose).

Isomers — Same molecular formula, different structure.

Disaccharides — Two sugars bonded together.

Glycosidic bond — Bond between sugar molecules.

Starch — Plant energy storage polysaccharide.

Glycogen — Animal energy storage polysaccharide.

Cellulose — Structural support in plant cell walls.

Peptidoglycans — Structural support in bacterial cell walls.

Chitin — Structural support in fungi and insect exoskeletons.

Glycosaminoglycans — Polysaccharides in connective tissue.

Lipids — Nonpolar molecules used for energy storage and membranes.

Triglycerides — Glycerol + 3 fatty acids; long-term energy storage.

Saturated fatty acids — No double bonds; straight chains; solid at room temp.

Phospholipids — Amphipathic lipids that form cell membranes.

Amphipathic — Has hydrophilic (water-loving) and hydrophobic (water-fearing) parts.

Steroids — Lipids with four fused carbon rings (example: cholesterol).

Waxes — Lipids used for waterproofing and protection.

Proteins — Polymers made of amino acids; perform most cellular functions.

Amino acid — Building block of proteins.

Peptide bond — Bond between amino acids.

Polypeptide — Chain of amino acids.

N-terminus — Start of polypeptide (amino end).

C-terminus — End of polypeptide (carboxyl end).

Primary structure — Amino acid sequence.

Secondary structure — Local folding (alpha helix or beta pleated sheet).

Alpha helix — Spiral protein structure.

Pleated sheet — Folded sheet protein structure.

Tertiary structure — Overall 3D shape of one polypeptide.

Protein subunits — Individual polypeptide chains.

Quaternary structure — Structure formed by multiple subunits.

Disulfide bridge — Covalent bond between sulfur atoms stabilizing protein shape.

Protein interactions — Hydrogen bonds, ionic bonds, hydrophobic interactions stabilizing structure.

Domains — Functional regions within a protein.

Nucleic acid — Polymer that stores genetic information.

DNA — Deoxyribonucleic acid; stores genetic instructions.

RNA — Ribonucleic acid; helps make proteins.

Nucleotide — Building block of nucleic acids (sugar + phosphate + base).

Base (nitrogenous base) — Nitrogen-containing molecule in DNA/RNA.

Deoxyribose — Sugar in DNA.

Ribose — Sugar in RNA.

Purine — Double-ring base (adenine, guanine).

Adenine — Purine base (A).

Guanine — Purine base (G).

Pyrimidine — Single-ring base (cytosine, thymine, uracil).

Cytosine — Pyrimidine base (C).

Thymine — Pyrimidine base in DNA.

Uracil — Pyrimidine base in RNA.

Double helix — Twisted ladder shape of DNA.

Matter — Anything that has mass and takes up space.

Atom — Smallest unit of an element that keeps its properties.

Element — Pure substance made of only one type of atom.

Molecule — Two or more atoms chemically bonded together.

Compound — Substance made of two or more different elements bonded together.

Protons — Positively charged particles in the nucleus.

Neutrons — Neutral particles in the nucleus.

Electrons — Negatively charged particles that move around the nucleus.

Orbitals — Regions around the nucleus where electrons are most likely found.

Electron shell — Energy level where electrons are located.

Valence electrons — Electrons in the outermost shell; involved in bonding.

Electron configuration rules — Rules that determine how electrons fill energy levels (lowest energy first).

Electroneutrality — Total positive charge equals total negative charge in a neutral atom.

Atomic number — Number of protons in an atom.

Dalton — Unit used to measure atomic mass (atomic mass unit).

Mole — 6.02 × 10²³ particles of a substance.

Molecular mass — Sum of the atomic masses of all atoms in a molecule.

Isotopes — Atoms of the same element with different numbers of neutrons.

Radioisotopes — Unstable isotopes that release radiation.

Trace elements — Elements required in very small amounts for life.

Energy — Ability to do work or cause change.

Octet rule — Atoms tend to gain, lose, or share electrons to have 8 in their outer shell.

Covalent bond — Bond formed when atoms share electrons.

Double bond — Two pairs of electrons shared between atoms.

Ionic bond — Bond formed when electrons are transferred from one atom to another.

Electronegativity — Ability of an atom to attract electrons toward itself.

Nonpolar covalent bond — Equal sharing of electrons.

Polar covalent bond — Unequal sharing of electrons.

Polar molecule — Molecule with partial positive and negative ends.

Nonpolar molecule — Molecule with no charge separation.

Hydrogen bond — Weak attraction between a slightly positive hydrogen and a slightly negative atom.

Van der Waals dispersion forces — Weak temporary attractions between molecules.

Chemical reaction — Process that changes reactants into products.

Reactants — Starting materials in a chemical reaction.

Products — Substances formed in a chemical reaction.

Catalyst — Substance that speeds up a reaction without being used up.

Enzyme — Biological catalyst (usually a protein).

Activation energy — Minimum energy required to start a chemical reaction.

Chemical equilibrium — State when forward and reverse reactions occur at equal rates.

Reversible reaction — Reaction that can go forward and backward.

Hydrolysis — Breaking a chemical bond by adding water.

Solute — Substance that is dissolved.

Solvent — Substance that does the dissolving.

Solution — Homogeneous mixture of solute and solvent.

Aqueous solution — Solution in which water is the solvent.

Concentration — Amount of solute in a given amount of solution.

Molar — Unit meaning moles per liter (M).

Molarity — Number of moles of solute per liter of solution.

Colligative properties — Properties that depend on the number of dissolved particles, not their identity.

Hydrophilic — Attracted to water.

Hydrophobic — Repelled by water.

Amphipathic — Has both hydrophilic and hydrophobic parts.

Micelles — Spherical structures formed when amphipathic molecules arrange in water.

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Cohesion — Attraction between molecules of the same substance.

Adhesion — Attraction between different substances.

Surface tension — Resistance of a liquid’s surface to breaking due to cohesion.

Heat of vaporization — Amount of energy needed to turn liquid into gas.

Heat of fusion — Amount of energy needed to turn solid into liquid.

Specific heat — Amount of heat needed to raise 1 gram of a substance by 1°C.

Heat capacity — Total amount of heat needed to raise an object’s temperature.

Evaporation — Process of liquid turning into gas.

Hydroxide ion (OH⁻) — Negatively charged ion that makes a solution basic.

Strong acid — Acid that completely dissociates in water.

Weak acid — Acid that partially dissociates in water.

Base — Substance that accepts hydrogen ions (H⁺) or releases hydroxide ions.

Acidic — Having a pH less than 7.

Alkaline (Basic) — Having a pH greater than 7.

Buffers — Substances that resist changes in pH.

Biology — Study of life.

Science — A systematic way of gaining knowledge about the natural world.

Knowledge — Information gained through observation, testing, and reasoning.

Scientific method — Process used to investigate questions through observation, hypothesis, experimentation, and conclusion.

Discovery-based science — Collecting and analyzing data without a specific hypothesis first.

Hypothesis testing — Making a testable explanation and designing experiments to test it.

Hypothesis — A testable explanation for an observation.

Prediction — Expected result if a hypothesis is correct.

Falsifiable — A hypothesis must be able to be proven wrong.

Theory — Broad explanation supported by large amounts of evidence.

Repeatable — Experiments must be able to be repeated with similar results.

Experimental group — Group exposed to the variable being tested.

Model organisms — Species widely studied to understand biological processes (ex: mice, fruit flies).

Model-based learning — Using models to understand complex biological systems.

II. Characteristics of Life

Cell — Simplest unit of life.

Organism — A living thing that maintains internal order and is separate from the environment.

Unicellular — Made of one cell.

Multicellular — Made of many cells.

Cell theory —

1. All living organisms are made of cells.

2. Cells are the smallest unit of life.

3. New cells come from pre-existing cells.

Metabolism — Sum of all chemical reactions in an organism.

Catabolism (you wrote “Catalism”) — Breakdown of molecules to release energy.

Anabolism — Building up of molecules using energy.

Cellular respiration — Process cells use to break down organic molecules to produce energy.

Photosynthesis — Process by which light energy is captured and used to make organic molecules.

Homeostasis — Maintaining stable internal conditions.

Reproduction — Process of producing offspring.

DNA — Molecule that stores genetic information.

Genes — Segments of DNA that determine traits.

Heritable — Trait that can be passed from parent to offspring.

RNA — Molecule that helps convert DNA instructions into proteins.

Protein — Functional molecule made of one or more polypeptides.

Polypeptide — Chain of amino acids.

III. Evolution

Evolution — Heritable changes in a population over generations.

Mutation — Change in genetic material.

Natural selection — Individuals with beneficial traits survive and reproduce more successfully.

Adaptation — Trait that improves survival and reproduction in an environment.

Vertical evolution — Evolution from parent to offspring over generations.

Horizontal gene transfer — Organism receives genetic material from another organism that is not its parent.

Emergent properties — New characteristics that arise from complex interactions.

IV. Classification & Diversity of Life

Taxonomy — Study of classifying organisms.

Domain — Largest taxonomic category.

Bacteria — Domain of prokaryotic microorganisms.

Archaea (you wrote “Arches”) — Domain of prokaryotes distinct from bacteria.

Domain containing eukaryotic organisms.

Eukaryotic — Cells with nucleus and membrane-bound organelles.

Supergroup — Large grouping within domain Eukarya.

Binomial nomenclature — Two-part scientific naming system (Genus species).