General Biology Chapters 1–4 Vocabulary Flashcards

Vocabulary flashcards covering key terms and definitions from Chapters 1 through 4 of General Biology.

Characteristics of Living Things

Organized; acquire material and energy; homeostasis; respond to the environment; reproduce and develop; adapt.

Levels of Biological Organization

Atom → molecule → cell → tissue → organ → organ system → organism → species → population → community → ecosystem → biosphere.

Emergent Property

A function or trait that emerges as biological complexity increases.

Taxonomic Hierarchy

Domain → Kingdom → Phylum → Class → Order → Family → Genus → Species (from most inclusive to most exclusive).

Binomial Nomenclature

The universal scientific naming system using Genus + species. Scientific names are italicized or underlined.

Three Domains of Life

Archaea, Bacteria, and Eukarya.

Prokaryotic vs. Eukaryotic Cells

Prokaryotic cells do not have a membrane-bound nucleus; eukaryotic cells do.

Scientific Method

Observation → hypothesis → experiment/observation → conclusion.

Hypothesis

A testable possible explanation that predicts an outcome.

Experimental Variable

The thing that is changed in an experiment.

Control Variables

Things that are kept the same during an experiment.

Control Group

The group in which everything stays the same for comparison.

Conclusion

A determination of whether the data support or do not support the hypothesis.

Matter

Anything that has mass and occupies space.

Subatomic Particles

Proton, neutron, and electron.

Proton

A subatomic particle in the nucleus with a $+1$ charge and a mass of about $1\,\text{AMU}$.

Neutron

A subatomic particle in the nucleus with a $0$ charge and a mass of about $1\,\text{AMU}$.

Electron

A subatomic particle in the electron shell with a $-1$ charge and a mass of about $0\,\text{AMU}$.

Atomic Number

The number of protons.

Mass Number

The number of protons + neutrons.

Atomic Mass

The average mass of an element's isotopes.

Isotopes

Atoms of the same element with different numbers of neutrons.

Octet Rule

Atoms are most stable when their valence shell is full.

Ionic Bond

A bond formed by electron transfer, creating oppositely charged ions that attract.

Covalent Bond

A bond in which atoms share electrons.

Nonpolar Covalent Bond

A covalent bond in which electrons are shared equally.

Polar Covalent Bond

A covalent bond in which electrons are shared unequally.

Electronegativity

The ability of an atom to attract electrons.

Hydrogen Bond

A weak attraction between slightly positive and slightly negative atoms of already-formed molecules.

Hydrophilic

Water-loving; polar molecules readily dissolve in water.

Hydrophobic

Water-fearing; nonpolar molecules do not readily dissolve in water.

pH

A measure of the amount of $\text{H}^+$ in a solution.

Acid

A substance that releases $\text{H}^+$ in water.

Base

A substance that adds $\text{OH}^-$ or decreases the $\text{H}^+$ ratio.

Buffer

A substance that resists pH changes by absorbing excess $\text{H}^+$ or $\text{OH}^-$.

Carbon Bonding

Carbon has four valence electrons and can bond with up to four other atoms, forming stable and varied carbon skeletons.

Functional Group

A cluster of specific atoms that reacts in a characteristic way and can change a molecule's chemical behavior.

Monomer

One subunit or building block of a larger molecule.

Polymer

A molecule made of many linked monomers.

Dehydration Reaction

A reaction that joins smaller units by removing water.

Hydrolysis

A reaction that uses water to break larger molecules into smaller pieces.

Carbohydrate Roles

Quick energy and structural support.

Structural Polysaccharides

Cellulose—plants; chitin—animals and fungi; peptidoglycan—bacteria.

Five Major Lipid Categories

Fats, oils, phospholipids, steroids, and waxes.

Fats

Lipids used for long-term energy storage and insulation in animals.

Oils

Lipids used for long-term energy storage in plants and seeds.

Phospholipids

Lipids that are major components of plasma membranes.

Steroid Functions

Membrane components such as cholesterol; sex hormones; and medicines.

Wax Functions

Protection and prevention of water loss.

Triglyceride

Glycerol + fatty acids; used for long-term energy storage.

Protein Functions

Structure, defense, enzymes, regulation, nutrient transport, and motion.

Polypeptide

A chain made of many amino acids linked by dehydration reactions.

Denatured Protein

A protein that has lost its natural 3D shape and therefore does not function.

Factors Affecting Protein Structure

pH and temperature.

Nucleotide

A single building block of a nucleic acid.

Nucleic Acid

A polymer made of nucleotides, such as DNA or RNA.

DNA vs. RNA

DNA: deoxyribose, A/G/T/C, double-stranded, stores genetic information. RNA: ribose, A/G/U/C, single-stranded, intermediate between DNA and protein.

ATP

Adenosine triphosphate; a high-energy molecule used to provide energy for cellular work.

ATP Energy Storage/Release

Its last two phosphate bonds are unstable/easily broken; ATP hydrolysis releases energy for cellular work.

Principles of Cell Theory

All organisms are made of cells; cells are the basic unit of structure/function; cells come only from preexisting cells.

Surface-Area-to-Volume Ratio

As a cell gets larger, volume increases faster than surface area, making exchange less efficient and limiting cell size.

Bacterial Cell Components

Cell envelope, cytoplasm/cell contents, and appendages.

Bacterial Plasma Membrane

Structure that separates the inside of the cell from the outside.

Bacterial Cell Wall

Structure that maintains cell shape and contains peptidoglycan.

Nucleoid

The region of a bacterial cell containing its single circular chromosome.

Bacterial Ribosomes

Organelles in bacteria that make proteins.

Bacterial Flagellum

A protein appendage used for motility/movement.

Fimbriae

Protein appendages used for adherence.

Conjugation Pilus

A protein appendage used to transfer DNA from cell to cell.

Endosymbiotic Theory

The theory explaining the origin of eukaryotic cells; mitochondria and chloroplasts resemble bacteria and have their own circular DNA and prokaryotic-sized ribosomes.

Nucleus

The membrane-bound organelle that contains DNA and defines a eukaryotic cell.

Ribosomes

Cellular structures that make proteins.

Endomembrane System

The nuclear envelope, ER, Golgi, and vesicles that communicate to make, modify, sort, and transport products.

Rough ER

Organelle with ribosomes that produces proteins.

Smooth ER

Organelle lacking ribosomes that produces lipids.

Golgi Apparatus

Organelle that modifies, sorts, and packages proteins and lipids into vesicles.

Lysosome

A membrane-bound vesicle with acidic hydrolytic enzymes that digests and recycles material.

Endocytosis

Movement of material into the cell.

Exocytosis

Movement of material out of the cell.

Plant Central Vacuole

Organelle that stores water, sugars, salts, pigments, toxins, nutrients, and waste; it also supports the cell.

Chloroplasts

Organelles that carry out photosynthesis, using sunlight to make sugar.

Mitochondria

Organelles that carry out cellular respiration and help produce ATP.

Cytoskeleton

A dynamic protein network that maintains cell shape and allows movement.

Actin

Long, thin, flexible protein fibers that help maintain shape and movement.

Microtubules

Hollow cylinders made of tubulin that help maintain shape and serve as tracks for vesicles.

MTOC in Animal Cells

The centrosome near the nucleus.

Centrosome

An animal-cell microtubule-organizing center containing two centrioles at right angles.

Centrioles

Short cylinders made of microtubules that are important in animal-cell division.

Universal Cell Structures

DNA, ribosomes, and a cell membrane.