Introductory Biology: Characteristics of Life, Cell Biology, and Transport

Comprehensive vocabulary flashcards covering basic biological principles, taxonomy, the scientific method, atomic structure and bonding, cell biology, organelles, and membrane transport processes.

Biology

The study of life.

Characteristics of Life

The criteria that must be met for something to be considered living: order/cellular structure, response to stimuli, reproduction, adaptation, growth, and a self-sustaining metabolism.

Chemical Level of Organization

The organizational level where atoms come together to form molecules that serve as the building blocks of life.

Cellular Level of Organization

The organizational level consisting of cells that contain organelles and act as the autonomous unit of life.

Tissue Level of Organization

The organizational level where tissues containing many types of cells perform a specific function in an organism.

Organ Level of Organization

The organizational level containing many types of tissues working together to perform a specific function.

Taxonomy

The science of how living things are classified and grouped together based on similarities.

Levels of Classification

The biological hierarchy ordered from most broad to most specific: kingdom, phylum, class, order, family, genus, species.

Kingdom Plantae

A kingdom of organisms characterized as autotrophs that make their own food and have a cell wall.

Kingdom Animalia

A kingdom of organisms characterized as heterotrophs that rely on other organisms for food and lack a cell wall.

Kingdom Fungi

A kingdom of organisms characterized as heterotrophs that possess a cell wall.

Kingdom Protista

A unique and diverse group of organisms that are typically unicellular and aquatic.

Binomial System of Naming

A two-part scientific naming convention consisting of a capitalized genus and a lowercase species, which is italicized when typed or underlined when handwritten.

Hypothesis

An educated guess required to begin an experiment in the scientific method.

Independent Variable

The variable being tested and investigated in a controlled experiment to observe its effect.

Dependent Variable

The variable measured as a result of an experiment.

Controlled Variables

All variables that remain constant throughout an experiment to isolate the effect of the variable of interest.

Control Group

The group of test subjects in an experiment that are not exposed to the independent variable.

Experimental Group

The group of test subjects in an experiment that are exposed to the independent variable.

Organic Compounds

Larger, more complex carbon-based compounds built upon a skeleton of carbon rings or chains.

ATP

An organic compound that serves as the energy currency of the cell.

Atom

The smallest unit of an element that retains that element's chemical properties, composed of protons, neutrons, and electrons.

Valence Shell

The outermost electron shell of an atom that determines how the atom behaves and combines with other atoms.

Covalent Bond

A chemical bond that results from the sharing of electrons between atoms.

Ionic Bond

A chemical bond that results from the stealing (transfer) of electrons between atoms.

Hydrogen Bond

A chemical bond resulting from the attraction between polar molecules that contain hydrogen.

Polar Compounds

Asymmetrical compounds with a positive end and a negative end that dissolve readily in water.

Nonpolar Compounds

Symmetrical compounds that share electrons equally and do not mix with water.

Prokaryotic Cells

Smaller, simpler cells lacking a true nucleus and membrane-bound organelles, possessing a single circular chromosome located in the nucleoid region.

Eukaryotic Cells

Larger, more complex cells containing a true, double membrane-bound nucleus housing multiple linear chromosomes, along with membrane-bound organelles.

Ribosomes

Nonmembranous organelles responsible for protein synthesis.

Cytoskeleton

A network composed of protein filaments that provides cell structure, anchors and moves organelles, and enables cellular movement and attachment.

Microtubules

Cytoskeletal elements that form the mitotic spindle and maintain cell shape.

Intermediate Filaments

Cytoskeletal elements that hold organelles in place and provide a structural framework for organelle movement.

Microfilaments

Cytoskeletal filaments that influence cell shape and allow for cellular movement such as cytoplasmic streaming and endocytosis.

Rough Endoplasmic Reticulum

A membranous organelle continuous with the nuclear membrane that contains ribosomes and serves as the site of protein synthesis.

Smooth Endoplasmic Reticulum

A membranous organelle continuous with the nuclear membrane that serves as the site of lipid synthesis.

Golgi Complex

An organelle that modifies, sorts, and packages products from the endoplasmic reticulum for use in the cell, transport to the cell membrane, or export.

Lysosome

A membrane-bound vesicle containing lysozyme, a hydrolytic enzyme responsible for digesting substances.

Mitochondria

The membranous organelle where cellular respiration occurs and ATP is generated.

Chloroplasts

Plant organelles that serve as the site of photosynthesis, using sunlight, water, and carbon dioxide to make food.

Central Vacuole

A large storage vesicle found in plant cells that stores substances such as water and starch.

Peroxisomes

Membranous vesicles responsible for lipid digestion and cellular detoxification.

Chromatin

The material inside the nucleus composed of DNA and its associated organizing proteins.

Nucleolus

The region within the nucleus where ribosomal subunits are synthesized.

Fluid Mosaic Model

The conceptual model of the cell membrane describing it as a dynamic phospholipid bilayer with laterally flowing components, embedded proteins, and cholesterol.

Phospholipid

A membrane lipid consisting of a polar, hydrophilic phosphate head and two nonpolar, hydrophobic fatty acid tails.

Passive Transport

The movement of substances along their concentration gradient (from high to low concentration) without expenditure of cellular energy.

Diffusion

The net movement of molecules from an area of high concentration to an area of low concentration driven by intrinsic kinetic energy until equilibrium is reached.

Facilitated Diffusion

A form of passive transport where integral membrane proteins provide a pathway for large or charged substances to move along their concentration gradient.

Osmosis

The diffusion of water across a semi-permeable membrane toward an area with a higher concentration of solutes.

Hypertonic

A solution that has a relatively higher concentration of solutes compared to another solution.

Hypotonic

A solution that has a relatively lower concentration of solutes compared to another solution.

Isotonic

A solution that has an equal solute concentration compared to another solution.

Hemolysis

The swelling and bursting of a red blood cell when placed in a hypotonic solution due to water rushing in.

Crenation

The shriveling of a red blood cell when placed in a hypertonic solution due to water leaving the cell.

Plasmolysis

The phenomenon in plant cells placed in a hypertonic solution where the cell membrane pulls away from the cell wall as water is lost.

Active Transport

Energy-requiring cellular processes that transport large or charged substances against their concentration gradient (from low to high concentration).

$Na^+/K^+$ Pump

A primary active transport protein that directly uses ATP to pump $Na^+$ ions out of the cell and $K^+$ ions into the cell against their concentration gradients.

Secondary Active Transport

Transport driven by the potential energy of an electrochemical gradient established by primary active transport, moving substances against their gradient without directly using ATP.

Endocytosis

An active transport process in which the cell engulfs very large substances by extending pseudopods and enclosing them into a vesicle.

Phagocytosis

A form of endocytosis specifically involving the cellular ingestion of solid particles.

Pinocytosis

A form of endocytosis specifically involving the cellular intake of liquids.

Exocytosis

An active transport process where large substances inside intracellular vesicles are ejected from the cell as vesicles fuse with the cell membrane.