Biology 1111 Test 1 Comprehensive Review

Vocabulary practice flashcards covering Chapters 1, 3, 4 (Parts A & B), and 5 review concepts for Biology 1111 Test 1.

Hierarchy of Biological Complexity

The ordered levels of structural organization in biology, listed in increasing size: atoms, molecules, organelles, cells, tissues, organs, organ systems, organisms, populations, communities, ecosystems, and the biosphere.

Metabolism

The sum of all biochemical reactions that occur within an organism, such as cellular respiration and photosynthesis.

Autotroph

An organism capable of producing its own organic food molecules from inorganic sources, such as plants, algae, and cyanobacteria.

Heterotroph

An organism that obtains energy and organic nutrients by consuming other living or once-living organisms, such as animals and fungi.

Homeostasis

The process by which an organism maintains a stable internal environment despite fluctuations in external conditions, such as maintaining constant body temperature.

Three Domains of Life

The top-level biological classification scheme that divides all living organisms into Domain Bacteria, Domain Archaea, and Domain Eukarya.

Domain Archaea

A domain of single-celled prokaryotic organisms that lack a nucleus and membrane-bound organelles, differing chemically from bacteria in cell wall and membrane structure, often surviving in extreme environments.

Domain Bacteria

A domain of unicellular prokaryotic organisms that lack a nucleus and membrane-bound organelles, possessing peptidoglycan in their cell walls.

Four Kingdoms of Eukarya

The major eukaryotic taxonomic kingdoms under Domain Eukarya: Protista, Fungi, Plantae, and Animalia.

Cell Theory

A fundamental principle of biology stating that all living organisms are composed of cells, cells are the basic unit of life, and all cells arise from pre-existing cells.

Prokaryotic Cell

A smaller, structurally simple cell that lacks a membrane-bound nucleus and membrane-bound organelles, characteristic of Bacteria and Archaea.

Eukaryotic Cell

A larger, structurally complex cell containing a membrane-bound nucleus and specialized membrane-bound organelles, characteristic of protists, fungi, plants, and animals.

Endomembrane System

A group of interconnected cellular membranes and organelles—including the nuclear envelope, endoplasmic reticulum, Golgi complex, lysosomes, vesicles, and plasma membrane—that function together to produce, modify, package, and transport lipids and proteins.

Nucleus

The double-membrane organelle in eukaryotic cells that encloses the genetic material (DNA) and coordinates cellular activities.

Nuclear Envelope and Pores

The double-membrane boundary surrounding the nucleus containing nuclear pores that regulate the traffic of proteins, RNA, and macromolecules between the nucleus and cytoplasm.

Ribosome

A cellular structure composed of protein and ribosomal RNA that serves as the site of protein synthesis in both prokaryotic and eukaryotic cells.

Rough Endoplasmic Reticulum

A region of the endomembrane system coated with ribosomes on its cytosolic surface, giving it a rough appearance, involved in the synthesis and folding of proteins.

Smooth Endoplasmic Reticulum

A membrane network lacking surface ribosomes that participates in lipid synthesis, phospholipid production, steroid synthesis, and cell detoxification.

Golgi Complex

A series of flattened membranous sacs in eukaryotic cells that receives, modifies, sorts, and packages proteins and lipids into vesicles for secretion or delivery to other organelles.

Lysosome

A specialized membrane-bound organelle containing digestive hydrolytic enzymes found in animal cells to break down cellular waste, debris, and foreign material.

Central Vacuole

A large central membrane-bound organelle in plant cells that stores water and dissolved nutrients, maintaining cell turgor pressure.

Centrioles

Organelles found in animal cells, but absent in plant cells, that play a key role in organizing microtubule assembly during cell division.

Chloroplast

A double-membrane organelle present in plant cells and algae that contains chlorophyll pigments and carries out photosynthesis.

Mitochondria

Membrane-bound metabolic organelles in eukaryotic cells that conduct cellular respiration to produce adenosine triphosphate ($ATP$).

Flagellum

A long, whip-like surface projection used by prokaryotic and eukaryotic cells for cell locomotion.

Oxidation-Reduction Reaction

A chemical reaction involving the transfer of one or more electrons from a reducing reactant to an oxidizing reactant.

Oxidation

The chemical process in which a reactant loses one or more electrons.

Reduction

The chemical process in which a reactant gains one or more electrons, resulting in a reduction (decrease) of its net electrical charge.

Enzyme

A catalytic protein molecule that increases the speed of specific biochemical reactions by lowering activation energy, depending on a precise three-dimensional active site shape to fit its substrate.

Denaturation

The structural alteration and loss of catalytic functionality of an enzyme when exposed to conditions outside its optimal temperature and pH range.

Biochemical Pathway

A linked sequence of cellular chemical reactions where the product of each step acts as the substrate for the subsequent step, with each reaction requiring a dedicated enzyme.

Diffusion

The passive movement of solute particles or molecules down their concentration gradient, moving from a region of higher concentration to lower concentration.

Osmosis

The passive movement of water molecules across a selectively permeable membrane from an area of higher water concentration to an area of lower water concentration.

Isotonic Solution

A solution having an identical solute concentration relative to the cytosol of a cell, preventing net water gain or loss and keeping blood cells intact without shrinking or swelling.

Hypotonic Solution

A solution containing a lower solute concentration (and higher water concentration) than the inside of a cell, causing water to diffuse into the cell and potentially causing it to swell or burst.

Hypertonic Solution

A solution containing a higher solute concentration (and lower water concentration) than the inside of a cell, causing water to flow out of the cell and leading to cellular shrinkage.

Facilitated Diffusion

A form of passive membrane transport that uses transmembrane carrier or channel proteins to transport polar or charged substances (such as glucose or ions) across the cell membrane down their concentration gradient without requiring cellular energy.

Active Transport

An energy-requiring membrane process where the cell consumes adenosine triphosphate ($ATP$) to pump molecules against their concentration gradient, from an area of low concentration to high concentration.

Sodium-Potassium Pump

A specific membrane-bound active transport protein pump that uses cellular $ATP$ energy to transport sodium ions out of the cell and potassium ions into the cell against their respective concentration gradients.

Endocytosis

An active cellular transport process in which the cell membrane folds inward to form vesicles, capturing extracellular materials and bringing them inside the cell.

Exocytosis

An active transport mechanism in which intracellular vesicles fuse with the cell plasma membrane to export cellular products, hormones, or metabolic wastes outside the cell.

Photosynthetic Organisms

Organisms capable of transforming solar light energy into chemical energy, including land plants, algae, and photosynthetic prokaryotes like cyanobacteria.

Visible Light Spectrum

The specific wavelengths of solar electromagnetic radiation absorbed by plant pigments (such as chlorophyll) and utilized in photosynthesis.

Chemical Equation for Photosynthesis

The chemical reaction formula $6CO_2 + 6H_2O \rightarrow C_6H_{12}O_6 + 6O_2$, where carbon dioxide ($CO_2$) and water ($H_2O$) are reactants, and glucose ($C_6H_{12}O_6$) and oxygen ($O_2$) are products.

Photolysis of Water

The photosynthetic process in plant thylakoids where water ($H_2O$) molecules taken in by the plant are split, releasing oxygen gas ($O_2$) into the environment.

Calvin Cycle

The carbon reactions of photosynthesis in which inorganic carbon dioxide ($CO_2$) gas is fixed into an organic carbon backbone to ultimately produce sugar molecules like glucose.