Essentials of Biology - Chapters 1-3 Review

Vocabulary flashcards covering key definitions and biological terms from Chapters 1 through 3 of Essentials of Biology (4th Edition).

Biology

The science that studies life, specifically living organisms and their interactions with one another and their environments.

Homeostasis

The maintenance of internal conditions within a narrow range almost constantly, despite environmental changes.

Metabolism

All chemical reactions occurring within a cell.

Cell

The structural and functional unit of all living things, and the smallest fundamental unit of structure and function in living organisms.

Tissue

A group of similar cells with a common structure and function.

Organ

A structure composed of tissues functioning together for a specific task.

Organ System

A group of organs working together within complex organisms.

Species

Organisms with similar structure that can interbreed and produce fertile offspring.

Population

A group of interbreeding individuals of the same species occupying the same area at the same time.

Community

Interacting populations in a particular area.

Ecosystem

A biological community together with the associated abiotic physical environment.

Biosphere

Regions of the Earth's crust, waters, and atmosphere inhabited by living things, formed by the collection of ecosystems.

Photosynthesis

The process by which solar energy is used to transform carbon dioxide and water into the chemical energy of food.

Adaptation

Inherited characteristics of an organism that enhance its survival and reproduction in a specific environment.

Evolution

The process of gradual change during which new species arise from older species.

Natural Selection

The mechanism for evolutionary change in which individuals with favorable traits survive and reproduce more prolifically under environmental changes.

Taxonomy

The discipline of naming and classifying organisms according to certain rules.

Systematics

The field that classifies organisms according to presumed evolutionary relationships.

Binomial Name

A two-part scientific name given to living organisms consisting of the genus name followed by the specific species name.

Domain Archaea

A domain of unicellular prokaryotes lacking a membrane-bound nucleus that often live in extreme aquatic environments lacking oxygen or being too salty, hot, or acidic.

Domain Bacteria

A domain of unicellular prokaryotes lacking a membrane-bound nucleus that are structurally simple, metabolically diverse, and found almost everywhere.

Domain Eukarya

A domain consisting of unicellular or multicellular organisms whose cells contain a membrane-bound nucleus.

Scientific Theory

An explanation for how the world works that is supported by hypotheses confirmed by many different studies, observations, and experiments.

Biodiversity

The variation in life on Earth, referring specifically to the number of different species.

Extinction

The death of an entire species or taxonomical group.

Electronegativity

An atom's affinity for shared electrons in a covalent bond.

Polar Bond

A covalent bond where electrons are shared unequally, causing atoms on both sides of the bond to bear partial charges.

Hydrophilic

Describes a polar substance that interacts readily with or dissolves in water.

Hydrophobic

Describes nonpolar compounds, such as oils and fats, that do not interact well with or dissolve in water.

Solvent

A substance capable of dissolving other polar molecules and ionic compounds.

Sphere of Hydration

A shell of surrounding water molecules formed around charged ions or polar particles that keeps them separated and dispersed in water.

Dissociation

The process that occurs when atoms or groups of atoms break off from molecules and form ions in solution.

Cohesion

The ability of water molecules to cling to each other due to hydrogen bonding.

Adhesion

The attraction between water molecules and other polar or charged molecules.

Capillary Action

The movement of water up a narrow tube occurring when adhesion to the tube walls is stronger than cohesive forces between water molecules.

Surface Tension

The capacity of a substance to withstand rupturing when placed under tension or stress due to cohesive hydrogen bonding.

Specific Heat

The amount of heat $1\,\text{g}$ of a substance must absorb or lose to change its temperature by $1^\circ\text{C}$.

Heat of Vaporization

The amount of energy required to change $1\,\text{g}$ of a liquid substance to a gas, requiring $586\,\text{cal}$ for water.

pH

A measure of hydrogen ion concentration in a solution, defined mathematically as $\text{pH} = -\log_{10}[H^+]$.

Acid

A substance that increases the concentration of hydrogen ions ($H^+$) in a solution and has a pH below $7$.

Base

A substance that provides hydroxide ions ($OH^-$) or accepts hydrogen ions ($H^+$), reducing their concentration and raising the solution's pH above $7$.

Buffer

A chemical or combination of chemicals that resists changes in pH by absorbing excess $H^+$ or $OH^-$ ions.

Acidosis

A condition in which the body is unable to buffer the excess production of $H^+$ ions, which can lead to coma or death if untreated.

Monomer

A simple subunit molecule that serves as a building block for biological polymers.

Polymer

A large biological molecule formed by linking many monomer subunits together.

Dehydration Synthesis Reaction

A chemical reaction that joins monomers into polymers by removing the equivalent of a water molecule.

Hydrolysis Reaction

A chemical reaction that breaks polymers apart into monomers by using water to break bonds.

Monosaccharide

A single sugar molecule containing $3\text{ to }7$ carbons in its backbone, such as glucose ($C_6H_{12}O_6$).

Disaccharide

A sugar molecule consisting of two monosaccharides bonded together, such as maltose or sucrose.

Polysaccharide

A complex carbohydrate polymer made up of many monosaccharide subunits bonded together.

Starch

An energy storage polysaccharide in plants composed of nonbranched or branched glucose subunits.

Glycogen

A highly branched energy storage polysaccharide in animals released by the liver under hormonal control.

Cellulose

The most abundant organic molecule on Earth; an unbranched structural polysaccharide in plant cell walls formed by parallel glucose chains held by hydrogen bonds.

Chitin

A structural polysaccharide polymer of glucose found in crab, lobster, and insect exoskeletons.

Triglyceride

A lipid composed of one glycerol molecule and three fatty acid chains, used for long-term energy storage.

Phospholipid

A membrane lipid consisting of a water-soluble polar phosphate head and two water-insoluble nonpolar fatty acid tails.

Steroid

A type of lipid derived from cholesterol that features a carbon skeleton of four fused rings with varying functional groups.

Kwashiorkor

A form of severe malnutrition in children caused by a protein-deficient diet, characterized by oedema and a protuberant belly.

Amino Acid

The monomer subunit of proteins, composed of a central carbon bonded to a hydrogen atom, an amino group, a carboxyl group, and a variable R-group.

Essential Amino Acids

The $9$ amino acids that human cells cannot synthesize and must be obtained through food.

Peptide Bond

A covalent amide bond formed between two amino acid monomers through a dehydration synthesis reaction.

Primary Structure of Protein

The specific sequence of amino acids in a protein determined by inherited genetic information.

Secondary Structure of Protein

The spatial coiling or folding of a polypeptide chain into an $\alpha$-helix or $\beta$-pleated sheet, stabilized by hydrogen bonds.

Tertiary Structure of Protein

The overall three-dimensional globular shape of a polypeptide chain formed by interactions among distant R-groups.

Quaternary Structure of Protein

The structural level of a protein that contains more than one polypeptide chain, such as hemoglobin.

Sickle Cell Disease

An inherited disorder caused by a single amino acid substitution from glutamate to valine in hemoglobin, leading to altered red blood cell shape and function.

Nucleotide

The monomer subunit of nucleic acids, consisting of a 5-carbon sugar, a phosphate group, and a nitrogen-containing base.

Deoxyribonucleic Acid (DNA)

A double-stranded helical nucleic acid containing deoxyribose sugar and storing genetic information in base pairs of adenine, thymine, cytosine, and guanine.

Ribonucleic Acid (RNA)

A single-stranded nucleic acid containing ribose sugar and the nitrogenous bases adenine, uracil, cytosine, and guanine.

Organic Molecule

A molecule containing carbon and hydrogen atoms that makes up portions of cells, tissues, and organs.

Inorganic Molecule

A molecule that does not contain both carbon and hydrogen atoms, such as water ($H_2O$) and table salt ($NaCl$).

Hydrocarbon

An organic molecule consisting entirely of carbon and hydrogen atoms.

Aliphatic Hydrocarbon

A hydrocarbon consisting of linear chains of carbon atoms.

Aromatic Hydrocarbon

A hydrocarbon consisting of closed rings of carbon atoms containing a benzene ring ($C_6H_6$) base.

Isomers

Molecules that share the same chemical formula but differ in the placement or structure of their atoms and covalent bonds.

Structural Isomers

Isomers that differ specifically in the arrangement or placement of their covalent bonds, such as butane and isobutane.

Geometric Isomers

Isomers that have similar bond placements but differ in spatial orientation around double bonds, taking cis or trans configurations.

Enantiomers

Molecules that share identical structures and bonds but differ in three-dimensional atom placement, forming non-superimposable mirror images.

Functional Group

A specific group of atoms attached to a carbon backbone that confers characteristic chemical properties to organic molecules.