Unit 1 and Unit 2 Biology Exam Review: Scientific Method and Chemistry of Life

Comprehensive vocabulary flashcards reviewing experimental design, characteristics of living things, basic chemistry, water properties, macromolecules, and enzyme kinetics from the Unit 1 and Unit 2 biology curriculum.

Science

A process used to answer questions about the natural world by gathering and using evidence.

Observation

Information gathered using the senses or laboratory tools that utilizes data.

Inference

A logical assumption or explanation based upon observations and prior knowledge or experience.

Hypothesis

A testable answer to a scientific question based on evidence or prior knowledge.

Quantitative Data

Scientific data that deals with numerical measurements.

Qualitative Data

Descriptive scientific data collected directly through the senses.

Controlled Experiment

An experiment where only one variable is changed at a time while all other variables remain constant.

Field/Observational Study

A scientific investigation where data is collected by watching subjects in their natural environment without changing any variables.

Independent Variable

The single factor that is deliberately tested or changed by the experimenter in an experiment.

Dependent Variable

The variable that is observed and measured to see how it is impacted by the independent variable.

Controlled Variables

All conditions and factors kept strictly the same across every experimental test group.

Control Group

The baseline group in a controlled experiment that isolates the independent variable by not receiving the experimental treatment.

Experimental Group

The group in an experiment that receives the specific treatment or change being tested.

Skepticism

The scientific attitude of doubting new information or ideas until provided with quality evidence.

Objectivity

The practice of avoiding personal bias in all parts of a scientific investigation.

Transparency

Sharing all experimental steps and procedures to serve as a safeguard against bias and allow others to learn from successes and mistakes.

Peer Review

A quality-control process where anonymous, independent experts in a field review an experiment and provide feedback before publication.

Scientific Theory

A broad, comprehensive explanation of natural phenomena that allows for predictions and is backed by a large body of evidence.

Primary Scientific Source

A publication reporting the original study or experiment conducted directly by the authors.

Secondary Scientific Source

A publication where someone analyzes, interprets, or reports on an original study conducted by others.

Line Graph

A graph format well-suited for displaying change that occurs continuously over a period of time.

Scatter Plot

A type of graph designed to examine the correlation or relationship between two continuous variables.

Cell

The most basic structural and functional unit capable of performing all capabilities of life.

Autotroph

An organism (also called a producer) that produces its own food and energy from inorganic sources.

Heterotroph

An organism (also called a consumer) that obtains energy by consuming other organisms.

Metabolism

The sum of all chemical reactions within an organism that process matter and energy.

Homeostasis

The physiological adjustments an organism makes to maintain a stable internal environment.

Evolution

The changes in the genetic makeup of a population of organisms across multiple generations.

Adaptation

Heritable traits possessed by an organism that enhance its ability to survive and reproduce in its environment.

Prokaryotic Cell

A simple type of cell that lacks a nucleus and membrane-bound organelles.

Eukaryotic Cell

A complex type of cell containing a membrane-bound nucleus.

Spontaneous Generation

The disproven hypothesis that living organisms could arise directly from non-living matter.

Atom

The most basic unit of matter, composed of protons, neutrons, and electrons.

Atomic Number

The number of protons in the nucleus of an atom, which uniquely determines the identity of an element.

Isotopes

Atoms of the same element containing an identical number of protons and electrons, but differing numbers of neutrons.

Macro-elements

The four primary chemical elements that make up over $96\%$ of all biomass: carbon ($C$), oxygen ($O$), hydrogen ($H$), and nitrogen ($N$).

Intramolecular Bond

A strong chemical bond formed within a single molecule holding its constituent atoms together.

Intermolecular Bond

An attractive force existing between two separate molecules that is weaker than an intramolecular bond.

Ionic Bond

An intramolecular chemical bond formed when valence electrons are transferred from one atom to another.

Covalent Bond

An intramolecular bond formed when two atoms share one or more pairs of valence electrons to achieve stability.

Hydrogen Bond

An intermolecular bond occurring between a partially positive hydrogen atom and a partially negative atom of a separate molecule.

Polar Molecule

A molecule characterized by an uneven distribution of electrical charge, resulting in distinct positive and negative regions.

Nonpolar Molecule

A molecule characterized by equal electron sharing and a uniform electrical charge distribution.

Cohesion

The intermolecular attraction that causes molecules of the same substance, such as water, to stick to each other.

Adhesion

The intermolecular attraction that causes water molecules to stick to other polar surfaces or substances.

Capillary Action

The upward movement of water against gravity through narrow tubes driven by adhesion to tube surfaces and cohesion among water molecules.

Hydrophilic

Polar or ionic compounds that interact favorably with and dissolve in water due to an attraction to water molecules.

Hydrophobic

Nonpolar compounds that avoid water and do not dissolve in aqueous solutions.

Solution

A homogeneous mixture in which all components are evenly distributed throughout.

Solute

The substance in a solution that is dissolved by the solvent.

Solvent

The dissolving agent of a solution that surrounds and breaks down solute particles.

Heat Capacity

The amount of thermal energy required to raise the temperature of a substance by $1\,^{\circ}\text{C}$.

Buffer Solution

A solution that resists sharp changes in pH when small quantities of acids or bases are introduced.

Organic Molecule

A molecule characterized by having carbon atoms covalently bonded directly to hydrogen atoms ($\text{C-H}$).

Polymerization

The chemical process by which monomer subunits chemically bond together to construct large polymer chains.

Monomer

A small, fundamental molecular building block that joins with other identical or similar subunits to build a polymer.

Polymer

A macromolecule formed from a repeating chain of covalently bonded monomer units.

Monosaccharide

The monomer subunit and simple sugar of carbohydrates, typically structured in ring shapes such as hexagons or pentagons.

Polysaccharide

A carbohydrate polymer formed by chains of monosaccharides, functioning in energy storage or structural support.

Saturated Fatty Acid

A lipid fatty acid chain containing exclusively single carbon-carbon bonds, forming a straight hydrocarbon chain.

Unsaturated Fatty Acid

A lipid fatty acid containing one or more carbon-carbon double bonds, which create bends or kinks along the hydrocarbon chain.

Amino Acid

The monomer building block of proteins, of which $20$ different biological varieties exist.

Peptide Bond

The specific covalent bond that links adjacent amino acids together during the synthesis of polypeptides and proteins.

Nucleotide

The monomer subunit of nucleic acids, consisting of a 5-carbon sugar, a nitrogenous base, and one to three phosphate groups.

Activation Energy

The minimum input of energy needed to start a chemical reaction and break initial chemical bonds.

Catalyst

A chemical agent that accelerates the rate of a chemical reaction by lowering the required activation energy.

Enzyme

A biological catalyst, typically a protein, that accelerates metabolic chemical reactions without being permanently altered.

Active Site

The uniquely shaped region on an enzyme molecule where the substrate binds to undergo a chemical reaction.

Substrate

The specific reactant molecule upon which an enzyme acts by binding into its active site.

Denaturation

The loss of a protein's functional native three-dimensional conformation due to external stress, such as extreme pH or temperature.

Enzyme Catalytic Cycle

A biochemical mechanism wherein an enzyme binds a substrate at its active site, facilitates a reaction to yield products, and is recycled unchanged.