General Biology, Chemistry of Life, Carbon, and Water Flashcards

Comprehensive vocabulary flashcards covering the introductory biology concepts, the scientific method, Chi-square statistical testing, basic chemistry of life, carbon functional groups, and emergent properties of water.

Biology

The scientific study of life.

Organism

Any individual form of life.

Unicellular Organism

An organism consisting of a single cell.

Multicellular Organism

An organism consisting of multiple cells.

Prediction

An expected outcome of an event that addresses what will happen and can be either correct or incorrect.

Hypothesis

A proposed and testable explanation for an observation that addresses both what will happen and why it will happen.

Theory

A testable and falsifiable explanation of many observations, supported by a large body of evidence.

Independent Variable

The variable in an experiment that is directly manipulated by the researcher.

Dependent Variable

The variable in an experiment that is measured by the researcher to determine the effect of the independent variable.

False Positive

An experimental outcome that falsely indicates the presence of a result.

False Negative

An experimental outcome that falsely indicates the absence of a result.

Negative Control

A control group expected to show no effect or response, used to help rule out false positives.

Positive Control

A control group treated with a substance known to produce a specific response, used to help rule out false negatives.

Null Hypothesis ($H_0$)

A statistical hypothesis asserting that there is no difference or preference compared to the expected outcome.

Degrees of Freedom ($df$)

A statistical metric calculated as the number of experimental categories minus $1$.

Chi-Square Decision Threshold ($p < 0.05$)

The statistical cutoff where a $p\text{-value}$ less than $0.05$ leads to the rejection of the null hypothesis ($H_0$), indicating that observed differences are statistically significant.

Matter

Anything that takes up space and has mass.

Chemical Element

A pure substance made of only one type of atom.

Atom

The smallest, most basic unit of a chemical element that retains its properties.

Proton

A positively charged subatomic particle located in the atomic nucleus with a mass of $1\text{ AMU}$.

Neutron

An electrically neutral subatomic particle located in the atomic nucleus with a mass of $1\text{ AMU}$.

Electron

A negatively charged subatomic particle that orbits the nucleus with negligible mass ($0\text{ AMU}$).

Trace Elements

Elements required by living organisms in only minute amounts.

Atomic Number

The total number of protons in an atom's nucleus, which uniquely identifies an element.

Mass Number

The total sum of protons and neutrons within an atom's nucleus.

Isotopes

Atoms of the same element that have identical atomic numbers (protons) but different mass numbers due to varying numbers of neutrons.

Half-Life

The time required for $50\%$ of a radioactive isotope sample to undergo decay.

Valence Electrons

Electrons located in the outermost energy shell (valence shell) of an atom.

Octet Rule

The principle stating that atoms are most stable and unreactive when their valence shell is completely filled.

Electronegativity

A measure of an atom's attraction for shared electrons in a chemical bond.

Nonpolar Covalent Bond

A chemical bond resulting from the equal sharing of electrons between atoms with similar electronegativities.

Polar Covalent Bond

A chemical bond resulting from the unequal sharing of electrons between atoms with different electronegativities, leading to partial electrical charges ($\delta+$ and $\delta-$).

Cation

A positively charged ion formed when an atom loses one or more electrons.

Anion

A negatively charged ion formed when an atom gains one or more electrons.

Ionic Bond

An electrical attraction between oppositely charged ions (cations and anions) formed by the complete transfer of electrons.

Hydrogen Bond

A noncovalent attraction between a hydrogen atom covalently bound to a highly electronegative atom (such as $\text{F}$, $\text{O}$, or $\text{N}$) and another electronegative atom.

Van der Waals Interactions

Weak attractions between molecules that occur due to transient, asymmetric electron distributions.

Organic Chemistry

The study of carbon-containing compounds, regardless of their origin.

Hydrocarbons

Organic molecules composed strictly of carbon and hydrogen atoms.

Isomers

Compounds that possess the same molecular formula but differing structures and properties.

Structural Isomers

Isomers that differ in the covalent arrangement of their carbon atoms.

Cis-Trans Isomers

Isomers that have identical covalent bonds but differ in spatial arrangements around a double bond.

Enantiomers

Isomers that are mirror images of each other and differ in 3D spatial arrangement around an asymmetric carbon.

Functional Groups

Specific combinations of atoms attached to a carbon skeleton that participate in chemical reactions and confer specific properties to organic molecules.

Hydroxyl Group

A functional group written as $-\text{OH}$ that is polar due to electronegative oxygen and forms hydrogen bonds with water (found in alcohols).

Carbonyl Group

A functional group consisting of a carbon atom double-bonded to an oxygen atom ($\text{C}=\text{O}$), forming ketones or aldehydes.

Carboxyl Group

An acidic functional group written as $-\text{COOH}$ that can release an $\text{H}^+$ ion into solution.

Amino Group

A basic functional group written as $-\text{NH}_2$ that can accept an $\text{H}^+$ ion from solution.

Sulfhydryl Group

A functional group written as $-\text{SH}$ that can form cross-linking covalent bonds to stabilize protein structure.

Phosphate Group

A functional group written as $-\text{OPO}_3^{2-}$ that confers a negative charge and allows molecules to release energy when reacting with water.

Methyl Group

A functional group written as $-\text{CH}_3$ that affects gene expression and the shape and function of sex hormones.

Cohesion

The property of water molecules binding to other water molecules via hydrogen bonding.

Adhesion

The property of water molecules binding to other polar or charged substances.

Surface Tension

A measure of how difficult it is to stretch or break the surface layer of a liquid.

Specific Heat

The amount of heat required to raise or lower the temperature of $1\text{ g}$ of a substance by $1\,^\circ\text{C}$.

Heat of Vaporization

The amount of heat energy needed to convert $1\text{ g}$ of a liquid into a gas.

Solvent

The dissolving agent of a solution, present in the largest quantity.

Solute

The substance that is dissolved within a solution.

Hydration Shell

A sphere of water molecules surrounding each dissolved ion or solute in an aqueous solution.

Acid

A substance that increases the hydrogen ion ($\text{H}^+$) concentration in a solution.

Base

A substance that reduces the hydrogen ion ($\text{H}^+$) concentration or increases the hydroxide ion ($\text{OH}^-$) concentration in a solution.

pH Scale

A logarithmic scale measuring the concentration of hydrogen ions in a solution.

Buffer

A substance that minimizes changes in $\text{H}^+$ and $\text{OH}^-$ concentrations in a solution, helping maintain acid-base homeostasis.