Introductory Biology I (BY 123) - Water and Carbon Chemistry

This set of flashcards covers vocabulary and key concepts from Chapter 3 and 4 regarding water's properties, pH, and the structural diversity of carbon-based organic molecules.

Polar molecule

A molecule, such as water, where the overall charge is unevenly distributed.

Partial negative charge ($8-$)

The charge at the oxygen end of a water molecule because oxygen pulls electrons toward itself.

Partial positive charge ($8+$)

The charge at the hydrogen atoms' end of a water molecule.

Hydrogen bonds

Weak attractions between oppositely charged regions of water molecules that allow them to bond to each other.

Cohesion

The attraction between like molecules, such as water molecules sticking to each other.

Adhesion

An attraction between different substances, such as between water and plant cell walls.

Surface Tension

A property of water, illustrated by the raft spider, resulting from the cohesiveness of water molecules.

Moderation of Temperature

Water's ability to absorb heat from warmer air and release stored heat to cooler air with only slight changes in its own temperature.

Specific Heat

The amount of heat required for $1\,\text{calorie}$ of energy to heat a gram of water by one degree.

Specific Heat of Water Value

$1\,\text{calorie/(g} \cdot \text{\u00baC)}$.

Calorie

A unit of heat energy mentioned in the context of warming water.

High Heat Capacity

A result of water resisting temperature changes because it takes a lot of energy to break hydrogen bonds.

Kinetic Energy

The energy of motion.

Thermal Energy

The kinetic energy associated with the random motion of atoms or molecules.

Heat

Thermal energy in transfer from one body of matter to another.

Temperature

A measure representing the average kinetic energy of the molecules in a body of matter.

Absorption of Heat

The process that occurs when hydrogen bonds in water break.

Release of Heat

The process that occurs when hydrogen bonds in water form.

Evaporation (Vaporization)

The transformation of a substance from a liquid state to a gaseous state.

Evaporative Cooling

A process where the remaining surface of a liquid cools as it evaporates, helping to stabilize temperatures.

Crystalline Lattice

The structure water molecules are locked into at $0\,^{\circ}\text{C}$ to form ice.

Water Density at $4\,^{\circ}\text{C}$

The temperature at which water reaches its greatest density.

Ice Density

Ice is approximately $10\,\%$ less dense than liquid water because hydrogen bonds keep molecules farther apart.

Solution

A liquid that is a completely homogeneous mixture of substances.

Solvent

The dissolving agent of a solution.

Solute

The substance that is dissolved in a solution.

Aqueous Solution

A solution in which water is the solvent.

Hydrophilic

A substance that has an affinity for water.

Hydrophobic

A substance that does not have an affinity for water, such as oil.

Hydrogen Ion ($H^+$)

A single proton with a charge of $\mathbf{+1}$ that leaves its electron behind when a hydrogen atom shifts between water molecules.

Hydroxide Ion ($OH^-$)

The water molecule that lost a proton during dissociation, carrying a negative charge.

Hydronium Ion ($H_3O^+$)

The molecule with an extra proton, often represented simply as $H^+$.

Acid

A substance that increases the $H^+$ concentration of a solution.

Base

A substance that reduces the $H^+$ concentration of a solution.

Strong Acids and Bases

Substances that dissociate completely when placed in water.

Weak Acids and Bases

Substances that reversibly release and accept back hydrogen ions.

Neutral Solution pH

A solution where the $[H^+]$ is $10^{-7}$, resulting in a $\text{pH}$ of $7$.

Product of $[H^+]$ and $[OH^-]$

In any aqueous solution at $25\,^{\circ}\text{C}$, this constant value is $10^{-14}$.

pH Scale Definition

Defined by the negative logarithm of $H^+$ concentration: $\text{pH} = -\log[H^+]$.

Acidic Solutions

Solutions that have $\text{pH}$ values less than $7$.

Basic Solutions

Solutions that have $\text{pH}$ values greater than $7$.

Biological Fluid pH Range

The typical $\text{pH}$ range of most biological fluids, which is between $6$ and $8$.

Buffer

A substance that minimizes changes in the concentrations of $H^+$ and $OH^-$ in a solution.

Organic Compounds

Carbon-based molecules that form the basis for all biological molecules.

Carbon Versatility

Carbon's ability to form four bonds, allowing it to make an inexhaustible variety of organic molecules.

Miller-Urey Experiment

An experiment demonstrating that organic molecules may have formed on early Earth through natural chemical reactions.

Major Elements of Life

The elements $\text{C}$, $\text{H}$, $\text{O}$, $\text{N}$, $\text{S}$, and $\text{P}$.

Valence of Carbon

Carbon has $4$ valence electrons and can form $4$ covalent bonds.

Tetrahedral Shape

The molecular shape formed when a carbon atom is bonded to four other atoms.

Carbon Double Bond Plane

When two carbon atoms are joined by a double bond, all atoms joined to those carbons are in the same plane.

Hydrocarbons

Organic molecules consisting only of carbon and hydrogen.

Carbon Skeleton

The chain of carbon atoms that forms the structural backbone of an organic molecule.

Isomers

Compounds with the same molecular formula but different structures and properties.

Structural Isomers

Isomers that have different covalent arrangements of their atoms.

Cis-trans Isomers

Isomers that have the same covalent bonds but differ in their spatial arrangements; also known as geometric isomers.

Enantiomers

Isomers that are mirror images of each other.

cis Isomer

A spatial arrangement where two identical groups ($X$) are on the same side of a double bond.

trans Isomer

A spatial arrangement where two identical groups ($X$) are on opposite sides of a double bond.

S-Ibuprofen

The effective enantiomer of ibuprofen used to reduce inflammation and pain.

R-Albuterol

The effective enantiomer of albuterol used to relax bronchial muscles in asthma patients.

Functional Groups

Specific components of organic molecules most commonly involved in chemical reactions.

Hydroxyl Group

The chemical group $\text{-OH}$, found in alcohols like ethanol.

Carbonyl Group

The chemical group $\text{C=O}$, found in ketones and aldehydes.

Carboxyl Group

The chemical group $\text{-COOH}$, found in carboxylic acids or organic acids.

Amino Group

The chemical group $\text{-NH}_2$, found in amines like glycine.

Sulfhydryl Group

The chemical group $\text{-SH}$, also known as a thiol group, found in compounds like cysteine.

Phosphate Group

The chemical group $\text{-OPO}_3^{2-}$, found in organic phosphates like glycerol phosphate.

Methyl Group

The chemical group $\text{-CH}_3$, found in methylated compounds like $5\text{-Methylcytosine}$.

Alcohol

A compound name for molecules containing a hydroxyl group.

Ketone

A compound where the carbonyl group is within a carbon skeleton, such as acetone.

Aldehyde

A compound where the carbonyl group is at the end of a carbon skeleton, such as propanal.

Carboxylic Acid

A compound containing a carboxyl group, such as acetic acid.

Amine

A compound containing an amino group, such as glycine.

Thiol

A compound containing a sulfhydryl group, such as cysteine.

Organic Phosphate

A compound containing a phosphate group, such as glycerol phosphate.

Methylated Compound

A compound containing a methyl group, such as $5\text{-Methylcytosine}$.

ATP

Adenosine triphosphate, an important organic phosphate that stores the potential to react with water and release energy.

Adenosine

The organic molecule in $ATP$ that is attached to a string of three phosphate groups.

Triphosphate chain

The group of three phosphate groups found in $ATP$ labeled alpha, beta, and gamma.

Phosphoanhydride bonds

The high-energy bonds linking the phosphate groups in $ATP$.

Ribose

The $5\text{-carbon}$ sugar component of $ATP$.

Adenine

The nitrogenous base component of $ATP$.

Methane ($CH_4$)

A simple hydrocarbon where carbon forms four bonds with hydrogen in a tetrahedral shape.

Ethane ($C_2H_6$)

A molecule consisting of two carbons joined by a single bond, with four hydrogens on each end.

Ethene ($C_2H_4$)

A molecule also known as ethylene where two carbons are joined by a double bond.

Butane

A straight unbranched carbon skeleton with the formula $C_4H_{10}$.

2-Methylpropane

A branched carbon skeleton isomer of butane, commonly called isobutane.

1-Butene

A hydrocarbon where the double bond is positioned between the first and second carbons.

2-Butene

A hydrocarbon where the double bond is positioned between the second and third carbons.

Cyclohexane

A common carbon skeleton arranged in a six-carbon ring.

Benzene

A six-carbon ring structure with alternating double bonds.

Steroids

Lipids characterized by a carbon skeleton consisting of four fused rings, such as estradiol and testosterone.

Estradiol

A female sex hormone that is a steroid with specific chemical groups attached to its carbon rings.

Testosterone

A male sex hormone that is a steroid differing from estradiol only in its attached chemical groups.

Dissociation of water

The process where a hydrogen atom shifts between water molecules, forming $H^+$ and $OH^-$.

Ionized Carboxyl Group

The form of $\text{-COOH}$ after it loses a proton ($H^+$), resulting in $\text{-COO}^-$.

Ionized Amino Group

The form of $\text{-NH}_2$ after it gains a proton ($H^+$), resulting in $\text{-NH}_3^+$.

Electron Configuration

The key to an atom's chemical characteristics and the kinds/number of bonds it will form.

Dopamine

A biological molecule shown in the text that promotes mother-infant bonding.

Propane ($C_3H_8$)

A three-carbon skeleton unbranched hydrocarbon mentioned as a variation in length.