DCAP Ch 2

Acid

Compound that releases hydrogen ions (H+) in solution; proton donors

Activation Energy

Amount of energy greater than the energy contained in the reactants, which must be overcome for a reaction to proceed

Adenosine Triphosphate (ATP)

Nucleotide containing ribose and an adenine base that is essential in energy transfer

Amino Acid

Building block of proteins

Anion

Atom with a negative charge

Amphipathic molecule

A molecule that has both hydrophilic (polar) and hydrophobic (nonpolar) properties, enabling it to interact with both water and lipid environments

Anabolic

endergonic reactions that build molecules

Atom

Smallest unit of an element that retains the unique properties of that element

Atomic Number

Number of protons in the nucleus of an atom

Base

Substance that produces hydroxide ions (OH^-) and accepts hydrogen ions (H⁺) proton acceptor

Buffer

Solution containing a weak acid or a weak base that opposes wide fluctuations in the pH of body fluids; ex: buffers in blood work to keep it between 7.35-7.45

Carbohydrate

Class of organic compounds built from sugars, molecules containing carbon, hydrogen, and oxygen in a 1-2-1 ratio

Catabolic

exergonic reaction that break down molecules

Catalyst

Substance that increases the rate of a chemical reaction without itself being changed in the process

Cation

Atom with a positive charge

Cellulose

A complex carbohydrate that is a source of indigestible fiber for humans

Compound

Substance composed of two or more different elements joined by chemical bonds

Concentration

Number of particles within a given space

Covalent Bond

Chemical bond in which two atoms share electrons, thereby completing their valence shells

Decomposition Reaction

Type of catabolic reaction in which one or more bonds within a larger molecule are broken, resulting in the release of smaller molecules or atoms; AB—> A+B

Denaturation

Change in the structure of a molecule through physical or chemical means

DNA

double-stranded nucleic acid that stores genetic information

Disaccharide

Pair of carbohydrate monomers; ex: sucrose, lactose

Electron

Subatomic particle having a negative charge and nearly no mass; found orbiting the atom's nucleus

Electron Shell

Area of space a given distance from an atom's nucleus in which electrons are grouped

Element

Substance that cannot be created or broken down by ordinary chemical means

Endergonic reactions

reactions that absorb more energy than they release and require energy input to proceed (endothermic)

Enzyme

Protein or RNA that catalyzes chemical reactions

Exchange Reaction

Type of chemical reaction in which bonds are both formed and broken, resulting in the transfer of components; AB + CD —> AC + BD

Exergonic reaction

reactions that release more energy than they absorb (exothermic)

Glycogen

common carbohydrate in animals; glucose storage in the liver and skeletal muscles

Hydrophilic

Substances that are attracted to water and can dissolve in it, often polar or charged molecules

Hydrophobic

Substances that repel water and do not dissolve in it, typically nonpolar molecules

Hydrogen Bond

Type of bond in which a hydrogen atom covalently bonded to an electronegative atom is weakly attracted to a second electronegative atom

Inorganic Compound

Substance that does not contain both carbon and hydrogen

Ion

an atom that has lost or gained one or more electrons and as a result has a non-neutral charge

Ionic Bond

Attraction between an anion and a cation

Isotope

One of the variations of an element in which the number of neutrons differ from each other

Lipid

Class of mostly nonpolar organic compounds built from hydrocarbons and distinguished by the fact that they are not soluble in water

Macromolecule

Large molecule formed by covalent bonding

Mass Number

Sum of the number of protons and neutrons in the nucleus of an atom

Matter

Physical substance; that which occupies space and has mass

Monomer

Building block of a macromolecule, capable of joining to form polymers

Monosaccharide

Monomer of carbohydrate; primary nutrient that provides energy to cells (glucose)

Neutron

Heavy subatomic particle having no electrical charge and found in the atom's nucleus

Nucleotide

monomers of nucleic acid composed of one or more phosphate groups, a pentose sugar, and a base

Organic Compound

Substance that contains both carbon and hydrogen

pH

Measurement of the hydrogen ion (H+) concentration of a solution; expressed as a number between 0-14

Phospholipid

The main component of a cell membrane; composed of a hydrophilic phosphate head and two fatty acid hydrophobic tails

Polymer

A large molecule composed of repeating structural units called monomers

Polysaccharide

Compound consisting of more than two carbohydrate monomers; function to store energy and provide structural support in cells

Product

One or more substances produced by a chemical reaction

Protein

Class of organic compounds that are composed of many amino acids linked together by peptide bonds

Proton

Heavy subatomic particle having a positive charge and found in the atom's nucleus

Reactant

One or more substances that enter into the reaction

RNA

Single stranded nucleic acid that functions to transmit genetic material

Solution

Homogeneous liquid mixture in which a solute is dissolved into molecules within a solvent

Starch

Complex plant carbohydrate that serves as a major source of glucose for humans

Steroid

Lipid compound composed of four hydrocarbon rings bonded to a variety of other atoms and molecules

Substrate

Reactant in an enzymatic reaction

Suspension

Liquid mixture in which particles distributed in the liquid settle out over time

Synthesis Reaction

Type of anabolic reaction in which two or more atoms or molecules bond, resulting in the formation of a larger molecule; A+B —> C

Triglyceride

lipid compound that contains three fatty acid chains; functions as a long-term energy storage molecule in the body

Valence Shell

Outermost electron shell of an atom

Polar covalent bond

A covalent bond in which electrons are not shared equally
e.g. H2O

CHONPS

Main elements in living organisms: carbon, hydrogen, oxygen, nitrogen, phosphorus, sulfur

Nonpolar covalent bond

Covalently bonded molecules that are electrically balanced

e.g fats, lipids, and oils

dehydration synthesis

A chemical reaction in which two molecules covalently bond to each other with the removal of a water molecule.

Hydrolysis

Breaking down complex molecules by the chemical addition of water

Factors that slow down reaction rate

More bonds

Less reactants

Decreased temperature

Decreased concentration and pressure

Factors that speed up reaction rate

Less bonds

More reactants

Increased temperature

Increased concentration and pressure