Openstax Biology chapters 1-3 (copy)

Anion

a negative ion formed by gaining electrons

Atomic number

the number of protons in an atom

Cation

a positive ion formed by losing electrons

Chemical bond

an interaction between two or more of the same or different elements that results in the formation of molecules

Covalent bond

a type of strong bond between two or more of the same or different elements; forms when electrons are shared between elements

Electron

a negatively charged particle that resides outside of the nucleus in the electron orbital; lacks functional mass and has a charge of ?1

Electron transfer

the movement of electrons from one element to another

Element

one of 118 unique substances that cannot be broken down into smaller substances and retain the characteristic of that substance; each element has a specified number of protons and unique properties

Hydrogen bond

a weak bond between partially positively charged hydrogen atoms and partially negatively charged elements or molecules

Ion

an atom or compound that does not contain equal numbers of protons and electrons, and therefore has a net charge

Ionic bond

a chemical bond that forms between ions of opposite charges

Isotope

one or more forms of an element that have different numbers of neutrons

Mass number

the number of protons plus neutrons in an atom

Matter

anything that has mass and occupies space

Neutron

a particle with no charge that resides in the nucleus of an atom; has a mass of 1

Nonpolar covalent bond

a type of covalent bond that forms between atoms when electrons are shared equally between atoms, resulting in no regions with partial charges as in polar covalent bonds

Nucleus

(chemistry) the dense center of an atom made up of protons and (except in the case of a hydrogen atom) neutrons

Octet rule

states that the outermost shell of an element with a low atomic number can hold eight electrons

Periodic table of elements

an organizational chart of elements, indicating the atomic number and mass number of each element; also provides key information about the properties of elements

Polar covalent bond

a type of covalent bond in which electrons are pulled toward one atom and away from another, resulting in slightly positive and slightly negative charged regions of the molecule

Proton

a positively charged particle that resides in the nucleus of an atom; has a mass of 1 and a charge of +1

Radioactive isotope

an isotope that spontaneously emits particles or energy to form a more stable element

Van der Waals interaction

a weak attraction or interaction between molecules caused by slightly positively charged or slightly negatively charged atoms

Acid

a substance that donates hydrogen ions and therefore lowers ph

Adhesion

the attraction between water molecules and molecules of a different substance

Base

a substance that absorbs hydrogen ions and therefore raises ph

Buffer

a solution that resists a change in ph by absorbing or releasing hydrogen or hydroxide ions

Cohesion

the intermolecular forces between water molecules caused by the polar nature of water; creates surface tension

Evaporation

the release of water molecules from liquid water to form water vapor

Hydrophilic

describes a substance that dissolves in water; water-loving

Hydrophobic

describes a substance that does not dissolve in water; water-fearing

Ph scale

a scale ranging from 0 to 14 that measures the approximate concentration of hydrogen ions of a substance

Solvent

a substance capable of dissolving another substance

Surface tension

the cohesive force at the surface of a body of liquid that prevents the molecules from separating

Temperature

a measure of molecular motion

Amino acid

a monomer of a protein

Carbohydrate

a biological macromolecule in which the ratio of carbon to hydrogen to oxygen is 1:2:1; carbohydrates serve as energy sources and structural support in cells

Cellulose

a polysaccharide that makes up the cell walls of plants and provides structural support to the cell

Chitin

a type of carbohydrate that forms the outer skeleton of arthropods, such as insects and crustaceans, and the cell walls of fungi

Denaturation

the loss of shape in a protein as a result of changes in temperature, ph, or exposure to chemicals

Deoxyribonucleic acid (DNA)

a double-stranded polymer of nucleotides that carries the hereditary information of the cell

Disaccharide

two sugar monomers that are linked together by a peptide bond

Enzyme

a catalyst in a biochemical reaction that is usually a complex or conjugated protein

Fat

a lipid molecule composed of three fatty acids and a glycerol (triglyceride) that typically exists in a solid form at room temperature

Glycogen

a storage carbohydrate in animals

Hormone

a chemical signaling molecule, usually a protein or steroid, secreted by an endocrine gland or group of endocrine cells; acts to control or regulate specific physiological processes

Lipids

a class of macromolecules that are nonpolar and insoluble in water

Macromolecule

a large molecule, often formed by polymerization of smaller monomers

Monosaccharide

a single unit or monomer of carbohydrates

Nucleic acid

a biological macromolecule that carries the genetic information of a cell and carries instructions for the functioning of the cell

Nucleotide

a monomer of nucleic acids; contains a pentose sugar, a phosphate group, and a nitrogenous base

Oil

an unsaturated fat that is a liquid at room temperature

Phospholipid

a major constituent of the membranes of cells; composed of two fatty acids and a phosphate group attached to the glycerol backbone

Polypeptide

a long chain of amino acids linked by peptide bonds

Polysaccharide

a long chain of monosaccharides; may be branched or unbranched

Protein

a biological macromolecule composed of one or more chains of amino acids

Ribonucleic acid (RNA)

a single-stranded polymer of nucleotides that is involved in protein synthesis

Saturated fatty acid

a long-chain hydrocarbon with single covalent bonds in the carbon chain; the number of hydrogen atoms attached to the carbon skeleton is maximized

Starch

a storage carbohydrate in plants

Steroid

a type of lipid composed of four fused hydrocarbon rings

Trans-fat

a form of unsaturated fat with the hydrogen atoms neighboring the double bond across from each other rather than on the same side of the double bond

Triglyceride

a fat molecule; consists of three fatty acids linked to a glycerol molecule

Unsaturated fatty acid

a long-chain hydrocarbon that has one or more than one double bonds in the hydrocarbon chain

Organic Compound

A compound containing carbon

Macromolecules

Critically important large molecules of all living things (carbohydrates, lipids, proteins, and nucleic acids)

Hydrocarbons

Organic molecules consisting of only carbon and hydrogen

Functional Group

Important chemical groups that affect molecular function by being directly involved in chemical reactions

ATP

Adenosine triphosphate; an organic molecule called adenosine attached to a string of three phosphate groups. When a phosphate group is broken off, a high amount of energy is released.

Polymer

A long molecule consisting of many similar or identical building blocks linked by covalent bonds.

Monomer

The repeating units that serve as the building blocks of a polymer

Enzymes

specialized macromolecules (usually proteins) that speed up chemical reactions.

Dehydration Reaction

A reaction in which two molecules are covalently bonded to each other, with the loss of a water molecule

Hydrolysis reaction

The breaking apart of the covalent bonds between two monomers by the addition of a water molecule.

Carbohydrate

sugars and polymers of sugars

Monosaccharide

molecular formulas that are some multiple of the unit CH2O

Disaccharides

two monosaccharides joined together by a glycosidic linkage

Glycosidic linkage

a covalent bond formed between two monosaccharides by a dehydration reaction

Polysaccharide

macromolecules; polymers with a few hundred to a few thousand monosaccharides joined by glycosidic linkages.

Starch

A polymer of glucose monomers, as granules within cells; made by plants

Glycogen

A polymer of glucose with many branches; made by animals

Cellulose

A polysaccharide that is a major component of the tough walls that enclose plant cells

Chitin

Polysaccharide used by arthropods to build their exoskeletons

Lipids

Molecules that mix poorly with water because they mostly consist of hydrocarbon regions

Fat

Constructed from two kinds of smaller molecules: glycerol and fatty acids

Fatty acid

A molecule that has a long carbon skeleton, usually 16 or 18 carbon atoms in length, with many hydrogen atoms bonded to it

Triglyceride

A fat with three fatty acid molecules joined to a glycerol molecule

Unsaturated fatty acid

A fatty acid which has one or more double bonds between carbon atoms on the hydrocarbon chain, resulting in one fewer hydrogen atom on each double-bonded carbon.

Saturated fatty acid

A fatty acid which has no double bonds between carbon atoms on the hydrocarbon chain, resulting in as many hydrogen atoms as possible bonded to the carbon skeleton

Phospholipids

The main constituent of cell membranes; a molecule with two fatty acid molecules and a phosphate group joined to the glycerol molecule

Steroids

Lipids characterized by a carbon skeleton consisting of four fused rings

Protein

A biologically functional molecule consisting of one or more polypeptides folded and coiled into a specific three-dimensional structure

Polypeptide

Polymer of amino acids; polypeptides make up proteins

Catalyst

Chemical agents that selectively speed up chemical reactions without being consumed by the reaction

Amino Acid

An organic molecule with both an amino group and a carboxyl group; the monomer of proteins

Peptide Bond

The covalent bond joining two amino acids together through a dehydration reaction

R group

The part of an amino acid that varies from one amino acid to the next. The R group gives the amino acid its chemical properties. For example, if the R group contains many carbon-hydrogen bonds, it is chemically nonpolar.

Primary structure of a protein

A protein's sequence of amino acids

Secondary structure of a protein

A protein's coils and folded patterns, which result from the hydrogen bonding of atoms in amino acids located near by each other

Tertiary structure of a protein

The overall shape of a polypeptide resulting from interactions between the R groups of the various amino acids

Alpha helix

A common secondary structure of a protein that results in a coil shape along the polypeptide chain