APHY 101 Ch. 2 Terms Flashcards
Chemistry
Considers the composition of substances and how they change.
Biochemistry
A branch of science dealing with the chemistry of life forms.
Matter
Anything that has weight and takes up space (solids, liquids, and gasses).
Mass
Refers to the amount of a substance.
Weight
Refers to how heavy something is.
Elements
Simplest example of matter with specific chemical properties. Most elements occur naturally and others are artificially made (refer to periodic table for examples)
Compounds
Elements that are are more commonly parts of chemical combinations.
Bulk Elements
Elements required in large amounts (carbon, hydrogen, oxygen, nitrogen, sulfur and phosphorus - these make up more than 95% of the human body).
Trace Elements
Elements required in small amounts (important parts of enzymes).
Ultratrace Elements
Elements that are normally toxic in large amounts, but are vital in very small amounts.
Atom
The smallest particle of an element that has the properties of that element.
Chemical Bonds
Atoms that can combine with atoms like themselves or with other atoms by forming attractions.
Electron
Extremely small particle within an atom: almost no weight; carries a negative electrical charge and is in constant motion around an atomic nucleus.
Proton
Relatively large particle within an atom; carries a positive electrical charge and is found within an atomic nucleus.
Neutron
Relatively large particle within an atom; about the same weight as a proton; uncharged and thus electrically neutral; found within an atomic nucleus.
Ion
A particle, formed from an atom, that is electrically charged because it has gained or lost one or more electrons.
Molecule
A particle formed by the chemical union of two or more atoms.
Atomic Number
The number of protons in the atoms of a particular element.
Atomic
The number of protons plus the number of neutrons in each of an elements atoms.
Isotope
Atoms that have the same atomic number but different in atomic weight.
Radioactive
Isotopes of an element that have unstable atomic nuclei that decompose and release energy until they reach a stable form.
Atomic Radiation
The energy fragments that are emitted from unstable isotopes. Includes three types: alpha, beta, and gamma.
Alpha Radiation
Particles from atomic nuclei, each of which includes two protons and two neutrons, that move slowly and cannot easily penetrate matter.
Beta Radiation
Smaller particles (electrons) that travel faster and more. deeply penetrate matter.
Gamma Radiation
A form of energy similar to X-Radiation; the most penetrating form of atomic radiation.
Molecular Formula
Used to depict the numbers and types of atoms in a molecule.
ex) H20 : 2 Hydrogen Atoms and 1 Oxygen Atom
Bonds
A link formed when atoms combine with other atoms
Electron Shells
One or more regions of space that the electrons of an atom occupy which surrounds the nucleus: Each electron shell can hold a limited number of shells.
1st: 2 electrons
2nd: 8 electrons
3rd: 8 electrons
Octet Rule
Atoms react in a way that leaves the outermost shell completely filled with electrons, achieving a more stable structure.
Inert
Atoms whose outermost electron shells are filled, already have stable structures and are chemically inactive: they cannot form chemical bonds.
Cations
Positively charged ions
Anions
Negatively charged ions
Ionic Bonds
Ions with opposite charges that attract
Covalent bond
A chemical bond between atoms that share electrons.
Structural Formula
Illustrations represented by two and three lines depicting atoms that share two pairs of electrons (double covalent bond) or three pairs of electrons (triple covalent bond).
Polar
A molecule that has an equal number of protons and electrons, but more of the electrons are at one end of the molecule, making that end slightly negative, while the other end of the molecule is slightly positive.
Hydrogen Bond
The attraction of the positive hydrogen end of a polar molecule to the negative nitrogen or oxygen end of another polar molecule: these bonds are relatively weak.
Reactants
The starting materials changed by chemical reactions
Chemical reaction
The formation or breakage of bonds between atoms, ions, or molecules
Products
The atoms, ions, or molecules formed at a chemical reactions conclusion.
Synthesis
When two or more atoms, ions or molecules bond to form a more complex structure.
ex) when hydrogen and oxygen bond to form water
A+B –> AB
Decomposition
The reaction when the bonds of a reactant molecule break to form simpler molecules, atoms or ions.
ex) decomposition reactions digest nutrient molecules into molecules small enough to be absorbed into the blood stream
AB –> A+B
Exchange Reaction
A chemical reaction where parts of two different types of molecules trade positions as bonds are broken and new bonds are formed.
ex) When an acid reacting with a base producing water and a salt.
AB+CD –> AD+CB
Reversible Reaction
A chemical reaction where the product(s) can change back into the reactant(s).
A + B AB
Catalysts
Molecules that influence the rates (not the direction) of chemical reactions but are not consumed in the process.
Dissociate
When ionically bound substances are placed in water, the ions are attracted to the positive and negative ends of the water molecules and tend to leave each other: The polarity of the water dissociates the salts in the internal environment.
Electrolytes
Substances that release ions in water
Acids
Electrolytes that dissociate to release hydrogen+ ions in water
ex) carbonic acid, hydrochloric acid, acetic acid, phosphoric acid
HCl –> H+ + Cl-
Base
Substances that release ions that combine with hydrogen ions
ex) sodium hydroxide, potassium hydroxide, magnesium hydroxide, sodium bicarbonate
NaOH –> Na+ + OH-
Salts
The formation of water and electrolytes when bases react with acids to neutralize them.
ex) sodium chloride, aluminum chloride, magnesium sulfate.
HCl + NaOH –> H2O + NaCl
pH Scale
A system that tracks the number of decimal places in a hydrogen ion concentration without writing them out.
Neutral
When the number of acidic hydrogen ions and basic hydroxide ions are equal
ex) water
H20 –> H+ + OH-
Alkalemia
Blood pH of 7.5 to 7.8
Alkalosis
A condition of Alkalemia (having a higher blood pH) that makes one feel agitated and dizzy.
Acidemia
Blood pH of 7.0 to 7.3
Acidosis
A condition of Acidemia (having a lower blood pH) that makes one feel disoriented and fatigued, and breathing may be difficult.
Buffers
Chemicals that resist pH change. They combine with hydrogen ions when these ions are in excess, or they donate hydrogen ions when these ions are depleted.
Organic Compounds
Compounds that have carbon and hydrogen. Most that dissolve in water do not release ions (nonelectrolytes).
Inorganic Compounds
All other chemicals that do not have carbon and hydrogen. These usually dissolve in water and dissociate, forming ions (electrolytes).
ex) inorganic substances in the cell: water, oxygen, carbon dioxide and inorganic salts.
Solvent
A substance in which other substances dissolve
ex) water is a solvent because substances dissolve in it
Solute
A substance dissolved in a solvent
ex) salt is a solute because it dissolves in a solvent like water
Solution
The combination of a solvent and any solutes dissolved in it.
ex) saline is a solution because it resulted from a solute (salt) being dissolved in a solvent (water)
Water Balance
Where gains and losses of water are equal.
ex) to maintain homeostasis, the body regularly gains and loses water, but the water must be present in order to correct the extracellular fluid.
Water
(H20)
inorganic molecule
Medium in which most biochemical reactions occur, transports various chemical substances, major component of body fluids, and helps regulate body temperature.
Oxygen
(O2)
inorganic molecule
Used in the release of energy from glucose molecules; cellular respiration, aerobic respiration
Carbon Dioxide
(CO2)
inorganic molecule
Waste product that results from metabolism reacts with water to form carbonic acid
Bicarbonate ions
HCO3-
inorganic ion
Help maintain acid-base balance
Calcium ions
CA+2
inorganic ion
Necessary for bone development, muscle contraction, and blood clotting
Carbonate ions
CO3-2
inorganic ion
Component of bone tissue
Chloride ions
Cl-
inorganic ion
Help maintain water balance, and a major negatively charged ion in the body fluids.
Hydrogen ions
H+
inorganic ion
pH of the internal environment
Magnesium ions
Mg+2
inorganic ion
Component of bone tissue, and required for certain metabolic processes.
Phosphate ions
PO4-3
inorganic ion
Required for synthesis of ATP and nucleic acids, a component of bone tissue, and helps maintain polarization of cell membranes.
Potassium ions
Na+
inorganic ion
Required for polarization of cell membranes, and a major positively charged ion in the intracellular fluid
Sodium ions
K+
inorganic ion
Required for polarization of cell membranes, helps maintain water balance, and a major positively charged ion in the extracellular fluid.
Sulfate ions
SO4-2
inorganic ion
Help maintain polarization of cell membranes
Organic Substances
Organic chemicals in cells; carbohydrates, lips, proteins and nucleic acids.
Carbohydrates
Provide much of the energy that cells require. They also supply materials to build certain cell structures and are often stored as reserve energy supplies.
Organic Substance
Water-soluble molecules that include atoms of carbon, hydrogen and oxygen.
Sugars
Organic Substance
Simple carbohydrates; include monosaccharide and disaccharides
Monosaccharide
Organic Substance
Single Sugars
The five-carbon sugars ribose and deoxyribose, as well as the six-carbon sugars; glucose, dextrose, fructose and galactose.
Disaccharide
Organic Substance
Double Sugars
Consist of two simple sugar building blocks sucrose and lactose.
Polysaccharide
Organic Substance
Complex Carbohydrates
Built of simple carbohydrates linked to form larger molecules of different sizes.
ex) Cellulose
Glycogen
A polysaccharide that humans synthesize that is similar to starch. It is stored in the liver and skeletal muscles.
Cellulose
A polysaccharide that humans cannot synthesize (break down and absorb into bloodstream) and is produced by plants.
Lipids
Organic Substance
A group of chemicals that are insoluble in water but soluble in organic solvents, such as ether and chloroform.
Include compounds such as fats, phospholipids and steroids and have a vital function in cells and are important constituents of cell membranes.
Triglycerides
Organic Substance
Three fatty acid molecules bound to a glycerol molecule
The most abundant lipid; primarily used for cellular activity; can supply more energy gram for gram than can carbohydrate molecules.
Stored in fat as energy, also provides insulation beneath the skin.
Fatty Acids
The building blocks of triglyceride molecules (includes glycerol)
All Fatty Acid molecules include a carboxyl group (-COOH) at the end of a chain of carbon atoms.
Saturated Fatty Acid
Single carbon-carbon bonds link all the carbon atoms. Each carbon atoms binds as many hydrogen atoms as possible and is thus saturated with them.
Unsaturated Fatty Acid
One or more double bonds between many carbon atoms.
Monounsaturated Fatty Acid
Fatty acids with one double bond
Polyunsaturated Fatty Acid
Fatty acids with two or more double bonds
Glycerol
One of the building blocks of triglyceride molecules
Combines three fatty acid molecules to form a single triglyceride molecule; have different lengths and degrees.
Saturated Triglycerides
Triglyceride molecules that have only saturated fatty acids (saturated fats).
More abundant in fatty foods solid at room temperature; butter, lard, and most animal fats. Exception; coconut and palm kernel oils (liquid at room temp.)
Unsaturated Triglycerides
Triglyceride molecules that have unsaturated fatty acids (unsaturated fats)
Found in foods that are liquid at room temperature; soft margarine and seed oils (corn, grape, soybean, sunflower, etc.).
Phospholipid
Two fatty acid molecules and a phosphate group bound to a glycerol molecule (may also include a nitrogen-containing molecule attached to the phosphate group).
Hydrophobic tail: two fatty acid chains and a hydrophilic head: phosphate group; attracted to and repelled by water making them form cell membranes.
Stored in the liver and parts of the nervous system.
Similar to a triglyceride molecule in that it includes a glycerol and fatty acid chains.
Steroids
Four connected rings of carbon atoms.
Widely distributed in the body with a variety of functions; include cholesterol, sex hormone, and certain hormone of the adrenal glands.
Enzymes
Catalysts in living systems; they speed specific chemical reactions without being consumed: many proteins play a vital role in metabolism as these.
Amino acids
The building blocks of proteins: twenty types comprise proteins in organisms.
Have an amino group (-NH2) art one end and a carboxyl (-COOH) at the other end. Between these groups is a single carbon atom: the central carbon which is bonded to a hydrogen atom and to another group of atoms called a side chain/”R” group
Conformations
Complex three-dimensional shapes assembled from simple chains of amino acids connected by peptide bonds.
Peptide Bond
Covalent Bonds that link the amino end of one amino acid with the carboxyl end of another.
Dipeptide Bond
Two amino acids connected by a peptide bond.
Polypeptide Bond
Many amino acids connected by a peptide bond.
Primary Structure
The amino acid sequence (characteristic of a particular protein), the order in which particular amino acids occur in the polypeptide chain.
Secondary Structure
The polypeptide chain either forms a springlike coil (alpha helix) or fold back and forth on itself (beta-pleated sheet) or into other shapes.
Arises from hydrogen bonding.
Tertiary Structure
Hydrogen bonding and even covalent bonding between atoms in different and distant parts of a polypeptide can impart another larger level of folding.
Quaternary Structure
Several polypeptide chains are connected in a fourth level to form a very large molecule.
Nucleic Acids
Carries the instructions in the form of genes that control a cells activities by encoding the amino acid sequence of proteins.
Nucleotides
Building blocked formed by the very large and complex nucleic acids which include atoms of carbon, hydrogen, oxygen, nitrogen and phosphorus.
Consist of a 5-carbon sugar (ribose or deoxyribose), a phonate group, and one of several nitrogen-containing bases called nitrogenous bases.
RNA
Ribose Nucleic Acid
Composed of nucleotides that have ribose sugar. Most molecules are single-stranded polynucleotide chains, but they can fold into shapes that enable them to interact with DNA.
DNA
Deoxyribose Nucleic Acid
A double polynucleotide chain wound into a double helix.
Hydrogen bonds hold the two chains together which differ by one oxygen atom.
