Chapter 2 - Chemistry of Life Flashcards
acid
a substance capable of reacting with a base to form a salt; reacts with some metals to liberate hydrogen
acidosis
abnormally low blood pH (too acidic)
alkaline
something with a pH above 7
alkalosis
abnormally high blood pH (too alkaline)
amino acid
the basic units that form to make proteins
aqueous solution
a mixture of molecules (solutes) that use water as the solvent
atherosclerosis
a life-threatening blockage of the arteries; this blockage is caused by plaque
atom
smallest unit of matter
atomic number
the number of protons in the nucleus of an atom
ATP
acronym for “adenosine triphosphate”, the primary carrier of energy in cells
base
a substance capable of reacting with an acid to form a salt; often bitter-tasting
biochemistry
the study of the chemical substances and processes occurring in live organisms
blood lipoprotein
a reference to the fact that fats can only travel in the blood if they are attached to a protein molecule; these fat-protein combinations are called lipoproteins
buffers
chemicals in the blood that maintain pH
catalyst
a substance that increases the rate of a chemical reaction without itself undergoing any permanent chemical change
chemical bonding
a reference to the fact that the number of electrons in the outer energy level of an atom determines how it behaves chemically and how it may unite with other atoms
cholesterol
a lipid molecule that works with phospholipids to build cell membranes; the body also uses cholesterol as a starting point in making steroid hormones such as estrogen, testosterone, and cortisone (cortisol)
collagen
a structural protein that has a fiber shape; this allows it to hold most of the body’s tissues together
compounds
mixed substances whose molecules have more than one element in them
covalent bond
a bond that forms between atoms that share electrons; this is in contrast to the ionic bond where the electron is given away
dehydration synthesis
the process of joining two molecules (or compounds) together, following the removal of water
disaccharide
a double sugar molecule; after they are eaten, the body breaks them apart, or digests them, to form monosaccharides that can be used as cellular fuel; sucrose (table sugar) and lactose (milk sugar) are two examples
DNA
acronym for deoxyribonucleic acid; a two-stranded molecule that exists in the form of a double helix; stores all the genetic material of a cell; it also contains instructions for the synthesis of other molecules, like proteins
electrolyte
a compound that forms ions when dissolved in water; in the body they regulate the osmotic pressure in cells and help maintain the function of muscle and nerve cells. If electrolyte levels are too low or too high, cell and organ functions will decline, which could lead to life-threatening conditions.
elements
pure substances composed of only one type of atom
energy level
also called shells; energy levels are stacks of orbitals; the farther the orbitals are from the nucleus, the higher the energy; there can be multiple levels; the first energy level has 1 orbital, the second has 4
enzymes
a substance produced by a living organism which acts as a catalyst to bring about a specific biochemical reaction
functional proteins
proteins that have shapes that enable them to participate in chemical processes of the body; some hormones are functional proteins
glucose
also called dextrose; the most abundant monosaccharide and the most important source of energy in all organisms; cells use it as their primary source of energy
glycogen
a short-term form of energy storage
HDL
acronym for high-density lipoprotein; a lipoprotein that has more protein than fat
homeostasis of pH
a reference to the fact that the pH of blood must be maintained within a narrow range or risk disrupting the body
hydrolysis
the chemical breakdown of a compound due to reaction with water
ion
an atom or molecule with a net electric charge (positive or negative) due to the loss or gain of one or more electrons
ionic bond
a bond that forms between an atom that has only one or two electrons in the outermost level (that would normally hold eight) and an atom that needs only one or two electrons to fill its outer level. The atom with one or two electrons simply “donates” its outer shell electrons to the one that needs one ortwo. In this sense, the electron is given away permanently.
ionic dissociation
a description of what happens when the addition of a solvent (e.g. water) or of energy in the form of heat causes ionic bonds to break up into free individual ions
ionize
convert (an atom, molecule, or substance) into an ion or ions, typically by removing one or more electrons
ionizing radiation
subatomic particles or electromagnetic waves that have sufficient energy to ionize atoms or molecules by detaching electrons from them
isotope
atoms that have the same atomic number but different atomic masses (e.g. hydrogen can be in three forms, all have the same atomic number of 1 proton, but different numbers of neutrons)
keratin
a structural protein that forms a waterproof network of fibers; it is used in the outer layer of skin
LDL
acronym for low-density lipoprotein; a lipoprotein that has more fat than protein; often associated with bad cholesterol because high levels of LDL are associated with atherosclerosis
matter
anything that occupies space and has mass
molecules
particles of matter composed of one or more atoms
monosaccharide
the basic unit of carbohydrate molecules; any of the class of sugars that cannot be hydrolyzed to give a simpler sugar
nuclear medicine
the branch of medicine that deals with the use of radioactive substances in research, diagnosis, and treatment
nucleotide
a molecule consisting of a nitrogen-containing base (adenine, guanine, thymine, or cytosine in DNA; adenine, guanine, uracil, or cytosine in RNA), a phosphate group, and a sugar (deoxyribose in DNA; ribose in RNA)
nucleus (chemistry)
the core of the atom, made up of protons and neutrons
orbital
an orbit that electrons make around a nucleus, to complete the atomic structure
each orbital has 2 electrons
organic compound
a compound composed of molecules that have a carbon-carbon or carbon-hydrogen covalent bond or both; inorganic compounds never have the aforementioned covalent bonds
peptide bond
a type of covalent bond that joins amino acids together
phospholipid
a lipid molecule that contains phosphorus; used to help build cell membranes
plaque (atherosclerosis)
a sticky substance made up of fat, cholesterol, calcium, and other substances found in the blood
polysaccharide
a molecule with more than 2 sugars; examples are glycogen and starch
product
any substance formed as a result of a chemical reaction
radiation
energy that comes from a source and travels through space at the speed of light
radiation sickness
illness caused by exposure of the body to ionizing radiation, characterized by nausea, hair loss, diarrhea, bleeding, and damage to the bone marrow and central nervous system
radioactive isotope
an isotope with an unstable nucleus that gives off radiation; these are sometimes used in nuclear medicine as the radiation can be measured
reactant
a substance consumed in the course of a chemical reaction
RNA
acronym for ribonucleic acid; a single-stranded molecule; its function is to carry out the instructions encoded in DNA
salt (not table salt)
a neutral ionic compound formed by the mixture of a base and an acid
solute
the minor component in a solution, dissolved in the solvent
solution
a liquid mixture in which the minor component (the solute) is uniformly distributed within the major component (the solvent)
solvent
a substance that dissolves a solute, resulting in a solution
stable atom
an atom is stable when its outer energy level is full (when it can hold the maximum number of electrons); atoms often interact with each other by bonding so that they can be stable
starch
a form of energy storage used by plants
structural protein
proteins shaped in ways that allow them to form essential structures of the body
subatomic particles
the positively charged protons, uncharged neutrons, and negatively charged electrons that make up an atom
synthesis
the forming or building of a more complex substance or compound from elements or simpler compounds
triglyceride
a lipid molecule that is the main constituent of body fat in humans and other vertebrates, as well as vegetable fat
