Chapter 1. Biochemistry: An Evolving Science Flashcards
a measure of the degree of randomness or disorder in a system; denoted by the symbol S in thermodynamics, the change in entropy (delta S) increases when a system becomes more disordered and decreases when the system becomes more ordered or less random.
Entropy
The domain of life that comprises single cell organisms lacking a nucleus. Formerly believed to be member of the domain Bacteria, Archaea are now known to have a unique evolutionary history with biochemical characteristics different from the other two domains of life.
Archaea
Low-molecular-weight molecules such as glucose and glycerol that are chemically transformed in biological processes.
Metabolite
The tendency of hydrophobic molecules to associate with one another in water. The association is powered by the resulting increase in the entropy of water.
Hydrophobic effect
A thermodynamic property that corresponds to the heat content of a system.
Enthalpy (H)
Large molecules such as proteins and nucleic acids, that are key functional and structural components of living systems.
Biological macromolecule
The domain of life that comprises single cell organisms lacking a nucleus. Members of this domain differ evolutionarily and biochemically from the Archaea, with whom they were formerly grouped.
Bacteria
a bond formed when two relatively electronegative atoms, such as oxygen or nitrogen, unequally share a hydrogen atom that is covalently bonded to one of the electronegative atoms.
Hydrogen bond
A member of the domain Eukarya. The defining characteristic of eukaryotes is the presence of a well-defined nucleus within each cell.
Eukaryote
A chemical bond formed by the sharing of pairs of electrons between adjacent atoms. Covalent bonds are the strongest chemical bonds.
Covalent bond
The domain of life that comprises all multicellular organisms, including human beings, as well as many microscopic unicellular organisms such as yeast. The defining characteristic of eukaryotes is the presence of a well-defined nucleus within each cell.
Eukarya
A charged group on one molecule can attract an oppositely charged group on the same or another molecule.
ionic interaction
the relationship between nucleic acid sequence information and protein sequence information.
genetic code
An aqueous solution consisting of a weak acid and it conjugate base (or vice versa) that resists changes in pH when strong acids or bases are added.
buffer
an organic acid with an alpha-carbon linked to a carboxylic acid, an amino group, a hydrogen and a side chain (the R group).
amino acid
Molecule that encodes genetic information in all cellular organisms.
deoxyribonucleic acid (DNA)
A structure composed of two intertwined DNA strands such that the sugar-phosphate backbone lies on the outside and the bases on the inside. The two strands run in opposite directions.
double helix
Refers to the tendency of nonpolar molecules in water to interact with one another; the interactions are driven by an increase in the entropy of water when the water molecules in contact with the nonpolar molecules are released into bulk water.
Hydrophobic interaction
form of energy capable of doing work under conditions of constant temperature and pressure. Also, a measure of the usable energy generated in a chemical reaction; denoted by the symbol G in thermodynamics. The change in free energy (delta G) of a system undergoing transformation at constant pressure is equal to the change in enthalpy (delta H) minus the product of the absolute temperature (T) and the change in entropy (delta S).
Free energy (Gibbs free energy)
Unicellular organisms, such as bacteria, which lack a nucleus.
Prokaryote
a biological macromolecule composed of a linear array of amino acids joined by peptide bonds. Roles of proteins in biological processes include catalysis, transport and storage, motion, mechanical support, immune protection, generation and transmission of nerve impulses and control of growth and differentiation.
Protein
The concentration of hydrogen ions in solution. Specifically, the pH of a solution is defined as pH = -log[H+].
pH
A measure of the susceptibility of a proton on an acid to removal by reaction with a base. pKa=-(log Ka), where Ka is the proton dissociation constant of the acid.
pKa value
alternative covalent bonding patterns for a molecule that are equally, or nearly so, likely.
Resonance structure
the attraction between two molecules based on transient electron asymmetry around an atom that induces a complementary asymmetry in a nearby molecule.
Van der Waals interaction
All of the microorganisms that live on and in humans that play roles in health and diseases.
microbiome
The tendency of the presence of a particular genetic variation or set of variations to result in the onset of a disease.
predisposition
