Test 1 Vocab Flashcards
Learn the vocab of Biology Cengage11e book
Biology
the science of life
cells
the basic structural and functional unit of life, which consists of living material enclosed by a membrane
cell theory
the scientific theory that the cell is the basic unit of life, of which all living things are composed, and that all cells are derived from pre-existing cells
plasma membrane
the selectively permeable surface membrane that encloses the cell contents and through which all materials entering or leaving the cell must pass
organelles
one of the specialized structures within the cell, such as the mitochondria, Golgi complex, ribosomes or contractile vacuole; many organelles are membrane-enclosed
prokaryotic cells
a cell that lacks a nucleus and other membrane-enclosed organelles; includes the bacteria and archaea
eukaryotic cells
an organism whose cells have nuclei and other membrane-enclosed organelles
nucleus
a cell organelle in eukaryotes that contains the DNA and serves as the control center of the cell
biological growth
involves an increase in the size of individual cells of an organism, in the number of cells, or in both
development
all the progressive changes that take place throughout the life of an organism
metabolism
the sum of all the chemical processes that occur within a cell or organism; the transformations by which energy and matter are made available for use by the organism
homeostasis
the balanced internal environment of the body; the automatic tendency of an organism to maintain such a steady state
stimuli
physical or chemical changes in their external or internal environment. Responses often involve movement
cilia
tiny hairlike extensions of a cell that the organisms use to move by beating it
flagella
longer cilia like structures
sessile
permanently attached to one location (eg coral animals)
asexual reproduction
reproduction in which there is no fusion of gametes and in which the genetic makeup of parent and of offspring is usually identical
mutation
any change in DNA; may include a change in the nucleotide base pairs of a gene, a rearrangement of genes within the chromosomes so that their interactions produce different effects,or a change in the chromosomes themselves
sexual reproductions
a type of reproduction in which two gamets (usually, but not necessarily, contributed by two different parents) fuse to form a zygote
adaptations
an evolutionary modification that improves an organism’s chances of survival and reproductive success
reductionism
learning about a structure or process by studying its simplest components
emergent properties
characteristics of an object, process, or behavior that could not be predicted from its component parts; emergent properties can be identified at each level as we move up the hierarchy of biological organization
atom
the smallest quantity of an element that retains the chemical properties of that element
molecule
the smallest particle of a covalently bonded element or compound; two or more atoms oined by covalent bond
tissue
a group of closely associated, similar cells that work together to carry out specific functions
organ
a specialized structure, such as the heart or liver, or a flower, made up of tissues and adapted to perform a specific function or group of functions
organ system
an organized group of tissues an organs that work together to preform a specialized set of functions (e.g. the digestive system or circulatory system)
organism
any living system consisting of one or more cells
population
a group of organisms of the same species that live in a defined geographic area at the same time
community
an association of population of different species living together in a defined habitat with some degree of interdependence
ecosystem
the interacting system that encompasses a community and its nonliving, physical environment
biosphere
all Earth’s communities of living organisms and their physical environments
ecology
a discipline of biology that studies the interrelations among living things and their environments
gene
a segment of DNA that serves as a unit of hereditary information; includes a transcribable DNA sequence (plus associated sequences regulating its transcriptions) that yields a protein or RNA product with a specific function
nucleotide
a molecule consisting of one or more phosphate groups, a 5-carbon sugar (ribose or deoxyribose), and a nitrogenous base (purine or pyrimidine)
protein
a large, complex organic compound composed of covalently linked amino acid subunits; contains carbon hydrogen, oxygen, nitrogen, and sulfur.
hormone
a chemical messenger, often produced in one region of the body of a multicellular organism and transported to another region where it signals cells to alter some aspect of growth, development, or metabolism
cell signaling
mechanisms of communication between cells. Cells signal one another with secreted signaling molecules, or a signaling molecule on one cell combines with a receptor on another cell
neurotransmitters
chemical signals used by neurons to transmit impulses across a synapse
autotrophs
an organism that synthesizes complex organic compounds from simple inorganic raw materials; also called producers or primary producers
photosynthesis
the biological process that captures light energy and transforms it into the chemical energy of organic molecules (eg carbohydrates), which are manufactured from carbon dioxide and water.
cellular respiration
is the process by which cells generate ATP through a series of redox reactions. in aerobic cellular respiration, the terminal electron acceptor is molecular oxygen; in anaerobic cellular respiration, the terminal acceptor is an inorganic molecule other than oxygen
heterotrophs
an organism that cannot synthesize its own food from inorganic raw materials and therefore must obtain body-building materials from other organisms. Also called consumers
primary consumers
an animal that eats producers
secondary consumers
an animal that eats herbivores (primary consumers)
decomposers
microbial heterotrophs that break down dead organic material and use the decomposition products as a source of energy. Also called saprotrophs or saprobes
evolution
any cumulative genetic changes in a population from generation to generation. Evolution leads to differences in populations and explains the origin of all the organisms that exist today or have ever existed.
systematics
the scientific study of the diversity of organisms and their evolutionary relationships. Taxonomy is an aspect of systematics
taxonomy
the science of naming, describing, and classifying organisms
species
according to the biological species concept, one or more populations whose members are capable of interbreeding in nature to produce fertile offspring and do not interbreed with members of other species.
gene pool
all the alleles of all the genes present in a freely interbreeding population
genus
a taxonomic category made of related species
binomial system of nomenclature
system of naming a species by the combination of the genus name and a specific epithet
specific epithet
the second part of the name of a species; designates a specific species belonging to that genus
family
a taxonomic category made up of related genera
order
a taxonomic category made up of related families
class
a taxonomic category made up of related orders
phylum (pl. phyla)
a taxonomic grouping of related, similar classes; a category beneath the kingdom and above the class
kingdom
a broad taxonomic category made up of related phyla; many biologist currently assign living organisms to five kingdoms and several “supergroups”
domains
the broadest taxonomic category; each domain includes one or more kingdoms
taxon (pl. taxa)
a formal taxonomic group at any level (eg phylum or genus)
clade
a group of organisms containing a common ancestor and all its descendants; a monophyletic group
cladogram
a branching diagram that illustrates taxonomic relationships based on the principles of cladistics
prokaryotes
a cell that lacks a nucleus and other membrane-enclosed organelles; includes the bacteria and archaea (domains Bacteria and Archaea)
Bacteria
prokaryotic organisms that have peptidoglycan in their cell walls; most are decomposers, but some are parasites and others are autotrophs, Bacteria is the name of one of the two prokaryotic domains
Archaea
one of the two prokaryotic domains. The absence of peptidoglycan in their cell walls sets them apart from the bacteria
eukaryotes
an organisim whose cells have nuclei and other membrane-enclosed organelles
Eukarya
the domain that includes all eukaryotes: protists, fungi, plants and animals
protists
Eukaryotic organisms that may be unicellular, colonial, or simple multicellular; for example, algae, amoebas, celiates, and slime molds
Plantae
a eukaryotic organisms that are complex multicellular organisms adapted to carry out photosynthesis. Includes both nonvascular (mosses) plants and vascular plants (ferns, conifers, and flowering plants)
Fungi
a heterotrophic eukaryote belonging to the opisthokont clade, with chitinous cell walls and a body usually in the form of a mycelium of branched, threadlike hyphae. Most fungi are decomposers; some are parasitic
Animalia
Eukaryotic organisms that is made up of multicellular organisms that obtain their nutrition by eating other organisms. most exhibit considerable cell and tissue specialization
natural selection
the mechanism of evolution proposed by Charles Darwin; the tendency of organisms that have favorable adaptations to their environment to survive and become the parents of the next generation. evolution occurs when natural selection results in changes in allele frequencies in a population.
scientific method
the process that scientists use to investigate the natural world; includes observing, recognizing a problem or stating a critical question, developing a hypothesis, making a prediction that can be tested, making further observations, preforming experiments, interpreting results, and drawing conclusions that support or falsify the hypothesis
deductive reasoning
the reasoning that operates from generalities to specifics and can make relationships among data more apparent
inductive reasoning
the reasoning that users specific examples to draw a general conclusion or discover a general principle
hypothesis
a testable statement about the nature of a observation or relationship
unfalsifiable hypothesis
an hypothesis that cannot be proven false; in fact, it cannot be scientifically investigated
control group
in a scientific experiment, a group in which the experimental variable is kept constant. The control group, which is as closely matched to the experimental group as possible, provides a standard of comparison used to verify the results of the experiment
experimental group
in a scientific experiment, a group in which the experimental variable is manipulated
scientific theory
in science, a widely accepted explanation supported by a large body of observations and experiments. A scientific theory relates facts that appear unrelated; it predicts new facts and suggest new relationships
systems biology
a field of biology that synthesizes knowledge of many small parts to understand the whole. also referred to as integrative biology or integrative systems biology
inorganic compounds
a simple substance that does not contain a carbon backbone
organic compounds
a compound consisting of a backbone made up of carbon atoms
elements
a substance that cannot be changed to a simpler substance by a normal chemical reaction
chemical symbol
the abbreviation for an element usually the first letter (or first and second letters) of the English or Latin name
matter
anything that has mass and takes up space
electron
a particle with one unit of negative charge and negligible mass, located outside the atomic nucleus
proton
a particle present in the nuclei of all atoms that has one unit of positive charge and mass of 1 atomic mass unit (amu)
neutron
an electrically neutral particle with a mass of 1 atomic mass unit (amu) found in the atomic nucleus
nucleus
the central region of an atom that contains the protons and neutrons
atomic number
the number of protons in the atomic nucleus of an atom, which the atom corresponds
periodic table
a chart of the elements arranged in order by atomic number
electron configuration
the arrangement of electrons around the atom. In a Bohr model, the electron configuration is depicted as a series of concentric circles
atomic mass unit (amu)
the approximate mass of a proton or neutrons; aka - dalton
chemical bonds
a force of attraction between atoms in a compound
isotopes
an alternative form of an element with a different number of neutrons but the same number of protons and electrons
radioisotopes
unstable isotopes that spontaneously emit radiation; also called radioactive isotopes
autoradiography
method for detecting radioactive decay; radiation cases the appearance of silver grains in special X-ray film
orbitals
region in which electrons occur in an atom or molecule
electron shell
group of orbitals of electrons with similar energies
valence electrons
the electrons in the outer electron shell, known as the valence shell, of an atom; in the formation of a chemical bond, an atom can accept electrons into its valence shell or donate or share valence electrons
acidic solution
a solution in which the concentration of hydroxide ions (H+) exceeds the concentration of hydroxide ions (OH-). An acidic solution has a pH less than 7
molecule
the smallest particle of a covalently bonded element or compound; two or more atoms joined by covalent bonds
buffer
a substance in a solution that tends to lessen the change in hydrogen ion concentration (pH) that otherwise would be produced by adding an acid or base
simplest formula
a type of chemical formula that gives the smallest whole-number ratio of the component atoms
molecular formula
the type of chemical formula that gives the actual numbers of each type of atom in a molecule
structural formula
a type of chemical formula that shows the spatial arrangement of the atom in a molecule
mole (mol)
the atomic mass of an element or the moecular mass of a compound, expressed in grams; one mole of any substance has 6.02x1023 units
reactants
Substance that participates in a chemical reaction
products
substance formed by a chemical reaction
dynamic equilibrium
the condition of a chemical reaction when the rate of change in one direction is exactly the same as the rate of change in the opposite direction (ie, the concentrations of the reactants and products are not changing), and the difference in free energy between reactants and products is zero
bond energy
the energy required to break a particular chemical bond
covalent compound
a compound in which atoms are held together by covalent bonds; covalent compounds consist of molecules
electronegativity
a measure of an atom’s attraction for electrons
nonpolar covalent bond
molecule that does not have a positively charged end and a negatively charged end; nonpolar molecules are generally insoluble in water
polar covalent bond
chemical bond formed by the sharing of electrons between atoms that differ in electronegativity; the end of the bond near the more electronegative atom has a partial negative charge, and the other end has a partial positive charge
single covalent bond
the covalent bond when an electron is shared between two atoms
orbital hybridization
a rearrangement of the orbitals in the valence shell that may occur when an atom forms covalent bonds with other atoms
ionic bond
the chemical attraction between a cation and an anion
ionic compound
a substance consisting of cations and anions, which are attracted by their opposite charges; ionic compounds do not consist of molecules
hydration
process of association of a substance with the partial positive and/or negative charges of water molecules
hydrogen bond
a weak attractive force existing between a hydrogen atom with a partial positive charge and an electronegative atom (usually oxygen or nitrogen) with a partial negative charge
redox reaction
the chemical reaction in which one or more electrons are transferred from one substance (the substance that becomes oxidized) to another (the substance that becomes reduced)
oxidation
the loss of one or more electrons (or hydrogen atoms) by an atom, ion, or molecule
reduction
the gain of one or more electrons (or hydrogen atoms) by an atom, ion, or molecule
cohesion
the property of sticking together
solvent
substance capable of dissolving other substances
solute
a dissolved substance
hydrophobic
not readily interacting with water; having less affinity for water molecules than they have for each other
hydrophobic interactions
the tendency of hydrophobic substances to cluster together due to strong
van der Waals interactions
weak attractive forces between atoms; caused by interactions among fluctuating charges
heat
the total amount of kinetic energy in a sample of a substance
heat vaporization
the amount of heat energy that must be supplied to change one gram of a substance from the liquid phase to the vapor phase
calorie (cal)
the amount of heat energy required to raise the temperature of 1 g of water 1°C; equivalent to 4.184 joules
pH
the negative logarithm of the hydrogen ion concentration of a solution (expressed as moles per liter). Neutral pH is 7, values less than 7 are acidic, and those greater than 7 are basic
neutral solution
a solution of pH 7; there are equal concentrations of hydrogen ions (H+) and hydroxide ions (OH-)
electrolytes
a substance that dissociates into ions when dissolved in water; the resulting solution can conduct an electric current
surface tension
the attraction that the molecules at the suface of a liquid may have for one another
temperature
the average kinetic energy of the particles in a sample of a substance
specific heat
the amount of heat energy that must be supplied to raise the temperature
salt
an ionic compound consisting of an anion other than a hydroxide ion and a cation other than a hydrogen ion. A salt is formed by the reaction between an acid and a base
hydrocarbon
an organic compound composed solely of hydrogen and carbon atoms
amino group
a weakly basic functional group
amylopasts
colorless plastids; which are used for starch storage in cells of roots and tubers
geometric isomers
one of two or more chemical compounds having the same arrangement of covalent bonds but differing in the spatial arrangement of their atoms or group of atoms
enantiomers
two isomeric chemical compounds that are mirror images
alpha carbon
asymmetrical carbon in an amino acid to which an amino group, a carboxyl group, a side chain (R group), and a hydrogen are covalently bonded
functional groups
a group of atoms that confers distinctive properties on an organic molecule (or region of a molecule) to which it is attached (e.g. hydroxyle, carbonyl, carboxyl, amino, phosphate, and sulfhydryl groups)
hydrophilic
interacting readly with water; having a greater affinity for water molecules than they have for each other
adenosine triphosphate (ATP)
an organic compound conaining adenine, ribose, and three phosphate groups; hydrolysis of the terminal phosphate yields adenosine diphosphate (ADP); of prime importance for energy transfers in cells
hydroxyl group
polar functional group; abbreviated -OH
carboxyl group
a wekly acidic functional group; abbreviated -COOH
condensation reaction
a reaction in which two monomers are combined covalently through the removal of the equivalent of water molecule; also called condensation synthesis
ketone
an organic molecule containing a carbonyl group bonded to two carbon atoms
disaccharide
a sugar produced by covalently linking two monoscaccharides
cellulose
a structural polysaccharide consisting of beta glucose subunits; the main constituent of plant primary cell walls
chitin
a nitrogen-containing structural polysaccharide that forms the exoskeleton of insects and the cell walls of many fungi
diacylglycerol
a lipid consisting of glycerol combinded chemically with two fatty acids; also called diglyceride
β-pleated sheet
a regular, folded, sheetlike type of protein secondary structure, resulting from hydrogen bonding between two different polypeptide chains or two regions of the same polypeptide chain
domain
a structural and functional region of a protein
deoxyribonecleic acid (DNA)
double-stranded nucleic acid; contains genetic information coded in specific sequences of its constituent nucleotides
hydrolysis reactions
reaction in which a covalent bond between two subunits is broken through the addition of the equivalent of a water molecule; a hydrogen atom is added to on subunit and a hydroxyl group to the other
cyclic adenosine monophosphate (cyclic AMP or cAMP)
a form of adenosine monophosphate in which the phosphate is part of a ring-shaped structure; acts as a regulatory molecule and second messenger in organisms ranging from bacteria to humans
cyclic guanosine monophosphate (cGMP)
a form of guanosine monophosphate in which the phosphate is part of a ring-shaped structure; involved in certain cell signaling processes
glucose
a hexose aldehyde sugar that is central to many metabolic processes
glycosidic linkage
covalent linkage joining two sugars; includes an oxygen atom bonded to a carbon of each sugar
glycogen
the principal storage plysaccharide in animal cells; formed from glucose and stored primarly in the liver and, to a lesser extent, in muscle cells
glycoproteins
a protein with covalently attached carbohydrates
glycolipids
a lipid with covalently attached carboydrates
glycerol
a 3-carbon alcohol with a hydroxyl group on each carbon; a component of triacylglycerols and phospholipids, as well as monoacylglycerols and diacylglycerols
fatty acid
a lipid that is an organic acid containing a long hydrocarbon chain, with no double bonds (saturated fatty acid), one double bond (monounsaturated fatty acid), or two or more double bonds (polyunsaturated fatty acid); components of triacylglycerols and phosphalipids, as well as monoacylglycerols and diacylglycerols
ester linkage
covalent linkage formed by the reaction of a carboxyl group and a hydroxyl group, with the removal of the equivalent of a water molecule; the linkage includes an oxygen atom bonded to a carbonyl group
enzymes
an organic catalyst (usually a protein) that accelerates a specific chemical reaction by lowering the activation energy required for that reaciton
essential amino acids
an amino acid that must be provided in the diet because the body cannot make it or cannot make it in sufficient quantites to meet nutritional needs
guanine (G)
a nitrogenous prine base that is a componenet of nucleic acids and GTP
guanosine triphosphate (GTP)
an energy transfer molecule similar to ATP that releases free energy with the hydrolysis of its terminal phosphate group, yielding guanosine diphosphate (GDP)
isomers
one of two or more chemical compounds having the same chemical formula but different structural formulas (e.g. structural and geometrical isomers and enatiomers)
structural isomers
one of two or more chemical compounds having the same chemical formula but differing in the covalent arrangement of their atoms (e.g. glucose and fructose)
methyl group
a nonpolar functional group abbreviated -CH3
sulfhydryl group
functional group abbreviated -SH; found in organic compounds called thiols
polymers
a molecule built up from repeating subunits of the same general type (monomers); examples include proteins, nucleic acids, or polysaccharides
monomers
a molecule that can link with other similar molecules; two monomers join to form a dimer, whereas many form a polymer. Monomers are small (e.g. tubulin or actin proteins)
polysacchride
a carbohydrate consisting of many monosaccharide subunits (e.g. starch, glycogen, and cellulose)
lipid
any of a group of organic compounds that are insoluble in water but soluble in nonpolar solvents; lipids serve as energy storage and are important components of cell membranes
monoacylgycerol
lipid consisting of glycerol combined chemically with a single fatty acid. Also called monoglyceride.
starch
a polysaccharide composed of alpha glucose subunits; made by plants for energy storage
polypeptide
a compound consisting of a chain of amino acid groups linked by peptide bonds. A dipeptide consists of two amino acids, a polypeptide of many
tiracylglycerols
the main storage lipid of organisms, consisting of a glycerol combined chemically with three fatty acids; also called triglyceride
molecular chaperones
proteins that help other proteins fold properly. Although chaperones do not dictate the folding pattern, they make the process more efficient
phospholipid
lipids in which two fatty acids and a phophorus-containing group are attached to glycerol; major components of cell membranes
retinal
visual pigment derived from vitamin A; present in eyes of insects, mollusks, and vertebrates
steroid
complex molecules containing carbon atoms arranged in four attached rings, three of which contain six carbon atoms each and the fourth of which contains five (e.g. cholesterol and certain hormones, including the male and female sex hormones of vertebrates)
phosphodiester linkages
covalent linkage between two nucleotides in a strand of DNA or RNA; uncludes a phosphate group bonded to the sugars of two adjacent nucleotides
secondary structure
a regular geometic shape produced by hydrogen bonding between the atoms of the uniform polypeptide backbone; includes the alpha helix and the beta-pleated sheet
quaternary structure
the overall conformation of a protein produced by the interaction of two or more polypeptide chains
ribonucleic acid (RNA)
a family of single-stranded nucleic acids that function mainly in protein synthesis
tertiary structure
the overall three-dimensional shape of a polypeptide that is determined by interactions involving the amino acid side chains
ribose
the 5-carbon sugar present in RNA and in important nucleoside triphosphate such as ATP
thymine (T)
a nitrogenous pyrimidine base found in DNA.
