BIO - TERMS - FREQUENCY > 1 PT 4 Flashcards
(103 cards)
ABC transporters
A large family of membrane transport proteins that use the energy of ATP hydrolysis to transfer peptides or small molecules across membranes. // Plasma membrane proteins with sequences that make up ATP-binding cassettes; serve to transport a large variety of substrates, including inorganic ions, lipids, and nonpolar drugs, out of the cell, using ATP as the energy source.
activation-induced deaminase // activation-induced cytidine deaminase // AID
The enzyme catalyzing the processes of somatic hypermutation and immunoglobulin class switching in activated B cells. // Enzyme that initiates somatic hypermutation and isotype switching by deaminating DNA directly at cytosine in immunoglobulin V regions or switch regions. Loss of AID activity in patients leads to loss of both activities, causing hyper IgM and lack of affinity maturation.
aerobic
Requiring oxygen for energy metabolism. // Requiring or occurring in the presence of oxygen.
alkene
A hydrocarbon containing one or more carbon–carbon double bonds. // A hydrocarbon that contains a carbon–carbon double bond, R2C=CR2.
aminoacyl-tRNA
An aminoacyl ester of a tRNA. // A transfer RNA (tRNA) with an amino acid covalently bound to its 3′ terminus.
Anchorage dependence
The inability of cultured cells to grow in the absence of a solid support. // Dependence of cell growth, proliferation, and survival on attachment to a substratum. anchoring junction Cell junction that attaches cells to neighboring cells or to the extracellular matrix.
antiparallel
Describes two linear polymers that are opposite in polarity or orientation. // Describes the relative orientation of the two strands in a DNA double helix or two paired regions of a polypeptide chain; the polarity of one strand is opposite to that of the other.
Arrestin
A cytoplasmic protein that binds to activated hormone receptors, inactivating them and marking them for endocytosis. // Member of a family of proteins that contributes to GPCR desensitization by preventing the activated receptor from interacting with G proteins and serving as an adaptor to couple the receptor to clathrin-dependent endocytosis.
attenuated vaccine // replication-competent vaccine
A vaccine containing live, attenuated (weakened) microorganisms. // A vaccine made from viral mutants that have reduced virulence but can reproduce; they oft en also have reduced capacity for transmission. (Chapter 8)
auxin
A plant growth hormone. // Plant hormone, commonly indole-3-acetic acid, with numerous roles in plant growth and development. axon Long nerve cell projection that can rapidly conduct nerve impulses over long distances so as to deliver signals to other cells.
base substitution
The replacement of a single base in DNA by another base, causing a mutation; also called point mutation. // A single base change in a DNA molecule. (See also Transition; Transversion.)
Biotin
The prosthetic group of carboxylase enzymes. // A vitamin; an enzymatic cofactor involved in carboxylation reactions.
brightfield microscope
A microscope that uses visible light for illumination; the specimens are viewed against a white background. // Normal light microscope in which the image is obtained by simple transmission of light through the object being viewed.
Carbamoyl phosphate
An intermediate in the synthesis of urea and pyrimidines. // A negatively charged compound that is a key compound in the urea cycle necessary to convert ammonia to urea for disposal.
Catabolic pathway
Degradative pathway. // A pathway by which an organic molecule is degraded in order to obtain energy for growth and other cellular processes; degradative pathway.
cerebrum
The largest part of the forebrain; also called telencephalon. // (ser′ē-brŭm, ser′ĕ- brŭm) The largest, most superior part of the brain; composed of the left and right cerebral hemispheres; location of conscious thought processes and origin of all complex intellectual functions.
chiral
A term that describes an environment or a molecule that is not superimposable on its mirror image; chiral molecules exhibit optical isomerism. // Having handedness. Chiral molecules are those that do not have a plane of symmetry and are therefore not superimposable on their mirror image. A chiral molecule thus exists in two forms, one right-handed and one left-handed. The most common cause of chirality in a molecule is the presence of a carbon atom that is bonded to four different substituents.
chromatophore
A compound or moiety (natural or synthetic) that absorbs visible or ultraviolet light. // An infolding in the plasma membrane where bacteriochlorophyll is located in photoautotrophic bacteria; also known as thylakoids.
Coiled coil
Two or three α-helices coiled around each other. // Especially stable rodlike protein structure formed by two or more α helices coiled around each other.
complex carbohydrate
Another term for a polysaccharide based on the fact that it is made up of many simple sugars. // Carbohydrates that are made of two or more simple sugars linked together by glycoside bonds.
connective tissue
A fibrous tissue that is involved in connecting other structures with one another and is composed of predominantly collagen protein. // Any supporting tissue that lies between other tissues and consists of cells embedded in a relatively large amount of extracellular matrix. Includes bone, cartilage, and loose connective tissue.
Copolymers
Polymers obtained when two or more different monomers are allowed to polymerize together. // Mixtures consisting of more than one monomer; for example, polymers of two kinds of organic bases such as uracil and cytosine (poly-UC) have been combined for studies of the genetic code.
Cytochrome oxidase
Complex IV in the respiratory chain; transfers electrons to O2. // A mitochondrial enzyme concentrated in cells that form the blobs in primary visual cortex.
Denitrification
Reduction of nitrate and nitrite ultimately releasing N2. // The reduction of nitrogen in nitrate to nitrite or nitrogen gas.
