BIO - TERMS - FREQUENCY > 1 PT 10

Question 1

acetyl CoA carboxylase

Answer 1

The rate-limiting enzyme of fatty acid biosynthesis. // A key enzyme that begins fatty acid synthesis by catalyzing the carboxylation of acetyl CoA to produce malonyl CoA.

Question 2

adenosine diphosphate (ADP)

Answer 2

(ADP)—A high-energy phosphate compound that can be used to form ATP. // The substance formed when ATP is hydrolyzed and energy is released.

Question 3

alanine cycle // alanine–glucose cycle

Answer 3

Cycling of alanine and glucose between muscle and liver during fasting. // A series of reactions between muscle and the liver, whereby amino acids in the muscle are converted to alanine, which is transported via the blood to the liver, where the alanine is converted first to pyruvate and then to glucose, which can then circulate back to muscle.

Question 4

alpha (α) particle

Answer 4

A particle released during alpha decay; equivalent to a helium-4 nucleus.

Question 5

ampulla

Answer 5

The bulge along a semicircular canal, which contains the hair cells that transduce rotation. // (am-pul′lă; pl., ampullae, -lē) Saccular dilation of a canal or duct, such as the ductus deferens in the male reproductive system.

Question 6

antibonding MO // antibonding orbital

Answer 6

A molecular orbital that is higher in energy than the atomic orbitals from which it is formed. // A molecular orbital that is higher in energy than any of the atomic orbitals from which it was formed.

Question 7

apoenzyme

Answer 7

The protein portion of an enzyme, which requires activation by a coenzyme. // The protein portion of an enzyme, exclusive of any organic or inorganic cofactors or prosthetic groups that might be required for catalytic activity.

Question 8

ataxia telangiectasia (ATM)

Answer 8

A syndrome that is caused by impaired repair of DNA double-strand breaks. // A disease characterized by a staggering gait and multiple disorganized blood vessels, and often accompanied by clinical immunodeficiency. It is caused by defects in the ATM protein, which is involved in DNA repair pathways that are also used in V(D)J recombination and class-switch recombination.

Question 9

autonomic nervous system (ANS)

Answer 9

The part of the nervous system that regulates processes that occur below the conscious level; i.e., the activity of cardiac muscle, smooth muscle, and glands. // A system of central and peripheral nerves that innervates the internal organs, cardiovascular system, and glands; also called visceral PNS. The ANS consists of sympathetic, parasympathetic, and enteric divisions.

Question 10

bacterial artificial chromosome (BAC)

Answer 10

Cloning vector that can accommodate large pieces of DNA, typically up to 1 million base pairs. // Cloning vectors constructed from bacterial fertility (F) factors; like YAC vectors, they accept large inserts of size 200 to 500 kb.

Question 11

Bile acids

Answer 11

Emulsifiers in bile; required for lipid absorption. // Polar derivatives of cholesterol, secreted by the liver into the intestine, that serve to emulsify dietary fats, facilitating lipase action on them.

Question 12

body mass index (BMI)

Answer 12

Weight/height2. // An index of a person’s weight in relation to height; determined by dividing the weight (in kilograms) by the square of the height (in meters). body weight The total mass of a person, expressed in pounds (lb) or kilograms (kg).

Question 13

calreticulin

Answer 13

Carbohydrate-binding chaperone protein in the endoplasmic reticulum (ER) lumen that binds to oligosaccharides on incompletely folded proteins and retains them in the ER. // A chaperone protein in the endoplasmic reticulum that, together with ERp57 and tapasin, forms the peptide-loading complex that loads peptides onto newly synthesized MHC class I molecules.

Question 14

cardiac output (CO), Q

Answer 14

The volume of blood pumped by the heart per minute. Calculated as stroke volume multiplied by heart rate. // Volume of blood ejected by the ventricle in 1 minute; calculated by multiplying heart rate times stroke volume.

Question 15

central memory T cells (TCM)

Answer 15

Self-renewing memory T cells that are abundant in lymph nodes and other lymphoid tissues. (Chapter 4) // Memory lymphocytes that express CCR7 and recirculate between blood and secondary lymphoid tissues similarly to naive T cells. They require restimulation in secondary lymphoid tissues to become fully mature effector T cells.

Question 16

chemistry

Answer 16

The science of the interactions between atoms and molecules. // The science that seeks to understand the behavior of matter by studying the behavior of atoms and molecules.

Question 17

Cholera toxin

Answer 17

The enterotoxin of Vibrio cholerae. // Secreted toxic protein of Vibrio cholerae responsible for causing the watery diarrhea associated with cholera. Comprises an A subunit with enzymatic activity and a B subunit that binds to host-cell receptors to direct subunit A to the host-cell cytosol.

Question 18

Clathrin

Answer 18

The protein that forms the coat of coated vesicles. // Protein that assembles into a polyhedral cage on the cytosolic side of a membrane so as to form a clathrin-coated pit, which buds off by endocytosis to form an intracellular clathrin-coated vesicle.

Question 19

commissure

Answer 19

Any collection of axons that connect one side of the brain with the other side. // (kom′i-shūr) Bundle of axons passing from one side to the other in the brain or spinal cord.

Question 20

conjugate base

Answer 20

Any acid from which a proton has been removed. // The product that results from deprotonation of a Brønsted–Lowry acid.

Question 21

continuous cell line

Answer 21

Cultures of a single cell type that can be propagated indefinitely in culture. (Chapter 2) // Animal cells that can be maintained through an indefinite number of generations in vitro.

Question 22

crRNA

Answer 22

Small noncoding RNAs (≈30 nucleotides) that are the effectors of CRISPR-mediated immunity in bacteria. // A short RNA derived from the spacers within the CRISPR arrays in the genomes of bacteria and archaea. See Clustered regularly interspersed palindromic repeats (CRISPR).

Question 23

defensins

Answer 23

Small peptide antibiotics made by human cells. // Small (29- to 51- residue), cysteine-rich, cationic proteins produced by lymphocytes and epithelial cells that are active against bacteria, fungi, and enveloped viruses; usually found in the gut. (Chapter 2)

Question 24

diabetes insipidus

Answer 24

Disease involving reduced ADH release or reduced kidney response to ADH; leads to excessive urine production. // A condition characterized by extreme water loss leading to extreme thirst. Normally caused by the lack of antidiuretic hormone.

Question 25

dipole–dipole force

Answer 25

Noncovalent electrostatic interactions between dipolar molecules. // An intermolecular force exhibited by polar molecules that results from the uneven charge distribution.

Question 26

DNA methylation

Answer 26

A covalent modification of DNA that suppresses transcription. // Addition of methyl groups to DNA. Extensive methylation of the cytosine base in CG sequences is used in plants and animals to help keep genes in an inactive state.

Question 27

dura mater

Answer 27

(dū′ră mah′ter) Tough, fibrous membrane forming the outer meningeal layer of the central nervous system. // The outermost of the three meninges, the membranes that cover the surface of the central nervous system.

Question 28

Elastin

Answer 28

The major component of elastic fibers. // Extracellular protein that forms extensible fibers (elastic fibers) in connective tissues.

Question 29

Electrostatic interaction

Answer 29

“Salt bond”; the attraction force between oppositely charged ions. // Chemical interaction occurring between charged atoms, as in the charged amino acid side chains and an ion in a salt bridge.

Question 30

endothelium

Answer 30

(en-dō-thē′lē-ŭm) The simple squamous epithelium that lines the lumen of blood vessels, lymphatic vessels, and heart chambers and valves. // The epithelium that forms the walls of blood capillaries and the lining of larger blood vessels.

Question 31

Erythropoietin

Answer 31

A kidney-derived growth factor that stimulates erythropoiesis in the bone marrow. // A hormone produced by the kidney that stimulates the production of red blood cells in bone marrow.

Question 32

extracellular polymeric substance (EPS)

Answer 32

A glycocalyx that permits bacteria to attach to various surfaces. // Hydrated biopolymers (proteins, polysaccharides, extracellular DNA) which form thematrix inwhich biofilmcells are immobilized.

Question 33

fertilization

Answer 33

(fer′til-i-zā′shŭn) Process of sperm penetration of the secondary oocyte. // The fusion of a male gamete (sperm) with a female gamete (egg) to form a zygote.

Question 34

flexion

Answer 34

The direction of movement that closes a joint. // (flek′shŭn) Movement of a joint in an anterior-posterior plane that decreases the angle between the articulating bones.

Question 35

free radical

Answer 35

An unstable formof oxygen molecule that can damage cells. // A molecule or ion with an odd number of electrons in its Lewis structure.

Question 36

gamma globulin

Answer 36

The serum fraction containing immunoglobulins (antibodies); also called immune serum globulin.

Question 37

genetic map

Answer 37

A diagram showing the relative sequence and position of specific genes along a chromosome. // A diagram of a chromosome with distances based on recombination frequencies—centiMorgans.

Question 38

glycerophospholipid

Answer 38

Lipids that contain a glycerol backbone linked to two fatty acids and a phosphoric acid. // An amphipathic lipid with a glycerol backbone; fatty acids are esterlinked to C-1 and C-2 of glycerol, and a polar alcohol is attached through a phosphodiester linkage to C-3.

Question 39

GPCR kinase (GRK)

Answer 39

Member of a family of enzymes that phosphorylates multiple serines and threonines on a GPCR to produce receptor desensitization. // A family of protein kinases that phosphorylate Ser and Thr residues near the carboxyl terminus of G protein–coupled receptors, initiating their internalization.

Question 40

growth cone

Answer 40

The specialized tip of a growing neurite. // Migrating motile tip of a growing nerve cell axon or dendrite.

Question 41

hematopoiesis

Answer 41

The formation of blood cells. // (hē′mat′ō-poy-ē′sis) Formation and development of blood cells.

Question 42

heterotroph

Answer 42

An organism that requires an organic carbon source; also called organotroph. // An organism that requires complex nutrient molecules, such as glucose, as a source of energy and carbon.

Question 43

hyaluronic acid

Answer 43

A glycosaminoglycan found in joints. // A large, unsulfated glycosaminoglycan (GAG), not bound to a core protein.

Question 44

hyper IgE syndrome (HIES)

Answer 44

Also called Job’s syndrome. A disease characterized by recurrent skin and pulmonary infections and high serum concentrations of IgE.

Question 45

Hypothesis

Answer 45

In science, a statement about how a phenomenon can be explained. // A tentative interpretation or explanation of an observation; a good hypothesis is falsifiable.

Question 46

immunotherapy

Answer 46

Making use of the immune system to attack tumor cells, either by enhancing the normal immune response or by using toxin-bearing specific antibodies. See also immunotoxin. // A treatment that provides an infected host with exogenous antiviral cytokines, other immunoregulatory agents, antibodies, or lymphocytes in order to reduce viral pathogenesis. (Chapter 8)

Question 47

induced fit

Answer 47

A change in the conformation of an enzyme in response to substrate binding that renders the enzyme catalytically active; also used to denote changes in the conformation of any macromolecule in response to ligand binding such that the binding site of the macromolecule better conforms to the shape of the ligand. // A principle for increasing the specificity of substrate recognition by proteins and RNAs. In protein synthesis, a ribosome, or enzyme folds around a codon– anticodon interaction and only when the match is correct is the subsequent reaction allowed to proceed.

Question 48

innate immune response

Answer 48

An early immune response in all organisms to a pathogen, which includes the production of antimicrobial molecules and the activation of phagocytic cells. Such a response is not specific for the pathogen, in contrast to an adaptive immune response.

Question 49

Interference

Answer 49

Crossing over at one point that reduces the chance of another crossover nearby; detected by studying the pattern of crossing over with three or more linked genes. // The superposition of two or more waves overlapping in space, resulting in either an increase in amplitude (constructive interference) or a decrease in amplitude (destructive interference).

Question 50

IκB

Answer 50

Inhibitory proteins that bind tightly to NFκB dimers and hold them in an inactive state within the cytoplasm of unstimulated cells. // A cytoplasmic protein that constitutively associates with the NFκB homodimer, composed of p50 and p65 subunits. When IκB is phosphorylated by activated IKK (IκB kinase), IκB becomes degraded and allows the NFκB dimer to be released as an active transcription factor.

Question 51

lactate

Answer 51

Chemical produced during glycolysis. // A salt formed from lactic acid. Lactate is not believed to be associated with fatigue but can be used to create energy.

Question 52

lectin pathway

Answer 52

Complement activation pathway that is triggered by mannose-binding lectins (MBLs) or ficolins bound to bacteria. // One of three complement pathways that lead to activation of C3-C5 convertases; mannose-binding, lectin-associated proteases cleave the C2 and C4 proteins. (Chapter 3)

Question 53

lignin

Answer 53

A noncarbohydrate component of insoluble dietary fiber composed of aromatic polymers. // Network of cross-linked phenolic compounds that forms a supporting network throughout the cell walls of xylem and woody tissue in plants.

Question 54

Long terminal repeats

Answer 54

The terminal repeat sequences of retroviral cDNAs. // Identical or nearly identical DNA sequences at opposite ends of an integrated retrovirus or a retroviruslike element. Typically these sequences are at least 300 base pairs in length. Abbreviation: LTRs.

Question 55

malignant

Answer 55

(mă-lig′nant) In reference to a neoplasm, having the property of invasiveness and spread. // Of tumors and tumor cells: invasive and/or able to undergo metastasis. A malignant tumor is a cancer.

Question 56

metabotropic receptor

Answer 56

A G-protein-coupled receptor whose primary action is to stimulate an intracellular biochemical response. // Neurotransmitter receptors that regulate ion channels indirectly through the activation of second-messenger molecules.

Question 57

microarray

Answer 57

DNA probes attached to a glass surface, used to identify nucleotide sequences in a sample of DNA. // A membrane or other solid support containing thousands of oligonucleotides or nucleic acid hybridization probes for use in detecting complementary DNAs or RNAs.

Question 58

mole fraction (χₐ) // (χsolute)

Answer 58

The number of moles of a component in a mixture divided by the total number of moles in the mixture. // A means of expressing solution concentration as the number of moles of solute per moles of solution.

Question 59

multidrug resistance

Answer 59

An observed phenomenon in which cells exposed to one anticancer drug evolve a resistance not only to that drug, but also to other drugs to which they have never been exposed.

Question 60

myoblast

Answer 60

(mı̄′ō-blast) Undifferentiated muscle cell with the potential of becoming a muscle fiber. // Mononucleated, undifferentiated muscle precursor cell. A skeletal muscle cell is formed by the fusion of multiple myoblasts.

Question 61

neural tube

Answer 61

The primitive embryonic central nervous system, consisting of a tube of neural ectoderm. // Tube of ectoderm that will form the brain and spinal cord in a vertebrate embryo.

Question 62

nitrogen cycle

Answer 62

The series of processes that converts nitrogen (N2) to organic substances and back to nitrogen in nature. // The cycling of various forms of biologically available nitrogen through the plant, animal, and microbial worlds, and through the atmosphere and geosphere.

Question 63

nonpolar // nonpolar molecules

Answer 63

Hydrophobic; describes molecules or groups that are poorly soluble in water. // Molecules containing nonpolar covalent chemical bonds; hydrophobic.

Question 64

olfaction

Answer 64

(ol-fak′shŭn) Sense of smell.

Question 65

orbital diagram

Answer 65

A diagram that gives information similar to an electron configuration but symbolizes an electron as an arrow in a box representing an orbital, with the arrow’s direction denoting the electron’s spin.

Question 66

osteocyte

Answer 66

(os′tē-ō-sı̄t) Bone cell in a lacuna within bone matrix. // Nondividing cell in bone that develops from an osteoblast and is embedded in bone matrix.

Question 67

Paracrine signaling

Answer 67

The action of an extracellular messenger on neighboring cells within its tissue of origin. // Short-range cell–cell communication via secreted signal molecules that act on neighboring cells.

Question 68

pectin

Answer 68

Mixture of polysaccharides rich in galacturonic acid which forms a highly hydrated matrix in which cellulose is embedded in plant cell walls. // A polysaccharide composed of repeating methylated or nonmethylated galacturonic acid subunits covalently bonded with a b1–4 linkage.

Question 69

Peroxisome proliferator-activated receptors (PPARs)

Answer 69

Nuclear receptors that regulate lipid and carbohydrate metabolism. // A family of nuclear transcription factors, activated by lipidic ligands, that alter the expression of specific genes, including those encoding enzymes of lipid synthesis and breakdown.

Question 70

photochemical reaction center

Answer 70

The part of a photosynthetic complex where the energy of an absorbed photon causes charge separation, initiating electron transfer. // The part of a photosystem that converts light energy into chemical energy in photosynthesis.

Question 71

phytochrome

Answer 71

Plant photoprotein that senses light via a covalently attached light-absorbing chromophore, which changes its shape in response to light and then induces a change in the protein’s conformation. Plant phytochromes are dimeric, cytoplasmic serine/threonine kinases, which respond differentially and reversibly to red and far-red light to alter cell behavior. // Red/far-red light photoreceptors that use a linear tetrapyrrole as chromophore; phytochromes normally exist as two stable conformers, the redlight- absorbing Pr- and the far-red light-absorbing Pfr-form.

Question 72

platelet-activating factor (PAF)

Answer 72

A lipid mediator that activates the blood clotting cascade and several other components of the innate immune system. // A soluble, biologically active phosphoglyceride released from white blood cells.

Question 73

polysaccharide capsules

Answer 73

A distinct structure in some bacteria—both Gram-negative and Gram-positive—that lies outside cell membrane and cell wall that can prevent direct phagocytosis by macrophages without the aid of antibody or complement. // Carbohydrate coverings with antigenic specificity that are present on some types of bacteria.

Question 74

potential energy

Answer 74

Stored energy. // The energy associated with the position or composition of an object.

Question 75

prokaryotic species

Answer 75

A population of cells that share certain rRNA sequences; in conventional biochemical testing, it is a population of cells with similar characteristics.

Question 76

pyrimidine dimer

Answer 76

A covalently joined dimer of two adjacent pyrimidine residues in DNA, induced by absorption of UV light; most commonly derived from two adjacent thymines (a thymine dimer). // A DNA lesion caused by ultraviolet radiation.

Question 77

receptor editing

Answer 77

Process by which a developing B cell that recognizes a self molecule changes its antigen receptors so that the cell no longer does so. // The replacement of a light or heavy chain of a selfreactive antigen receptor on immature B cells with a newly rearranged chain that does not confer autoreactivity.

Question 78

reducing sugar

Answer 78

A sugar in which the carbonyl (anomeric) carbon is not involved in a glycosidic bond and can therefore undergo oxidation. // Sugars that reduce silver ion in the Tollens test or cupric ion in the Fehling or Benedict tests.

Question 79

Replicon

Answer 79

A unit of replication in large genomes, defined by discrete origin and termini. (Chapter 9) // A unit of replication. In bacteria, replicons are associated with segments of the cell membrane that control replication and coordinate it with cell division.

Question 80

respiratory quotient (RQ)

Answer 80

The ratio of respiratory CO2 produced to O2 consumed. // Ratio of carbon dioxide produced and oxygen consumed at the cell or tissue level. resting energy expenditure (REE) Is similar to basal metabolic rate and is the calories expended while at rest; but the subject does not have to be fasting as one does for basal metabolic rate.

Question 81

Rheb

Answer 81

A small GTPase that activates mTOR when in its GTP-bound form, and is inactivated by a GTPase-activating protein (GAP) complex TSC1/2. rheumatic fever Disease caused by antibodies elicited by infection with some Streptococcus species. These antibodies cross-react with kidney, joint, and heart antigens. // A monomeric Ras-related GTPase that in its active form (Rheb-GTP) activates mTOR, which promotes cell growth.

Question 82

sarcoma

Answer 82

Cancer of connective tissue. // Malignant connective tissue tumor.

Question 83

Sec61 // Sec61 complex

Answer 83

A multisubunit transmembrane protein pore complex that resides in the membrane of the endoplasmic reticulum and allows peptides to be translocated from the ER lumen into the cytoplasm. // Three-subunit core of the protein translocator that transfers polypeptide chains across the endoplasmic reticulum membrane.

Question 84

septic shock

Answer 84

Systemic shock reaction that can follow infection of the bloodstream with endotoxin-producing Gram-negative bacteria. It is caused by the systemic release of TNF-α and other cytokines. Also called endotoxic shock. // A sudden drop in blood pressure induced by bacterial toxins.

Question 85

sigma (σ) bond

Answer 85

The resulting bond that forms between a combination of any two s, p, or hybridized orbitals that overlap end to end. // A covalent bond formed by headon overlap of atomic orbitals.

Question 86

Sister chromatid

Answer 86

One of the products of chromosome duplication. // Tightly linked pair of chromosomes that arise from chromosome duplication during S phase. They separate during M phase and segregate into different daughter cells.

Question 87

species

Answer 87

The most specific level in the taxonomic hierarchy. See also bacterial species; eukaryotic species; viral species. // Interbreeding, natural populations that are reproductively isolated from other such groups.

Question 88

spinal cord

Answer 88

Bundle of neurons and support cells that extends from the brain. // The part of the central nervous system in the vertebral column.

Question 89

sterol regulatory element-binding protein (SREBP)

Answer 89

A transcription factor that has several isoforms, all of which are involved in lipid or cholesterol biosynthesis. // A cholesterolregulated transcription factor.

Question 90

superoxide radical

Answer 90

A toxic anion (O2-) with an unpaired electron. // A free radical formed by the transfer of a single electron to molecular oxygen.

Question 91

Taq polymerase

Answer 91

A heat-stable DNA polymerase isolated from the thermophilic bacterium Thermus aquaticus. // A heat-stable DNA polymerase used for polymerase chain reaction (PCR).

Question 92

terminator

Answer 92

Signal in bacterial DNA that halts transcription; in eukaryotes, transcription terminates after cleavage and polyadenylation of the newly synthesized RNA. // The site on a DNA strand at which transcription ends.

Question 93

TH2

Answer 93

A subset of effector CD4 T cells that are characterized by the cytokines they produce. They are involved in stimulating B cells to produce antibody, and are often called helper CD4 T cells.

Question 94

titration

Answer 94

A laboratory procedure in which a substance in a solution of known concentration is reacted with another substance in a solution of unknown concentration in order to determine the unknown concentration; see also acid–base titration. // Treatment of a weak acid or base with a strong base or acid, respectively.

Question 95

transcriptional control

Answer 95

The regulation of a protein’s synthesis by regulation of the formation of its mRNA. // Regulation by a cell of gene expression by controlling when and how often a given gene is transcribed.

Question 96

transmembrane adhesion proteins

Answer 96

Cytoskeletonlinked transmembrane molecules with one end linking to the cytoskeleton inside the cell and the other end linking to other structures outside it.

Question 97

tumor progression

Answer 97

Process by which an initial mildly disordered cell behavior gradually evolves into a full-blown cancer. // The progressive accumulation of oncogenic mutations in neoplastic cells.

Question 98

uric acid

Answer 98

The end product of purine degradation. // Nitrogenous waste produced from breakdown of nucleic acids; eliminated in urine.

Question 99

van der Waals interaction

Answer 99

Weak intermolecular forces between molecules as a result of each inducing polarization in the other. // Weak attractions between atoms placed in close proximity.

Question 100

Vitamin B2 complex

Answer 100

Obsolete term for the thermostable “second nutritional factor” in yeast, which was found to be a mixture of niacin, riboflavin, pyridoxine, and pantothenic acid

Question 101

white matter

Answer 101

A generic term for a collection of central nervous system axons. When a freshly dissected brain is cut open, axons appear white. See also gray matter. // Brain or spinal cord tissue that derives its color from myelin in myelinated axons.

Question 102

zoonotic

Answer 102

Describes a disease of animals that can be transmitted to humans. // Transmitted among humans and other vertebrates; refers to infections and diseases. (Chapter 1)