Category - Definitions

Query - What definition best describes the term below?

Reversal

Category - Term Recognition

Query - What term does the description below refer to?

Term | Definition | Figure | 9+2 Array | Arrangement scheme of microtubules in the internal part of an axoneme. |  | A bands | Region of sarcomere encompassing full length of thick filaments. Contains thick filaments, ends of adjacent thin filaments, and H zone. | Figures 8.8, 8.9a, 8.10 | 'A' Fiber | A complete microtubule composing one of the nine microtubule doublets in the 9+2 array of a cilium. |  | Actin | A protein which, in combination with myosin, ATP, and calcium, provides contractile motion in cells. |  | and Tubulin | Subunits of tubulin present in equimolar quantities. | Figure 8.19 | Axoneme | In a cilium, a highly organized bundle of microtubules enveloped by an extension of the plasma membrane. | Figure 8.22b | Axons | Long projections that allow one nerve cell to contact another |  | 'B' Fiber | An incomplete microtubule, carrying only 10 or 11 protofilaments in one of the nine microtubule doublets in the 9+2 array of a cilium. |  | Basal Body | In a cilium, an anchoring structure to which an axoneme is attached. | Figure 8.22b | Cardiac Muscle | A specialized form of striated muscle found in the heart. |  | Chemotaxis | The process by which bacteria sense a concentration gradient of a particular substance in the medium and move either up or down the gradient. | Figure 8.31 | Cleavage Furrow | Ringed structure that forms during cytokinesis. It defines a plane perpendicular to the mitotic spindle. | Figure 8.15 | Creatine Kinase | Enzyme that catalyzes the reaction - Creatine phosphate + ADP <=> Creatine + ATP |  | Creatine Phosphate | High-energy compound that maintains high ATP levels for muscular contraction. |  | Cross-bridges | Stable structural links that form between the actin and myosin filament during muscular contraction. |  | Cytokinesis | The division of cells in the last stages of mitosis |  | Cytoplasmic Dynein | In a cell, a protein responsible for transport from the plus end of a microtubule toward the minus end by 'walking' along a microtubule track. |  | Cytoskeleton | An organized network of rodlike and fiberlike proteins that pervades a cell and helps give it its shape and motility. It includes actin filaments, microtubules, and a diverse group of filamentous proteins collectively called intermediate filaments. |  | Dynein | 'Sidearms' of an outer doublet structure in the 9+2 array of cilia. | Figure 8.23 | F-actin | A long, helical polymer of actin resulting from binding of ATP by the actin monomer. |  | Flagellin | Protein composing a bacterial flagellum. |  | Flagellum | Bacterial appendage providing motility. | Figure 8.29 | G-actin | The monomeric form of actin. |  | H zone | Region in center of A band of sarcomere between adjacent ends of thin filaments. | Figures 8.8, 8.9a, 8.10 | Headpieces | Portion of myosin molecule involved in binding to actin during contractile motion. |  | Heavy Meromyosin | A fragment of myosin produced by action of trypsin cleavage in the tail of myosin. | Figure 8.4 | I bands | Region between ends of adjacent thick filaments. Contains Z line. | Figures 8.8, 8.9a, 8.10 | Kinesin | In a cell, a protein responsible for transport from the minus end of a microtubule toward the plus end by 'walking' along a microtubule track. |  | Kinetochore Microtubules | Part of the mitotic spindle attached to the kinetochores of the individual chromosomes. They appear to function to pull the chromatids to the poles in telophase of mitosis. | Figure 8.28 | Light Meromyosin | A fragment of myosin produced by action of trypsin cleavage in the tail of myosin. | Figure 8.4 | Microtubule Associated Proteins (MAPs) | Proteins that bind to microtubules. |  | Microtubules | Long, tubular structures built from a helical wrapping of the protein tubulin. They are found in places as diverse as the mitotic spindle, protozoan and sperm flagella, and nerve axons. |  | Myofibers | Individual muscle fibers | Figure 8.8 | Myofibrils | A bundle of protein structures that produce muscular contraction within a myofiber. | Figure 8.8 | Myosin | A protein which, in combination with actin ATP, and calcium, provides contractile motion in cells. |  | Nexin | A protein connecting the outer doublets in the 9+2 array of cilia | Figure 8.23 | Polar Microtubules | Part of the mitotic spindle that extends between the centrioles, apparently pushing them apart. | Figure 8.28 | Radial Spokes | Connections between the nine microtubule doublets and the two central microtubules of a 9+2 array of a cilium. |  | Red Muscle | A type of striated muscle designed for relatively continuous use. |  | S1 Fragments | Pieces of myosin produced by papain cleavage of heavy meromyosin. | Figure 8.4 | Sarcomere | A basic contracting unit of striated muscle. | Figures 8.8, 8.9a, 8.10 | Sarcroplasmic Reticulum | Structure surrounding each myofibril that releases calcium in response to stimulation by the nervous system. | Figure 8.15 | Sliding Filament Model of Muscular Contraction | Model proposed by Hugh and Andrew Huxley to explain muscular contraction. | Figure 8.10, Figure 8.11 | Smooth Muscle | Type of muscle controlling involuntary muscular movement. It surrounds internal organs, such as blood vessels, intestines, and gallbladder and produces slow, sustained contractions. |  | Striated Muscle | Type of muscle controlling voluntary muscular movement. Found in arms, legs, eyelids, etc. |  | Tau () | Microtubule Associated Protein (MAP) found in neuronal tissue whose phosphorylation results in dissociation from microtubules and their destabilization. Hyperphosphorylation of this MAP results in formation of tangles of filaments in neural axons - a major cellular symptom of Alzheimer's disease. |  | Thick Filaments | Parts of a sarcomere composed of myosin. | Figure 8.9a | Thin Filaments | Parts of a sarcomere composed of actin | Figure 8.9a | Transverse Tubules | Invaginations of the plasma membrane that connect at periodic intervals with the sarcoplasmic reticulum to ensure that signals from the nervous system are transmitted across the entire sarcoplasmic reticulum. | Figure 8.15 | Tropomyosin | A fibrous protein that exists as elongated dimers lying along, or close to, the groove in the F-actin helix | Figure 8.13 | Troponin C | Part of the troponin complex that binds to calcium. | Figure 8.13 | Troponin Complex | Three proteins (Troponins I,C, and T) that make up a structure that controls access of myosin heads to actin, thereby regulating cross-bridge formation and muscular contraction. | Figure 8.13 | White Muscle | A type of striated muscle employed for occasional, often rapid motions. |  | Z line (Z disks) | Region in center of I band of sarcomere forming a dark line. | Figures 8.8, 8.9a, 8.10

Category - General

Query - Is contained in the left column below

Reversal - there is no reversal

Query | Solutions | Figures | List the steps in the sliding filament model of muscular contraction | 1. Binding of ATP leads to release of the myosin-actin cross-bridge. 2. Hydrolysis of ATP leads to 'cocking' of the myosin headpiece. 3. Binding of Ca2+ causes the myosin headpiece to rebind to actin, but at a new site, because it was cocked. 4. Release of ADP and Pi yields the power stroke, which pulls the thin filament toward the center of the sarcomere. |  | In muscular contraction, to which protein does calcium binding cause a conformational change in the sarcomere, allowing myosin headpieces to bind to actin? | Troponin C |  | What is the primary energy source in red muscle? | Oxidation of fat. |  | What is the primary energy source in white muscle? | Glycogen metabolism |  | Is myosin required for cytokinesis? | Yes |  | Is myosin required for mitosis? | No |  | Name at least two places where microtubules are found | Mitotic spindle, protozoan and sperm flagella, and nerve axons. |  | Hyperphosphorylation of which MAP results in tangles in neural axons - a symptom associated with Alzheimer's disease? | Tau () |  | What proteins are involved in 'walking' along a microtubule track? | Cytoplasmic dynein and kinesin |  | How are microtubules arranged in the internal part of an axoneme? | 9+2 array. |  | What is the rotational velocity of a bacterial flagellum? | 100 revolutions per second or 6000 rpm. |  | What is the energy source of the motion of a bacterial flagellum? | A proton gradient generated by ATP hydrolysis. |  | How many protons must be passed through the proton gradient in bacteria in order to rotate the flagellum one full revolution? | 1000 |