Answer:
The perception of pain throughout the body arises when neural signals originating from the terminals of nociceptors are propagated to second-order neurons in the spinal cord or brainstem, whereupon they are transmitted to specific higher-order brain areas (Price, 2000). Recent studies have begun to elucidate some of the molecular mechanisms underlying the transduction of noxious stimuli. Many stimuli have been found to activate ion channels present on nociceptor terminals that act as molecular transducers to depolarize these neurons, thereby setting off nociceptive impulses along the pain pathways (Price, 2000; Costigan and Woolf, 2000). Among these ion channels are the members of the transient receptor potential (TRP) family. To date, the most studied member of the TRP family is the TRPV1 receptor. This is because it is the only one activated by capsaicin, the compound in chili pepper responsible for its “hot” taste; also, inhibiting TRPV1 has been shown to have therapeutic value (DiMarzo et al., 2002; Cortright and Szallasi, 2004). Although we will focus on the presence of these channels in nociceptors, we note that they have been identified in many other cell types and in various cortical and subcortical areas (Toth et al., 2005). The transient receptor potential vanilloid 1 (TRPV1) channel is predicted to have six transmembrane domains and a short, pore-forming hydrophobic stretch between the fifth and sixth transmembrane domains (see Figure 5.1A). It is activated not only by the vanilloid capsaicin (Caterina et al., 1997), but also by noxious heat (>43°C) and low pH (Caterina et al., 1997; Tominaga et al., 1998), voltage (Gunthorpe et al., 2000; Piper et al., 1999), and various lipids (Julius and Basbaum, 2001; Caterina and Julius, 2001; Clapham, 2003; Cortright and Szallasi, 2004, Szallasi and Blumberg, 1999; Prescott and Julius, 2003; Jung et al., 2004; Bhave et al., 2003). In cells, TRPV1 is inactivated by its binding to PIP2 and is released from this block by PLC-mediated PIP2 hydrolysis (Prescott and Julius, 2003). TRPV1 is widely expressed in central nervous system (CNS) tissue and highly expressed in sensory neurons of the dorsal root ganglion [19]. This receptor also localizes to neurons that line the oral and nasal cavities [10], where it is found in a subpopulation of sensory afferent nociceptive nerve fibers [20].
(this is for question 1.)
Explanation:
Answer:
population - community - ecosystem - biosphere
Explanation:
<em>The correctly sorted level of organization of an ecosystem from the least inclusive to the most inclusive would be from population to community to ecosystem and finally to biosphere.</em>
A population consists of a group of organism of the same species living in a particular area at a particular time and capable of interbreeding to produce fertile progeny.
A community represents different population of organisms that are interacting with one another. Several populations make up a community.
An ecosystem consists of different communities of organisms that are interacting with themselves and the non living component of the environment.
A biosphere consists of all regions of the earth where living organisms can be found. It consists of different ecosystems that make up the earth.
<u>Hence, the population is least inclusive, followed by the community, then the ecosystem and finally the biosphere.</u>
The last stage of embryonic development where the embryonic stem cells are found is the blastocycst. In this stage the cell differentiates and group themselves into different body parts and specialized cells. This stage is reached with in the period of 3 to 5 days of the embryo development.
False, a lipid bilayer is a MOSTLY apolar cell structure,which means polar molecules can't easily go through it
Cellular respiration is the process of oxidizing organic molecules such as glucose to form carbondioxide and water.The energy released during this process is stored in the form of ATP molecules which is further used for all energy consuming activities of cell. So the answer is A.
