The three-dimensional compositions have more silicon in comparison to those composed of independent tetrahedra.
The silicate minerals refer to the most general of Earth's minerals and involve feldspar, quartz, mica, pyroxene, amphibole, and olivine. On the other hand, the silica tetrahedra composed of oxygen and silicon, produce sheets, chains, and frameworks, and bonds with other cations to produce silicate minerals.
Answer:
Explanation:
Pharmacophore (pharmacology) - The molecular framework responsible for a drug's biological activity. According to IUPAC — A pharmacophore is the ensemble of steric and electronic features that is necessary to ensure the optimal supramolecular interactions with a specific biological target structure and to trigger (or to block) its biological response.
Privileged structures are defined as molecular frameworks which are able of providing useful ligands for more than one type of receptor or enzyme target by judicious structural modifications.
1) The 1,4-dihydropyridine ring is present in many biologically important molecules that acts as an important scaffold for cardiovascular drug - a calcium antagonists and although it is technically not considered as a pharmacophore, it is considered as a privileged structure.
1,4-Dihydropyridine (DHP), belongs to the class of calcium antagonist that inhibits the influx of extracellular Ca+2 through the L-type voltage-dependent calcium channels.
A positional substitution in the 4-position is feasible in the heterocyclic ring which in turn culminates in various calcium channel antagonist activities and this heterocyclic ring is the common feature for various pharmacological activities such as anti-inflammatory activity, analgesic activity,
antihypertensive, antianginal, antitumor, antitubercular activity and antithrombotic .
Position on the heterocyclic ring binds to the L-type channel and also to N-type channel on membranes.
2.) The bioisosteres are not a suitable bioisostere for the traditional C-4 aryl or heteroaryl substitution which is necessary for calcium ion blockage thereby inhibiting it to function with the mechanism shared above.
Mitotic division in onion root cells:
- Prophase: the emergence of chromatin threads that form chromosomes, the chromosomes are visible and overlap.
- Metaphase: chromosomes line up and line up in the middle of the equatorial plane. The centromere of the chromosome appears to have bonds with the kinetochores connected to the spindle threads.
- Anaphase: the centromere of the chromosome undergoes division then the chromosomes are pulled by the spindle threads towards the two opposite poles and leave the center of the equator that looks empty.
- Telophase: The cytoplasm divides into two identical-looking daughter cells. At the telophase stage, the process of cell division occurs in two parts and has identical properties.
Mitosis is a cell division through the stages of prophase, metaphase, anaphase, and telophase. The purpose of mitosis is for growth and regeneration which results in two daughter cells that are identical to the original parent cell. Mitosis occurs only once and lasts only during somatization.
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Mitosis
because the cell split into two identical copies!
It was developed by scientists throughout history of mankind
