Low molecular weight calcium-binding proteins found predominantly in developing enamel belong to_____________?
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Answer: B. Amelogenin
Explanation
Amelogenin is a low molecular weight hydrophobic protein that binds calcium during enamel formation. It constitutes the vast majority of the organic matrix secreted by developing ameloblasts. This protein regulates crystal growth orientation and spacing within developing enamel. Enamel matrix proteins include amelogenin, enamelin, tuftelin, and ameloblastin. Amelogenins assemble into nanospheres that guide hydroxycrystal ribbon elongation. Most organic matrix proteins are degraded and removed as enamel mineralization proceeds.
Mutations in the amelogenin gene cause hereditary conditions such as amelogenesis imperfecta. Understanding amelogenin function helps scientists engineer biomimetic enamel substitutes. Protein degradation is essential to achieve the high mineral density characteristic of enamel. Enamelin is a higher molecular weight protein involved in early crystal nucleation events. Tuftelin is an acidic protein found near the dentinoenamel junction rather than bulk enamel. Ameloblastin promotes ameloblast adhesion and cell signaling during matrix apposition.
Related questions
Q1. What is the average diameter of coronal dentinal tubules close to the pulp____________?
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Answer: B. 2-3 microns
Coronal dentinal tubules located close to the pulp have an average diameter of two to three microns. This larger caliber near the pulp chamber reflects a higher density and wider space of tubules. Tubular diameter gradua...
Q2. The cells responsible for eliminating bone matrix during bone resorption are_____________?
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Answer: D. Osteoclasts
Osteoclasts are specialized multinucleated cells specialized for bone resorption. They derive from hematopoietic stem cells belonging to the monocyte-macrophage lineage. These cells break down bone matrix by secreting ac...
Q3. The cells ranking 2nd in terms of prominence within the pulp tissue are______________?
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Answer: C. Odontoblasts
Odontoblasts form a distinctive single-layered palisade along the peripheral border of the healthy dental pulp tissue. After fibroblasts, which are the most numerous overall cells, odontoblasts are the second most promin...
Q4. The enamel organ cells that undergo differentiation to become future ameloblasts are_____________?
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Answer: A. Cells of inner enamel epithelium
Cells of the inner enamel epithelium undergo terminal differentiation to become secretory ameloblasts. These epithelial cells line the inner surface of the enamel organ during early tooth development. Upon interacting wi...
Q5. Calcified masses discovered within the periodontal ligament are_____________?
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Answer: A. Cementicles
Cementicles are small calcified masses found within the periodontal ligament. They can exist either free within the connective tissue or embedded in cementum. Their presence represents mineralized structures forming arou...
Q6. The cell-free zone of the pulp is located____________?
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Answer: B. Below odontoblast
The cell-free zone of Weil is a narrow, acellular band located immediately beneath the primary layer of odontoblasts. It is found principally in the coronal pulp horn regions where odontoblast activity is exceptionally h...