NEET MDS Shorts
35926
General Medicine
Vitamin K is a crucial cofactor in the carboxylation of glutamate residues in the synthesis of prothrombin (factor II), which is essential for its activity. Vitamin K deficiency can lead to decreased levels of factor II, resulting in a bleeding tendency known as hypoprothrombinemia.
76368
Oral PathologyPagets disease shows a characteristic mosaic pattern of bone on radiographs due to irregular bone remodeling with alternating areas of bone resorption and formation. This creates a "jigsaw puzzle" or mosaic appearance with cement lines separating areas of old and new bone. Fibrous dysplasia shows ground-glass appearance, osteopetrosis shows marble bone appearance, and osteogenesis imperfecta shows thin cortices.
24144
Oral Pathology
The commonest site for carcinoma of the tongue is the lateral margin.
Carcinoma of the tongue is the most frequent oral cancer, and it typically
arises from the squamous cells that cover the surface of the tongue. The lateral
margin of the tongue is the part of the tongue that lies next to the teeth and
the gingivae. This site is often exposed to various carcinogens, such as those
found in tobacco and alcohol, which can increase the risk of developing cancer.
53785
BiochemistryThe principal role of Vitamin E in the prevention of oxidative damage is to potentiate the action of superoxide dismutase
41855
ProsthodonticsExplanation: Increasing the VDO can lead to increased vertical clearance between the teeth, potentially causing them to click during function. This can also affect the patient's speech and the stability of the denture. It is important to carefully evaluate and adjust the VDO to minimize these issues.
70457
NEETMDS
The Bowdler-Henry lateral trephination technique is a surgical method used specifically for the removal of impacted mandibular third molars that are partially formed or deeply embedded. This approach involves accessing the tooth from the side (laterally) of the mandible rather than the top (occlusally).
18596
General Medicine
Alpha-fetoprotein is produced primarily by the yolk sac and fetal liver during pregnancy. Its main function is osmotic regulation and it acts as a binding and carrier protein for various substances, including drugs and metals.
96260
PhysiologyThe normal plasma concentration of glucose that does not lead to its excretion in the urine is approximately 100 mg/100 ml, below which glucose is typically reabsorbed completely.
73212
Dental Materials
High expansion dental stones are designed to expand more than typical dental stones to compensate for the contraction of other materials and ensure a precise fit for restorations.
17726
Biochemistry
The correct sulfur-containing amino acid among the options provided is:
1. Cystine
Explanation:
Amino acids are the building blocks of proteins, and they are characterized by
the presence of an amino group (-NH2) and a carboxyl group (-COOH). Some amino
acids also contain a side chain that is unique to each amino acid and determines
its chemical properties. Sulfur is an important element in the structure and
function of certain amino acids.
Cystine is a sulfur-containing amino acid, which is formed by the oxidation of
two cysteine molecules. Cysteine is the amino acid that contains a sulfur atom
in its side chain as a thiol group (-SH). When two cysteine residues are
adjacent in a polypeptide chain and the thiol groups react with each other, they
form a disulfide bond (-S-S-), resulting in the formation of cystine. This
disulfide bond is crucial for the tertiary structure of proteins, contributing
to their stability and function, particularly in the context of protein folding
and maintaining the integrity of protein domains.
The other options listed are not sulfur-containing amino acids:
2. Proline is an imino acid, meaning it contains an -NH group instead of an -NH2
group. Its side chain is a cyclic secondary amine and does not contain sulfur.
3. Arginine is a basic amino acid with a guanidino group in its side chain,
which is composed of nitrogen, carbon, and hydrogen atoms but no sulfur.
4. Isoleucine is a branched-chain amino acid, with a methyl group and an
isobutyl group on its side chain. It is a hydrophobic amino acid and does not
contain sulfur.