NEET MDS Shorts
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BiochemistryThe rate limiting step in glycolysis is catalyzed by Phosphofructokinase
796029
BiochemistryVitamin C deficiency is due to defect of Lysyl hydroxylase
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BiochemistryThe reaction used for estimating free amino, groups in proteins is Deamination with HNO2
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BiochemistryTyrosine is Aromatic amino acid
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BiochemistryMethionine is sulphur containing AminoAcid
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BiochemistryThe concentration of ketones is increased in body due to:
1. Starvation
2. High fat diet
3. Diabetes mellitus
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BiochemistryThe 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.
638919
BiochemistrySaturated fatty acids are a type of fat that has a chemical structure with a
single bond between each carbon atom in the fatty acid chain and no double
bonds. These types of fats are typically solid at room temperature. Out of the
given options, stearic acid (C18:0) is the only saturated fatty acid. The others
are:
1. Oleic acid (C18:1) is a monounsaturated fatty acid, which means it has one
double bond. It is commonly found in olive oil, canola oil, and avocados.
2. Linolenic acid (C18:3) is a polyunsaturated fatty acid, specifically an
omega-3 fatty acid, with three double bonds. It is found in plant sources like
flaxseeds, chia seeds, and walnuts.
3. Arachidonic acid (C20:4) is also a polyunsaturated fatty acid, an omega-6
fatty acid with four double bonds. It is found in animal fats, such as meat, and
in smaller amounts in some plant oils like sunflower oil and peanut oil.
Stearic acid, on the other hand, is a common saturated fatty acid found in
various animal fats and certain vegetable oils like coconut oil, palm kernel
oil, and cocoa butter. It is known for its role in the structure of cell
membranes and as a precursor for the biosynthesis of cholesterol in the body.
While it is important to consume fatty acids for good health, excessive
consumption of saturated fatty acids has been associated with higher levels of
LDL (low-density lipoprotein) cholesterol, which is often referred to as "bad"
cholesterol, and an increased risk of heart disease. However, it is important to
maintain a balanced diet that includes both saturated and unsaturated fatty
acids in moderation.