[HDquiz quiz = “1960”]
[HDquiz quiz = “1957”]
The plot of the torsional angles of the amino acid residues in a peptide is called the Ramachandran plot. The two torsional angles are the phi (φ)and psi (ψ). The phi (φ) is formed between the nitrogen and the α-carbon atom (N-Cα) while the psi (ψ) is formed between the α-carbon and the carbon atom of the carbonyl group (Cα-C).
[HDquiz quiz = "1955"]
The sulfur-containing vitamin is Biotin (Vitamin B7). Biotin is a part of the B complex vitamin. Biotin works as a coenzyme in the carboxylation reactions catalyzed by the enzyme pyruvate carboxylase that converts pyruvic acid to oxaloacetic acid. It also helps in gluconeogenesis, citric acid cycle, and fatty acid synthesis.
[HDquiz quiz = "1953"]
β-oxidation is the biochemical process through which fatty acids are broken down for the production of energy in different tissues. In the β-oxidation pathway, one Acetyl CoA molecule is formed in each cycle of fatty acid β-oxidation. Palmitic acid is a 16C long-chain fatty acid. Palmitic acid undergoes seven cycles of β-oxidation which releases a 2C molecule is each time producing one Acetyl CoA in each cycle. The last 2C also produces one Acetyl CoA molecule. Thus, a total of 8 Acetyl CoA is produced due to the β-oxidation of Palmitic acid.
[HDquiz quiz = "1950"]
A chiral Carbon atom in a molecule is that Carbon atom where all the four valencies of Carbon atoms are occupied by four different groups. Due to the presence of two hydrogen atoms the Carbon atom of the amino acid Glycine is achiral in nature. Thus, Glycine is the only amino acid that is optically inactive in nature.
A polypeptide or protein is made up of amino acids. These amino acids are joined to one another by a peptide bond.
In a polypeptide/protein, if all the peptide bonds are broken, the remaining part left is the amino acids.
Glutenin is a protein that is generally found in wheat. It is mostly present in the endosperm (which makes wheat flour). The protein glutenin is constitute about 50% of the protein in wheat flour. Glutenin protein consists of low molecular weight and high molecular weight subunits that are bound together by disulfide bonds.
Together with gliadin proteins, glutenin forms a complex protein called the Gluten protein. Gluten protein provides elasticity to the dough and helps to rise during the bread-making process. It also provides shape and chewy texture to the bread.
Decarboxylation is the process in which a carboxyl group (C(=O)OH) is removed and is associated with the release of carbon dioxide (CO2) from a chemical reaction.
Decarboxylation reactions are important reactions in the Kreb’s cycle or the citric acid cycle. The following three steps of Kreb’s cycle include a decarboxylation reaction are:
- Pyruvate to acetyl-CoA: Removal of a carboxylic group from pyruvate (C3) to form acetyl-CoA (C2)
- Oxalosuccinate to α-ketoglutarate: Removal of a carboxylic group from Oxalosuccinate (C6) to form α-ketoglutarate (C5)
- α-ketoglutarate to succinyl-CoA: Removal of a carboxylic group from α-ketoglutarate (C5) to form succinyl-CoA (C4)
Lysine (C6H14N2O2, mol weight: 146) is an essential α-amino acid that is not synthesized by the human body. The amino acid belonging to the amino acid family is called the oxaloacetate/ aspartate family. The oxaloacetate/aspartate family also contains amino acids such as asparagine, methionine, isoleucine, and threonine.
As Lysine is an essential amino acid, it is not synthesized by humans and synthesized by organisms such as bacteria, fungi, and higher plants. In higher plants, the amino acid lysine is synthesized using oxaloacetic acid (an intermediate of Kreb’s cycle) as the precursor molecule.