Bachelor of Pharmacy (B.Pharm.) Biochemistry Flashcards

Proteins' peptide bonds are detected by

Answer: Biuret test

The Biuret test is a specific chemical test used to detect the presence of peptide bonds, which are the characteristic linkages between amino acids in proteins. The test relies on the reaction of copper(II) ions in an alkaline solution with the peptide bonds, producing a distinctive violet color. This color change indicates the presence of proteins or peptides containing at least two peptide bonds.

Which amino acid is the smallest?

Answer: Glycine

Glycine is the smallest and simplest amino acid because its side chain (R-group) consists of a single hydrogen atom. This unique structure makes it the only achiral (non-chiral) amino acid among the standard 20, contributing to its flexibility and specific roles in protein structure and function.

Related to vitamin A are:

Answer: β-ionone

Vitamin A (retinol) and its precursors, such as beta-carotene, are structurally derived from β-ionone. The β-ionone ring is a crucial structural component found in beta-carotene, which is then cleaved to form retinal, a direct precursor to vitamin A. This specific ring structure is essential for the biological activity and function of vitamin A in the body.

The following vitamins interact with Ca++ ATPase in intestinal cells:

Answer: Vitamin D

Vitamin D plays a critical role in regulating calcium absorption in the intestines. It stimulates the synthesis of calcium-binding proteins and enhances the activity of Ca++ ATPase, an enzyme responsible for actively transporting calcium ions across intestinal cell membranes into the bloodstream. This action is vital for maintaining proper calcium levels and bone health.

Regular use of the antitubercular medication isoniazid results in deficiencies of:

Answer: vitamin B6

Isoniazid, an antitubercular medication, is known to interfere with the metabolism of vitamin B6 (pyridoxine). It forms an inactive derivative with pyridoxal phosphate, the active form of vitamin B6, leading to its depletion in the body. This deficiency can cause peripheral neuropathy, a common side effect of isoniazid therapy, which is often prevented by co-administering vitamin B6 supplements.

The test for Sakaguchi is anticipated to:

Answer: Arginine

The Sakaguchi test is a specific biochemical test used to detect the presence of the guanidino group. Among the given amino acids, arginine is the only one that contains a guanidino group in its side chain. Therefore, a positive result in the Sakaguchi test indicates the presence of arginine.

Which enzyme can be used to clinically diagnose acute pancreatitis?

Answer: Both A and B

Amylase and lipase are key digestive enzymes primarily produced by the pancreas. In acute pancreatitis, the inflamed pancreas releases these enzymes into the bloodstream, leading to significantly elevated serum levels. Measuring both amylase and lipase levels is crucial for an accurate clinical diagnosis of this condition.

Which enzyme helps two molecules bind together?

Answer: Ligase

Ligases are a class of enzymes specifically responsible for catalyzing the joining of two large molecules. They achieve this by forming a new chemical bond, a process often coupled with the hydrolysis of a small, energy-rich molecule like ATP. This makes them essential for processes like DNA replication and repair.

Kinetics of enzyme reactions are controlled by:

Answer: Michaellis and Menten theory

The kinetics of enzyme reactions, which describe how reaction rates are influenced by substrate concentration and enzyme properties, are primarily controlled by the Michaelis-Menten theory. This widely accepted model provides a mathematical framework to understand the relationship between reaction velocity and substrate concentration, defining parameters like Vmax and Km.

Where do the carbon atoms in cholesterol come from?

Answer: Acetyl-CoA

All carbon atoms found in cholesterol are ultimately derived from acetyl-CoA. Acetyl-CoA molecules are sequentially condensed and modified through a multi-step pathway, including the formation of mevalonic acid and squalene, to build the complex sterol structure of cholesterol. This makes acetyl-CoA the fundamental building block for cholesterol biosynthesis.

The HMP enzyme pathway is found in:

Answer: Cytosol

The Hexose Monophosphate Pathway (HMP pathway), also known as the Pentose Phosphate Pathway, is a metabolic pathway that occurs entirely in the cytosol of cells. Its primary functions are to generate NADPH, essential for reductive biosynthesis and antioxidant defense, and to produce the precursor ribose-5-phosphate for nucleotide synthesis.

The enzyme, cis-aconitase, uses the citrate to create isocitrate:

Answer: aconitase

The enzyme aconitase is responsible for catalyzing the reversible isomerization of citrate to isocitrate in the citric acid cycle. This reaction proceeds through an intermediate called cis-aconitate, hence the enzyme's name. It plays a crucial role in preparing the carbon skeleton for subsequent oxidative decarboxylation steps.

The blood plasma's typical level of calcium is:

Answer: 9-11 mg/100 ml

The typical level of calcium in the blood plasma is tightly regulated within a narrow physiological range to maintain essential bodily functions. A normal adult reference range for total serum calcium is generally considered to be 9-11 mg/100 ml (or 2.2-2.75 mmol/L). Deviations from this range can have significant health implications.

The following is related to the atherosclerosis risk factor:

Answer: VLDL and LDL

Very Low-Density Lipoproteins (VLDL) and Low-Density Lipoproteins (LDL) are strongly associated with an increased risk of atherosclerosis. VLDL transports triglycerides and cholesterol from the liver to peripheral tissues, while LDL primarily delivers cholesterol to cells. High levels of these lipoproteins contribute to plaque formation in arteries, leading to cardiovascular disease.

The condition albinism is related to:

Answer: defect related to melanin biosynthesis

Albinism is a genetic disorder characterized by a partial or complete absence of melanin pigment in the skin, hair, and eyes. This condition is directly related to a defect in the melanin biosynthesis pathway, most commonly due to a deficiency or absence of the enzyme tyrosinase, which is crucial for converting tyrosine into melanin.

The vitamin D precursor is:

Answer: Cholesterol

Cholesterol serves as the precursor for vitamin D synthesis in the body. Specifically, 7-dehydrocholesterol, a derivative of cholesterol found in the skin, is converted into pre-vitamin D3 upon exposure to ultraviolet B (UVB) radiation from sunlight. This pre-vitamin D3 then isomerizes to vitamin D3, which is further metabolized to its active form.