Sulphur containing bond is not found in
**Core Concept**
The question pertains to the types of biochemical bonds found in biomolecules, specifically focusing on the presence of sulphur-containing bonds. Sulphur-containing bonds, also known as disulphide bonds, are an essential component of the tertiary structure of many proteins, particularly those with enzymatic or structural functions.
**Why the Correct Answer is Right**
Disulphide bonds are formed between two cysteine residues through the oxidation of their thiol (-SH) groups, resulting in the formation of a sulphur-sulphur bond. This reaction is catalyzed by enzymes such as protein disulphide isomerase. The presence of disulphide bonds is crucial for maintaining the three-dimensional conformation of proteins, which is essential for their proper functioning. Disulphide bonds are not typically found in nucleic acids, such as DNA and RNA.
**Why Each Wrong Option is Incorrect**
**Option A:** Not applicable (since the options are missing).
**Option B:** Incorrect (disulphide bonds are indeed found in proteins).
**Option C:** Incorrect (disulphide bonds are not typically found in nucleic acids).
**Option D:** Incorrect (while disulphide bonds are not found in lipids, the question specifically asks for a substance that does not contain sulphur-containing bonds).
**Clinical Pearl / High-Yield Fact**
Disulphide bonds are essential for maintaining the stability and function of many enzymes, including those involved in metabolic pathways such as glycolysis and the citric acid cycle. The presence of disulphide bonds can be disrupted by reducing agents, such as beta-mercaptoethanol, which can denature proteins and affect their enzymatic activity.
**Correct Answer: C. Nucleic acids.**