Problem 111 - Objective Biology for NEET

Question

Select the incorrect from the following: (b) Starch \(\stackrel{\text { Amylase }}{\longrightarrow}\) Disaccharides (c) Fats Iipases \(\longrightarrow\) Diglycerides \(\rightarrow\) Monoglycerides (d) Nucleotides \(\stackrel{\text { Nuclease }}{\longrightarrow}\) Nucleosides

Step-by-Step Solution

Answer

The incorrect statement is (d): Nucleotides \(\stackrel{\text { Nuclease }}{\longrightarrow}\) Nucleosides. Nuclease does not directly convert nucleotides into nucleosides.

Step 1: Analyzing Statement (b)

In the case of starch, the enzyme amylase breaks it down into simpler disaccharides. This is a known and accepted metabolic process in the human body. Therefore, this statement is correct.

Step 2: Analyzing Statement (c)

Concerning fats, they are broken down by lipases into diglycerides and further into monoglycerides. This also aligns with standard metabolic processes. Therefore, this statement is correct.

Step 3: Analyzing Statement (d)

For nucleotides, the enzyme nuclease does not result in nucleosides. In fact, nuclease first breaks nucleotides down into nucleic acids and novel nucleotides. Then, another enzyme, nucleosidase, is responsible for converting these to nucleosides. Therefore, this statement is incorrect.

Key Concepts

Amylase

Amylase is an enzyme that plays a crucial role in the digestive system by breaking down complex carbohydrates, like starches, into simpler sugars such as disaccharides. Imagine amylase as a pair of scissors cutting through the long chains of starch, making it easier for the body to utilize these sugars for energy. Amylase is found in both saliva and the pancreas, which means that the digestion of starch begins in the mouth and continues in the small intestine.

Understanding amylase's function helps us comprehend:

• Efficiency in digestion: By converting starch into smaller sugar molecules, amylase makes it easier for the body to absorb nutrients.
• Energy production: The sugars produced by amylase are crucial energy sources for the body.
• Health implications: Abnormal levels of amylase can indicate issues with the pancreas or salivary glands.

Lipases

Lipases are critical enzymes that assist in breaking down fats, known scientifically as lipids, into more digestible forms. Unlike proteins and carbohydrates, fats require a special process for digestion due to their hydrophobic nature. Lipases take on the task of breaking fats into diglycerides and ultimately monoglycerides, allowing the body to absorb and utilize these components.

Here are some key points about lipases:

• Enzyme variety: Different types of lipases act on different lipid molecules, including triglycerides and phospholipids.
• Source of energy: The breakdown of fatty acids by lipases provides essential energy, particularly when carbohydrate resources are low.
• Role in health: Proper lipase activity is critical for maintaining healthy levels of cholesterol and preventing diseases like pancreatitis and cardiovascular diseases.

Nuclease

Nucleases are enzymes with the vital function of cleaving the bonds within nucleic acids, such as DNA and RNA. These enzymes play a significant role in cellular processes, including DNA replication and repair. In the digestive process, nucleases break down dietary nucleic acids into smaller components, preparing them for further breakdown and absorption.

It's important to note some functions and facts about nucleases:

• DNA/RNA processing: Nucleases help maintain genome stability by repairing DNA and managing RNA transcripts in cells.
• Incorrect digestion pathway: Contrary to what some might believe, nucleases first degrade nucleic acids into nucleotides, not directly into nucleosides.
• Health implications: Defective nuclease activity is linked to genetic disorders and can affect immune system functions.