Problem 3 - Objective Biology for NEET

Question

The percentage of oxygen in human body is (a) \(65 \%\) (b) \(46.6 \%\) (c) \(18.5 \%\) (d) \(3.3 \%\)

Step-by-Step Solution

Answer

The correct answer is (a) \(65\%\).

Step 1: Analyze the exercise

This exercise does not require calculations or in-depth logical problem solving. It simply tests whether you know the correct percentage of oxygen in the human body.

Step 2: Recall or research the bio-chemistry knowledge

If you can recall the composition of human body from your biology knowledge, you should be able to answer this question right away. Otherwise, you may need to look this information up in your textbook or a reliable online source. For instance, oxygen is the most abundant element in the human body accounting for about \(65\%\) of the body's mass.

Step 3: Make your choice

Now that you know the correct percentage of oxygen in human body is \(65\%\), you can pick up the correct choice from the given options. Here, option (a) \(65\%\) is the correct answer.

Key Concepts

Oxygen Percentage in Humans

Oxygen is one of the most vital elements in the human body. It is primarily known for its role in cellular respiration, a process necessary for producing energy. The percentage of oxygen by mass in the human body is approximately 65%. This figure reflects its abundance as a component of water, making up a significant portion of our body mass, considering that humans are mostly composed of water. Oxygen's high percentage underscores its critical importance in human physiology.

• Forms the backbone of water (H₂O), which constitutes most of our body weight.
• Essential for the breakdown of glucose to produce adenosine triphosphate (ATP), the energy currency of the cell.
• Vital part of DNA and proteins, crucial for genetic and structural integrity.

Remember, while oxygen is crucial, it must be maintained at proper levels as both deficiency and excess can be harmful to health. The balance of oxygen in the body is an example of the intricacies of human biochemistry.

Biochemistry

Biochemistry bridges the gap between biology and chemistry, exploring the chemical processes that make life possible. It focuses on the molecular mechanisms within living organisms, including complex reactions and compounds that occur in our bodies. Biochemistry helps us understand:

• How nutrients are converted into energy via metabolic pathways.
• The role of enzymes as biological catalysts speeding up reactions.
• How DNA provides instructions for building proteins and other cellular components.

Biochemistry is at the heart of medical advancements, enabling understanding of disease mechanisms and the development of therapeutic drugs. For instance, biochemical research has been fundamental in the battle against diseases like cancer by uncovering cellular pathological processes. Everyday applications include understanding nutrition, evaluating supplements, and recognizing metabolic disorders. As biochemical principles can be complex, breaking them down into simpler components helps in grasping its critical role in health and disease.

Elemental Composition of the Body

The human body is composed of several elements that form the basis of all the structures and functions within it. These elements are combined in various ways to create proteins, carbohydrates, fats, and nucleic acids, essential for survival and growth. Key elements include:

• Oxygen (O): As mentioned, makes up around 65% of the body's mass, supporting various biological processes.
• Carbon (C): Accounts for about 18.5% and is the backbone of organic life, forming essential compounds like proteins, lipids, and nucleic acids.
• Hydrogen (H): Comprises around 9.5% and is crucial in forming water and organic molecules essential for life.
• Nitrogen (N): Part of 3.3% of the body, crucial for making amino acids, which are building blocks of proteins.

Together, these elements make up about 96.2% of the human body's mass, highlighting their significance in maintaining life. Smaller amounts of elements like calcium, phosphorus, potassium, sulfur, sodium, chlorine, and magnesium also play critical roles in physiological processes, such as muscle contraction, nerve function, and bone health. Understanding the elemental composition provides insight into the biological and chemical framework that supports human life.