Out of all four major organic molecules (carbohydrates, lipids, proteins, and nucleic acids) which ones are present in blood?

All are in the blood. Think on what is blood: water, dissolved gases, cells, foods (sugars, lipids, amino acids, etc)

To determine which of the four major organic molecules are present in blood, we need to understand the components of blood. Blood contains several essential components, including water, dissolved gases, cells, and nutrients.

Carbohydrates: Carbohydrates are one of the main sources of energy for the body. In the blood, carbohydrates are present in the form of glucose, which is derived from foods we consume. Glucose is the primary sugar molecule found in blood and is vital for providing energy to cells.

Lipids: Lipids, commonly known as fats, are another type of organic molecule present in the blood. Lipids in the blood include triglycerides and cholesterol. Triglycerides are the main storage form of fat in the body and can be used as an energy source. Cholesterol, although often associated with negative health effects, is an essential component for cell membranes and hormone production.

Proteins: Proteins are complex molecules composed of amino acids and play a crucial role in various functions within the body. In the blood, proteins are present in the form of serum albumin, globulins, and fibrinogen. These proteins are responsible for transporting nutrients, hormones, and waste products, as well as maintaining fluid balance and assisting in blood clotting.

Nucleic acids: Nucleic acids, specifically DNA and RNA, are not typically found in significant amounts in blood. However, small amounts of DNA can be detected in the blood due to cell turnover or in certain disease states.

In summary, all four major organic molecules (carbohydrates, lipids, proteins, and nucleic acids) can be found in the blood to some extent. Carbohydrates, lipids, and proteins are the most abundant and have important roles in various physiological processes.