BIOCHEMISTRY IN NURSING

INTRODUCTION TO BIOCHEMISTRY 

1.     What is biochemistry?

Biochemistry derives its name from bio= life, chemistry= study of chemicals. So, simply biochemistry is the study of the chemistry of life.  In other words, Biochemistry is the science in which chemistry is applied to the study of living organisms and the atoms and molecules that comprise living organisms.

2.     Who gave the term biochemistry?

The term Biochemistry (bios=life) was first coined by a German chemist, Carl Neuberg, in 1903.

3.     What are biomolecules?

Biomolecules, also called biological molecules, are substances that are produced by cells and living organisms, which include carbohydrates, proteins, lipids, nucleic acids, etc.

1.     Explain the importance of biochemistry in Health/ Nursing.

Clinical biochemistry is very important in nursing because it helps in understanding, diagnosing, and monitoring the health conditions of patients. It deals with the chemical changes that occur in the body due to diseases or treatments.

1. Understanding Body Functions- Biochemistry helps nurses understand how the human body functions at the molecular and cellular levels. It explains how nutrients such as carbohydrates, proteins, and lipids are metabolized to produce energy and maintain normal physiological processes. For example, the process of converting glucose into energy through cellular respiration is essential for the proper functioning of organs and tissues. Knowledge of biochemical reactions also helps nurses understand how enzymes, hormones, and electrolytes regulate body activities and maintain homeostasis.

2. Disease Diagnosis- Biochemistry plays a vital role in the diagnosis of many diseases because most illnesses cause measurable biochemical changes in body fluids such as blood, urine, and cerebrospinal fluid. Laboratory tests that measure biochemical substances help healthcare professionals identify and monitor diseases. For example, increased blood glucose levels are used to diagnose Diabetes Mellitus, while low hemoglobin levels help detect Anemia. Similarly, abnormal liver enzymes in blood tests can indicate Liver Disease.

3. Interpretation of Laboratory Tests- Biochemical knowledge is essential for understanding and interpreting laboratory investigations commonly used in clinical practice. Nurses frequently deal with biochemical reports such as blood glucose, cholesterol, urea, creatinine, and electrolyte levels. For example, high serum creatinine levels may indicate Kidney Disease, while elevated cholesterol levels are associated with Cardiovascular Disease. Understanding these biochemical parameters helps nurses assist doctors in monitoring patient health and treatment progress.

4. Drug Action and Treatment- Biochemistry helps nurses understand how drugs interact with biochemical pathways in the body. Many medications work by altering enzyme activity, hormone levels, or metabolic reactions. For instance, insulin therapy is used to regulate blood glucose levels in patients with Diabetes Mellitus, while certain antibiotics inhibit bacterial metabolic processes to treat infections. Knowledge of biochemical mechanisms helps nurses administer drugs safely and observe their therapeutic and side effects.

5. Nutrition and Diet Planning- Biochemistry provides the scientific basis for understanding the nutritional requirements of patients. Nutrients such as carbohydrates, proteins, fats, vitamins, and minerals are necessary for energy production, tissue repair, and immune function. For example, iron deficiency in the diet can lead to Iron Deficiency Anemia, while excessive fat intake may increase the risk of Obesity. Nurses use biochemical knowledge to guide patients on proper nutrition for recovery and health maintenance.

6. Monitoring Patient Condition- Biochemistry is important for monitoring the physiological and metabolic status of patients during treatment. Changes in biochemical parameters such as electrolyte levels, hormone concentrations, and metabolic products can indicate improvement or deterioration of a patient’s condition. For example, abnormal sodium or potassium levels can lead to serious complications in patients with Kidney Disease or heart problems. Nurses use biochemical test results to continuously assess patient progress and support effective clinical care.

Scope of Biochemistry

The scope of biochemistry means the range of areas, fields, and applications where biochemistry is used or can be applied.

1. Medicine and Health Care
• Understanding diseases at the molecular level.
• Development of drugs and vaccines.
• Clinical diagnosis through biochemical tests (like blood glucose, liver function tests, etc.).
2. Clinical and Diagnostic Laboratories
• Biochemists work in pathology labs testing blood, urine, and other samples for disease markers.
• Helps in clinical biochemistry and medical research.
3. Pharmaceutical Industry
• Drug design and formulation.
• Studying how drugs interact with enzymes, proteins, or DNA.
4. Agriculture and Food Industry
• Improving crop yield using biochemical techniques.
• Food preservation, fermentation, and nutritional analysis.
5. Environmental Science
• Studying pollution effects on organisms.
• Biochemical analysis of soil, water, and air.
6. Biotechnology and Genetic Engineering
• Cloning, gene editing (CRISPR), and recombinant DNA technology.
• Producing insulin, enzymes, and vaccines using microbes.
7. Forensic Science
• Identification of biological samples (DNA fingerprinting, toxicology).
8. Research and Education
• Teaching biochemistry at schools, colleges, and universities.
• Conducting biochemical and molecular biology research.

Define Solution

A solution is a homogeneous mixture of solvent and solute molecules in which the solute diffuses through the solvent until the concentration is equal in all parts of the solution. Eg. Glucose (solute) dissolved in water (solvent).

What are the components of the solution?

The components of a solution are

·       Solute: substance (or substances) present in a lesser amount being dissolved. E.g., salt, sugar,

·       Solvent: a substance present in a greater amount that does the dissolving. Eg- water

 

Define the Concentration of the solution.

The concentration of a solution is the amount of solute dissolved in a specific quantity of solvent or solution.

Common Units of Concentration:

Type	Definition	Example
1. Percentage (%)	Amount of solute in 100 parts of solution	5% glucose solution = 5 g glucose in 100 mL solution
2. Molarity (M)	Gram Molecular weight or Moles of solute per liter of solution	1 M NaCl = 1 mole (58.5 g) NaCl in 1 L solution
4. Normality (N)	Gram equivalents of solute per liter of solution	1 N HCl = 36.5 g HCl per liter

 

What is a percent solution?

A percent solution simply means per hundred. It is the solution expressed in the unit %. It is better defined as the solution having the amount of solute in grams or milliliters dissolved in the solvent, making the final volume 100ml.

Eg- 10% NaCl solution means ten grams of sodium chloride dissolved in 100 ml of solution.

 List types of percent solution

Types of percent solution

•        Percentage weight by volume (w/v)

•        Percentage volume by volume (v/v)

•        Percentage weight by weight (w/w)

Type	Symbol	Meaning	Example
1. Weight by Volume	(w/v)	grams of solute per 100 mL of solution	5% glucose = 5 g glucose in 100 mL solution
2. Volume by Volume	(v/v)	mL of solute per 100 mL of solution	70% ethanol = 70 mL ethanol in 100 mL total solution
3. Weight by Weight	(w/w)	grams of solute per 100 g of solution	10% NaCl (w/w) = 10 g NaCl in 90 g water (total 100 g)

 

What is Normal Saline? How is it prepared?

Normal saline (also called physiological saline) is a 0.9% sodium chloride (NaCl) solution in water. It means 0.9 grams of NaCl are present in 100 mL of solution, or 9 grams in 1 liter.

It is isotonic with human blood plasma — meaning it has the same osmotic pressure as body fluids, so it does not cause red blood cells to shrink or swell.

It is prepared as follows

1.     Weigh 9.0 g of pure NaCl using a balance.

2.     Transfer the NaCl into a 1-liter volumetric flask or beaker.

3.     Add about 800 mL of distilled water and stir until the NaCl dissolves completely.

4.     Add more distilled water to make the final volume up to 1 liter.

5.     Mix thoroughly.

6.     Sterilize by autoclaving at 121°C for 15 minutes if it is to be used for medical or microbiological purposes.

Define a molar solution.

A molar solution is defined as a solution that contains the molecular weight of solutes in grams or moles of substance per liter of solution, and such a solution is called a 1mol/liter solution. 

In other words, the molar solution is defined as the number of moles of solute per liter of solution. 

How will you prepare 1M NaCl solution?

The molecular weight of a sodium chloride molecule (NaCl) is 58.44, so one gram-molecular mass (=1 mole) is 58.44 g. We know this by looking at the periodic table. The atomic mass (or weight) of Na is 22.99, the atomic mass of Cl is 35.45, so 22.99 + 35.45 = 58.44.

If we dissolve 58.44g of NaCl in a final volume of 1 liter, we have made a 1M NaCl solution, a 1 molar solution.

 To make molar NaCl solutions of other concentrations dilute the mass of salt to 1000ml of solution as follows:

0.1M NaCl solution requires 0.1 x 58.44 g of NaCl = 5.844g

0.5M NaCl solution requires 0.5 x 58.44 g of NaCl = 29.22g

2M NaCl solution requires 2.0 x 58.44 g of NaCl = 116.88g

Define normality or normal solution

The normality of a solution is the gram equivalent weight of a solute per liter of solution. In other words, a Normal solution is a solution in which the gram equivalent weight of solute dissolves in solvent, making the final volume 1000 ml.

E.g., the equivalent weight of NaOH=40, so 1 Normal solution means 40 gm of NaOH dissolves in 1 liter of solution.

How will you prepare a 1N NaOH solution?

The molecular weight of a sodium hydroxide molecule (NaOH) is 40, so its equivalent weight is

Equivalent weight of alkali molecular weight/number of replaceable hydroxyl groups

Equivalent weight of NaOH 40/1=40

If we dissolve 40g of NaOH in a final volume of 1 liter, we have made a 1N NaOH solution, a 1 normal solution.

To make normal NaOH solutions of other concentrations, dilute the mass of alkali to 1000ml of solution as follows:

0.1 N NaOH solution requires 0.1 x 40 g of NaOH = 4 g

0.5 N NaOH solution requires 0.5 x 40 g of NaOH = 20 g

2 N NaOH solution requires 2.0 x 40 g of NaOH = 80 g

What is diffusion?

Diffusion is the movement of molecules from an area of high concentration of the molecules to an area with a lower concentration of molecules until the equilibrium is maintained or until the concentrations are equalized.

As shown in the figure, initially, the particles are all near one corner of the glass. If the particles all randomly move around ("diffuse") in the water, they will eventually become distributed randomly and uniformly. Eg- Sugar and salt diffuse in water.

Explain the role of diffusion in the human body.

Ø  Gas Exchange in Lungs (Respiration)- Oxygen diffuses from the alveoli (high O₂ concentration) into the blood (low O₂ concentration). Carbon dioxide diffuses from the blood (high CO₂ concentration) into the alveoli to be exhaled.

Ø  Absorption of Nutrients- In the small intestine, nutrients like glucose and amino acids diffuse from the intestinal lumen (high concentration) into the blood capillaries (low concentration).

Ø  Removal of Waste Products- Waste materials like urea diffuse from cells into the bloodstream and are transported to the kidneys for excretion.

Ø  Transmission of Nerve Impulses- During nerve signaling, ions such as sodium (Na⁺) and potassium (K⁺) diffuse across the neuron membrane, helping generate electrical impulses.

  D Define Osmosis

Osmosis is the movement of the solvent (water) from a region of higher concentration of water to a region of lower concentration of water through a semipermeable membrane, to maintain the equilibrium.  Water moves into and out of cells by osmosis.

Osmosis is the movement of solvent molecules (usually water) from a region of lower solute concentration (more water) to a region of higher solute concentration (less water) through a semipermeable membrane, until equilibrium is reached.

List out examples of Osmosis in the Human Body

1. Movement of Water in Red Blood Cells
• When red blood cells are placed in a hypotonic solution (e.g., pure water), water enters the cells by osmosis → they swell and may burst (hemolysis).
• In a hypertonic solution (e.g., concentrated saline), water leaves the cells → they shrink (crenation). This principle is important when giving IV fluids.

2. Reabsorption of Water in the Kidneys
• In the nephrons, water moves by osmosis from the filtrate in the renal tubules back into the blood capillaries.
  This helps maintain the body’s water balance and prevents dehydration

Explain the importance of osmosis while administering intravenous (IV) fluids

The osmosis principle is fundamental in nursing, especially when administering intravenous (IV) fluids. Depending on the solute concentration of a fluid compared to that of the body’s cells, solutions are categorized as hypotonic, isotonic, or hypertonic. Understanding how each type affects the movement of water and the size of red blood cells helps nurses choose and manage IV therapy safely.

1. Hypotonic Solution

A hypotonic solution has a lower solute concentration compared to the fluid inside the body’s cells. According to the principle of osmosis, water moves from the area of higher water concentration (outside the cell) to the area of lower water concentration (inside the cell). As a result, water enters the cell, causing it to swell and sometimes burst (hemolysis) if the process continues.

In nursing practice, hypotonic fluids are used to treat cellular dehydration, when cells have lost water. Common examples include 0.45% Sodium Chloride (Half Normal Saline) and 0.33% Sodium Chloride. These fluids are helpful in conditions like hypernatremia (high sodium level) and diabetic ketoacidosis (DKA) after initial isotonic fluid therapy. Nurses must monitor for signs of cerebral edema, confusion, or headache due to excessive water entering brain cells.

2. Isotonic Solution

An isotonic solution has the same solute concentration as that inside the cells and body fluids. In this case, there is no net movement of water across the cell membrane, as the osmotic pressure is balanced on both sides. The cells remain their normal size and shape.

In clinical and nursing use, isotonic fluids are the most commonly administered because they maintain fluid balance without altering cell volume. Examples include 0.9% Sodium Chloride (Normal Saline) and Lactated Ringer’s solution. These are used for fluid replacement in dehydration, hemorrhage, shock, or surgery, and during blood transfusions. Nurses must monitor for fluid overload in patients with heart or kidney conditions, even though isotonic fluids are generally safe.

3. Hypertonic Solution

A hypertonic solution has a higher solute concentration compared to the fluid inside the cells. By osmosis, water moves out of the cell into the extracellular space to balance the solute concentration. This causes the cells to shrink (crenate) and may lead to cellular dehydration if used excessively.

In nursing care, hypertonic fluids are used to draw water out of swollen cells and reduce edema or to correct severe hyponatremia (low sodium levels). Examples include 3% Sodium Chloride and 5% Dextrose in Normal Saline (D5NS). These solutions must be administered slowly and under close monitoring, as rapid infusion can cause fluid overload, hypertension, or damage to veins due to their high osmolarity.

Difference between diffusion and osmosis

Diffusion	Osmosis
Movement of particles from a region of higher concentration to a region of lower concentration.	Movement of water molecules through a semi-permeable membrane from a region of higher water concentration to a region of lower water concentration.
General physical process.	Special type of diffusion involving water.
Can occur in gases, liquids, or solids.	Occurs only in liquids (mainly water).
Does not require a semi-permeable membrane.	Requires a semi-permeable membrane.
Any type of molecules (gas, solute, etc.) are involved	Only water molecules involved
Particles move until concentration is uniform throughout.	Water moves until concentration of solvent and solute reaches equilibrium on both sides.
Eg- Exchange of oxygen and carbon dioxide in lungs or between cells.	Eg- Absorption of water by root hair cells in plants.