UNIT I

Biologically important elements, the study of their atomic number, mass number, atomic mass, equivalent weight & molecular weight. Importance of Basic chemistry in medical laboratory technology.

Biological important elements are also called essential elements. They are chemical elements essential for living organisms to perform various physiological functions. These elements are required for the growth, development, and survival of the living organism. The following are some examples of biologically important elements

Definitions

1. Elements: elements are pure substances consisting of only one type of atom. Elements cannot be broken down into simpler substances or built from simpler substances. To date, 118 elements exist.

Types of Elements: Elements are divided into three types: Metals, Non Metals, and Metaloids.

• Metals: Metals are solid and hard except mercury. Mercury is liquid at room temperature. eg. Iron, copper, silver, gold, zinc, aluminum, mercury, etc.

• Nonmetals: Nonmetals do not have metallic properties. They exist as solid, liquid, or gas at room temperature. eg.  nitrogen, oxygen, hydrogen, sulfur, iodine, phosphorus, etc.

• Metaloids: Metaloids have properties of both metals and nonmetals eg. arsenic, bismuth, and antimony.

2. Atomic Number: The atomic number of an element is several unit positive charges present in the nucleus of an atom. OR The atomic number of an element is a number of protons in an atom nucleus. It is denoted by the symbol z.

Atomic Number = Number of protons.

eg. Carbon atomic number is 6. It means the carbon atom nucleus has six protons.

3. Mass Number: The mass number of an atom is the total number of protons and neutrons in its nucleus. The mass number is usually represented by the symbol B.

• Mass Number = Number of protons + Number of neutrons. OR

• Mass Number = Atomic Number + Number of Neutrons

4. Atomic Mass: Atomic mass is the weighted average mass of an element's atoms. It is measured in atomic mass units (AMU). This value is normally close to the mass number.

Calculation

The atomic number of carbon is 6 and the mass number is 12. Calculate several electrons, protons, and neutrons in the atom of carbon.

Solution

• Number of electrons = Atomic Number (z) = 6

• Number of protons = Atomic Number (z) = 6

• Number of Neutrons = mass number (A) – atomic number (z) = 12 – 6 = 6.

5. Isotopes: A large number of element atoms has the same number of protons but a different number of neutrons. Thus they have the same atomic number but different mass numbers. “They are called isotopes. The isotopes are the atoms of the same element having same atomic number and different mass numbers”.

6. Equivalent Weight: Equivalent weight is the mass of a substance that reacts with or supplies one mole of hydrogen ions (H⁺) or electrons in a chemical reaction. It is calculated by dividing the molar mass of the substance by its valence (the number of moles of electrons exchanged in the reaction).

7. Molecular weight: Molecular mass is also known as molecular weight. Molecules are made of atoms. Molecular mass is the sum of the atomic masses of all the atoms present in a molecule. It is measured in atomic mass units (amu) or daltons (Da). The molecular mass helps determine the mass of a single molecule. It is calculated by adding the atomic masses of each atom in the molecule according to its chemical formula.

Calculation of molecular mass:

• Molecular Mass of CaCO3 = Atomic Mass of Ca + Atomic Mass of C + Atomic Mass of OX3.

• = Atomic mass of Ca (40) + Atomic Mass of C (12) + Atomic Mass of O(16) X 3.

• 40 + 12 + 16 X3 = 40 + 12 + 48 = 100

• Molecular Mass of CaCO3 u = 100.

Biologically Important Elements:

1. Carbon (C): Carbon is the backbone of organic molecules Such as carbohydrates, lipids, proteins, and nucleic acid. These are essential compounds for cell structure and function.

• · Atomic No 6

• · Mass No 12 (6 proton and 6 Neutron)

• · Atomic mass (Molar mass): Approximately 12.01 g/mol. It is the average mass of carbon’s naturally occurring isotopes.

• · Equivalent Weight (gram equivalent mass). It depends on reaction and valency of carbon in specific reaction.

• · Molecular weight: Molecular weight of carbon varies depending upon the composition of molecule.

2. Hydrogen (H): Hydrogen is a component of water and many organic compounds. It is required for the energy transfer and pH regulation.

• · Atomic No: 1

• · Mass No: There are three isotopes of hydrogen. Mass No hydrogen-1 (Protium): 1, hydrogen-2 (deuterium): 2 (1 proton 1 neutron), Hydrogen-3 (tritium): 3 (1 proton, 2 neutrons).

• · Atomic mass (Molar mass): Approximately 1.008 of hydrogen-1. Hydrogen-1 is most abundant hydrogen

• · Equivalent Weight (gram equivalent mass). 1.008

• · Molecular weight: 2.016

3. Oxygen (O): Oxygen is utilised by the cells to produce energy from glucose. It is also a component of water and several organic compounds.

• · Atomic No: 8

• · Mass No: Approximately 16

• · Atomic mass (Molar mass): Approximately 15.9994

• · Equivalent Weight (gram equivalent mass). 8

• · Molecular weight: 32

4. Nitrogen (N): Nitrogen is a component of proteins and nucleic acid. It play important role in protein synthesis and genetic coding.

• · Atomic No: 7

• · Mass No: Approximately 14

• · Atomic mass (Molar mass): Approximately 14.007

• · Equivalent Weight (gram equivalent mass). Nitrogen equivalent weight depends upon the reaction.

• · Molecular weight: 28.014. (Sum of atomic masses of two nitrogen atoms).

5. Phosphorous (P): Phosphorous is a component of nucleic acid such as DNA and RNA. It is used in the formation of high-energy molecules such as ATP. ATP is a primary energy carrier in cells.

• · Atomic No: 15

• · Mass No: Approximately 31

• · Atomic mass (Molar mass): Approximately 30.974

• · Equivalent Weight (gram equivalent mass). 30.974

• · Molecular weight: The molecular weight of phosphorous depends upon a specific compound.

6. Sulphur (S): Sulphur is present in some amino acids. These amino acids are critical for the structure and function of the proteins.

• · Atomic No: 16

• · Mass No: Approximately 32

• · Atomic mass (Molar mass): Approximately 32.06

• · Equivalent Weight (gram equivalent mass). 16.03

• · Molecular weight: 256.48.

7. Potassium (K), Sodium (Na), Calcium (Ca) and Magnesium (Mg): These are essential elements also called electrolytes. They play a crucial role in nerve function, muscle contraction, and to maintain body fluid balance.

8. Iron (Fe): Iron is a component of haemoglobin in red blood cells. They carry oxygen and carbon dioxide inside living organism.

• · Atomic No: 26

• · Mass No: Approximately 56

• · Atomic mass (Molar mass): Approximately 55.845

• · Equivalent Weight (gram equivalent mass). 27.9225

• · Molecular weight: 55.845

9. Zinc (Zn): Zinc is cofactor for many enzymes that participates in several biological reactions, DNA synthesis and immune functions.

• · Atomic No: 30

• · Mass No: Approximately 64

• · Atomic mass (Molar mass): Approximately 65.38

• · Equivalent Weight (gram equivalent mass). Equvalent weight of zinc depends upon nature of reaction.

• · Molecular weight: zinc is a atom not molecule. It does not have molecular weight.

• 10. Copper (Cu): Copper is necessary for iron metabolism, antioxidant defence and synthesis of connective tissues.

• · Atomic No: 29

• · Mass No: Approximately 63.546

• · Atomic mass (Molar mass): Approximately 63.546

• · Equivalent Weight (gram equivalent mass). 31.773

• · Molecular weight: 63.546

11. Manganese (Mn): Manganese participates in various enzymetic reactions. It palys important role in bone formation.

• · Atomic No: 25

• · Mass No: Approximately 55 and 54

• · Atomic mass (Molar mass): Approximately 54.94

• · Equivalent Weight (gram equivalent mass). 27.47

• · Molecular weight: 86.94

12. Molybdenum: It is a cofactor for certain enzymes. It is involved in nitrogen metabolism.

• · Atomic No: 42

• · Mass No: Approximately 98

• · Atomic mass (Molar mass): Approximately 95.95

• · Equivalent Weight (gram equivalent mass). Equivalent weight depends upon specific chemical reaction.

• · Molecular weight: Molybdenum is an element; It does not have molecular weight.

Dr Pramila Singh

Importance of Basic chemistry in medical laboratory technology.

Basic chemistry is the backbone of medical laboratory technology. It helps in accurate diagnosis and understanding of diseases. It helps in research and medical advancement. This improves patient care and patient outcomes. Basic chemistry importance in medical laboratory technology can be explained as per the below details

• 1. Diagnostic test: Most of Diagnostic tests under medical laboratory technology depend upon chemical analysis of the sample.

• 2. Understanding of the human body Physiology: Knowledge of basic chemistry helps medical laboratory professionals to understand chemical processes inside the human body.

• 3. Quality control: Knowledge of basic chemistry helps medical laboratory professionals to maintain quality control measures. This assures reliable and accurate results of tests.

• 4. Toxicology: Knowledge of basic chemistry helps medical laboratory professionals to identify and measure toxic substances in patient’s samples.

• 5. Research and development: Knowledge of basic chemistry helps medical laboratory professionals to develop new medical technologies and diagnostic methods.

• 6. Immunology and serology: Knowledge of basic chemistry helps medical laboratory professionals to detect antigens and antibodies in the patient sample.

• 7. Hematology: Knowledge of basic chemistry helps medical laboratory professionals to study blood components and other parameters related to blood.