Amino acids are a crucial, yet basic unit of protein, and they contain an amino group and a carboxylic group. They play an extensive role in gene expression processes.

Amino acids become proteins when 50 or more are bonded together in a chain. All the millions of different proteins in living things are formed by the bonding of only 20 amino acids.

Eight of these amino acids are essential and cannot be produced by the body.

They are:

• Leucine

• Isoleucine

• Lysine

• Threonine

• Methionine

• Phenylalanine

• Valine

• Tryptophan

•  Histidine is an amino acid that is categorized as semi-essential since the human body doesn't always need it to properly function

Nonessential amino acids are produced by the human body either from essential amino acids or from normal protein breakdowns. Nonessential amino acids include:

• Asparagine

• Alanine

• Arginine

• Aspartic acid

• Cysteine

• Glutamic acid

• Glutamine

• Proline

• Glycine

• Tyrosine

• Serine.

Ribosomes are the sites where proteins are synthesised. The transcription process where the code of the DNA is copied occurs in nucleus but the main process of translating that code to form other protein occurs in ribosomes.

An atom is composed of three subatomic particles. They are ::

1) Electron (-vely charged particle)

2) Proton (+vely charged particle)

3) Neutron (No charge particle)

Hence, Neutron is the subatomic particle which has no charge.

Chlamydial infection is very common in both males and females.

NGU (Non-Gonococcal Urethritis) is an infection of the urethra caused by pathogens (germs) other than gonorrhea.

Several types of germs cause NGU. The most common and serious is chlamydia.

In chemistry, Weak bonds are those forces of attraction that, do not take a large amount of energy to break.

For example, hydrogen bonds are broken by energies in the order of 4 - 5 kcal/mol.

Ionic bonds, hydrogen bonds and van der Waals interactions are considered weak bonds.

Weak bonds are transient and easily reversible.

TIME is what we can measure in Years, Months, Days, Hours, Minutes and Seconds but we cannot see.

When water is cooled from 4°C to 0°C, its density decreases.

When water cools from 4°C to 0°C, ice crystals begin to form because the water is approaching its freezing point. When water freezes, the water molecules form a lattice that increases the volume. As a result, the density decreases. This is why ice will float on top of water; ice has a lower density than the water.