Photosynthesis is a chemical process that plants, algae, and some bacteria use to create food and energy. It’s important because it:
Provides food and energy
Photosynthesis is the primary source of food and energy for all living organisms. Animals that eat plants get their energy from the sugar stored in plants, and animals that eat those animals get the same energy.
Produces oxygen
Photosynthesis releases oxygen into the atmosphere, which all living species need.
Regulates carbon dioxide and oxygen levels
Photosynthesis helps keep the levels of carbon dioxide and oxygen in an ecosystem in check.
Influences agricultural crop productivity
The rate of photosynthesis affects how productive agricultural crops are.
Creates fossil fuels
The energy stored in fossil fuels like petroleum, natural gas, and coal comes from the sun via photosynthesis.
Here’s how photosynthesis works:
1. Light-dependent reactions
Chlorophyll, a pigment in plants, absorbs light energy from the sun. This breaks down water molecules to create energy and oxygen.
2. Calvin cycle
The energy created in the light-dependent reactions fuels the Calvin cycle, a light-independent reaction that converts carbon dioxide into glucose.

The law of conservation of mass is significant because it helped scientists understand that matter is not created or destroyed during chemical reactions, but rather transformed into other substances with the same mass. This discovery was a key factor in the progression of chemistry and the development of modern science.
Here are some other details about the law of conservation of mass:
Explanation
The law states that the total mass of all reactants and products in a chemical reaction is the same at any point in time. This is because mass can be rearranged in space and the entities associated with it can change shape.
Discovery
The law was discovered by multiple scientists, including Russian scientist Mikhail Lomonosov and French chemist Antoine Lavoisier. Lavoisier is sometimes credited with discovering the law, and it is sometimes known as Lavoisier’s Law.
Chemical equations
A balanced chemical equation satisfies the law of conservation of mass. In a balanced chemical equation, the number of each type of atom is the same on both sides of the equation.
Physical changes
The law of conservation of mass does not apply to physical changes, such as ice melting to water. In a physical change, the physical properties of a substance change, but its chemical identity remains the same.

Ribonucleic acid (RNA) plays a central role in protein synthesis by carrying genetic information from DNA to ribosomes, where proteins are assembled:
Messenger RNA (mRNA)
Carries the genetic information from DNA in the nucleus to the ribosomes in the cytoplasm. The ribosomes use this information to build proteins.
Transfer RNA (tRNA)
Carries amino acids to the ribosomes. Each tRNA molecule is specific to one amino acid and carries it to the ribosome, where it is added to the growing protein chain.
Ribosomal RNA (rRNA)
Forms the core of the ribosomes, where protein synthesis takes place. rRNA molecules interact with mRNA and tRNA to facilitate protein assembly.
RNA also has other roles in cells, including:
Catalytic: Some types of RNA carry out biochemical reactions, similar to enzymes.
Regulatory: Many types of RNA regulate gene expression and protect against viruses.
Initiating DNA synthesis: RNA primers are introduced at the template DNA site to initiate DNA synthesis.
Errors in RNA production or sequence can cause disease in humans. For example, Diamond Blackfan anemia is caused by a defect in ribosome production, and some forms of diabetes are caused by mutations in tRNA.