Biology: Biochemistry and Plant Physiology - Biological Molecules, Biochemistry, and Metabolism

Biological molecules are the building blocks of life, categorized into four main types: carbohydrates, lipids, proteins, and nucleic acids.

Carbohydrates are composed of carbon, hydrogen, and oxygen, typically in a ratio of $1:2:1$. The basic monomer is a monosaccharide, such as glucose ($C_6H_{12}O_6$).

Lipids (fats and oils) are hydrophobic molecules used for long-term energy storage and cell membrane structure. They are primarily composed of glycerol and fatty acid chains.

Proteins are polymers of amino acids linked by peptide bonds. They function as enzymes, structural components, and signaling molecules. Each amino acid contains an amine group ($-NH_2$) and a carboxyl group ($-COOH$).

Enzymes are biological catalysts that speed up chemical reactions by lowering the activation energy ($E_a$) required for the reaction to occur.

Metabolism is the sum of all chemical reactions in an organism, consisting of catabolism (breaking down molecules to release energy) and anabolism (using energy to build complex molecules).

Photosynthesis is the process by which plants convert light energy into chemical energy, occurring in the chloroplasts. The primary pigment involved is chlorophyll.

Cellular Respiration is the process of breaking down glucose to produce Adenosine Triphosphate ($ATP$), which serves as the universal energy currency for cells.