Introduction to Biochemistry

Introduction to Biochemistry

• Biochemistry is the study of chemical processes within and relating to living organisms.
• It encompasses a wide range of topics, including the structure and function of biological molecules, metabolism, and the regulation of biochemical pathways.
• Key biological molecules include carbohydrates, lipids, proteins, and nucleic acids.
• These molecules are essential for various life processes, including energy production, cell signaling, and genetic information transmission.

Carbohydrates

• Carbohydrates are the primary source of energy for most organisms.
• They are composed of carbon, hydrogen, and oxygen atoms.
• Simple sugars (monosaccharides) are the basic building blocks of carbohydrates.
• Common monosaccharides include glucose, fructose, and galactose.
• Disaccharides are formed by the condensation of two monosaccharides. Sucrose, lactose, and maltose are examples.
• Polysaccharides are long chains of monosaccharides. Starch and glycogen are energy storage polysaccharides, while cellulose is a structural polysaccharide.
• Carbohydrates play a crucial role in cell recognition and structure.

Lipids

• Lipids are a diverse group of hydrophobic molecules, including fats, oils, and waxes.
• They are primarily composed of carbon and hydrogen atoms.
• Fats and oils are composed of fatty acids and glycerol.
• Fatty acids can be saturated or unsaturated.
• Saturated fats contain only single bonds between carbon atoms, while unsaturated fats contain one or more double bonds.
• Phospholipids are a crucial component of cell membranes.
• Steroids, such as cholesterol, serve various functions within the body.
• Lipids play roles in hormone production, insulation, and energy storage.

Proteins

• Proteins are complex organic molecules composed of amino acids linked together by peptide bonds.
• Twenty different amino acids are common.
• The specific sequence and arrangement of amino acids determine the unique structure and function of each protein.
• Proteins play diverse roles in biological systems, including catalyzing reactions as enzymes, providing structural support, and regulating cellular processes.
• The four levels of protein structure are primary, secondary, tertiary, and quaternary.
• Primary structure is the linear sequence of amino acids.
• Secondary structure involves local folding patterns, such as alpha-helices and beta-sheets.
• Tertiary structure is the overall three-dimensional shape of a protein.
• Quaternary structure is the arrangement of multiple polypeptide chains in a protein.
• Protein function is directly determined by its three-dimensional structure.

Nucleic Acids

• Nucleic acids, DNA and RNA, store and transmit genetic information.
• DNA (deoxyribonucleic acid) is the primary genetic material in most organisms.
• RNA (ribonucleic acid) plays several roles in protein synthesis and gene regulation.
• Both DNA and RNA are composed of nucleotides.
• Nucleotides each consist of a sugar, a phosphate group, and a nitrogenous base.
• DNA is a double helix structure, while RNA is typically single-stranded.
• Nucleic acids are essential for inheritance and protein synthesis.

Enzymes

• Enzymes are biological catalysts that speed up chemical reactions in living organisms.
• Most enzymes are proteins.
• Enzymes lower the activation energy required for a reaction to occur.
• The active site of an enzyme is where the substrate binds.
• Enzyme activity is affected by factors such as temperature, pH, and substrate concentration.
• Enzymes are highly specific for their substrates.