IndietroAnatomy & Physiology: Biochemistry Fundamentals
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Termini in questo insieme (21)
Biochemistry is the study of the chemical composition and reactions of living matter, including both organic and inorganic compounds essential to life.
Inorganic compounds do not contain carbon, e.g., water and salts. Organic compounds contain carbon bonded with hydrogen and are often large molecules like carbohydrates, fats, proteins, and nucleic acids.
Water has high heat capacity, high heat of vaporization, acts as a polar solvent, participates in reactivity (hydrolysis and dehydration synthesis), and provides cushioning for organs.
Salts contain cations and anions, conduct electrical currents in solution (electrolytes), and are vital for ionic balance and homeostasis. Examples include NaCl and KCl.
Acids release hydrogen ions (H+), acting as proton donors. Bases release hydroxyl ions (OH-), acting as proton acceptors.
pH measures the concentration of hydrogen ions (H+). Acidic solutions have pH 0–6.99, neutral is pH 7.00, and alkaline (basic) solutions have pH 7.01–14.
Buffers resist large swings in pH by releasing or binding hydrogen ions, converting strong acids or bases into weak ones. The carbonic acid–bicarbonate system is a key blood buffer.
Carbohydrates, lipids, proteins, and nucleic acids are the four main classes of organic compounds essential to life.
Carbohydrates contain C, H, and O with a 2:1 H to O ratio. They include monosaccharides (single sugars), disaccharides (two sugars), and polysaccharides (many sugars). They provide energy and storage forms like glycogen.
Saturated fatty acids have single bonds between carbon atoms and maximum hydrogen. Unsaturated fatty acids have one or more double bonds, reducing hydrogen atoms and causing 'kinky' tails.
Phospholipids are modified triglycerides with a glycerol backbone, two fatty acid tails (nonpolar), and a phosphorus-containing polar head. They are amphipathic and crucial for cell membrane structure.
Amino acids have a central carbon bonded to an amine group (-NH2), a carboxyl group (-COOH), a hydrogen atom, and an R group (side chain).
Primary: amino acid sequence; Secondary: alpha helices and beta sheets; Tertiary: 3D folding of secondary structures; Quaternary: interaction of multiple polypeptide chains.
Fibrous proteins are strandlike, insoluble, and provide structural support (e.g., collagen). Globular proteins are compact, soluble, and functional (e.g., enzymes, hemoglobin).
Denaturation is the unfolding and loss of a protein's 3D structure due to environmental changes like pH or temperature, often deactivating its function. It can be reversible or irreversible.
Enzymes are globular proteins that act as biological catalysts, lowering activation energy and increasing reaction speed without being consumed.
1. Substrate binds to enzyme's active site forming enzyme-substrate complex. 2. Complex rearranges substrate to form product. 3. Product is released, and enzyme is free to catalyze again.
Nucleic acids are polymers of nucleotides, each containing a nitrogen base, a pentose sugar, and a phosphate group. They include DNA and RNA.
In DNA, adenine (A) pairs with thymine (T), and guanine (G) pairs with cytosine (C) via hydrogen bonds.
RNA is single-stranded, contains ribose sugar instead of deoxyribose, and uses uracil (U) instead of thymine (T). It functions in protein synthesis.
ATP (adenosine triphosphate) is the primary energy carrier in cells, providing immediate usable energy by hydrolyzing its terminal phosphate bond.