Biomolecules Reviewer PDF

REVIEWER IN BIOMOLECULES I. Nucleic Acids Largest macromolecules. Composed of nucleotide subunits. Two main types: DNA and RNA. A. Structure Nucleotides: Building blocks with a phosphate group, pentose sugar, and nitrogenous bases. Nitrogenous Bases: DNA: Adenine-Thymine (2 hydrog...

REVIEWER IN BIOMOLECULES I. Nucleic Acids Largest macromolecules. Composed of nucleotide subunits. Two main types: DNA and RNA. A. Structure Nucleotides: Building blocks with a phosphate group, pentose sugar, and nitrogenous bases. Nitrogenous Bases: DNA: Adenine-Thymine (2 hydrogen bonds), Guanine-Cytosine (3 hydrogen bonds). RNA: Adenine-Uracil, Guanine-Cytosine. Types of Nucleic Acids B. DNA (Deoxyribonucleic Acid): Found in nucleus, mitochondria, and chloroplasts. Double-stranded, helical structure with deoxyribose sugar. Functions: Stores genetic information, essential for protein coding, cellular functions, and replication. C. RNA (Ribonucleic Acid): Found in nucleus, cytoplasm, and ribosome. Single-stranded, with ribose sugar. Types and functions: Messenger RNA (mRNA): Transmits DNA messages for protein synthesis. Ribosomal RNA (rRNA): Major component of ribosomes, aiding mRNA alignment. Transfer RNA (tRNA): Transports amino acids for protein synthesis. Regulatory RNA: Involves microRNA and siRNA for gene regulation. Comparison of DNA and RNA DNA: Double helix, deoxyribose, stays in the nucleus, thymine as a pyrimidine. RNA: Single-stranded, ribose, travels from the nucleus, uracil replaces thymine.  II. Lipids A. Characteristics Non-polar, hydrophobic hydrocarbons. Key functions: Long-term energy storage, structural components, insulation, and hormone production. B. Structure Composed of glycerol and fatty acids, connected by ester bonds. Glycerol: Three hydroxyl groups. Fatty Acids: Aliphatic carboxylic acids, differing by saturation levels. C. Types of Fatty Acids Saturated Fatty Acids: Single bonds, tightly packed, solid at room temperature. Often derived from animal sources, considered "bad fats." Unsaturated Fatty Acids: One or more double bonds, liquid form ("oils"). Cis configuration (hydrogens on the same side) vs. Trans configuration (hydrogens on opposite sides). Mono (one double bond) or polyunsaturated (multiple double bonds). D. Essential Fatty Acids Omega-3 (Alpha-linolenic acid) and Omega-6 (Linoleic acid) are crucial dietary components. E. Lipid Varieties and Functions Phospholipids: Integral to biological membranes. Waxes: Protective coatings on plants and animals. Steroids: Fused-ring structure, hydrophobic, includes hormones like cortisol. Cholesterol: Precursor for sex hormones and vitamin D synthesis.  F. Cholesterol and Lipoproteins High-Density Lipoprotein (HDL): "Good cholesterol," moves cholesterol to the liver. Low-Density Lipoprotein (LDL): "Bad cholesterol," can lead to plaque buildup in arteries. III. Carbohydrates Commonly referred to as sugars. Produced via photosynthesis. A. Functions Energy supply and storage. Production of fats. Structural elements in RNA, DNA, and cell communication. B. Classification Monosaccharides (simple sugars). Aldoses: Carbonyl group as aldehyde. Ketoses: Carbonyl group as ketone. C. Monosaccharides Structure: Single sugar units, such as glucose, fructose, and galactose. Aldoses: Contain an aldehyde group (e.g., glucose). Ketoses: Contain a ketone group (e.g., fructose). Structure Conversions: Fischer to Haworth: Converting open-chain structures into ring forms (pyranose or furanose). Anomeric carbons define alpha and beta anomers based on the position of -OH.  D. Disaccharides Formation and Bonding Formed by a dehydration (condensation) reaction between two monosaccharides. Linked by glycosidic bonds, which can vary in type, influencing the structure and digestibility. Examples of Disaccharides Sucrose (glucose + fructose): Common table sugar. Lactose (glucose + galactose): Found in milk, requires lactase for digestion. Maltose (glucose + glucose): Found in malted foods and formed during starch digestion. Functions Serve as energy sources that can be readily broken down by organisms. Play roles in plant and animal metabolism. E. Polysaccharides Structure Complex carbohydrates made of long chains of monosaccharide units. Can be branched or unbranched, influencing their function and solubility. Types and Examples Starch: Main energy storage in plants. Composed of amylose (linear) and amylopectin (branched) chains of glucose. Glycogen: Main energy storage in animals, highly branched structure. Stored in the liver and muscles, providing quick-release energy. Cellulose: Structural component of plant cell walls. Composed of linear chains of beta-glucose; not digestible by humans due to beta glycosidic bonds. Chitin: Structural polysaccharide in exoskeletons of arthropods and fungal cell walls. Similar to cellulose but contains nitrogen, making it a modified polysaccharide. Functions of Polysaccharides Energy Storage: Starch and glycogen provide accessible energy reserves. Structural Support: Cellulose and chitin offer rigidity and protection in plants and certain animals. Digestibility and Enzyme Specificity Starch and glycogen are digestible by humans due to enzymes like amylase. Cellulose is indigestible, acting as dietary fiber, which aids in digestive health. IV. Proteins Macromolecules consisting of long chains of amino acids. One of the most abundant organic molecules in living systems. Diverse Functions. A. Functions of Proteins Structural Proteins: Examples: Actin, Keratin, Tubulin, Collagen. Transport Proteins: Examples: Hemoglobin, Integral Proteins. Defense Proteins: Highly specific proteins responsible for detecting foreign substances. Example: Antibodies. Contractile Proteins: Involved in muscle contraction. Examples: Actin, Myosin. Storage Proteins: Provide nourishment during early development (e.g., embryo). Examples: Albumin, Legume storage proteins. B. Structure of Proteins Amino Acid: Organic compounds that combine to form proteins. Considered the monomers of proteins. Linked by peptide bonds. Polypeptide: Linear organic polymer consisting of a chain of amino acid residues. C. Types of Amino Acids Essential Amino Acids: Must be obtained through diet as the body cannot synthesize them. Non-Essential Amino Acids: Can be synthesized by the body. Examples: Alanine, Arginine, Asparagine, Aspartic acid, Cysteine, etc. D. Levels of Protein Organization Primary Structure: Linear sequence of amino acids in a polymer. Secondary Structure: 3D folding of the polypeptide chain due to interactions between the N-terminus and C-terminus. Common forms: Alpha-helix and Beta-pleated sheet. Tertiary Structure: 3D folding pattern due to interactions of side chains. Quaternary Structure: Structure formed by more than one amino acid chain. Can be globular or fibrous.