Biomolecules The Chemical Building Blocks of Life Condensation It’s not just for the water cycle anymore • Macromolecules are constructed by covalently bonding monomers by condensation.
Download ReportTranscript Biomolecules The Chemical Building Blocks of Life Condensation It’s not just for the water cycle anymore • Macromolecules are constructed by covalently bonding monomers by condensation.
Biomolecules The Chemical Building Blocks of Life Condensation It’s not just for the water cycle anymore • Macromolecules are constructed by covalently bonding monomers by condensation reactions where water is removed from the functional groups of the monomers • Dehydration synthesis (water is removed) • A hydroxyl (-OH) from one monomer and a hydrogen (-H) from another are removed • Anabolic reaction Hydrolysis • Hydrolysis is the reverse of condensation • Results in the break down of polymers • Hydration reactions add water and break bonds releasing energy Macromolecules • Perform complex tasks with precision • Basic structure and function of each family similar in all organisms (bacteria – humans) Families of Biomolecules • Carbohydrates •Lipids •Proteins •Nucleic Acids Carbohydrates How Sweet It Is! • General formula (CH2O)n • Monosaccharides (monomer) – C6H12O6 – are covalently linked by condensation reaction to form polysaccharides (polymers) Sugars • Monosaccharides – Five carbon: Ribose – Six carbon: glucose and fructose •Disaccharides –Sucrose –Lactose •Polysaccharides –Starch –Cellulose –Glycogen Polysaccharides Three Types • Glycogen – animal storage product that accumulates in the liver - Highly branched GlucoseGlycogenglucosebloodstream • Starch – plant energy storage - Helical - Easily digested by animals through hydrolysis Cellulose • Polysaccharide found in plant cell walls • For humans cellulose is indigestible and forms dietary fiber • Made up entirely of β glucoses – Structure is constrained into straight microfibrils • Chitin – insect exoskeletons Lipids • Long-term energy storage • Generally insoluble in water • Structural components of cells (phospholipids) • Cellular messengers (hormones) More FAT • Triglycerides are composed of three fatty acids covalently bonded to one glycerol molecule •Fatty acids are composed of CH2 units and are hydrophobic •Fatty acids can be saturated (all single bonds) or unsaturated (one or more double bonds) •A fat (mostly saturated) is solid at room temp. while an oil (mostly unsaturated) is liquid at room temp. Phospholipids • Important structural component of cell memranes • Phosphate group (head) is polar and water soluble (hydrophilic) • Fatty acid tails are hydrophobic •This allows the phospholipids to form bilayers and membranes • Steroids Other Lipids – Built around a four ringed skeleton – Based around Cholesterol • Cholesterol – Component for animal cell membranes – Formation of myelin sheath covering nerves • Hormones – Chemical messengers • Waxes – Many fatty acids linked to a long backbone – Waterproofing in plants, ears, beehives Proteins • 50% dry mass of body and cells • Mammal cell contains 10,000 proteins • Control elements (enzymes) • Structural elements (cell membrane, muscles, ligaments, hair, fingernails) • Regulate what goes into/out of cells • Contractile structure in muscles • Antibodies Building Blocks of Proteins Amino Acids • Amino acids (monomers) are linked together to form proteins (polymers) – Each unique sequence of amino acids forms a different protein – All living things (even viruses) use the same 20 amino acids • 20 different Amino Acids – – – – Amino end (NH2) Carboxyl end (COOH) Hydrogen R group – variable component Protein Assembly • AA’s are linked together by joining the amino end of one molecule to the carboxyl end of another •Peptide bond forms a chain called a polypeptide •Transcription in nucleus –DNA code mRNA •Translation on ribosomes –mRNA protein Protein Structure • Primary structure – Specific linear sequence of AA’s in a polypeptide – Determined from code in inherited genetic material – Changes in primary structure can alter proper functioning of the protein Protein Structure • Secondary structure - the tendency of the polypeptide to coil or pleat due to H-bonding between R- groups - -helix, -pleated sheet, or random coil Protein Structure • Tertiary structure - shape of entire chain; folded, twisted, or globular - shape related to function and properties Protein Structure •Quaternary structure - more than one polypeptide chain Nucleic Acids • Polymers composed of monomer units known as nucleotides • Information storage – DNA (deoxyribonucleic acid) • Protein synthesis – RNA (ribonucleic acid) • Energy transfers – ATP (adenosine tri-phosphate) and NAD (nicotinamide adenine dinucleotide) Nucleotides • Nucleotide structure – Phosphate – Nitrogenous base Purines (double-rings) Adenine and Guanine Pyrimidines (single-rings) Cytosine, Thymine, and Uracil – Sugar – either ribose or deoxyribose pentoses in ring form Deoxyribose lacks one oxygen Functions of Nucleic Acids • DNA – Physical carrier of genetic information – Restricted to nucleus • RNA – key component of protein synthesis – Messenger RNA (mRNA) – blueprint for construction of a protein – Ribosomal RNA (rRNA) – construction site where the protein is made – Transfer RNA (tRNA) – truck delivering the proper AA to the site of construction The End