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Unformatted text preview: Chapter 5
Exam 1 – September 30 Quiz – September 23 MACROMOLECULES MACROMOLECULES •Carbohydrates •Lipids •Proteins •Nucleic Acids 1. Most (not all) are polymers made 1. up of repeating units called monomers monomers 2. Synthesis is by condensation, 2. condensation breakdown is by hydrolysis of hydrolysis monomers monomers Fig. 5.2 Synthesis is by condensation, condensation (removing water). (removing Breakdown is by Breakdown hydrolysis hydrolysis (addition of water). water). 1. CARBOHYDRATES 1. •Made up of C, H, and O •Linear or ringed structures •Classified as monosaccharides, Classified monosaccharides dissaccharides, and polysaccharides dissaccharides and polysaccharides •Functions: Energy storage, Functions: mobile energy molecules and structural functions structural Monosaccharides - (CH2O)n Monosaccharides 1. Trioses C3H6O3 •glyceraldehyde •dihydroxyacetone 2. Pentoses C5H10O5 •ribose •ribulose 3. Hexoses C6H12O6 •glucose •galactose •fructose Fig. 5.3 In solution, carbohydrates normally form ring structures (example, glucose) ring
Fig. 5.4 Abbreviated ring formulae omit ring Abbreviated carbons carbons Disaccharides – Two monosaccharides joined by a glycosidic bond (formed by hydrolysis) glycosidic Important Disacchrides: •Sucrose = glucose + fructose Sucrose (table sugar, transported in plants) (table •Lactose = glucose + galactose Lactose (milk sugar) (milk •Maltose = glucose + glucose Maltose (malt sugar) (malt Formation of Disaccharides Formation Fig. 5.5 Carbohydrate functions: 1. Energy Storage polysaccharides 1. •Starch – mostly plant cells •Glycogen - animals 2. Mobile energy molecules •Glucose – animals (in the blood) •sucrose – plant mobile sugar 3. Structural molecules •Cellulose – plant cell walls •Chitin – fungal cells wall, insect and arachnid exoskeletons and Polysaccharides – Sugar polymers of monosaccharides (100’s to 1000’s of monomers joined by glycosidic bonds) by 1. Storage polysaccharides •Starch – 1-4 linkage of alpha glucose Amylose – unbranched polymer Amylopectin –branched polymer STARCH IS A MAJOR STORAGE STARCH MOLECULE IN PLANTS MOLECULE •Glycogen – like amylopectin but Glycogen more highly branched more GLYCOGEN IS A STORAGE GLYCOGEN MOLECULE IN VERTEBRATES (abundant in liver and muscle cells) (abundant 2. Structural polysaccharides •Cellulose – 1-4 linkage of beta Cellulose glucose, generally unbranched glucose, MAJOR STRUCTURAL COMPONENT MAJOR OF PLANT CELL WALLS OF Glucose can be an alpha or beta ring Fig. 5.7a Glucose linkage – different properties Fig. 5.7 Figure 5.10 2. LIPIDS 2. •Made up of C, H, and O •Building blocks are glycerol and Building fatty acids fatty •Classified as triglycerides, Classified triglycerides diglycerides (Phospholipids) diglycerides •Functions: Energy storage, Functions: Main component of membranes Fig. 5.11 a Triglyceride Fig. 5.11 b Fig. 5.12 This is a phospholipid!
Fig. 5.13 Fig. 5.14 (5.13 old) 3. PROTEINS 3. •Made up of C, H, O, N and S •Building blocks are amino acids Proteins have an incredibly wide Proteins Variety of functions Variety •Functions: Structural, catalysis, Functions: movement, just about everything! 20 Different Amino Acids Can Be Found in Proteins Found Classes of Amino Acids (Table 5.15) Nonpolar (9 amino acids) Polar (6 amino acids) Electrically Charged acidic (2 amino acids) basic (3 amino acids) amino carboxyl carboxyl variable side chain Formation of Polypeptides Formation Bond forms between carboxyl and amino Bond groups of two amino acids groups Bond forms by CONDENSATION Polypeptide has amino and carboxy ends
Fig. 5.18 Polypeptide
Fig. 5.18 Protein shape or Confirmation Confirmation determines functionality determines Shape is controlled by four possible Shape levels of structure structure 1. Primary - amino acid sequence 1. Primary 2. Secondary - coils and folds of primary 2. Secondary chain chain 3. Tertiary - shape produced by 3. Tertiary bonds between side chains bonds 4. Quaternary - aggregation of 4. Quaternary polypeptides polypeptides Primary Structure (protein Primary confirmation) - amino acid sequence as determined by genetic code genetic Fig. 5.20 Page 82 Secondary Structure (protein confirmation) - coils and folds of primary chain (hydrogen bonds in backbone) chain
Fig. 5.22 Tertiary Structure (protein confirmation) Tertiary shape produced by bonds between side chains chains Hydrogen Hydrogen bonds bonds Hydrophobic Hydrophobic interactions interactions Disulfide bonds Ionic bonds
Fig. 5.20 Quaternary Structure (protein confirmation) - aggregation of polypeptides aggregation Fig. 5.20 Page 83 Importance of structure to proteins shape and function and Hemoglobin in red blood cells and sicklecell disease Change in one amino acid changes Change protein function protein 4. NUCLEIC ACIDS 4. Building blocks -- nucleotides Two major types of nucleic acids DNA (deoxyribonucleic acid) RNA (ribonucleic acid) Store and “transmit” genetic Store information information 4. NUCLEIC ACIDS 4. DNA (deoxyribonucleic acid) Double stranded Bases are: A,T,C,G Extremely long-lived molecule RNA (ribonucleic acid) Sinlgle stranded Bases are: A,U,C,G Shorter-lived molecule PROTEIN SYNTHESIS DNA RNA Protein
Translation cytoplasm of eukaryotes eukaryotes Transcription Transcription nucleus of eukaryotes eukaryotes Transcription (nucleus) Transport Translation (cytoplasm)
Fig. 5.25 NUCLEIC ACID STRUCTURE NUCLEIC Nucleotide (monomer) 1. Pentose Sugar •ribose •deoxyribose 2. Phosphate group 3. Nitrogenous Base •pyrimidine •purine
Fig. 5.26 PENTOSE SUGAR PENTOSE Fig. 5.26 NITROGENOUS BASE NITROGENOUS Pyrimidine – single ring structure Fig. 5.26 •cytosine (C) •thymine (T) •uracil (U) Purine – double ring structure •adenine (A) •quanine (G) Nucleic acid – polymer of nucleotides Nucleic Bond phosphate Bond 5’ on Carbon 5 to oxygen on Carbon 3 Carbon Nucleic acid Nucleic polymer has a 5’ end and a 3’ end end Information is Information stored in the sequence of 3’ bases bases Fig. 5.26 DNA Structure DNA Double-Stranded – Two nucleic acid chains joined at the nucleotide bases bases Bases in separate chains Bases pair: pair: A - T (purine to pyrimidine) G - C (purine to pyrimidine) Fig. 5.27 DNA RNA Protein ...
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- Spring '07