Sugars and polymers of sugars Classes Monosaccharides - PowerPoint PPT Presentation

1. CONDENSATION (DEHYDRATION)  Loss of H 2 O ▪ - OH (hydroxyl group) ▪ - H (hydrogen)  Covalent bonds are formed  Energy is expended  Polymerase enzyme 2. HYDROLYSIS  Addition of H 2 O  Covalent bonds are broken  Energy is released  Hydrolase enzyme How many molecules of water are needed to completely hydrolyze a polymer that is 10 monomers long?

 Sugars and polymers of sugars  Classes  Monosaccharides  Disaccharides and oligosaccharides  Polysaccharides  Importance  Fuel  Building materials

Importance Major cell nutrients  Incorporated into more complex  carbohydrates Classification Location of carbonyl group (C=O)   Aldose  Ketose Size of C-skeleton (3- 7 C’s)  Arrangement around C’s   Linear form  Ring form (in aqueous solutions)   - H on top of plane of ring ▪   -OH on top of plane of ring ▪

IMPORTANCE Maltose (glucose + glucose)  Lactose (glucose + galactose)  Sucrose (glucose + fructose)  FORMATION AND STRUCTURE Glycosidic linkage – covalent  bond between 2 1-4 GLYCOSIDIC LINKAGE monosaccharides Condensation or dehydration  synthesis reactions Draw the structure of sucrose formed from a 1-2 a) glycosidic linkage of glucose and fructose galactose formed from the 1-4 b) glycosidic linkage of glucose and galactose.

STRUCTURE AND FORMATION • Hundreds to thousands of monosaccharides joined by glycosidic linkages • Homopolysaccharides Starch (  1,4 linkages) • IMPORTANCE Amylose •  Structural polysaccharides • Amylopectin Cellulose (  1,4 linkages)  Cellulose and chitin •  Storage polysaccharides • Heteropolysaccharides  Starch and glycogen

large molecules assembled  from smaller molecules by dehydration reactions hydrophobic and non-  polar glycerol + fatty acid  fat  fatty acids have long C-  skeletons (16-18 atoms) with a carboxyl end ester linkages are formed  when 3 fatty acids join to glycerol  Functions  Energy storage  Cushioning of vital organs  Insulation

 glycerol + 2 fatty acids and phosphate group  amphipathic  hydrophobic tails  hydrophilic heads  assemble into bilayers  major components of cell membranes

 C-skeleton with four fused rings  Vary in the functional group attached to the rings  Cholesterol  Cell membranes  Used for synthesis of sex hormones ▪ Testosterone ▪ Estrogen

 Amino acids arranged in a linear chain and folded into a globular form  Amino acids Structure  Carboxyl (-COOH) end  Amino (-NH2) end  R (variable) group attached to the  -Carbon Classification  Nonpolar  Polar  Charged (acidic/basic)

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 Sequence of amino acids in a polypeptide chain  Change in one amino acid may change properties of entire chain  Glu  Val substitution causes sickle cell anemia

Coiling/folding due to H-bond formation  between carboxyl and amino groups of non- adjacent amino acids. R groups are NOT involved. 

 3d structure resulting from folding of the 2  structures  stabilized by bonds formed between amino acid R groups  forms many shapes (e.g. globular compact proteins, fibrous elongated proteins)  disruption  denaturation

 Present in some proteins whose tertiary structures (subunits) join to form a protein complex

 Structure affected by  pH  salt concentration  presence of solvents  temperature  Chaperone proteins in cell help in refolding proteins

 DNA (deoxyribonucleic acid)  Provides directions for own replication  Directs RNA synthesis  Controls protein synthesis  RNA (ribonucleic acid)  mRNA directs protein synthesis in the ribosome  tRNA transfers a specific amino acid to a polypeptide chain  rRNA combines with a protein to make up a ribosome

Nucleotide Nucleoside Phosphate Nitrogenous base Pentose sugar

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