Glucose (a) Linear and ring forms(b) Abbreviated ring structure

Disaccharides (b) Dehydration reaction in the synthesis of sucrose GlucoseFructose Sucrose MaltoseGlucose (a) Dehydration reaction in the synthesis of maltose

Different Ring Strucutres (a)  and  glucose ring structures  Glucose  Glucose

 and  Configurations

Cellulose  Glucose monomer Cellulose molecules Microfibril Cellulose microfibrils in a plant cell wall 0.5 µm 10 µm Cell walls

Chitin The structure of the chitin monomer. (a) (b) (c) Chitin forms the exoskeleton of arthropods. Chitin is used to make a strong and flexible surgical thread.

Fats ( Triacylglycerols ) Fatty acid (palmitic acid) (a) Dehydration reaction in the synthesis of a fat Glycerol

Saturated Fats (a) Saturated fat Structural formula of a saturated fat molecule Stearic acid, a saturated fatty acid

Unsaturated Fats (b) Unsaturated fat Structural formula of an unsaturated fat molecule Oleic acid, an unsaturated fatty acid cis double bond causes bending

Phospholipids (b) Space-filling model (a)(c) Structural formula Phospholipid symbol Fatty acids Hydrophilic head Hydrophobic tails Choline Phosphate Glycerol Hydrophobic tails Hydrophilic head

Fig Hydrophilic head Hydrophobic tail WATER

Steroids

Fig Enzyme (sucrase) Substrate (sucrose) Fructose Glucose OH H O H2OH2O

Fig. 5-UN1 Amino group Carboxyl group α carbon

Amino Acids

Peptide Bond

Sickle-cell Disease

Secondary Structure

Tertiary Structure

Quaternary Structure

4 Levels of Protein Structure

What determines a proteins structure? The unique conformation endows each protein with a specific function Physical and chemical environment affects struture - _________________: protein unravels and losses its conformation - pH, [salt], temperature

Protein Folding in the Cell It is hard to predict a protein’s structure from its primary structure Go through several intermediate structures ____________ are protein molecules that assist the proper folding of other proteins Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

Fig Hollow cylinder Cap Chaperonin (fully assembled) Polypeptide Steps of Chaperonin Action: An unfolded poly- peptide enters the cylinder from one end The cap attaches, causing the cylinder to change shape in such a way that it creates a hydrophilic environment for the folding of the polypeptide. The cap comes off, and the properly folded protein is released. Correctly folded protein

DNA, RNA and Proteins mRNA Synthesis of mRNA in the nucleus DNA NUCLEUS mRNA CYTOPLASM Movement of mRNA into cytoplasm via nuclear pore Ribosome Amino acids Polypeptide Synthesis of protein 1 2 3

Fig. 5-27ab 5' end 5'C 3'C 5'C 3'C 3' end (a) Polynucleotide, or nucleic acid (b) Nucleotide Nucleoside Nitrogenous base 3'C 5'C Phosphate group Sugar (pentose)

Fig. 5-27c-1 (c) Nucleoside components: nitrogenous bases Purines Guanine (G) Adenine (A) Cytosine (C) Thymine (T, in DNA)Uracil (U, in RNA) Nitrogenous bases Pyrimidines

Fig. 5-27c-2 Ribose (in RNA)Deoxyribose (in DNA) Sugars (c) Nucleoside components: sugars

Fig. 5-27ab 5' end 5'C 3'C 5'C 3'C 3' end (a) Polynucleotide, or nucleic acid (b) Nucleotide Nucleoside Nitrogenous base 3'C 5'C Phosphate group Sugar (pentose)

Fig Sugar-phosphate backbones 3' end 5' end Base pair (joined by hydrogen bonding) Old strands New strands Nucleotide about to be added to a new strand

DNA and Proteins as Tape Measures of Evolution Siblings share similarity in DNA and protein sequences than unrelated species members Two species that appear closely related based on fossil and anatomical evidence should more similar in DNA sequences than more distantly related species Molecular biology can be used to assess evolutionary kinship

You should now be able to: 1. List and describe the four major classes of molecules 2. Describe the formation of a glycosidic linkage and distinguish between monosaccharides, disaccharides, and polysaccharides 3. Distinguish between saturated and unsaturated fats and between cis and trans fat molecules 4. Describe the four levels of protein structure

You should now be able to: 5. Distinguish between the following pairs: pyrimidine and purine, nucleotide and nucleoside, ribose and deoxyribose, the 5 end and 3 end of a nucleotide