HO HO 1 2 3 H H Trioses (C3H6O3) Pentoses (C5H10O5) Hexoses (C6H12O6)
Short polymer Unlinked monomer
Dehydration removes a water molecule, forming a new bond H2O
HO 1 2 3 4 H
Aldoses Glyceraldehyde Longer polymer (a) Dehydration reaction in the synthesis of a polymer Ribose Glucose Galactose HO 1 2 3 4 H
Hydrolysis adds a water H O molecule, breaking a bond 2
Ketoses Dihydroxyacetone
HO 1 2 3 H HO H Ribulose (b) Hydrolysis of a polymer Fructose 1 2
1–4 glycosidic linkage
Glucose Glucose Maltose (a) Dehydration reaction in the synthesis of maltose 1–2 glycosidic linkage
(a) Linear and ring forms (b) Abbreviated ring structure
Glucose Fructose Sucrose (b) Dehydration reaction in the synthesis of sucrose
3 4
Chloroplast Starch Mitochondria Glycogen granules
(a) α and β glucose ring structures
0.5 µm α Glucose β Glucose
1 µm
Amylose Glycogen (b) Starch: 1–4 linkage of α glucose monomers (b) Cellulose: 1–4 linkage of β glucose monomers
Amylopectin
(a) Starch: a plant polysaccharide (b) Glycogen: an animal polysaccharide
5 6 Cell walls Cellulose microfibrils in a plant cell wall Microfibril
10 µm
0.5 µm
Cellulose molecules
β Glucose monomer 7 8
Fatty acid (palmitic acid)
Glycerol (a) Dehydration reaction in the synthesis of a fat
Ester linkage
(a) The structure (b) Chitin forms the (c) Chitin is used to make of the chitin exoskeleton of a strong and flexible monomer. arthropods. surgical thread.
(b) Fat molecule (triacylglycerol) 9 10
Structural formula of a saturated fat Choline molecule Phosphate Stearic acid, a saturated fatty Glycerol acid
(a) Saturated fat Hydrophilic head
Fatty acids
Hydrophilic Structural formula head of an unsaturated fat molecule Hydrophobic tails Hydrophobic Hydrophobic tails Oleic acid, an unsaturated fatty acid (a) Structural formula (b) Space-filling model (c) Phospholipid symbol cis double bond causes (b) Unsaturated fat bending 11 12 Hydrophilic WATER head
Hydrophobic WATER tail
13 14
Substrate (sucrose)
Glucose Enzyme (sucrase) OH H2O Fructose
H O
15 16
Nonpolar α carbon
Glycine Alanine Valine Leucine Isoleucine (Gly or G) (Ala or A) (Val or V) (Leu or L) (Ile or I)
Methionine Phenylalanine Trypotphan Proline (Met or M) (Phe or F) (Trp or W) (Pro or P)
Polar
Serine Threonine Cysteine Tyrosine Asparagine Glutamine (Ser or S) (Thr or T) (Cys or C) (Tyr or Y) (Asn or N) (Gln or Q)
Electrically charged Acidic Basic Amino Carboxyl group group Aspartic acid Glutamic acid Lysine Arginine Histidine (Asp or D) (Glu or E) (Lys or K) (Arg or R) (His or H) 17 18 Peptide bond
(a) Groove Groove
Side chains Peptide bond (a) A ribbon model of lysozyme (b) A space-filling model of lysozyme
Backbone
Amino end Carboxyl end (b) (N-terminus) (C-terminus) 19 20
Antibody protein Protein from flu virus
Primary Secondary Tertiary Quaternary Structure Structure Structure Structure
β pleated sheet
+ H3N Amino end Examples of amino acid subunits
α helix
21 22
Hydrophobic interactions and Polypeptide β Chains van der Waals chain interactions
Polypeptide backbone Hydrogen bond
Disulfide bridge Iron Heme
α Chains Ionic bond Hemoglobin Collagen
23 24 Normal hemoglobin Sickle-cell hemoglobin Primary Val His Leu Thr Pro Glu Glu Val His Leu Thr Pro Val Glu Primary structure structure 1 2 3 4 5 6 7 1 2 3 4 5 6 7 Exposed Secondary Secondary hydrophobic and tertiary β subunit and tertiary region β subunit structures structures Denaturation
α α β β Quaternary Normal Quaternary Sickle-cell structure hemoglobin structure hemoglobin (top view) α β β α
Function Molecules do Function Molecules not associate interact with with one one another and another; each crystallize into carries oxygen. a fiber; capacity to carry oxygen is greatly reduced. Normal protein Renaturation Denatured protein 10 µm 10 µm
Red blood Normal red blood Red blood Fibers of abnormal cell shape cells are full of cell shape hemoglobin deform individual red blood cell into hemoglobin sickle shape. moledules, each carrying oxygen.
25 26
DNA
1 Synthesis of mRNA in the Correctly nucleus folded mRNA protein Polypeptide Cap
NUCLEUS CYTOPLASM Hollow cylinder mRNA 2 Movement of Chaperonin Steps of Chaperonin 2 The cap attaches, causing the 3 The cap comes mRNA into cytoplasm Ribosome (fully assembled) Action: cylinder to change shape in off, and the properly via nuclear pore 1 An unfolded poly- such a way that it creates a folded protein is peptide enters the hydrophilic environment for released. cylinder from one end. the folding of the polypeptide. 3 Synthesis of protein
Amino Polypeptide acids 27 28
5' end 3' end
5ʹ end Nitrogenous bases Sugar-phosphate Pyrimidines 5ʹC backbones
3ʹC Base pair (joined by Nucleoside hydrogen bonding)
Nitrogenous base Cytosine (C) Thymine (T, in DNA) Uracil (U, in RNA) Old strands Purines Nucleotide about to be added to a Phosphate new strand group Sugar 5ʹC (pentose) 3' end Adenine (A) Guanine (G) 3ʹC (b) Nucleotide
Sugars 3ʹ end 5' end (a) Polynucleotide, or nucleic acid New strands
Deoxyribose (in DNA) Ribose (in RNA) 3' end 5' end (c) Nucleoside components: sugars
5' end 3' end 29 30 31