Gliceraldeide - lo zucchero più piccolo. Aldeide (CH 2 0) 3

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Demetrio Vitali
5 anni fa
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2 Acqua (H 2 O) 2

3 Gliceraldeide - lo zucchero più piccolo H C O Aldeide H COH H 2 C OH (CH 2 0) 3 = Carbo - idrato (CH 2 0) n n compreso tra 3 e 8 3

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5 monomeri polimeri 5

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13 What is a protein? A protein is a polymer of of fixed length, composition and structure made by a combination of the 20 naturally occurring amino acids. 13

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21 I legami che aiutano le proteine a ripiegarsi 21

22 cisteine:cisteine ponti disolfuro 22

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24 The structure of proteins can be defined in a hierachical way Primary structure: the AA sequence (Thr-Gly-Leu-Pro- ) Secondary structure: local repetitive motifs common to most classes of protein structures Tertiary structure: the 3D arrangement of the secondary structure motifs to form a compact protein. Quaternary structure: the arrangements of several proteins units to form a functional multimeric structure. The coordinates of all the known structures of proteins can be found in the Protein Data Bank: 24

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26 a-helix 26

Favorable dipolar interaction in the backbone.

27 Secondary structure. The a-helix. The a-helix is the most common secondary structure found in proteins. a-helices are stabilized by a number of factors. Favorable dipolar interaction in the backbone. Low strain and intramolecular repulsion of backbone and side chains. Very compact structure, small solvent exposed surface. 27

28 1998 GARLAND PUBLISHING Beta foglietto 28

29 Secondary structure. The b-sheet. The b-sheet is made by parallel or antiparallel extended strands connected by a network of hydrogen bonds. Parallel b-sheet Antiparallel b-sheet 29

30 Tertiary structure. a-b proteins. 30

31 Tertiary structure. b-barrel. Greek key motif 31

32 Tertiary structure. Membrane proteins. 32

33 Tertiary structure. DNA-binding proteins. Cys Cys Zn Cys Cys The zinc finger 33

34 Quaternary structures. K+ channel Haemoglobin HIV-1 protease 34

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(42-43 residues) is derived by proteolytic cleavage of the amyloid precursor protein, a

44 Alzheimer s: Protein Folding gone Wrong. An amyloid plaque in Alzheimer s disease is a tangle of protein filaments The amyloid protein (42-43 residues) is derived by proteolytic cleavage of the amyloid precursor protein, a constituent of many healthy cells APP has a-helical conformation, the amyloid protein can change into b-conformation forming aggregates, and plaques 44

45 monomeri polimeri 45

46 Struttura tipo di un nucleotide 46

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48 A Nucleoside(-tide) H + - HO Nucleotide Phosphate 2-Deossiribosio 5 4 OH P HO CH 2 O Sugar 3 OH O 2 HOH Base N H N 1 NH 2 N N Legame N-b glicosilico Nucleoside Ribosio 48

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50 A G C U T 50

51 cytosine C OH NH2 51

52 Struttura tipo di un nucleotide 52

53 nucleoside nucleotide H adenosina ATP ADP AMP 53

54 Functions of nucleotides: Energy cycle Cofactors for enzymes Phosphate donors Information flow 54

Nucleotides Are Very Important Nucleotides have many other functions: They carry chemical energy in their easily hydrolyzed phosphoanhydride bonds. Example - ATP 2.

55 Nucleotides Are Very Important Nucleotides have many other functions: They carry chemical energy in their easily hydrolyzed phosphoanhydride bonds. Example - ATP 2. They combine with other groups to form coenzymes. Example - coenzyme A (CoA) 3. They are used as specific signaling molecules in the cell. Example - cyclic AMP (camp) 55

56 What is ATP? An organic molecule that storesr and releases chemical energy for use in body cells 56

57 8 NTP NDP + Pi 57

58 ATP + Pi ADP 58

59 LA CELLULA PERSEGUE DUE OBIETTIVI FONDAMENTALI: la crescita cellulare il differenziamento cellulare In un contesto cellulare sociale, quale il tessuto e/o l organo, i meccanismi responsabili della crescita e del differenziamento cellulare devono essere tra loro integrati e finemente regolati (omeostasi cellulare). I programmi di crescita e differenziamento cellulare sono geneticamente determinati. 59

60 Gli Acidi Nucleici sono le macromolecole depositarie dell informazione genetica. Due Tipi di Acidi Nucleici DNA polimero di desossiribonucleotidi RNA polimero di ribonucleotidi I Nucleotidi sono le subunità degli Acidi Nucleici 60

61 Il DNA è un polimero di desossiribonucleotidi 61

62 Il RNA è un polimero di ribonucleotidi 62

63 Gli Acidi Nucleici sono polimeri di nucleotidi legati tra loro da legami fosfodiesteri tra i C 5 e 3 estremità 5 5 end estremità 3 3 end 63

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