moléculas orgánicas proteina qui403 usc

Carbon Atoms

• form four covalent bonds– single, double, or triple– straight or branched chains– rings

• bond with many different elements

Fig. 3-1, p. 46

C

H

H

H H C

H

H

H OH C

O

H OHC

O

H H

C

H

H

H C

H

H

H C

H

H

H C

H

H

OH C

H

H

H C

O

H C

O

OHC

H

H

H

C

H

H

HC

H

H

H C

O

C

H

H

HC

H

H

H C

H

HC

H

H

OHC

H

H

H C

H

H

C

H

O

HC

H

H

H C

H

C

H

O

OHC

H

H

H C

H

Animation: Functional Group

Table 3-1a, p. 49

Table 3-1b, p. 49

Polymers and Macromolecules

• Polymers – long chains of monomers – linked through condensation reactions

• Macromolecules – large polymers– polysaccharides, proteins, and DNA– broken down by hydrolysis reactions

Condensation and Hydrolysis

Monosaccharides

Fig. 3-6, p. 51

Dihydroxyacetone (C3H6O3)(a ketone)

(a) Triose sugars (3-carbon sugars)

Glyceraldehyde (C3H6O3)(an aldehyde)

Fig. 3-6, p. 51

Disaccharides

Polysaccharides

• Starch Glycogen

• Starch • Glycogen

Cellulose

**chitosan

Chitin

• Triglycerides = three fatty acids attached to one molecule of glycerol

Triglyceride Formation

Figure 2.15

Lipids

Triacylglycerol

Fatty acids

Figure 2.13

Fig. 3-13, p. 58

Fatty acidsCholine

PhosphategroupGlycerol

Hydrophilichead

Hydrophobictail

Water

Steroids

• Carbon atoms arranged in 4 rings – cholesterol, bile salts, some hormones

Figure 2.16 Steroids

Figure 2.16

Estructura y función de las proteínas

DNA MoleculeNucleic Acid

Nucleic Acid

• RNA

Nucleotides

• ATP (adenosine triphosphate)– essential in energy metabolism

• NAD+ – electron acceptor in biological oxidation and

reduction reactions

Fig. 4-6, p. 81

Plasmamembrane

0.5 μm

Pili

Storage granule

FlagellumRibosome

Cell wall

CapsuleNucleararea

DNA

• The cell membrane is a phospholipid bilayer with proteins, lipids and carbohydrates.

Figure 3.3

Sistema de Endomembranas

Peroxisomas

Figure 3.11

Lisosomas

Fig. 4-19, p. 95

Cristae

0.25 μm

Outermitochondrialmembrane

Innermitochondrialmembrane

Matrix

Mitocondrias

Figure 2.5

H2O

Figure 2.6

Na+ Cl-

Fig. 3-1, p. 46

Moléculas no polares son insolubles en agua o hidrofóbicas

Solubilidad de hexanol = 0.0058 mol/100g H2OSolubilidad de glucosa = 0.5 mol/100g H2O hexanol

Figure 2.8

Moléculas anfipáticas

Fig. 3-13, p. 58

Fatty acidsCholine

PhosphategroupGlycerol

Hydrophilichead

Hydrophobictail

Water

Ionización del Agua

Kw = [1 X 10-7 M ] [1 X 10-7 M ] = 1 X 10-14 M2

[ H+ ] =1 X 10-7 M

Kw = [ H+ ] [OH- ] = 1 X 10-14 M2 constante de producto iónico del agua

[ OH- ] = 1 X 10-7 M

pH = - log [H+] = 7

pOH = - log [OH-] = 7

H2O H+ + OH-

ácido base

Kw= keq [H2O]

Figure 2.9

pH = - log [H+] [H+] = 1 x 10-pH

Metros de pH

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings

• Acids release hydrogen ions into solution• Bases remove hydrogen ions from solution

• Strong acids and strong bases ionize completely

Acids and Bases

HCL H+ + CL

NaOH Na+ + OH

OH + H+ H2O

NaOH + HCl NaCl + H2O

ácido

base

HCl -- pH ácido

NaOH -- pOH base

NaOH + HCl NaCl + H2O

pH = - log [H+]

[H+] = 1 x10-pH :. [H+] = 10-pH

 1. Busque el pH para los siguientes: a) HCl 0.0001M b) HCl 0.01M c) NaOH 0.0001M d) HCl 0.0013M e) NaOH 0.00008M 2. Busque la concentración del [H+] para los siguientes: a) pH = 3 b) pH = 9 c) pH = 5 d) pOH = 9 e) pOH = 4

CH3COOH H+ + CH3CO¯

ácidos débiles

Ka = [H+] [A-] [HA]

HA H++ A-

Ka = [H+] [CH3CO¯] [CH3COOH]

CO

OHCH

HH C

O

O¯CH

HH + H+

* pKa = 4.75448

CH3COOH H+ + CH3CO¯ácidos débiles

Ka = [H+] [A-] [HA]

log Ka = log [H+] + log [A-] [HA]

-log [H+] = - log Ka + log [A-] [HA]

pH = pKa + log [A-] [HA]

Henderson-Hasselbalck

Si [HA] = [A- ] :.pH = pKa + 0

HA H++ A-

Acetic acid pK=4.8 Prepare a Buffer pH=5.8

pH = pKa + log [A-] [HA]

5.8 = 4.8 + log [Acetate] [Acetic Acid]

5.8 - 4.8 = log [Acetate] [Acetic Acid]

1 = log [Acetate] [Acetic Acid]

101 = [Acetate] [Acetic Acid]

10 [Acetic Acid] = 1 [Acetate]

CH3COOH H+ + CH3CO

Acidos Débiles

PBS(PhosphateBufferedSaline) for pH 7.4

AmortiguadoresH2O + CO2 H2CO3 HCO3

+ H+

H2O + CO2 H2CO3 HCO3 + H+

NaCL Na+ + Cl

HCL NaHCO3

Ácido clorhídrico Bicarbonato de Sodio

Estructura y función de las proteínas

¿Funciones?

1. Many proteins function as enzymes, the biochemical catalysts.

2. Some proteins bind other molecules for storage and transport.

3. Several types of proteins serve as pores and channels in membranes

4. Some proteins provide support and shape to cells and tissues.

5. Assemblies of proteins can do mechanical work

6. Some are involved in translation whereas others play a role in regulating gene expression by binding to nucleic acids.

7. Some proteins are hormones other proteins serve as receptors for hormones.

9. Some proteins are antibodies to defend against bacterial and viral infections.

N- terminal C-Terminal

Glutamato Histidina

Tyrosina Tyrosina

Serotonin(Tryptophan)

GABA(Glutamate)Glutamate

Glycine Dopamine Norepinephrine Epinephrine

Neurotransmitters

Histamine

Dipolar Ions

Amino acid pKa1 pKa2 pKa3 pIGlycine 2.34 9.60 --- 5.97Alanine 2.34 9.69 --- 6.00Valine 2.32 9.62 --- 5.96Leucine 2.36 9.60 --- 5.98Isoleucine 2.36 9.60 --- 6.02Methionine 2.28 9.21 --- 5.74Proline 1.99 10.60 --- 6.30Phenylalanine 1.83 9.13 --- 5.48Tryptophan 2.83 9.39 --- 5.89Asparagine 2.02 8.80 --- 5.41Glutamine 2.17 9.13 --- 5.65Serine 2.21 9.15 --- 5.68Threonine 2.09 9.10 --- 5.60Tyrosine 2.20 9.11 --- 5.66Cysteine 1.96 8.18 --- 5.07Aspartic acid 1.88 9.60 3.65 2.77Glutamic acid 2.19 9.67 4.25 3.22Lysine 2.18 8.95 10.53 9.74

Arginine 2.17 9.04 12.48 10.76Histidine 1.82 9.17 6.00 7.59

Table of pKa and pI values

•The pKa values and the isoelectronic point, pI, are given below for the 20 α-amino acids. •pKa1= α-carboxyl group, pKa2 = α-ammonium ion, and pKa3 = side chain group.

Primary Structure• Linear sequence of amino acids in

polypeptide chain

N- terminal C-Terminal

Secondary Structure

Amino ácidos polares hacia el agua y no polares hacia adentro

Tertiary Structure

Motifs

Domains Pyruvate kinase from cat

Domains

Tertiary structure of polypeptide

Estructura terciaria y pH

Lactate dehydrogenase Malate dehydrogenase

Citocromo Cb- tunac- riced- yeaste- bacterial

Aplysia myoglobin Tuna myoglobin Whale myoglobin Human myoglobin

Alzheimer's disease has been identified as a protein misfolding disease, or proteopathy, due to the accumulation of abnormally folded Amyloid-beta proteins in the brains of AD patients.[1] Amyloid-beta, also written Aβ, is a short peptide that is a proteolytic byproduct of the transmembrane protein amyloid precursor protein (APP), whose function is unclear but thought to be involved in neuronal development. The presenilins are components of a proteolytic complex involved in APP processing and degradation.[3] Although amyloid beta monomers are harmless, they undergo a dramatic conformational change at sufficiently high concentration to form a beta sheet-rich tertiary structure that aggregates to form amyloid fibrils[6] that deposit outside neurons in dense formations known as senile plaques or neuritic plaques.

AD is also considered a tauopathy due to abnormal aggregation of the tau protein, a microtubule-associated protein expressed in neurons that normally acts to stabilize microtubules in the cell cytoskeleton. Like most microtubule-associated proteins, tau is normally regulated by phosphorylation; however, in AD patients, hyperphosphorylated tau accumulates as paired helical filaments[7] that in turn aggregate into masses inside nerve cell bodies known as neurofibrillary tangles and as dystrophic neurites associated with amyloid plaques.

Enzyme-Substrate Complex• Substrate binds to enzyme’s active site

– forming enzyme–substrate complex – changes shapes of enzyme and substrate– induced fit helps break and form bonds

Quaternary Structure

Reverse transcriptase(RNA-dependent DNA polymerase)

Figure 19.3

Myoglobin b subunit ofhemoglobin

Color code: -globin (blue), -globin (purple), myoglobin (green).

Chemical structure of the Fe(II)-protoporphyrin IX heme group inmyoglobin and hemoglobin.

Figure 23.21

Figure 23.22a, b

BPGAllosteric modulator

Antibody Diversity

Figure 10–1

Figure 10–3

Figure 10–13

A Thin Filament

Figure 10–7a

Troponin and Tropomyosin

Figure 10–7b

A Thick Filament

Figure 10–7c

The Mysosin Molecule

Figure 10–7d

Sliding Filaments

Figure 10–8

Skeletal Muscle Innervation

Figure 10–10a, b (Navigator)

Figure 10–9 (Navigator)

Figure 10–11

Regulación de la contracción por Ca++

Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

The Contraction Cycle

Figure 10–12 The Contraction Cycle.

Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

The Contraction Cycle

[INSERT FIG. 10.12, step 1]

Figure 10–12 The Contraction Cycle.

Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

The Contraction Cycle

Figure 10–12 The Contraction Cycle.

Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

The Contraction Cycle

Figure 10–12 The Contraction Cycle.

Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

The Contraction Cycle

Figure 10–12 The Contraction Cycle.

Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

The Contraction Cycle

Figure 10–12 The Contraction Cycle.