Celulas Procarióticas

Presentación del tema: "Celulas Procarióticas"— Transcripción de la presentación:

1 Celulas Procarióticas
Células procarióticas [pro = antes; karyon = grano (núcleo)] Incluye bacterias y arqueobacterias. 1

2 Su material genético se encuentra en una región nucleoide.
Figure 7.4x2 E. coli NO tienen núcleo. Su material genético se encuentra en una región nucleoide. NO tiene organelos membranosos. 2

3 Celulas Procarióticas
Nucleoid region Bacterial cromosome Ribosomes Plasma membrane Cytoplasm Cell wall Glycocalyx Pili Flagella 0.5 µm (a) A typical rod-shaped bacterium (b) An electron micrograph of Escherichia coli Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. 3

4 ¿Qué factores determinan los límites?
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. 1 nm 0.1 nm 10 nm 100 nm 1 mm 1 cm 0.1 m 1 m 10 m Atoms Lipids Proteins Ribosomes Viruses Mitochondria Nucleus Fish egg Bird egg Human height Electron microscope Light microscope Unaided human eye Small molecules Most bacteria Most plant and animal cells 1 m 10 m 100 m Smallest 4

5 Límite menor

6 Límite mayor está impuesto por Difusión
Razón Area de superficie a Volumen (A/V). 6

7 Surface area increases while total volume remains constant
Fig. 6-8 Surface area increases while total volume remains constant 5 1 1 Total surface area [Sum of the surface areas (height  width) of all boxes sides  number of boxes] 6 150 750 Total volume [height  width  length  number of boxes] Figure 6.8 Geometric relationships between surface area and volume 1 125 125 Surface-to-volume (S-to-V) ratio [surface area ÷ volume] 6 1.2 6 7

8 Funciones de Proteínas Membranales
Signaling molecule Enzymes Receptor ATP Signal transduction (a) Transport (b) Enzymatic activity (c) Signal transduction Figure 7.9 Some functions of membrane proteins Glyco- protein (d) Cell-cell recognition (e) Intercellular joining (f) Attachment to the cytoskeleton and extracellular matrix (ECM) 8

9 Figure 6.8 Geometric relationships between surface area and volume
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