Así
bombean sustancias de un lugar a otro en la membrana
La bomba mas importante en las células animales es nombrada Na-K bomba
sodio-potasio; que mediante la energía aportada de cada ATP, bomnea 3 Na =
sodio hacia el exterior y 2k = potasio al interior.
Resumen de los organelos
Desde el núcleo sale una molécula, desde el ADNque contiene la clave exacta
para producir una proteína de secreción.
Los ribositas son estructuras pequeñas muy numerosas formadas por congregado de
particulas
El organelo tubular es liso y con gran contenido de grasas hacia la periferia
En la región nuclear se ve rigurosa por la presencia de los ribosomas
La proteína es traspasada en vesículas membranosas hacia el aparato de golgi.
Las vacuolas llamadas fagosoma contiene desechos y luego se fusionara con otro
organelo que surge de las membranas del retículo de golgi. Contienen
eficientes encimas para desintegrar sustancias toxicas para la célula como
el agua oxigenada.
Mitocondrias o plastidos
Están cubiertos con una doble membrana. Tiene una matriz que
posee material genético. También posee ribosomas para
la producción de proteínas propias, cuenta con sustancias llamadas enzimas que
intervienen cuando la energía es procesada.
La mitocondria procesa la energía contenida en los nutrientes y la deja
disponible para su uso inmediato.
Las mitocondrias son ovales o esféricas y su membrana interna forma plebes
hacia la matriz
Los plastidos presentes solo en vegetales, poseen bolsitas membranosas, se
distinguen los leucoplastos (blancos y almacena almidón) cromoplastos (se ven en
flores y frutos
Célula procarionte:
No presenta núcleo, su material genetico DNA circular formado por 1 cromosoma
bacteria, su ribosoma 70s, no posee endomenbranas, su fisiologia célular es en
el mesosoma y su reproducción es de división binaria.
Célula eucarionte
Si presenta núcleo, su material genetico de DNA avierto formado varios
cromosomas independientes, su ribosoma ese 80s, si posee endomembranas, su
fisiología celular es en granulos diferentes y su reproducción es por meiosis.
Diferenciación de la membrana: son estructuras formadas a partir de la membrana
o que la recubren externamente.
Intestino del gado: tiene la función de absorver sustancias por esto necesita un tipo de microvellosidades
Uniones celulares: son estructuras para unir y comunicar las células.
Una propiedad de las membranas celulares es que pueden autofucionarse
Cito esqueleto: son tubos proteicos de 3 tipos.
intermediate or, more commonly, is combusted for heat or power. In the
thermochemical platform, biomass is degraded into small gas molecules
(hydrogen, carbon monoxide, carbon dioxide, methane, etc.) under high
temperature and certain pressure conditions, then these gas molecules are
converted chemically or biologically into Fischer-Tropsch (FT) liquid fuel,
alcohols, or other intermediate chemicals. This chapter focuses on the
processes, potential, and challenges associated with each of these platforms.
2 Background Research 2.1 Natural Resource Limitation and Economic Security
Although the potential adverse environmental effects of CO2 emission is a major
factor pressuring governments to steer theirenergy policy away from fossil
fuels, the global decline of fossil fuel reserves is also a major driver for
public and private organizations around the world to develop technologies to
use renewable energy sources. Various estimates exist for the current proved
reserves (Rp), and the Rp:consumption ratio (Rp:c),
with units of years. For example, the global Rp:c of
coal, oil, and natural gas have been estimated as 140, 40, and 60 [3, 13].
Using the widely-recognized global energy database provided in the British
Petroleum (BP) energy report [14], we calculated Rp:c
for coal, oil and natural gas as 133, 35, and 60, respectively. For coal and
natural gas, the Rp:c value is similar to the
previously published estimates and indicates that issues may arise later in
this century. However, for oil, our Rp:c value of 35 (years) is even less than
that published previously, indicating a serious situation with near-term
pressure building to replace oil reserves either with new discoveries (perhaps
some, but unlikely to be major) or with new alternatives (biofuels can play a
role). The earliest fuel ethanol production from lignocellulose biomass began
in Germany,
in 1920s [15], using sulfuric acid to hydrolyze wood. The ethanol yield was low
at approximately 75–130 L (20–34 gallons) of ethanol per ton of wood
hydrolyzed. From 1945 to1960s, several acid-hydrolysis ethanol plants were
built in Europe, the USA,
and the former Soviet Union. The capacities of
these plants ranged from 10,000 to 45,000 tons of wood materials a year.
Ethanol yield reached 190–200 L (50–53 gallons) per ton ofwood. Subsequently,
almost all of these woodbased ethanol plants were closed due to competition
from the rapid development of the petroleum industry and relatively inexpensive
crude oil feedstock. The ï¬rst gasiï¬cation of biomass can be dated back to
the 1800s, when wood was gasiï¬ed to generate “town gas” for lighting and
cooking. Although there are around 140 large gasiï¬cation facilities in operation
around the world today [16], these gasiï¬ers are basically used to generate
heat and/or electricity from coal (55% of total 140 large gasiï¬cation
facilities), oil, or natural gas, with a few plants using residues from the
wood/pulp industry. The current main products generated from gasiï¬er syngas
are power (18%), chemicals (44%), and FT fuel (38%) [16]. Todate, there are no
commercial scale gasiï¬cation or pyrolysis facilities dedicated for
biofuels production from lignocellulosic biomass. However, many research units
have been built to investigate the mechanism, kinetics, and economical
feasibility of biofuel production via syngas from biomass gasiï¬cation.
2.2 Limitation of Mainstream Agricultural Crops for Biofuels
In recent years, fuel ethanol production has been revived for use in gasoline
transport fuel markets. The main driver for fuel ethanol expansion use has been
the need for a gasoline oxygenate, following the issues that were uncovered
concerning the previous widespread petroleum industry oxygenate, methyl
tert-butyl ether (MTBE). Ethanol is biologically safer, biodegradeable,
renewable, and carries 88% more oxygen than MTBE(especially
useful in the higher compression modern gasoline engines). A secondary, but
nonetheless important, driver for ethanol expansion has been to reduce
dependence on foreign oil for those countries that import large volumes of
crude oil. The success of ethanol to-date has relied on the harvested portions
of mainstream agricultural crops, where modern-technology yield increases have
allowed increasing harvest volumes [17]. The global production of crop-based
renewable ethanol is projected at around 20 billion gallons (77 B liters) for
2008. Figure 1 shows the brea
• Micro filamentos de activo: de función estructural y para permitir los
movimientos ameboideos y de contracción celular.
• Filamento intermedio: de proteínas fibrosas, con función estructural.
• Microtúbulos de tubina: forman los centríolos, el huso acromático, los
undolipolios.
