Top PDF The origin of eukaryotes: the difference between prokaryotic and eukaryotic cells

The origin of eukaryotes: the difference between prokaryotic and eukaryotic cells

The origin of eukaryotes: the difference between prokaryotic and eukaryotic cells

In 1998, two hypotheses, based on the comparative biochemistry of energy metabolism (Martin & MÏller 1998) and the comparison of fundamental di¡erences in genome organization between prokaryotes and eukaryotes (Vellai et al. 1998), led independently to the conclusion that the origin of the intracellular symbiont being the precursor of the ¢rst energy-producing organelle is iden- tical to the origin of eukaryotes. The proposed scenarios assume that some ancient anaerobic archaebacteria could engulf respiring a -proteobacteria, although not by a phagocytosis-like process (see ½ 5). The cellular merger between two di¡erent bacteria resulted in the appearance of the ¢rst complex cells (¢gure 1) that, contrary to the traditional predictions, had probably no nucleus; thus, they were actually proto-eukaryotes. After a special initial advantage of the symbiotic association (that was presum- ably not ATP export to cytosol by virtue of oxygen respira- tion, as previously thought), the symbionts developed into mitochondria (aerobic or anaerobic), whereas the hosts evolved into real nucleus-bearing eukaryotic cells.
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T he idea that the eukaryotic cell is actually a colony of microbes was first suggested in the

T he idea that the eukaryotic cell is actually a colony of microbes was first suggested in the

T he transition between eukaryotes, cells with nuclei, and prokaryotes, cells which lack nuclei, is considered by many biologists to be the most profound change in evolutionary history. In an attempt to describe the way in which this gap was bridged, scientists have proposed the serial endosymbiosis theory (SET). The term "endosymbiosis" specifies the relationship between organisms which live one within another (symbiont within host) in a mutually beneficial relationship. The SET states that the evolution of eukaryotes from prokaryotes involved the symbiotic union of several previously independent ancestors. According to the theory, these ancestors included a host cell, an ancestor of mitochondria, an ancestor of chloroplasts, and, more controversially, a prokaryote that brought with it the structures that today provide cellular motion.
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Biology Campbell & Reece 9th Edition A&P version Test Bank chapter06

Biology Campbell & Reece 9th Edition A&P version Test Bank chapter06

This chapter introduces the topics of microscopy and cell fractionation, followed by a review of the cell and the major organelles and structures of eukaryotic cells. A challenge with this chapter is to keep this data from simply being a list of parts. In addition to the structure and function of individual organelles, questions probe student understanding of the cell as a dynamic, interconnected system: the flow of membrane and proteins in the endomembrane system to the plasma membrane; the flow of information from the nucleus to the cytoplasm; and the connection between the cytoskeleton, the plasma membrane, and the extracellular matrix. An evolutionary perspective goes beyond structural distinctions between prokaryotes and eukaryotes to examine theories concerning the evolutionary origins of eukaryotes and key eukaryotic cell structures.
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lecturer 1 cells structure

lecturer 1 cells structure

4. Cell Membrane or Plasma Membrane - Surrounds the cell's cytoplasm and regulates the flow of substances in and out of the cell. Prokaryotic cells can have multiple plasma membranes. Prokaryotes known as "gram-negative bacteria," for example, often have two plasma membranes with a space between them known as the periplasm. Just inside the cell wall, the plasma membrane is a selective barrier which regulates the passage of materials to from the cell. It is through this membrane that a cell must exchange food molecules, gases and other vital ingredients. Composed of phospholipid and protein membranes form thin, flexible, self-sealing, highly selective barriers between the inside of the cell and the outside world. As in all cells, the plasma membrane in prokaryotic cells is responsible for controlling what gets into and out of the cell. A series of proteins stuck in the membrane (poor fellas) also aid prokaryotic cells in communicating with the surrounding environment. Among other things, this communication can include sending and receiving chemical signals from other bacteria and interacting with the cells of eukaryotic organisms during the process of infection. Infection is the kind of thing that you don't want prokaryotes doing to you. Keep in mind that the plasma membrane is universal to all cells, prokaryotic and eukaryotic. Because this cellular component is so important and so common, it is addressed in great detail in its own In Depth subsection.
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Staff Site Universitas Negeri Yogyakarta

Staff Site Universitas Negeri Yogyakarta

4. Cell Membrane or Plasma Membrane - Surrounds the cell's cytoplasm and regulates the flow of substances in and out of the cell. Prokaryotic cells can have multiple plasma membranes. Prokaryotes known as "gram-negative bacteria," for example, often have two plasma membranes with a space between them known as the periplasm. Just inside the cell wall, the plasma membrane is a selective barrier which regulates the passage of materials to from the cell. It is through this membrane that a cell must exchange food molecules, gases and other vital ingredients. Composed of phospholipid and protein membranes form thin, flexible, self-sealing, highly selective barriers between the inside of the cell and the outside world. As in all cells, the plasma membrane in prokaryotic cells is responsible for controlling what gets into and out of the cell. A series of proteins stuck in the membrane (poor fellas) also aid prokaryotic cells in communicating with the surrounding environment. Among other things, this communication can include sending and receiving chemical signals from other bacteria and interacting with the cells of eukaryotic organisms during the process of infection. Infection is the kind of thing that you don't want prokaryotes doing to you. Keep in mind that the plasma membrane is universal to all cells, prokaryotic and eukaryotic. Because this cellular component is so important and so common, it is addressed in great detail in its own In Depth subsection.
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Sillabus of Sociolingusitics

Sillabus of Sociolingusitics

Upon completion of the course, students are able to identify the relationships between language and society, the difference/s between sociolinguistics and sociology of language, language variation and the factors related to it, language change, reform, planning, and speech communities and code choice. Added to this, students are expected to be able to explain the above topics.

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Effect of hypoxia-inducible factor-1α induction by CoCl 2 on breast cancer cells survival: influence of cytochrome-c and survivin

Effect of hypoxia-inducible factor-1α induction by CoCl 2 on breast cancer cells survival: influence of cytochrome-c and survivin

expression of HIF-1α myocardial cells increased gradually in line with the duration of hypoxia and reached a peak at day 21. We also found a strong positive relationship between the concentration of HIF-1α protein and of cytochrome-c in the cytoplasm of T47D cells induced by CoCl 2, and between the expression of HIF-1α mRNA and the concentration of cytochrome-c. These results are consistent with the study of Ardyanto which show that the apoptotic index of myocardial cells increases with duration of hypoxia, although there is no significant association between increased expression of HIF-1α with the increase in the apoptotic index. 16
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Effect of hypoxia-inducible factor-1α induction by CoCl2 on breast cancer cells survival: influence of cytochrome-c and survivin

Effect of hypoxia-inducible factor-1α induction by CoCl2 on breast cancer cells survival: influence of cytochrome-c and survivin

It has been known that the increased stability of HIF affects mainly the increase in survivin gene expression compared to the release of cytochrome-c into the cytoplasm. Inhibition of HIF is expected to suppress anti-apoptotic protein survivin so that apoptotic will continue. Inhibition of HIF-1α would also suppress the release of cytochrome-c into the cytoplasm which causes apoptosis does not occur so that cancer cells will continue to proliferate. This cancer cells proliferation can be inhibited by administration of cytotoxic chemotherapy drugs. 22 Sekarutami 23 have shown that patients
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The Origin and Evolution of Baseball

The Origin and Evolution of Baseball

Keywords: baseball, baseball drills, baseball pitches, baseball salaries, baseball terms, baseball tips, baseball facts, baseball school, who invented baseball, baseball lessons Articl[r]

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Ethical Behavior, Work Values and Performance of the Provincial Government Officers of Agusan, del Sur, Philippines, in the light of ASEAN Integration | P. ACERO | Jurnal Studi Pemerintahan: Journal of Government and Politics 1948 5594 2 PB

Ethical Behavior, Work Values and Performance of the Provincial Government Officers of Agusan, del Sur, Philippines, in the light of ASEAN Integration | P. ACERO | Jurnal Studi Pemerintahan: Journal of Government and Politics 1948 5594 2 PB

This study is anchored on Section 4 of RA 6713 otherwise known as the Code of conduct of Philippines’ Government offi- cials and Employees. Although there are eight norms under this law; but in this study it is summarized into honesty, respect of law, conflict of interest, equality and democratic responsibility. The work values are based on motivation-hygiene theory by Herzberg as cited by Hellriegel, et.al.,(1989). He said the responses suggest that the opposite of satisfaction is not dissatisfaction, as was traditionally believed. Removing dissatisfying characteristics from a job does not necessarily make the job satisfying.The Work Values Assessment test is based on Dawis and Lofquist’s (1984) theory of work adjustment. The theory, which has evolved over four decades of research, provides a comprehensive model for conceptualizing the interaction between individuals and their work environments. On Performance, it is based on Douglas McGregor’s Theory X-Theory Y view of human nature and mo- tivation as cited by Robbins (2004).
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The difference of Natural Killer cell activities of the people live in the aircraft noise area of Adi Soemarmo Airport Boyolali, Surakarta, Indonesia | Hartono | Journal of the Medical Sciences (Berkala ilmu Kedokteran) 4128 6785 1 SM

The difference of Natural Killer cell activities of the people live in the aircraft noise area of Adi Soemarmo Airport Boyolali, Surakarta, Indonesia | Hartono | Journal of the Medical Sciences (Berkala ilmu Kedokteran) 4128 6785 1 SM

In the activity of chronic SAM (symphatetic- adrenal-medullary), epinephrine and norepinephrine can disrupt the immune functions. The course from the sympathetic nervous system to the immune system is based on the observation on the noradrenergic sympathetic nervous ends which comes from CNS and goes to two lymphoid tissues, both primary and secondary ones. It proves that the sympathetic nervous ends have relation to the immune cells. In such a relation, the sympathetic nervous ends release norepinephrine. Furthermore, when the epinephrine is released by adrenal medullar into the blood circulation, it is bound to the immune cells by adrenergic receptors, and this produces the same effects as the sympathetic nerves when they are directly stimulated. The catecholamine has effect on the target cells through adrenergic receptors and several immune cells such as lymphocytes, NK cells, and macrophages, which express adrenergic receptors. 8,18,19
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The Difference Between Sculpting Male Abs And Female Abs

The Difference Between Sculpting Male Abs And Female Abs

These full-body workouts are strongly recommended as women do not overstrain their abdominal muscles in order to craft those streamlined abs.. For the purposes of an abs diet, men should[r]

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Directory UMM :Data Elmu:jurnal:B:Biosystems:Vol54.Issue1-2.1999:

Directory UMM :Data Elmu:jurnal:B:Biosystems:Vol54.Issue1-2.1999:

One of the conclusions we can draw from the study of ecological neural networks is that over- simplified body structure, suitable for modeling robots with an adaptive behavior, is not appropri- ate to model the behavior of biological organisms. An animal body cannot be regarded as a robot even if we have to simplify it during the modeling process. In the case of a robot we can separate the body from the neural net. The neural net can be treated as an interchangeable module; we only have to connect the motors to the appropriate motoneurons. In the case of biological beings even the simplest movements require the coordi- nated work of many muscles and their effect depends on their positions in the body. To model the movement of an animal we have to take into account the body structure, because it defines the potential modes of behavior. It follows from this that the construction and evolution of the nervous system are not separable from the anatomy and morphogenesis of the modeled animal.
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Conference paper

Conference paper

composed of gross, systematic and random errors (Wise, 2000) and is normally distributed (Heuvelink, 1998). The assessment method consists in calculating the Root Mean Square Error (RMSE) for the elevation using Ground Control Points (GCP) and then this value is considered as the DEM accuracy (Wise, 2000). If the sample of reference points is sufficiently large, this method can be efficient in evaluating the elevation accuracy of the DEM (Li et al., 2005). However, as it neglects the spatial autocorrelation of the elevation error, the position accuracy does not reflect the geomorphic indices quality (Heuvelink, 2002). Indeed, one value is not sufficient to characterize the DEM error (Heuvelink, 2002) because the spatial distribution of the error has not been taken into consideration (Hebeler and Purves, 2009). Therefore, this accuracy is not sufficient to evaluate the quality of the DEM for geomorphological and hydrological applications.
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Chapter 8. SOFTWARE TESTING STRATEGIES

Chapter 8. SOFTWARE TESTING STRATEGIES

The organization aspects of code inspection are similar to those of code walkthrough (i.e., the number of participants, duration of the meeting, psychological attitudes of the participants etc should be about the psychological attitudes of the participants, etc., should be about the same), but there is a difference in goals.

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Directory UMM :Data Elmu:jurnal:A:Atmospheric Research:Vol52.Issue1-2.Aug1999:

Directory UMM :Data Elmu:jurnal:A:Atmospheric Research:Vol52.Issue1-2.Aug1999:

Ž . Ž . Ž . Ž . Ž . Ž . The sourcesrsinks of water substance in Eqs. 1a , 1b , 1c , 1d , 1e and 1f describe phase changes and they are parameterized based on the following assumptions Ž see Appendix A for details . Cloud water is formed when the air becomes supersatu- . rated with respect to water. The condensation instantaneously brings the air back to saturation. The cloud water moves with the air and evaporates instantaneously in undersaturated conditions. The cloud water is a source of rain. Rain moves relative to the air, collects cloud water as it falls through the cloud, and can evaporate in the undersaturated conditions outside clouds. Raindrops are assumed to follow the size
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The Difference Between Successful and Unsuccessful Learners in The Use of Learning Strategies in Listening Skill

The Difference Between Successful and Unsuccessful Learners in The Use of Learning Strategies in Listening Skill

Based on the explanations and classifications of learning strategies above, it can be inferred that it is worth noting that the students have to be independent learners since they do not always need the teacher around to guide them. In order to reach that, the students are to have suitable strategies in their learning so that they can learn easier, faster, more enjoyable, more self-directed, and more effective in order to reach greater self-confidence, involvement, and proficiency. Besides, the researcher also concludes learning strategy as a term that refers to particular thoughts and attitudes used in the purpose of achieving learning goals independently. The thoughts and attitudes can be categorized into metacognitive, e.g. managing the learning objectives; cognitive, like summarizing; and social, such as sharing ideas and thoughts to peers.
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Wuchereria Kalimantani infected Presbytis cristatus (A primate model for drug trials in lymphatic filariasis)

Wuchereria Kalimantani infected Presbytis cristatus (A primate model for drug trials in lymphatic filariasis)

Data collected were cell viability, morphology and vimentin expression. Cell morphologies were presented as figures, and MCF-7 cell viabilities and vimentin mRNA expressions were presented as mean ± standard deviation (SD) of three experiments. Statistical analyses were performed with one-way ANOVA. p<0.05 was taken to be statistic ally significant difference. If one-way ANOVA showed significant difference, then we proceeded with Tukey’s multiple comparison method.

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Directory UMM :Data Elmu:jurnal:P:PlantScience:Plant Science_BioMedNet:101-120:

Directory UMM :Data Elmu:jurnal:P:PlantScience:Plant Science_BioMedNet:101-120:

Models for stem-cell maintenance in the root and shoot meristem. (a) In the root meristem, the quiescent center (QC) functions as an organizing center. Those cells in immediate contact with the QC are stem cells (dark shading), which are initials for all cell files: endodermis (end), cortex (cort), epidermis (epi), lateral root cap (lrc) and columella (col). (b) In the shoot meristem, WUS is functionally equivalent to the QC in the root meristem in maintaining the presence of stem cells (dark shading). Long-range signaling for stem cell maintenance is also postulated for ZLL, which is expressed in the vascular cells. CLV3 is expressed in the presumptive stem cells that are the initials for the L1 (epidermis), L2 (subepidermal tissues, i.e. mesophyll cells) and L3 (subepidermal tissues, i.e. vascular cells) tissue layers.
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Information technology economics

Information technology economics

developm ent proj ect s eit her fail com plet ely or fail t o m eet som e of t he original t arget s for feat ures developm ent t im e or cost Many t he original t arget s for feat ures, developm ent t im e, or cost . Many of t hese are relat ed t o econom ic issues, such as an incorrect cost- benefit analysis.

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