Read and Download Ebook EBOOK RELEASE Cell And Molecular Biology: by by Gerald Karp PDF File: EBOOK RELEASE Cell 1 And Molecular Biology. Cell and Molecular Biology. Fourth Edition. Chapter Cell Signaling and Signal Transduction: Communication by John Wiley & Sons, Inc. Gerald Karp. Molecular Cell Biology Karp 7th usaascvb.info DOWNLOAD Cellular & Molecular Biology BIO Cell and Molecular Biology by Gerald Karp 7th edition,
|Language:||English, Spanish, German|
|Genre:||Health & Fitness|
|Distribution:||Free* [*Registration needed]|
Read Books Molecular Biology of the Gene (PDF, ePub, Mobi) by James D. .. Biology Concepts Cell Molecular Experiments Gerald Karp. Home · Topics · Documents · Karp-Cell and Molecular Biology Concepts and Experiments, usaascvb.info Mb Molecular and Cell Biology Quizzes Cell and Molecular Biology_ Concepts and Experiments, 7th Edition - Gerald usaascvb.info . Cell and Molecular Biology Concepts and Experiments Gerald Karp 6th edition John Wiley & Sons, Inc. usaascvb.info 8/7/09
A special thanks is owed Laura Ierardi who skillfully laid out the pages for each chapter. I am especially thankful to the many biologists who have contributed micrographs for use in this book; more than any other element, these images bring the study of cell biology to life on the printed page.
Finally, I would like to apologize in advance for any errors that may occur in the text, and express my heartfelt embarrassment.
I am grateful for the construc- tive criticism and sound advice from the following reviewers: The next semester, I took Introductory Biology and began to seriously consider becoming a cell biologist. I am burdening you with this personal trivia so you will understand why I wrote this book and to warn you of possible repercussions. My primary goal in writing this text is to help generate an appreciation in students for the activities in which the giant molecules and minuscule structures that inhab- it the cellular world of life are engaged.
Another goal is to pro- vide the reader with an insight into the types of questions that cell and molecular biologists ask and the experimental approaches they use to seek answers. As you read the text, think like a researcher; consider the evidence that is presented, think of alternate explanations, plan experiments that could lead to new hypotheses.
To take this photograph, you would be sitting in a small, pitch- black room in front of a large metallic instrument whose col- umn rises several meters above your head. You are looking through a pair of binoculars at a vivid, bright green screen. The parts of the cell you are examining appear dark and colorless against the bright green background. The electrons that strike the screen are accelerated through the evacuated space of the column by a force of tens of thousands of volts.
One of your hands may be gripping a knob that controls the magnifying power of the lenses. Because the study of cell function requires the use of con- siderable instrumentation, such as the electron microscope just described, the investigator is physically removed from the subject being studied.
To a large degree, cells are like tiny black boxes. We have developed many ways to probe the boxes, but we are always groping in an area that cannot be fully illuminat- ed. A discovery is made or a new technique is developed and a new thin beam of light penetrates the box. With further work, our understanding of the structure or process is broadened, but we are always left with additional questions. We generate more complete and sophisticated constructions, but we can never be sure how closely our views approach reality.
In this regard, the study of cell and molecular biology can be compared to the study of an elephant as conducted by six blind men in an old Indian fable. The six travel to a nearby palace to learn about the nature of elephants. When they arrive, each approaches the elephant and begins to touch it.
The second touches the trunk and decides that an ele- phant is round like a snake. The other members of the group touch the tusk, leg, ear, and tail of the elephant, and each forms his impression of the animal based on his own limited experi- ences. Cell biologists are limited in a similar manner as to what they can learn by using a particular technique or experimental approach. Although each new piece of information adds to the preexisting body of knowledge to provide a better concept of the activity being studied, the total picture remains uncertain.
Before closing these introductory comments, let me take the liberty of offering the reader some advice: There are several reasons for urging such skepticism. But, more importantly, we should consider the nature of biological research. Biology is an empirical science; nothing is ever proved. We compile data concerning a particular cell organelle, metabolic reaction, intracellular movement, etc. Some conclusions rest on more solid evidence than others.
Hypotheses are put forth and generally stimulate further research, thereby leading to a reeval- uation of the original proposal. Most hypotheses that remain valid undergo a sort of evolution and, when presented in the text, should not be considered wholly correct or incorrect.
These ideas are often described as models. Moreover, they reinforce the idea that cell biologists operate at the frontier of science, a boundary between the unknown and known or thought to be known. Remain skeptical. The Growing Problem of Antibiotic Resistance 3. The Prospect of Cell Replacement Therapy 19 1. An Example of Plasma Membrane Structure 4.
Anchoring Cells to Their Substratum 7. The First Step in Vesicular Transport 8. Disorders Resulting from Defects in Lysosomal Function 8. The Role of Cilia in Development and Disease 9. The Molecular Motor of Actin Filaments 9.
Diseases that Result from Expansion of Trinucleotide Repeats From Transcription to Translation Chromosomal Aberrations and Human Disorders Epigenetics: Communication Between Cells The Origin of Eukaryotic Cells 1 Introduction to the Study of Cell and Molecular Biology ells, and the structures they comprise, are too small to be directly seen, heard, or touched. In spite of this tremendous handicap, cells are the subject of hundreds of thousands of publications each year, with virtually every aspect of their minuscule structure coming under scrutiny.
In many ways, the study of cell and molecular biology stands as a tribute to human curiosity for seeking to discover, and to human creative intelligence for devising the complex instruments and elaborate techniques by which these discoveries can be made.
This is not to imply that cell and molecular biologists have a monopoly on these noble traits. At the other end of the spectrum, nuclear physicists are focusing their attention on subatomic particles that have equally inconceivable properties. Clearly, our universe consists of worlds within worlds, all aspects of which make for fascinating study. As will be apparent throughout this book, cell and molecular biology is reductionist; that is, it is based on the view that knowledge of the parts of the whole can explain the character of the whole.
This light micrograph shows a cell lying on a microscopic bed of synthetic posts. When the cell moves, it pulls on the attached posts, which report the amount of strain they are experiencing. The cell nucleus is stained green. FROM J. To the degree to which this occurs, it is hoped that this loss can be replaced by an equally strong appreciation for the beauty and complexity of the mechanisms underlying cellular activity. By the mids, a handful of pioneering scientists had used their handmade microscopes to uncover a world that would never have been revealed to the naked eye.
The discov- ery of cells Figure 1. One of the many questions Hooke attempted to answer was why stoppers made of cork part of the bark of trees were so well suited to holding air in a bottle.
As he wrote in In actual fact, Hooke had observed the empty cell walls of dead plant tissue, walls that had originally been pro- duced by the living cells they surrounded. Meanwhile, Anton van Leeuwenhoek, a Dutchman who earned a living selling clothes and buttons, was spending his spare time grinding lenses and constructing simple micro- scopes of remarkable quality Figure 1. For 50 years, Leeuwenhoek sent letters to the Royal Society of London de- scribing his microscopic observations—along with a rambling discourse on his daily habits and the state of his health.
Hooke did just that, and Leeuwenhoek was soon a worldwide celebrity, receiving visits in Holland from Peter the Great of Russia and the queen of England. In , Matthias Schleiden, a German lawyer turned botanist, concluded that, despite differences in the structure of various tissues, plants were made of cells and that the plant embryo arose from a single cell.
Schwann concluded that the cells of plants and animals are similar structures and proposed these two tenets of the cell theory: The biconvex lens, which was capa- ble of magnifying an object approximately times and providing a resolution of approximately 1. By , Rudolf Virchow, a German pathologist, had made a convinc- ing case for the third tenet of the cell theory: Life, in fact, is the most basic property of cells, and cells are the small- est units to exhibit this property.
Unlike the parts of a cell, which simply deteriorate if isolated, whole cells can be re- moved from a plant or animal and cultured in a laboratory where they will grow and reproduce for extended periods of time.
If mistreated, they may die. Death can also be consid- ered one of the most basic properties of life, because only a liv- ing entity faces this prospect. The cells were obtained from a malignant tumor and named HeLa cells after the donor, Henrietta Lacks. Because they are so much simpler to study than cells situated within the body, cells grown in vitro i.
In fact, much of the information that will be dis- cussed in this book has been obtained using cells grown in laboratory cultures. We will begin our exploration of cells by examining a few of their most fundamental properties. For the present, we can think of com- plexity in terms of order and consistency.
The more complex a structure, the greater the number of parts that must be in their proper place, the less tolerance of errors in the nature and in- teractions of the parts, and the more regulation or control that must be exerted to maintain the system.
Cellular activities can be remarkably precise. DNA duplication, for example, occurs with an error rate of less than one mistake every ten million nucleotides incorporated—and most of these are quickly cor- rected by an elaborate repair mechanism that recognizes the defect. During the course of this book, we will have occasion to consider the complexity of life at several different levels. As will be apparent, there is a great deal of consistency at every level. Each type of cell has a consistent appearance when viewed under a high-powered electron microscope; that is, its organelles have a particular shape and location, from one individual of a species to another.
Similarly, each type of organelle has a consistent composition of macromolecules, which are arranged in a predictable pattern. Consider the cells lining your intestine that are responsible for removing nutrients from your digestive tract Figure 1.
The epithelial cells that line the intestine are tightly con- nected to each other like bricks in a wall. The apical ends of these cells, which face the intestinal channel, have long processes microvilli that facilitate absorption of nutrients.
At their basal ends, intestinal cells have large numbers of mitochondria that provide the energy required to fuel various membrane trans- port processes. Each of these various levels of organization is illustrated in the insets of Figure 1. Fortunately for cell and molecular biologists, evolution has moved rather slowly at the levels of biological organiza- FIGURE 1.
The brightly colored photograph of a stained section shows the microscopic structure of a villus of the wall of the small intestine, as seen through the light microscope. Inset 1 shows an electron micrograph of the epithelial layer of cells that lines the inner intestinal wall.
The apical surface of each cell, which faces the channel of the intestine, contains a large number of microvilli involved in nutrient absorption. The basal region of each cell contains large numbers of mitochondria, where energy is made available to the cell.
Inset 4 shows an individual mitochondrion sim- ilar to those found in the basal region of the epithelial cells. Inset 5 shows a portion of an inner membrane of a mitochondrion including the stalked particles upper arrow that project from the membrane and correspond to the sites where ATP is synthesized. Insets 6 and 7 show molecular models of the ATP-synthesizing machinery, which is dis- cussed at length in Chapter 5.
In humans, glucose is re- leased by the liver into the blood where it circulates through the body delivering chemical energy to all the cells.
Cells expend an enormous amount of energy simply breaking down and rebuilding the macromolecules and organelles of which they are made.
Even the simplest bacterial cell is capable of hundreds of different chemical transformations, none of which occurs at any sig- tion with which they are concerned.
Whereas a human and a cat, for example, have very different anatomical features, the cells that make up their tissues, and the organelles that make up their cells, are very similar. Information obtained by studying cells from one type of organism often has direct application to other forms of life.
Many of the most basic processes, such as the synthesis of pro- teins, the conservation of chemical energy, or the construction of a membrane, are remarkably similar in all living organisms. Remarkably, this vast amount of information is packaged into a set of chromosomes that occupies the space of a cell nucleus—hundreds of times smaller than the dot on this i.
Genes are more than storage lockers for information: The molecular structure of genes allows for changes in genetic information mutations that lead to variation among individuals, which forms the ba- sis of biological evolution. Discovering the mechanisms by which cells use their genetic information has been one of the greatest achievements of science in recent decades.
Cells Are Capable of Producing More of Themselves Just as individual organisms are generated by reproduction, so too are individual cells.
Prior to division, the genetic material is faith- fully duplicated, and each daughter cell receives a complete and equal share of genetic information. In most cases, the two daughter cells have approximately equal volume. In some cases, however, as occurs when a human oocyte undergoes division, one of the cells can retain nearly all of the cytoplasm, even though it receives only half of the genetic material Figure 1.
Cells Acquire and Utilize Energy Every biological process requires the input of energy. The energy of light is trapped by light-absorbing pigments present in the membranes of photosynthetic cells Figure 1. Light energy is converted by photosynthesis into chemical energy that is stored in energy-rich carbohydrates, such as sucrose or starch.
This mammalian oocyte has recently undergone a highly unequal cell division in which most of the cytoplasm has been retained within the large oocyte, which has the potential to be fertilized and develop into an embryo.
The other cell is a nonfunctional remnant that consists almost totally of nuclear material indicated by the blue-staining chromosomes, arrow. The ribbon-like chloroplast, which is seen to zigzag through the cell, is the site where energy from sunlight is captured and con- verted to chemical energy during photosynthesis. Virtually all chemical changes that take place in cells require enzymes—molecules that greatly increase the rate at which a chemical reaction oc- curs. Cells Engage in Mechanical Activities Cells are sites of bustling activity.
Materials are transported from place to place, structures are assembled and then rapidly disassembled, and, in many cases, the entire cell moves itself from one site to another.
Cells Are Able to Respond to Stimuli Some cells respond to stimuli in obvious ways; a single-celled protist, for example, moves away from an object in its path or moves toward a source of nutrients. Cells within a multicellu- lar plant or animal respond to stimuli less obviously. Cells possess receptors to hormones, growth factors, and extracellular materials, as well as to substances on the surfaces of other cells.
Cells Are Capable of Self-Regulation In addition to requiring energy, maintaining a complex, ordered state requires constant regulation.
We are gradually learning how a cell controls its activities, but much more is left to discover. Consider the following experiment conducted in by Hans Driesch, a German embryologist.
How can a cell that is normally destined to form only part of an embryo reg- ulate its own activities and form an entire embryo? How can a part of an embryo have a sense of the whole? We are not able to answer these questions much better today than we were more than a hundred years ago when the experiment was performed.
In the cell, the information for product design resides in the nu- cleic acids, and the construction workers are primarily pro- teins. It is the presence of these two types of macromolecules that, more than any other factor, sets the chemistry of the cell apart from that of the nonliving world.
Each step of a process must occur spontaneously in such a way that the next step is automatically triggered. Each type of cellular activity requires a unique set of highly complex molecular tools and machines—the products of eons of natural selection and biological evolution. A pri- mary goal of biologists is to understand the molecular struc- ture and role of each component involved in a particular activity, the means by which these components interact, and the mechanisms by which these interactions are regulated.
Cells Evolve How did cells arise? The left panel depicts the normal develop- ment of a sea urchin in which a fertilized egg gives rise to a single em- bryo. Rather than developing into half of an embryo, as it would if left undisturbed, each isolated cell recognizes the absence of its neighbor, regulating its development to form a com- plete although smaller embryo. It is presumed that cells evolved from some type of precellular life form, which in turn evolved from nonliving organic materials that were present in the primordial seas.
Whereas the origin of cells is shrouded in near-total mystery, the evolution of cells can be studied by examining organisms that are alive today. If you were to observe the features of a bacterial cell living in the human intestinal tract see Fig- ure 1.
Yet both have evolved from a common ancestral cell that lived more than three billion years ago. Those struc- tures that are shared by these two distantly related cells, such as their similar plasma membrane and ribosomes, must have been present in the ancestral cell.
We will examine some of the events that occurred during the evolution of cells in the Experimental Pathways at the end of the chapter. Keep in mind that evolution is not simply an event of the past, but an ongoing process that continues to modify the properties of cells that will be present in organisms that have yet to appear. It became apparent from these studies that there were two basic classes of cells—prokaryotic and eukary- otic—distinguished by their size and the types of internal structures, or organelles, they contain Figure 1.
The existence of two distinct classes of cells, without any known intermediates, represents one of the most fundamental evolutionary divisions in the biological world. The structurally simpler, prokaryotic cells include bacteria, whereas the structurally more complex eukaryotic cells include protists, fungi, plants, and animals. Evidence of prokaryotic life has been obtained from rocks approximately 2. Not only do these rocks contain fossilized microbes, they contain complex or- ganic molecules that are characteristic of particular types of prokaryotic organisms, including cyanobacteria.
It is unlikely that such molecules could have been synthesized abiotically, that is, without the involvement of living cells. Cyanobacteria almost certainly appeared by 2. List the fundamental properties shared by all cells. Describe the importance of each of these properties. Describe the features of cells that suggest that all living organisms are derived from a common ancestor.
What is the source of energy that supports life on Earth? How is this energy passed from one organism to the next?
Pace in Nature The dawn of the age of eukaryotic cells is also shrouded in uncertainty. Complex multicellular ani- mals appear rather suddenly in the fossil record approximately million years ago, but there is considerable evidence that simpler eukaryotic organisms were present on Earth more than one billion years earlier.
The estimated time of appearance on Earth of several major groups of organisms is depicted in Fig- ure 1. Characteristics That Distinguish Prokaryotic and Eukaryotic Cells The following brief comparison between prokaryotic and eu- karyotic cells reveals many basic differences between the two types, as well as many similarities see Figure 1. You are looking through a pair of binoculars at a vivid, bright green screen. The parts of the cell you are examining appear dark and colorless against the bright green background.
The electrons that strike the screen are accelerated through the evacuated space of the column by a force of tens of thousands of volts. One of your hands may be gripping a knob that controls the magnifying power of the lenses. Because the study of cell function requires the use of considerable instrumentation, such as the electron microscope just described, the investigator is physically removed from the subject being studied. To a large degree, cells are like tiny black boxes.
We have developed many ways to probe the boxes, but we are always groping in an area that cannot be fully illuminated. A discovery is made or a new technique is developed and a new thin beam of light penetrates the box. With further work, our understanding of the structure or process is broadened, but we are always left with additional questions. We generate more complete and sophisticated constructions, but we can never be sure how closely our views approach reality.
In this regard, the study of cell and molecular biology can be compared to the study of an elephant as conducted by six blind men in an old Indian fable. The six travel to a nearby palace to learn about the nature of elephants. When they arrive, each approaches the elephant and begins to touch it. The second touches the trunk and decides that an elephant is round like a snake. The other members of the group touch the tusk, leg, ear, and tail of the elephant, and each forms his impression of the animal based on his own limited experiences.
Cell biologists are limited in a similar manner as to what they can learn by using a particular technique or experimental approach. Although each new piece of information adds to the preexisting body of knowledge to provide a better concept of the activity being studied, the total picture remains uncertain.