Lodish H. Молекулярная Цитобиология (5ed, Почетный гражданин, 2003) (ISBN 0716743663), Lodish H. Molecular Cell Biology (5ed, Freeman, 2003)(ISBN 0716743663)(C)(967s).pdf:

Lodish H. Молекулярная Цитобиология (5ed, Почетный гражданин, 2003) (ISBN 0716743663)

Lodish H. Molecular Cell Biology (5ed, Freeman, 2003)(ISBN 0716743663)(C)(967s).pdf

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Date Aug 18, 2004

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characteristic of eukaryotic cells is segregation of the cellular DNA within a defined nucleus, which is bounded by a double membrane. The outer nuclear membrane is continuous with the rough endoplasmic reticulum, a factory for assembling proteins. Golgi vesicles process and modify proteins, mitochondria generate energy, lysosomes digest cell materials to recycle them, peroxisomes process molecules using oxygen, and secretory vesicles carry cell materials to the surface to release them.
[Part (a) courtesy of I. D. J. Burdett and R. G. E. Murray. Part (b) from P C. Cross and K. L. Mercer, 1993, Cell and Tissue Ultrastructure: . A Functional Perspective, W. H. Freeman and Company.]...

generally much larger than bacteria. A typical human fibroblast, a connective tissue cell, might be about 15 m across with a volume and dry weight some thousands of times those of an E. coli bacterial cell. An amoeba, a singlecelled protozoan, can be more than 0.5 mm long. An ostrich egg begins as a single cell that is even larger and easily visible to the naked eye. All cells are thought to have evolved from a common progenitor because the structures and molecules in all cells have...

event that brings on the fevers and shaking chills that are the well-known symptoms of malaria. Some of the released merozoites infect additional RBCs, creating a cycle of production and infection. Eventually, some merozoites develop into male and female gametocytes 5 , another metamorphosis. These cells, which contain half the usual number of chromosomes, cannot survive for long unless they are transferred in blood to an Anopheles mosquito. In the mosquito’s stomach, the gametocytes are transformed into sperm or eggs (gametes), yet another metamorphosis marked by development of long hairlike flagella on the sperm 6 . Fusion of sperm and eggs generates zygotes 7 , which implant into the cells of the stomach wall and grow into oocysts, essentially factories for producing sporozoites. Rupture of an oocyst releases thousands of sporozoites 8 ; these migrate to the salivary glands, setting the stage for infection of another human host. (b) Scanning electron micrograph of mature oocysts and emerging sporozoites. Oocysts abut the external surface of stomach wall cells and are encased within a membrane that protects them from the host immune system. [Part (b) courtesy of R. E. Sinden.]...

1.1 • The Diversity and Commonality of Cells
(a) T4 bacteriophage (b) Tobacco mosaic virus...

▲ FIGURE 1-8 Five genetically identical cloned sheep. An early sheep embryo was divided into five groups of cells and each was separately implanted into a surrogate mother, much like the natural process of twinning. At an early stage the cells are able to adjust and form an entire animal; later in development the cells become progressively restricted and can no longer do so. An alternative way to clone animals is to replace the nuclei of multiple single-celled embryos with donor nuclei from cells of an adult sheep. Each embryo will be genetically identical to the adult from which the nucleus was obtained. Low percentages of embr yos survive these procedures to give healthy animals, and the full impact of the techniques on the animals is not yet known.
[Geoff Tompkinson/Science Photo Library/Photo Researchers, Inc.]...

Proteins Give Cells Structure and Perform Most Cellular Tasks
The varied, intricate structures of proteins enable them to carry out numerous functions. Cells string together 20 different amino acids in a linear chain to form a protein (see Figure 2-13). Proteins commonly range in length from 100 to 1000 amino acids, but some are much shorter and others longer. We obtain amino acids either by synthesizing them from other molecules or by breaking down proteins that we eat. The “essential” amino acids, from a dietary standpoint, are the eight that we cannot synthesize and must obtain from food. Beans and corn together have all eight, making their combination particularly nutritious. Once a chain of amino acids is formed, it folds into a complex shape, conferring a distinctive three-dimensional structure and function on each protein (Figure 1-9)....

l e c u l a r weight of 52,700 (g/mol). Assuming this value is typical of eukaryotic proteins, we can calculate the total 1 number of protein molecules per liver cell as about 7.9 09 from the total protein weight and Avogadro’s number, t h e number of molecules per mole of any chemical comp o u n d (6.02 10 23) . To carry this calculation one step f u r t h e r, consider that a liver cell contains about 10,000 different proteins; thus, a cell contains close to a million molecules of each type of protein on average. In actuality the abundance of different proteins varies widely, from the quite rare insulin-binding receptor protein (20,000 molec u l e s ) to the abundant structural protein actin (5 10 8 molecules)....

as templates to produce complementary strands. The outcome is two copies of the original double helix, each containing one of the original strands and one new daughter (complementary) strand....

The Genome Is Packaged into Chromosomes and Replicated During Cell Division
Most of the DNA in eukaryotic cells is located in the nucleus, extensively folded into the familiar structures we know as chromosomes (Chapter 10). Each chromosome contains a single linear DNA molecule associated with certain proteins. In prokaryotic cells, most or all of the genetic information resides...

▲ FIGURE 1-12 Chromosomes can be “painted” for easy identification. A normal human has 23 pairs of morphologically distinct chromosomes; one member of each pair is inherited from the mother and the other member from the father. (Left) A chromosome spread from a human body cell midway through mitosis, when the chromosomes are fully condensed. This preparation was treated with fluorescent-labeled staining reagents that allow each of the 22 pairs and the X and Y...

Cells Build and Degrade Numerous Molecules and Structures
As chemical factories, cells produce an enormous number of complex molecules from simple chemical building blocks. All...

cells. The cytosols of adjacent animal or plant cells often are connected by functionally similar but structurally different “bridges” called gap junctions in animals and plasmodesmata in plants. These structures allow cells to exchange small molecules including nutrients and signals, facilitating coordinated functioning of the cells in a tissue....

Animal Cells Produce Their Own External Environment and Glues
The simplest multicellular animals are single cells embedded in a jelly of proteins and polysaccharides called the extracellular matrix. Cells themselves produce and secrete these materials, thus creating their own immediate environment (Chapter 6). Collagen, the single most abundant protein in the animal kingdom, is a major component of the extracellular matrix in most tissues. In animals, the extracellular matrix cushions and lubricates cells. A specialized, especially tough matrix, the basal lamina, forms a supporting layer underlying sheetlike cell layers and helps prevent the cells from ripping apart. The cells in animal tissues are “glued” together by celladhesion molecules (CAMs) embedded in their surface membranes. Some CAMs bind cells to one another; other types bind cells to the extracellular matrix, forming a cohesive unit. The cells of higher plants contain relatively few such molecules; instead, plants cells are rigidly tied together by extensive interlocking of the cell walls of neighboring...