Glossary - Inside the Cell - National Institute of General Medical Sciences
In telophase, nuclear membranes form around each of the two sets of chromosomes, the chromosomes begin to spread out, and the spindle begins to break down. Crossing over A process that occurs during meiosis in which chromosome partners, one inherited from each parent, physically swap sections with one another
They are concerned with structural framework, orientation and distribution of cell organelle, movement by or within cells and maintenance of shape of the cells. Microfilaments Microfilaments Discovered by Paleviz and his co-workers (1974).They are long, thin, very fine protein filaments which are about 5-10nm in diameter and show beaded appearance due to the close helical arrangement of actin molecules
Their distinctive features are: A large central vacuole (enclosed by a membrane, the tonoplast ), which maintains the cell's turgor and controls movement of molecules between the cytosol and sapPowerPoint Presentation: A primary cell wall containing cellulose , hemicellulose and pectin , deposited by the protoplast on the outside of the cell membrane Chloroplasts that contain chlorophyll , the pigment that gives plants their green color and allows them to perform photosynthesis Higher plants, including conifers and flowering plants lack the flagella and centrioles that are present in animal cells . This leads to growth in multicellular organisms (the growth of tissue ) and to procreation ( vegetative reproduction ) in unicellular organisms .PowerPoint Presentation: Prokaryotic cells divide by binary fission
Animal Cell
cilia, flagella, pseudopodia.) The animal kingdom is unique amongst eukaryotic organisms because animal tissues are bound together by a triple helix of protein, called collagen. Making up about three-quarters of the species on Earth, they run the gamut from sponges and jellyfish to ants, whales, elephants, and -- of course -- human beings
The electron transport system transfers protons from the inner compartment to the outer; as the protons flow back to the inner compartment, the energy of their movement is used to add phosphate to ADP, forming ATP. Water flows across the respiratory surface of the gill in one direction while blood flows in the other direction through the blood vessels on the other side of the surface
They are also involved in the digestion of food particles brought into the cell through infoldings in the plasma membrane Structure A membrane bound sac lysosomes are a small vacuoles or vesicles in the cytoplasm filled with digestive enzymes. Structure Each cilia (or flagella) is a circular series of 9 pairs of microtubules (often containing an additional central pair of tubules) surrounded by a long slender sheath of plasma membrane
Cell Membrane Functions
In endocytosis, the plasma membrane creates a small depression (pseudopodium), into which the materials to be transported are gathered, to form a vesicle. Back to top What Does a Cell Membrane Do? Anchors the Cytoskeleton: In short, a cell membrane works as an enclosure for the internal organelles and protect them
Cell Structure and Function
Eukaryotes Organisms whose cells normally contain a nucleus are called Eukaryotes; those (generally smaller) organisms whose cells lack a nucleus and have no membrane-bound organelles are known as Prokaryotes. Membrane proteins A variety of protein molecules are embedded in the basic phospholipid bilayer Some proteins are attached to the surface of the cell membrane on both the internal and external surface
Interactive Eukaryotic Cell Model
Smooth ER plays different functions depending on the specific cell type including lipid and steroid hormone synthesis, breakdown of lipid-soluble toxins in liver cells, and control of calcium release in muscle cell contraction. Smooth Endoplasmic Reticulum: Throughout the eukaryotic cell, especially those responsible for the production of hormones and other secretory products, is a vast network of membrane-bound vesicles and tubules called the endoplasmic reticulum, or ER for short
The Cytoskeleton
(photo at right) In the photo (courtesy of Mary Osborn), a fluorescent stain has been used to show the intermediate filaments of keratin in two epithelial cells. Microtubule motors There are two major groups of microtubule motors: kinesins (most of these move toward the plus end of the microtubules) and dyneins (which move toward the minus end)
The cytoskeleton works with the cell membrane to support the shape of the cell, and is important to be aware of when discussing the function of the cell membrane
Animal Cell Mitosis
Some mitotic spindle fibers elongate from the centrosomes and attach to kinetochores, protein bundles at the centromere region on the chromosomes where sister chromatids are joined
The Actin Cytoskeleton - Molecular Cell Biology - NCBI Bookshelf
The platelet cytoskeleton must undergo complicated rearrangements that are responsible for a repertoire of changes in cell shape during a blood clotting reaction (Figure 18-8). In this type of experiment, an excess of myosin S1, the globular head domain of myosin, is mixed with actin filaments and binding is permitted to occur
The animal kingdom is unique among eukaryotic organisms because most animal tissues are bound together in an extracellular matrix by a triple helix of protein known as collagen. The process of cell fractionation enables the scientist to prepare specific components, the mitochondria for example, in large quantities for investigations of their composition and functions
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