Cell biology

Understanding cells in terms of their molecular components.

Cell biology (formerly cytology, from the humans, plants, and sponges.

Knowing the components of cells and how cells work is fundamental to all biological sciences. Appreciating the similarities and differences between cell types is particularly important to the fields of cell and molecular biology as well as to biomedical fields such as cancer research and developmental biology. These fundamental similarities and differences provide a unifying theme, sometimes allowing the principles learned from studying one cell type to be extrapolated and generalized to other cell types. Therefore, research in cell biology is closely related to genetics, biochemistry, molecular biology, immunology, and developmental biology.

Processes

Movement of proteins

Endothelial cells under the microscope. Nuclei are stained blue with DAPI, microtubles are marked green by an antibody and actin filaments are labelled red with phalloidin.

Each type of protein is usually sent to a particular part of the cell. An important part of cell biology is the investigation of molecular mechanisms by which proteins are moved to different places inside cells or secreted from cells.

Most

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• Cell Centered Database
• Cell Biology at DMOZ
• Aging Cell
• "Francis Harry Compton Crick (1916-2004)" by A. Andrei at the Embryo Project Encyclopedia

External links

• Cell and Molecular Biology by Karp 5th Ed., ISBN 0-471-46580-1
•  This article incorporates public domain material from the NCBI document "Science Primer".

• Penner-Hahn, James E. (2013). "Chapter 2. Technologies for Detecting Metals in Single Cells. Section 4. Intrinsic X-Ray Fluorescence". In Banci, Lucia (Ed.). Metallomics and the Cell. Metal Ions in Life Sciences 12. Springer.  electronic-book ISBN 978-94-007-5561-1 ISSN 1559-0836electronic-ISSN 1868-0402

Notes

• Cell disruption
• Cellular microbiology
• Institute of Molecular and Cell Biology
• Prokaryotic cell
• The American Society for Cell Biology
• Cell physiology
• Green fluorescent protein(GFP)

See also

Notable cell biologists

• Cell fractionation
  • Release of cellular organelles by disruption of cells.
  • Separation of different organelles by centrifugation.
• Flow cytometry
• Immunoprecipitation
• Proteins extracted from cell membranes by detergents and salts or other kinds of chemicals.

Purification of cells and their parts Purification may be performed using the following methods:

• Cell culture is the basic technique of growing cells in a laboratory independent of an organism.
• Immunostaining, also known as immunohistochemistry, is a specialized histological method used to localize proteins in cells or tissue slices. Unlike regular histology, which uses stains to identify cells, cellular components or protein classes, immunostaining requires the reaction of an antibody directed against the protein of interest within the tissue or cell. Through the use of proper controls and published protocols (need to add reference links here), specificity of the antibody-antigen reaction can be achieved. Once this complex is formed, it is identified via either a "tag" attached directly to the antibody, or added in an additional technical step. Commonly used "tags" include fluorophores or enzymes. In the case of the former, detection of the location of the "immuno-stained" protein occurs via fluorescence microscopy. With an enzymatic tag, such as horse radish peroxidase, a chemical reaction is carried out that results in a dark color in the location of the protein of interest. This darkened pattern is then detected using light microscopy.
• Computational genomics is used to find patterns in genomic information ^[2]
• DNA microarrays identify changes in transcript levels between different experimental conditions.
• Gene knockdown mutates a selected gene.
• In situ hybridization shows which cells are expressing a particular RNA transcript.
• PCR can be used to determine how many copies of a gene are present in a cell.
• Transfection introduces a new gene into a cell, usually an expression construct

There are several different methods used in the study of cells:

Cells may be observed under the microscope, using several different techniques; these include optical microscopy, transmission electron microscopy, scanning electron microscopy, fluorescence microscopy, and confocal microscopy.

Electron micrograph.

Techniques used to study cells

• photosynthesis (only found in plant cells)
• Cell wall - extra layer of protection (only found in plant cells)
• Cell membrane - the part of the cell which separates the cells from the outside environment and protects the cell, as well as regulating what goes in and out of the cell
• Cilium - motile structure of eukaryotes having a cytoskeleton, the axoneme.
• Cytoplasm - contents of the main fluid-filled space inside cells. Any chemical reactions also happen in here.
• Cytoskeleton - protein filaments inside cells
• Endoplasmic reticulum - major site of membrane protein synthesis
• Flagellum - motile structure of bacteria, archaea and eukaryotes
• Golgi apparatus - site of protein glycosylation in the endomembrane system
• cell membranes
• Lysosome - break down cellular waste products and debris into simple compounds (only found in animal cells)
• Membrane lipid and protein barrier
• Mitochondrion - major energy-producing organelle by releasing it in the form of ATP
• Nucleus - holds most of the DNA of eukaryotic cells and controls all cellular activities
• Organelle - term used for major subcellular structures
• Ribosome - RNA and protein complex required for protein synthesis in cells
• Vesicle - small membrane-bounded spheres inside cells

Internal cellular structures

• Active transport and Passive transport - Movement of molecules into and out of cells.
• Autophagy - The process whereby cells "eat" their own internal components or microbial invaders.
• Adhesion - Holding together cells and tissues.
• Division - By which cells reproduce either by either mitosis (to produce clones of the parent cell) or Meiosis (to produce haploid gametes)
• Cell movement - Chemotaxis, contraction, cilia and flagella.
• Cell signaling - Regulation of cell behavior by signals from outside.
• DNA repair - Cell death and cell senescence.
• Metabolism - Glycolysis, respiration, photosynthesis, and chemosynthesis.
• Transcription and mRNA splicing - Gene expression.

Other cellular processes

Extracellular and cell surface proteins destined to be degraded can move back into intracellular compartments upon being incorporated into endocytosed vesicles, some of which fuse with lysosomes where the proteins are broken down to their individual amino acids. The degradation of some membrane proteins begins while still at the cell surface when they are separated by secretases. Proteins that function in the cytoplasm are often degraded by proteasomes.

Some proteins that are made in the cytoplasm contain structural features that target them for transport into mitochondria or the cell nucleus. Some mitochondrial proteins are made inside mitochondria and are coded for by mitochondrial DNA. In plants, chloroplasts also make some cell proteins.

. neurons terminals of axon tracks to distant parts of cells such as the cytoskeletal transport membrane protein-containing vesicles along Motor proteins (ER) and Golgi can be thought of as the "membrane protein synthesis compartment" and the "membrane protein processing compartment", respectively. There is a semi-constant flux of proteins through these compartments. ER and Golgi-resident proteins associate with other proteins but remain in their respective compartments. Other proteins "flow" through the ER and Golgi to the plasma membrane. endoplasmic reticulum, to other sub-cellular compartments, or they can be secreted from the cell. The plasma membrane From the Golgi, membrane proteins can move to the [1]