Keller Cell in Health Disease Review Objective 1 All life is composed of cells and new cells arise from preexisting cells This is known as Cell Theory Prokaryotes vs Eukaryotes Similarities Cells of each are able to replicate divide into two daughter cells autonomously Each cell is bounded by a living membrane that establishes an environment inside the cell that is different from outside of the cell Each cell contains full complement of organism specific coded genetic information that is organized into genes on chromosomes each cell can control which cell specific subset of that information code will be read through a process known as transcription into messenger RNA and used translation to make the protein components of the cell All cells contain the protein synthetic machines known as ribosomes that translate the mRNA code to make specific proteins the active components of cells Differences Prokaryotic cells are unicellular but can form colonies Eukaryote are single celled or multi cellular Prokaryotic are not compartmentalized DNA in cytoplasm but Eukaryotic are compartmentalized into specialized membrane bounded compartments Prokaryotic must synthesize folic acid for DNA synthesis Eukaryotic obtain folic acid neccessary for DNA synthesis as a vitamin in diet Prokaryotic have specialized cell wall Eukaryotic have cell specialization in multi cellular organisms Although all cells contain ribosomes Eukaryotic Prokaryotic differ in key features which make it possible to inhibit protein synthesis in bacteria without affecting protein synthesis in humans Antibiotics exploit these differences preventing Prokaryotic from making folic acid which they need for DNA synthesis inhibiting prokaryotic cell protein synthesis inhibits prokaryotic cell wall formation Don t randomly kill cells don t prevent eukaryotic cells from making folic acid Specifically for prokaryotic don t engulf kill Objective 2 Know that all cells are enclosed in a plasma membrane that is strong flexible fusible and semipermeable Understand that cell membrane properties are due to the intrinsic nature of the amplified phospholipids Know how membrane proteins function to move the phospholipid bilayers living membrane by transporting molecules into and out of the cells thereby establishing an environment outside the cell Understand that drugs can influence cell behaviors by affecting the activity of membrane transporting proteins and that defects in membranes transporting proteins can lead to human diseases such as cystic fibrosis Objective 3 Understand how cell membranes can use specific uptake mechanisms to import molecules such as LDL RME and bacteria phagocytosis without compromising the integrity of the cell Cells take in more than 50 diff types of molecules by the process of Receptor Mediated Endocytosis Know that defects in membrane uptake of macromolecules such as LDL can cause human diseases such as hypercholesterolemia Familial hypercholesterolemia hereditary genetic disease that results in defective LDL uptake into the cells causing cells to fail to clear the blood well enough resulting in accumalation of LDL on walls of blood vessels Appreciate that understanding the cell biology of uptake mechanisms such as RME can lead to rational treatments for human diseases Phagocytosis is the process by which cells can ingest bacteria and parasites Objective 4 Viruses are NOT cells Viruses infect cells The contain genetic material enclosed in capsid of protein Viruses cannot replicate on their own and lack ribosomes with which to make proteins They are intracellular parasites that rely on commandeering the processes of either Eukaryotic or Prokaryotic cells to make their component parts in order to make multiple copies of themselves Tamiflu inhibits the virus release process HIV Influenza virus composition Genome RNA Genetic info Capsid around genome Coat with few specialized proteins No organelles Use proteases to trim proteins and become mature Infect cells by binding to normal cells Membrane proteins Antiretroviral Therapies AZT inhibits viral reverse transcriptase activity Protease Inhibitors Cell mimic agents Preventative methods and education Objective 5 Know that extracellular primary signaling molecules can affect the behavior of cells by binding to cytoplasmic or plasma membrane receptors Estrogen Tamoxifen binds to estrogen receptors and prevents estrogen from binding Can diffuse across plasma membrane and bind to receptors in cytoplasm which takes it into the nucleus Growth factor signaling released in response to tissue wounds They bind to membrane proteins Active G protein activates an enzyme C which produces Production of cAMP as a second messenger Objective 6 Cancer is a family of diseases Cultures mimic behavior of cancer cells in the body May be oncogenes ON Stay on May be mutated tumor suppressor gene No Off Cancer genes can be passed on retinoblastoma P53 Ras proteins Objective 7 Actin microfilaments made of highly conserved protein actin assembled like building blocks can be assembled and dissassembled Contribute to structure of cell component Defective dystrophin protein in some forms of muscular dystrophy cause actin microfilaments to not be properly moved to muscle membrane Cell cytoplasm highly structured can change shape slowly resists rapid deformation allows cells to have different shapes allows cells to move Muscle Anatomy Sarcomere contractile unit of muscle Myofibrils end to end arrangements of sacromeres Contains multiple nuclei Muscle contraction Actin Myosin in sarcomere contraction occurs when myosin heads use ATP energy to work along and pull actin thin filaments Objective 8 Mitotic spindle Spindle structure accomplishes mitosis Spindle made forms linkage of micro tubules to chromosomes occurs during cell divisions Stem Cells Used in medical research can be separated from human embryos May be useful in treating heart disease and nerve cell damage with cell therapy Stem cells can develop into diff types of special cells like nerve and muscle cells Stem cells are like blood and skin cells Cell Therapy Uses human stem cells are placed where cell damage has occurred to regenerate lost or malfunctioning tissue May be useful in treating type 1 diabetes child onset and Parkinson s disease
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