08 29 2012 Notes Cell biology emphasizes how cells function primarily Eukaryotes while Physiology looks at how cells become specialized and functionally integrated Reductionist approach the whole is the sum of its parts take for example an animal cell Contains many organelles mitochondria etc Mitochondria contain double membrane a matrix and many compartments with unique compositions of various proteins which are all made outside in the cytoplasm Experimentally make protein from mRNA and then put in test tube with mitochondria to see how it finds its place in the compartment Liver for example has two pathways consisting of cells for breakdown of glucose into subunits but also gluconeogenesis for example after period of starvation Office Hours Monday 11 00 12 00 BPS 1245 Friday 10 00 11 00 BPS 2249 Read Lab Manual on Elms 08 31 2012 Notes Work of Greek physicians such as Hippocrates and Golen left legacies of ideas that had influence of medicine up to the middle ages Some of their modeled ideas however slowed down the progress of medicine Hippocrates established many fundamental ideas of how physicians should practice even applied today the recording and exchange of medical data He believed that there is a rational basis for the disturbances due to diseases i e no mystical factors Four humors or fluids that the Greek believed were in us Blood black bile yellow bile and limb They believed that the change in proportion of these fluids that affected personalities as well as responsible for ailments For example he believed that fevers were a result of excess blood so they would draw their blood Discovery of Eukaryotic Cells Examine the work of 17th century English physician Percivall Pott Around this time many Italian physicians established relationships between diseases or conditions and an individual s profession such as neurological issues associated with painters etc At this time physicians began to take case histories of patients and when going back to studying them made important discoveries Percivall Pott was an English physician at St Bartholomew and many diseases are named after him like Pott s disease or Pott s gangrene He examined patients with testicular cancer they were young men So the two biases against them were that they were now sexually active and that they probably had poor hygiene since they were from a poor background In the case histories he found that they had all worked as chimney sweeps at one point in their lives this profession was usually left to young boys Percivall Pott established that there was a link between the exposure to sut and the development of the cancer Furthermore he realized that the mutation took time to accumulate as there was an 8 10 years period time between the exposure and manifestation In this period many discoveries were the result of the development of new technologies such as various microscopes light microscope to see larger organelles in cells like nucleus and usually nothing else electron microscopes to see organelles in some detail scanning electron microscopes and scanning tunneling microscopes It started with Robert Hooke s Micrographia were he detailed various things he saw through his microscope The first thing he looked at was the cork he saw chambers which he dubbed celluli He also saw a fungus called mucor and depicted it in Micrographia Anton Van Leeuwenhoek was a Dutch scientist son of a basket maker and worked in the shop of a textile merchant He was good at grinding lenses to look at whatever he wanted He looked at a drop of water from a pond and saw a lot of different creatures swimming such as paramecium etc He looked at red blood cells ejaculate from animals to describe spermatozoa as well as insects Robert Brown looked at plant tissue and found what were referred to as opaque spots he called them Nucleua now nucleus Cell Theory Matthias Schleiden and Theodor Schwann They would always see nuclei separated by what looked like compartmental sections Each compartment had nucleus They then made the intellectual leap that they were cells So the difference between an elephant and a mouse was in the number of cells Also they used a light microscope so they did not even see the plasma membrane but only noticed the difference in contrast between cytoplasm and surrounding medium They argued that 1 cells were the fundamental unit of life and that 2 all living things are made up of cells Rudolph Virchow suggested that all cells originated from previous cells This was the final tenet of the cell theory Eukaryotic cells vs Prokaryotic cells Eukaryotic cells have nuclei and internal membrane bound organelles Different classes of eukaryotic cells are plant cells algae protists fungi and animal cells Plant cells typically have a cell wall a vacuole and chloroplasts Algae have flagella and are unicellular You can also look at paramecium freshwater unicellular organism can reproduce asexually or sexually If a paramecium is swimming and hits an object it can change direction and move coordinated cilia To study and understand this coordination a researcher glued a paramecium to the cover of a plate with a film of water and looked under a microscope to watch frame by frame the orientation of the beat It turns out they have mechanosensory channels gradient of calcium concentration which allow them to respond to stimuli Prokaryotes are generally much smaller then eukaryotes and usually have the dimensions of a cylinder 0 5 micrometer to 2 micrometer whereas eukaryotes can go from 20 30 micrometer with a nucleus of 8 micrometer Prokaryotes have a plasma membrane as well as a capsule and even a flagellum work by rotating are less flexible than other flagellum 1 5 millimeter length of DNA in prokaryote but up to 2 meter length of DNA in eukaryote In secretory cells they have ducts with nuclei far away from the ducts to make room for secretory vesicles Studies of retroviruses RNA Viruses led to many breakthroughs such as oncology as well as the establishment of recombinant DNA technology etc 09 05 2012 Notes The length of the chromosome in the prokaryote can be up to a thousand times the length of the cell Prokaryotes have a capsule outer envelope surrounding the phospholipid bilayer plasma membrane that regulates the passages of the molecules from the outside to the plasma membrane Gram positive or gram negative refers to the staining properties of a cell in a gram stain Gram positive if the cytoplasm can stain whereas negative if the
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