1. Cells are the fundamental units of life that grow, convert energy, sense their environment, and reproduce. 2. A cell contains various organelles that carry out specialized functions. It is enclosed by a plasma membrane and contains a nucleus and cytoplasm. 3. The nucleus contains genetic material and directs protein synthesis. Other organelles such as mitochondria, endoplasmic reticulum, Golgi apparatus, lysosomes, and peroxisomes have specialized metabolic functions critical for cell survival and homeostasis.

1. Cell Ultrastructure<br /> <br />Cells are the fundamental units of life. <br />Cells grow, convert energy from one form to another, sense and respond to their environment, and reproduce themselves. <br />Cell has general functions (synthesize proteins, transform energy, move vesicles and substances throughout the cell, and duplicate genetic material), however cells also specialize by emphasize a specific structural component. <br />Cells are enclosed in a plasma membrane that separates the inside of the cell from the environment. <br />Understand and identify the components of the cytoplasm.<br />Cell contents outside the nucleus<br />Organelles<br />Non membrane bound inclusions<br />Cytoskeleton<br />Understand that the nucleus is the largest cellular organelle.<br />Plasma membrane<br />Function<br />Maintain structural integrity<br />Provide physical barrier<br />Control substance movement<br />Regulate cell-cell interaction<br />Cell recognition<br />basic structure<br />phospholipid bilayer <br />Phosphate head is stained via osmium tetroxide<br />None stained region will appear translucent on electron micrograph<br />Hydrophobic<br />Transmembrane proteins<br />Be able to identify and understand the functions of membrane bound organelles in electron micrographs:<br />Students need to recognize the following nuclear structures in micrographs and understand their biological importance: <br />Nuclear envelope (nuclear membrane). <br />Continuous with RER<br />Supported by nuclear lamina that is made out of intermediate filaments<br />Nuclear pores. <br />Very highly regulated <br />Appear as a tiny break in the nuclear membrane<br /> <br />tiny black circle rings circles. <br /> <br />Karyoplasm (nucleoplasm).<br />Chromatin <br />Heterochromatin-dark areas usually long the edge of the nucleus<br /> <br />Euchromatin-Near empty white space inside the nucleus<br />Nucleolus-production site of ribosome, round and closer to the center of the karyoplasm<br /> <br />Mitochondrial<br />Biological Importance<br />Cristae.<br />Folds formed by the inner membrane to increase surface area<br />Outer and inner membranes.<br />Inner membrane<br />Contains ATP synthase (10 nm between each) and cytochromes that is part of electron transport chain.<br />Less permeable <br />Out membrane<br />Controls the movement of substance into the mitochondria with many transport protein. It is more permeable<br />Intramembrane space (intracristal space).<br />High [H]<br />Matrix (intercristal space). <br />Site of the kreb cycle<br />ID Feature<br />Membrane<br />Cristae (not always continuous)<br /> <br /> <br />Students need to recognize the following endoplasmic reticulum structures in micrographs and understand their biological importance. <br />Smooth<br />Lipid synthesis <br />ID Feature<br />No membrane around, look like just lose irregular vesicles<br />Continuous with RER<br /> <br /> <br />Screen clipping taken: 8/21/2011 12:16 PM<br />Rough<br />Ribosomes<br />Extrinsic protein synthesis <br />Id Features-ribosome <br />Students need to recognize the Golgi apparatus and its associated structures in micrographs and understand their biological importance. <br />Transfer (or shuttle) vesicles.<br />RER side<br />Small<br />Clear<br /> <br />Forming (cis) and maturing (trans) faces.<br />Secretory vesicles (condensing vacuoles). <br />Plasma membrane side<br />Large<br />Dark<br /> <br />Serves to make post-translational modification and package, concentrate and store proteins. <br />Students need to recognize endosomes and its associated structures in micrographs and understand their biological importance.<br />Gets extracellular contents<br />Clathrin coated pits<br />Transport vesicles<br />Look for endocytosis<br />Students need to recognize lysosomes in micrographs and understand their biological importance.<br />Transport of proteins into lysosomes<br />Synthesize in RER, packaged in Golgi<br />Function of lysosomes<br />Contain acid hydrolase (hydrolytic enzyme) that digest a variety of substance. <br />Ph properties <br />Ph at 5.0<br />Lyso-bisphosphatidic acid that resist low ph.<br />Heterophagic vacuoles-contains extracellular material<br />Autophatic vacuoles-contain intracellular material<br />Looks pretty much just like lysosome<br />peroxisomes (microbodies)<br />Function<br />Contain catalase that is involved in the hydrolysis of hydrogen peroxide<br />ID<br />Smaller than mitochondria but larger than vesicles<br />Some times contain dark nucleoid<br /> <br /> <br />Be able to identify and understand the functions of non-membranous organelles in micrographs and understand their biological importance.<br />Ribosomes-make protein-small black dots<br />Cytoskeleton<br />Microtubules<br />Structure<br />Hollow cylinders made of tublin<br />25nm diameter<br />+/- ends<br />Generated from organizing center-centrolsome-gamma tubulin<br />Function<br />Act as track for intracellular transportation/cell division<br />Part of cilia and flagella<br />ID features<br />Lines in the cytoplasm (fairly straight)<br />In cilia and flagella: 9+2-9 sets of doublet microtube surrounds two microtubes in the center<br /> <br /> <br />MTOC-9 sets of triplet microtubes with no center<br /> <br /> <br />Microfilaments<br />Structure<br />7nm Diameter<br />Highly Concentrated in cell cortex<br />Function-<br />Shape of the cell<br />Movement of cell surface (lamellipodium in neurophils)<br />Muscle contraction<br />ID-<br />Thin lines in the microvilli<br />Intermediate filaments<br />Structure<br />10nm<br />Rope like<br />Function<br />Mechanical strength<br />Cell junctions<br />Nuclear Lamins<br />ID Feature<br />Not straight<br />Dark plaque near the membrane<br /> <br />Inclusions<br />Glycogen<br />Lipid droplets<br />Pigment granules <br /> <br />Answer the following questions based on the information in the textbook. <br />What are the sites of synthesis of extrinsic proteins and intrinsic proteins?<br />How do lysosomes function?<br />Denatures the proteins with low ph then cut them hydrolytic enzymes<br />What is the source of lysosome proteins?<br />Produced in the RER, Modified and Sorted in the Golgi before sending to lysosome<br />How do cells increase surface area on the membrane?<br />By making various folds<br />Clinical Correlations <br />Lysosomal Storage Diseases<br />Abnormalities in Cytoskeletal Proteins<br />Also look up Epidermolysis Bullosa – Which proteins contribute to this disease? <br /> <br /> <br /> <br />