2081CellStructure - Hmm... What is the difference between a...

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Unformatted text preview: Hmm... What is the difference between a 3-carbon sugar and a 3-sugar carbohydrate? Summary of Cell Biology What is a cell? Prokaryotes versus eukaryotes Functions of the cell Components of the cell What Is a Cell? Cell Theory: All living things are comprised of cells Smallest livingtrillion cells inunit of organization bacteria ~10 unit/basic your body and 100 trillion Cells arise from division of previously existing cells Found alone or working together in groups Microscopic normally A mass of protoplasm bounded by a membrane and contains at least one nuclei or piece of chromosomal material What characteristics of cells do you observe here? QuickTime and a MPEG-4 Video decompressor are needed to see this picture. Phagocyte and bacillus Does Size Matter? Life at the cellular scale Surface area to Volume Ratio How Does the Eukaryotic Cell Overcome the Problem of Increased Volume? Compartmentalization! Prokaryote Cell Structures What Are the Compartments of the Cell? Protection Control Processing Energy Transformation Movement Storage Control: Nucleus Surrounded by the nuclear envelope A double lipid bilayer membrane structure Contains 99.99% of the genetic material in the form of DNA DNA is organized into chromosomes Number of chromosomes varies between species Directs protein synthesis and reproduction "Little net within the cytoplasm" Beginning of the secretory pathway. Two types of ER Processing: Endoplasmic Reticulum Rough ER has ribosomes present Located at the beginning of the ER Site of protein synthesis that are to be secreted Smooth no ribosomes Inner region or cisternal space has an environment similar to outside of the cell External region of the ER is called the cytosol Processing:Golgi Apparatus Second stage of the secretory pathway A series of flatten stacks of membranes or Golgi Bodies Three regions Cis-Golgi nuclear envelope facing Medial-Golgi - middle Trans-Golgi plasma membrane facing Site of protein maturation and delivery Golgi apparatus: Exocytosis of coccoliths in a marine golden alga, Pleurochrysis QuickTime and a YUV420 codec decompressor are needed to see this picture. Where Does the Cell's Energy Come From? Double membrane organelle that is about the size of bacterium Cristae folded inner membrane Matrix found inside of the cristae Intermembrane space found in-between the inner and outer membrane Energy: Mitochondria Powerhouse of the cell Contains its own DNA Always maternal during sexual reproduction Performs its own reproduction during the cell cycle Energy: Chloroplast Double membrane organelle that contains DNA Manufactures food via photosynthesis Eukaryotic cells that carry out photosynthesis will have one to several hundred of these Stacked grana captures light and converts it to stored energy Lesser Known Parts of the Cell Vacuole Found in plant cells and in some fungi and protists Stores Water Sugar Ions Pigments Increases Surface to area volume of plant cells Processing: Lysosomes and Peroxisomes Digests worn out or damaged organelles (lysosome) and proteins (lysosome and proteasome) Lysosome has a role in programmed cell death or apoptosis Peroxisome has hydrogen peroxide Peroxisome Cytoskeletal elements A crisscrossing network of polymerized protein fibers that give shape and support to a cell Three types (largest to smallest) Microtubules Facilitate protein movement and cellular movement Cytoskeletal functions Intermediate Filaments Provides structural stability to the cell QuickTime and a YUV420 codec decompressor are needed to see this picture. Actin Filaments Responsible for cellular movement, pinching during cell division, and formation of cellular extensions Chromatophore and melanophore function in fish scales Variety of motions Crawling is based on the cell reaching out and pulling itself along a surface Gammas include those who cause legionnaire's disease, salmonella, and gut bacteria Cell Movement Cellular tails... This is controlled by the rapid polymerization of actin filaments QuickTime and a Sorenson Video decompressor are needed to see this picture. Swimming is based on the cell moving due to specialized appendages called flagella or cilia Normally there or only a few flagella or hundreds of cilia The movement of these appendages propels the cell and is caused by the movement of microtubules Why is the cytoskeleton so important? The ExtraCellular Matrix Makes cells into tissues Exchange source (kidney, circulatory) Filters Strengthens Plasma membrane and cell wall Protection Control Processing Energy Transformation Movement Storage Nucleus Mitochondria and chloroplasts Centrioles Cytoskeleton, cilia and flagella Endoplasmic reticulum Golgi apparatus Vacuole ...
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This note was uploaded on 04/07/2008 for the course BIOSCI 0150 taught by Professor Dr.roberts during the Spring '08 term at Pittsburgh.

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