Cell Chemistry and Biotechnology Strand 4

Plant Cells Cell wall* Cell membrane Cytoplasm Large central vacuole* Nucleus Nuclear Envelope Nucleuous Mitochondria Chloroplast* Ribosomes Smooth & Rough ER Golgi Apparatus Peroxisomes Plasmodesmata * organelles only found in plant cells

Differences? Similarities? Only in PLANT cells: Plants have cell walls. Plants have chloroplasts for photosynthesis. Plants have a large, central vacuole. Only in ANIMAL cells: Animal cells have centrioles. Animal cells have small vacuoles. Similarities? The following organelles are found in BOTH cells: Vacuoles Nucleus Cytoplasm Cell Membrane Mitochondrion

DNA, RNA and Protein Synthesis DNA contains the instructions for manufacturing proteins Instructions contain information to make all cellular proteins DNA is too important and therefore must stay in the nucleus (this is why we have RNA!) RNA Messenger RNA (mRNA) carries the genetic information copied from DNA In the form of a series of three- base code “words,” each of which specifies a particular amino acid Codons are translated into proteins at the Ribosome

Enzymes are necessary for life! Role of Enzymes What are enzymes? Special proteins that speed up the chemical reactions of a cell to biologically useful rates They lower the activation energy required for these reactions Without enzymes, metabolism would neither progress through the necessary steps, nor would it be fast enough to serve the needs of the cell. Enzymes are necessary for life!

Virus Bacteria Can only reproduce using a ‘host’ or living cells Takes over host cell Does not have nuclei Don’t have cell membrane Each viral particle, or virion, consists of genetic material, DNA or RNA, within a protective protein coat called a capsid Bacteria Have cell walls Considered ‘living’ Wide-range of shapes, ranging from spheres to rods to spirals One cell living organism Reproduce independently Prokaryotes No nucleus

Transmission of Diseases Direct Transmission: Direct exchange of bodily fluids leading to disease Ex: Touching an open wound Indirect Transmission: Spread from person to person through a carrier Breathing in a sneeze (air) Drinking contaminated water (water) Bitten by infected mosquito (animal) Contaminated water is the leading cause of transmission in areas of poor sanitation and untreated sewage Vaccination Giving the body a weaker form of the pathogen allowing the person to build immunity to the disease When encountering the actual disease they will get sick for a shorter period of time or not at all

Micro-organisms IN MY FOOD?! Bacteria Produce lactic acid during fermentation Helps preserve foods Makes sour cream, buttermilk, cheese and yogurt (dairy) Yeast Produces alcohol and air bubbles during fermentation Helps bread rise Creates the alcoholic content in some alcoholic beverages

Biotechnology Utilizing biological processes for technology Genetic Engineering Changing an organism's DNA to produce different proteins Transformation Process where a cell takes in and expresses foreign material Transduction When bacteriophages (viruses that infect bacteria) are used to inject foreign DNA into a bacteria Viruses are designed to have the DNA we want to put in the bacteria Conjugation Process where genetic material is passed between bacteria through cell-to-cell contact

Risks: Benefits: Biotechnology Health risks Food production New allergens and toxins Exposure to toxic metals Other unknown effects Creation of resistant organisms Antibiotic resistant bacteria (super-bugs) Herbicide resistant weeds (super-weeds) Pesticide resistant pests (super-pests) Ecosystem effects Breeding/cross-pollination between transgenic and non-modified organism can create a new unexpected species Introduction of an invasive species disrupting an ecosystem Benefits: Food production More nutritious and plentiful Lower land use Using less pesticides and herbicides by making food that is less susceptible to pests Longer shelf life Stress resistant food Able to make more food for a cheaper price to help feed countries that are struggling Ecosystem effects Help rehabilitate damaged or less-fertile land Reduction of environmental impact of food production and processing Biofuel production Renewable form of energy Biotechnology