WHAT DO CELLS DO? CHALLENGE QUESTION What are the functions of the structures inside of cells?
WHAT DO CELLS DO? Understanding normal cell structures and their functions help scientists understand how diseases adapt and evolve, including infectious diseases caused by microbes, like bacteria. For example, in response to antibiotics, some types of bacterial microbes of have adapted ways to form resistant strains that make antibiotics ineffective [useless]. Although there are many differences between cells of various organisms, there are some key similarities in cells. One structure common to every cell is a cell membrane that separates the cell itself from the outside environment. Similarly, every cell has genetic material in the form of DNA (deoxyribonucleic acid). Cells also have a large number of proteins and other molecules that carry out the chemical reactions needed for the cell to grow, develop, and reproduce. However, there are some organisms which composed one or more cells with structures that are surrounded by a membrane [covering], which creates a barrier between the inside of the structure and the rest of the cell. These membranebound structures are called organelles. Key terms: infectious, microbes, adapt, evolve, cell membrane, organelles Second-tier vocabulary: cell structures, cell functions, antibiotics, resistant strains, various, DNA, proteins, molecules
WHAT DO CELLS DO? Animal and plant cell groups are two different ways life has found a way to exist in nature. You will now use a computer simulation to compare the similarities and differences between animal and plant cells commonly found in the world that surrounds you. To run the simulation: Carefully read the information presented from the simulation this will help you understand and construct two different types of eukaryotic cells: animal and plant Use the Student Sheet (or create a table in your science notebook) to record information List ALL of the cell structures seen in the simulation Record the function (the organelle purpose) for each cell structure (the organelle itself) After you have completed the simulation, try the Venn diagram test Transfer the Venn diagram results from the computer screen on to your Student Sheet Turn in Student Sheet (or show the teacher the information recorded within the table from your science notebook) at the end of class
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WHAT DO CELLS DO? CHALLENGE QUESTION What are the functions of the structures inside of cells?
COMPARING BACTERIAL CELLS TO EUKARYOTES Look at the Venn diagram that you created earlier in the activity Use the diagram to help you draw a new, three-circle Venn diagram with the addition of a bacterial cell group in your science notebook. Complete the new Venn diagram by recording each cell group s similar and different structures (organelles) in the appropriate part of your new, three-circle Venn diagram. Where can you find information on bacterial cells to complete the diagram?
COMPARING BACTERIAL CELLS TO EUKARYOTES New Venn diagram comparing animal, plant, and bacterial cells. A P B
COMPARING BACTERIAL CELLS TO EUKARYOTES Bacterial Cell Structure A bacterial cell does not have a nucleus or other membrane-bound structures. Organisms having cells with no nucleus and no membrane-bound cell parts are classified as prokaryotic. The genetic information of bacterial cells is stored in a large circular chromosome in the cytoplasm. Chromosomes contain an organism s DNA or genetic instructions. The cell membrane of a bacterial cell performs the same functions of many of the organelles found in the cells of other organisms, such as plants, animals, and Protists. For example, bacterial cells use specific enzymes located in its cell membrane to perform cellular jobs, like generating energy to move around. Some bacterial cells can even perform photosynthesis at the cell membrane. On the other hand, eukaryotic organisms organisms containing cells with true membrane-bound structures use certain cell organelles in the cytoplasm to make specific enzymes that help generate the cell s energy. The ribosomes in bacteria cells differ from ribosome in eukaryotes in size and molecular composition, but like the ribosomes in eukaryotes, their function is to synthesize [make] proteins needed by the cell. In bacteria, as it does in eukaryotes, the cytoplasm also contains numerous enzymes that speed up reactions, such as those involved in digestion. Bacteria have a cell wall outside of their cell membrane that makes them rigid and gives them shape. The cytoskeleton of a prokaryotic cell serves some of the same functions as those found in eukaryotic cells. However, prokaryotic cells are made of different kinds of proteins. To move around, some bacteria use long tail-like structures called flagella, or short hair-like structures called cilia. Although these flagella and cilia appear similar to those of eukaryotes, they are made of different proteins and produce their motion by through a different mechanism than that of cilia and flagella eukaryotic organisms.
WHAT DO CELLS DO? CHALLENGE QUESTION What are the functions of the structures inside of cells?