MIC 230 1st Edition Lecture 7 Outline of Last Lecture I. Gram Positive and Negative Cell Wall II. Outside of the Cell WallIII. Cell Wall Comparison Chart IV. Motility using Flagella Outline of Current Lecture V. Motility using flagellaVI. Fimbriae VII. Cytoplasm Current LectureMotility using flagellaI. Movement a. Random walkb. Can react to environment i. Sense temporally, not spatiallyii. Chemotaxis- movement in response to chemicals based on temporal readings…sense gradient 1. Biases the random walk 2. With attractantif moving up the gradient (toward the sourceof attractant) you get longer runs, less frequent tumblesIf moving down gradient, you get more frequent tumbles, shorter runs II. Outer motilities a. Gliding done on surfacesb. Gas vacuoles (Fig. 3.30 in text) positioning mechanism, not true motility i. Air can diffuse in, making the cell less dense allows them to raise upin the water column c. Spirochetal motility endoflagella i. Good for viscous environment d. Twitchinguses piliThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.i. For many organisms, pili are only used for attachmentii. Shorter and straighter than flagella and generally more numerous iii. Used for movement on surfaces FimbriaeEven shorter than pili, very numerous, used for attachment, also helps form pellicles and biofilms Cytoplasm I. Small molecules/solublea. Ions, water, sugar, AA, nucleic acids, fatty acid “building blocks”II. Ribosomes/RNAa. Prokaryotic70s30s16s rRNA 50s5s rRNZ 23s rRNAe.
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