MMG 301 Exam 1 MSU Questions with Correct Answers Latest Update 2025/2026

MMG 301 Exam 1 MSU Questions with Correct Answers Latest Update 2025/2026 Coccus - Answers spherical cells Diplococcus - Answers Pair of spherical cells (cocci) Staphylococcus - Answers cluster of spherical cells (cocci) Staphylococcus - Answers a genus of gram-positive bacteria that are potential pathogens, causing local lesions and serious opportunistic infections Vibrio - Answers bean shaped bacteria Bacillus - Answers Rod shaped bacteria Magnification - Answers ocular x objective Numerical Aperture - Answers a number that expresses the ability of a lens to resolve fine detail in an object being observed. Stamped on the side of a lens. resolving power (resolution) - Answers ability to show detail Lambda - Answers wavelength used for microscopy oil immersion - Answers A technique used to increase the resolution of a microscope by immersing both the objective lens and the specimen in a transparent oil. bright field microscopy - Answers generates a dark image of an object over a light background dark field microscopy - Answers shows the specimen against a dark background and provides good resolution phase contrast microscope - Answers An optical-microscopy technique that converts phase shifts in light passing through a transparent specimen to brightness changes in the image. Phase shifts themselves are invisible, but become visible when shown as brightness variations. fluorescence microscopy - Answers uses a fluorescent dye that emits fluorescence when illuminated with ultraviolet radiation Simple Stains - Answers the use of a single stain, used with a bright field microscope. Increases contrast to aid in visualization. differential stain - Answers the use of multiple stains of different colors to distinguish different types of microorganisms. Gram stain - Answers A staining method that distinguishes between two different kinds of bacterial cell walls. acid fast stain - Answers a differential stain used to identify bacteria that are not decolorized by acid-alcohol, that are waxy. Microscopes that use optical methods for contrast enhancement and visualization - Answers Phase Contrast, Dark Field, Fluorescence Phase Contrast - Answers improved contrast between unstained (living) bacteria, ideal for examining cell morphology. Dark Field - Answers uses a cardioid condenser that produces a hollow cone of light, ideal for examining very thin cells like spirochete syphilis Excitation - Answers absorbing of light, leads to a shorter wavelength. Emission - Answers emission of light at a longer wavelength. autofluorescent - Answers have cell components that fluoresce, don't need to be stained transmission electron microscope - Answers A microscope that uses an electron beam to study the internal structure of thinly sectioned specimens. Has to be done in a vacuum because electrons won't be able to travel thru the specimen. Cells need to be embedded into a plastic and use heavy metal ions to provide contrast. scanning electron microscope - Answers scans the surface of a specimen with a beam of electrons 30 times/second, ideal for looking at the outside of cells. Performed in a vacuum, and coated with metal ions to provide contrast. Electron Microscopes - Answers magnetic lens Optical Microscopes - Answers glass lens Components of the Cytoplasmic Membrane - Answers Cytoplasmic Membrane, Cell Wall, Internal/External Components proton-motive force - Answers The potential energy stored in the form of an electrochemical gradient, generated by the pumping of hydrogen ions across biological membranes during chemiosmosis. Phospholipids - Answers fatty acids linked to a glycerol phosphate by an ester bond. Are amphipathic Archaea - Answers use ester linkages and can form mono or bilayers. functions of cytoplasmic membrane - Answers permeability barrier, protein anchor for membrane proteins, site of energy generation. Transport Proteins - Answers facilitate the entry of these chemicals into the cells, when nutrients are transported against a concentration gradient. Chemiososis - Answers the movement of ions across a semipermeable membrane, down their electrochemical gradient, which releases energy. Simple Transport - Answers driven by the energy in the proton motive force Uniport - Answers A membrane transport process that carries a single substance. no use of energy. Antiport - Answers A membrane transport process that carries one substance in one direction and another in the opposite direction. Symport - Answers A membrane transport process that carries two substances in the same direction across the membrane. Group Translocation - Answers chemical modification of the transported substance driven by phosphoenolpyruvate ABC transporters - Answers carrier proteins that use energy from ATP to transport solutes. only done in gram negative bacteria that contain periplasm. Mycoplasmas - Answers a group of bacteria that lack cell walls and are highly pleomorphic peptidoglycan - Answers A protein-carbohydrate compound that makes the cell walls of bacteria rigid What is peptidoglycan made of - Answers N-acetylmuramic acid (NAM) with a small peptide chain and N-acetylglucosamine (NAG), linked by a glycosidic bond murein sacculus - Answers Peptidoglycan completely surrounds the cell in a massive molecule What is the peptidoglycan of E.coli made of? - Answers polymer of glycan-tetra peptide repeating units Gram Positive Bacteria - Answers 10-15 or more sheets, many crosslinks, reinforced by teichoic and lipoteichoic acids and forms into cables. Gram Negative Bacteria - Answers 1-3 sheets, few crosslinks, lipoprotein help space outer membrane from peptidoglycan Periplasm - Answers The gel-like material that fills the region between the cytoplasmic membrane and the outer membrane of Gram-negative bacteria. teichoic acid - Answers polymers of repeating ribitol or glycerol phosphate which create an overall negative charge on cell surface to provide rigidity lipoteichoic acid - Answers covalently linked teichoic acids connected to membrane lipids.