Textbook Question
Mycobacterium avium-intracellulare was considered relatively harmless until the late 20th century, when it became common in certain infections. Explain how this bacterium’s pathogenicity changed.
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Ch. 19 - Pathogenic Gram-Positive Bacteria
Bauman6th EditionMicrobiology with Diseases by TaxonomyISBN: 9780134832302
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Table of contents
- Ch. 1 - A Brief History of Microbiology31
- Ch. 2 - The Chemistry of Microbiology28
- Ch. 3 - Cell Structure and Function39
- Ch. 4 - Microscopy, Staining, and Classification25
- Ch. 5 - Microbial Metabolism51
- Ch. 6 - Microbial Nutrition and Growth37
- Ch. 7 - Microbial Genetics51
- Ch. 8 - Recombinant DNA Technology21
- Ch. 9 - Controlling Microbial Growth in the Environment36
- Ch. 10 - Controlling Microbial Growth in the Body: Antimicrobial Drugs21
- Ch. 11 - Characterizing and Classifying Prokaryotes29
- Ch. 12 - Characterizing and Classifying Eukaryotes34
- Ch. 13 - Characterizing and Classifying Viruses, Viroids, and Prions23
- Ch. 14 - Infection, Infectious Diseases, and Epidemiology35
- Ch. 15 - Innate Immunity34
- Ch. 16 - Adaptive Immunity21
- Ch. 17 - Immunization and Immune Testing29
- Ch. 18 - Immune Disorders22
- Ch. 19 - Pathogenic Gram-Positive Bacteria25
- Ch. 20 - Pathogenic Gram-Negative Cocci and Bacilli28
- Ch. 21 - Rickettsias, Chlamydias, Spirochetes, and Vibrios25
- Ch. 22 - Pathogenic Fungi47
- Ch. 23 - Parasitic Protozoa, Helminths, and Arthropod Vectors44
- Ch. 24 - Pathogenic DNA Viruses23
- Ch. 25 - Pathogenic RNA Viruses30
- Ch. 26 - Applied and Industrial Microbiology29
- Ch. 27 - Microbial Ecology and Microbiomes22
Bauman6th EditionMicrobiology with Diseases by TaxonomyISBN: 9780134832302Not the one you use?Change textbook
Chapter 19, Problem 2
Label acetylcholine. Color the sites of action of botulism toxin on a nerve cell.
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Identify acetylcholine as a neurotransmitter that is released from the presynaptic terminal of a motor neuron to stimulate muscle contraction by binding to receptors on the postsynaptic muscle cell membrane.
Label acetylcholine molecules in the synaptic cleft, which is the space between the presynaptic nerve terminal and the postsynaptic muscle cell membrane.
Understand that botulism toxin acts by preventing the release of acetylcholine from the presynaptic nerve terminal, thereby blocking nerve signal transmission to the muscle.
Color the presynaptic nerve terminal, specifically the synaptic vesicles and the membrane fusion machinery (such as SNARE proteins), as the sites of action where botulism toxin inhibits acetylcholine release.
Optionally, indicate that the postsynaptic receptors for acetylcholine remain unaffected by botulism toxin, emphasizing that the toxin's effect is presynaptic.
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Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Acetylcholine Structure and Function
Acetylcholine is a neurotransmitter involved in transmitting signals across nerve synapses, especially at neuromuscular junctions. It is synthesized in nerve terminals and binds to receptors on muscle cells to trigger contraction. Understanding its chemical structure helps identify its role and interaction sites.
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Functional Groups
Mechanism of Botulinum Toxin Action
Botulinum toxin blocks acetylcholine release by cleaving SNARE proteins essential for vesicle fusion in nerve terminals. This inhibition prevents neurotransmitter release, leading to muscle paralysis. Recognizing the toxin’s target sites on the nerve cell clarifies its effect on nerve signaling.
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Nerve Cell Anatomy Relevant to Neurotransmission
Key parts of a nerve cell involved in neurotransmission include the axon terminal, synaptic vesicles, and synaptic cleft. Acetylcholine is stored in vesicles at the axon terminal and released into the synaptic cleft to activate receptors. Identifying these structures is crucial for labeling and understanding toxin action.
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Related Practice
Textbook Question
Which of the following conditions is a systemic disease caused by Staphylococcus?
a. Impetigo
b. Folliculitis
c. Carbuncle
d. Toxic shock syndrome
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Textbook Question
How does Staphylococcus aureus affect the matrix between cells in the human body?
a. S. aureus triggers blood clotting, which coats the matrix and inhibits cellular
communication.
b. S. aureus produces an enzyme that dissolves hyaluronic acid and thus enables it to pass between the cells.
c. S. aureus possesses a hyaluronic acid capsule that causes leukocytes to ignore the bacterium as if it were camouflaged.
d. S. aureus does not affect the matrix but instead produces a necrotizing agent that dissolves body cells.
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Textbook Question
Which of the following bacteria causes a common type of food poisoning?
a. Streptococcus sanguis
b. Clostridium tetani
c. Staphylococcus aureus
d. Streptococcus pyogenes
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Textbook Question
Match the genera of pathogens to their appearance in stained smears: Actinomyces, Bacillus, Clostridium, Mycobacterium, Staphylococcus, Streptococcus.
(a) Methenamine silver <IMAGE>
(b) Gram <IMAGE>
(c) Gram <IMAGE>
(d) Acid fast <IMAGE>
(e) Gram <IMAGE>
(f) Gram <IMAGE>
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Textbook Question
Contrast tuberculoid leprosy with lepromatous leprosy in terms of pathogenesis. How does the cellular immune response of a patient affect the form of the disease?
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