Ch. 17 - Organelle Inheritance and the Evolution of Organelle Genomes

Sanders - Genetic Analysis: An Integrated Approach 3rd Edition

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Sanders 3rd Edition

Ch. 17 - Organelle Inheritance and the Evolution of Organelle Genomes

Problem 24

Chapter 17, Problem 24

Considering the phylogenetic assignment of Plasmodium falciparum, the malarial parasite, to the phylum Apicomplexa, what might you speculate as to whether the parasite is susceptible to aminoglycoside antibiotics?

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Understand the classification of Plasmodium falciparum: It belongs to the phylum Apicomplexa, which consists of eukaryotic organisms. Aminoglycoside antibiotics typically target prokaryotic ribosomes, so this classification is important for determining susceptibility.

Recall the mechanism of action of aminoglycoside antibiotics: These antibiotics bind to the 30S subunit of prokaryotic ribosomes, interfering with protein synthesis. Eukaryotic organisms, like Plasmodium falciparum, have 40S ribosomal subunits, which are structurally different.

Consider the evolutionary relationship: Apicomplexans, including Plasmodium falciparum, are more closely related to other eukaryotes than to prokaryotes. This suggests that their ribosomes are unlikely to be targeted by aminoglycosides.

Evaluate any exceptions: Some eukaryotic organisms have prokaryotic-like ribosomes in their organelles (e.g., mitochondria). Check if Plasmodium falciparum has organelles with ribosomes that could be targeted by aminoglycosides.

Conclude based on the evidence: Given the eukaryotic nature of Plasmodium falciparum and the specificity of aminoglycosides for prokaryotic ribosomes, it is unlikely that the parasite is susceptible to these antibiotics. However, further research into its organelles may provide additional insights.

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Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Phylogenetics

Phylogenetics is the study of evolutionary relationships among biological entities, often represented as a tree-like diagram. It helps in understanding how species are related through common ancestry. In the context of Plasmodium falciparum, its classification within the phylum Apicomplexa provides insights into its evolutionary adaptations and potential vulnerabilities to treatments.

Apicomplexa

Apicomplexa is a phylum of parasitic protists known for their complex life cycles and specialized structures for host invasion. Members of this group, including Plasmodium falciparum, have unique cellular features that differentiate them from other organisms. Understanding the biology of Apicomplexa is crucial for predicting their susceptibility to various antibiotics, including aminoglycosides.

Aminoglycoside Antibiotics

Aminoglycoside antibiotics are a class of drugs that inhibit bacterial protein synthesis by binding to the 30S ribosomal subunit. They are primarily effective against aerobic Gram-negative bacteria and some Gram-positive bacteria. However, their efficacy against eukaryotic parasites like Plasmodium falciparum is limited due to differences in ribosomal structure and function, suggesting that these antibiotics may not be effective in treating malaria.

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