Shikimic acid pathway

Definition

The shikimic acid pathway is a metabolic route found in plants, fungi, and some bacteria that leads to the biosynthesis of aromatic amino acids such as phenylalanine, tyrosine, and tryptophan. This pathway is crucial for the production of not only these amino acids but also various secondary metabolites like flavonoids and alkaloids, which play essential roles in plant metabolism and defense mechanisms.

5 Must Know Facts For Your Next Test

1. The shikimic acid pathway consists of seven enzymatic steps starting from phosphoenolpyruvate and erythrose 4-phosphate, ultimately producing chorismate.
2. This pathway is vital because humans and animals cannot synthesize aromatic amino acids and must obtain them through their diet.
3. The shikimic acid pathway is targeted by certain herbicides and antibiotics due to its absence in animals, making it a key focus in agricultural biotechnology.
4. Shikimic acid itself is an important compound derived from this pathway and has been historically used in the production of the antiviral drug oseltamivir (Tamiflu).
5. The pathway is tightly regulated and responds to the plant's developmental stage and environmental factors, highlighting its importance in adapting to stress conditions.

Review Questions

• How does the shikimic acid pathway contribute to the biosynthesis of essential compounds for plants?
  • The shikimic acid pathway plays a critical role in synthesizing essential aromatic amino acids like phenylalanine, tyrosine, and tryptophan. These amino acids are vital for protein synthesis and serve as precursors for various secondary metabolites important for plant growth, development, and defense against herbivores and pathogens. Without this pathway, plants would struggle to produce these necessary compounds.
• Discuss the ecological significance of secondary metabolites produced via the shikimic acid pathway.
  • Secondary metabolites generated through the shikimic acid pathway provide significant ecological benefits for plants. These compounds often serve as natural pesticides or repellents against herbivores, helping to protect the plant from damage. Additionally, some secondary metabolites play roles in attracting pollinators or facilitating plant interactions with beneficial microbes. Overall, they enhance plant survival and reproductive success in diverse environments.
• Evaluate the implications of targeting the shikimic acid pathway for agricultural biotechnology and medicine.
  • Targeting the shikimic acid pathway has profound implications for both agricultural biotechnology and medicine. In agriculture, manipulating this pathway can lead to developing herbicide-resistant crops or enhancing their resistance to pests through increased production of defensive secondary metabolites. In medicine, understanding this pathway enables researchers to synthesize important pharmaceuticals, such as oseltamivir. This dual focus on improving crop resilience and advancing drug discovery showcases the versatile applications of the shikimic acid pathway.

Related terms

Aromatic Amino Acids: A class of amino acids that contain an aromatic ring in their structure, including phenylalanine, tyrosine, and tryptophan, which are synthesized through the shikimic acid pathway.

Secondary Metabolites: Compounds produced by plants that are not directly involved in their growth, development, or reproduction but serve important ecological functions such as defense against pests.

Chorismate: An intermediate compound in the shikimic acid pathway that is a precursor to aromatic amino acids and various secondary metabolites.