Structure of Tetracyclines

Tetracyclines have a distinctive four-ring structure, which gives them their name. The basic structure consists of four fused rings, labeled A, B, C, and D. This structure allows tetracyclines to bind to the bacterial ribosome and interfere with protein synthesis.

Mechanism of Action

Tetracyclines inhibit protein synthesis in bacteria by binding to the 30S ribosomal subunit. This prevents the attachment of aminoacyl-tRNA to the mRNA-ribosome complex, leading to the inhibition of protein synthesis and ultimately bacterial growth.

Common Uses

Tetracyclines are used to treat a wide range of bacterial infections, including respiratory tract infections, skin and soft tissue infections, urinary tract infections, and sexually transmitted diseases such as chlamydia and gonorrhea. They are also used to treat acne and certain types of malaria.

Pharmacokinetics

Tetracyclines are usually taken orally and are well-absorbed from the gastrointestinal tract. They distribute widely in the body, including into tissues and fluids, and are excreted primarily through the kidneys. It is important to note that tetracyclines can chelate with divalent and trivalent cations, such as calcium, magnesium, and aluminum, which can reduce their absorption and effectiveness.

Adverse Effects

Common adverse effects of tetracyclines include gastrointestinal disturbances, such as nausea, vomiting, and diarrhea. They can also cause photosensitivity, so patients are advised to avoid excessive sun exposure while taking these medications. In addition, tetracyclines can affect bone and tooth development in children and should be avoided during pregnancy.

Resistance

Overuse and misuse of tetracyclines have led to the development of bacterial resistance. This has led to the need for judicious use of these antibiotics to preserve their effectiveness.

Study Guide

To study tetracyclines effectively, consider the following key points:

Understand the chemical structure of tetracyclines and how it relates to their mechanism of action.
Learn about the specific bacterial infections that tetracyclines are commonly used to treat.
Explore the pharmacokinetics of tetracyclines, including absorption, distribution, metabolism, and excretion.
Understand the adverse effects of tetracyclines and the factors that contribute to bacterial resistance.

◂Physics Worksheets and Study Guides High School. Laws of Motion - Set I

Worksheet/Answer key

Laws of Motion - Set I

Worksheet/Answer key

Laws of Motion - Set I

Worksheet/Answer key

Laws of Motion - Set I

Worksheet/Answer key

Laws of Motion - Set I

The resources above cover the following skills:

PHYSICAL SCIENCE (NGSS)

Energy

Students who demonstrate understanding can:

Develop and use models to illustrate that energy at the macroscopic scale can be accounted for as either motions of particles or energy stored in fields.