What are some ways i can improve my performance in a class?
It is important to avoid missing class sessions. In addition, be sure to re-write notes after lectures. The act of re-writing notes helps with memorization of the content. It is also important to study in smaller bursts than to cram the night before an exam. Your brain learns through repetition, reviewing your notes several times many days before the exam is a more effective strategy than cramming for long periods of time right before an exam.
After gram staining a bacterial species collected from a patients urine who is complaining of a urinary tract infection, you visualize pink bacteria with a rod shaped morphology. Identify a potential species of bacteria that could cause symptoms of a urinary tract infection.
It is possible that the bacteria from the sample is E. coli. The sample shows that the bacteria is gram negative due to pink coloration. Gram negative bacteria do not retain the initial crystal violet stain due to their thin cells walls. Instead, they stain pink from the safranin counter stain. This result, in addition to rod morphology leads me to believe the sample contains E.coli. E. coli is one of the most common bacteria to cause urinary tract infections.
The innate immune system is the first line of defense against foreign invaders. Macrophages are one cell type in the category of innate immunity. How do macrophages kill bacteria?
Macrophages first engulf bacteria by sensing pathogen associated molecules found on microbes. They reach out and surround the bacteria creating a vesicle and ultimately isolating the bacteria from surrounding tissues. After engulfment the macrophage fuses with several vesicles acquiring the enzymes required for killing. Some of these enzymes produce reactive oxygen and nitrogen species that kill microbes. The vesicle becomes increasingly acidic and eventually fuses with the lysosome which causes degradation of bacteria. Once a macrophage detects an immune challenge, it up regulates its killing mechanisms and signals to other immune cells to create a robust inflammatory response and rapidly kill bacteria. This is not true for all types of bacteria. In fact, some bacteria can evade the immune system and live within macrophages.