Question

1. What is the ultimate reason that a health professional or scientist would be looking to see if a bacterial infection was gram negative or gram positive? Explain your answer.

2. Why might an antibiotic work better for some bacteria species than others? Be specific.

3. What are nitrogen fixing bacteria? Hint: Describe them, where they are located, what they do, and why they are important ecologically.

4. Do Cyanobacteria have chloroplasts? Why or why not?

Answer 1

1) Gram negative bacteria are more dangerous than gram positive bacteria because most of them are resistant to antibiotics. Other reason is that the gram negative bacteria possess endotoxins and exotoxins which are fatal for human body. So it is necessary to identify if it's gram negative or positive bacteria.

2) As described in the first answer antibiotics work well on gram positive bacteria and not that well on gram negative. This is because the gram negative bacteria has another layer of membrane other than peptidoglycan layer which hides the antigens and antibiotics cannot penetrate this layer which makes them more dangerous. Whereas the antibiotics can penetrate the gram positive bacteria as they don't have that layer and can easily be killed. Therefore antibiotics work for better for some bacterial species than others.

3) Nitrogen fixing bacterias are microorganisms which help convert the atmospheric nitrogen into fixed nitrogen compounds such as ammonia which is used by the plants for their growth. They are the most important part of the nitrogen cycle. One of the nitrogen fixing bacteria is rhizobium which are found in root nodules of leguminous plants having a symbiotic relationship and another one is Cyanobacteria which do not have such symbiotic relationships with plants. Their important role in Nitrogen cycle makes them important ecologically.

4) Cyanobacteria do not have chloroplasts but they do have thylakoids in which the photosynthesis takes place. These thylakoids are present in the cytoplasm and they don't have special organelle such as chloroplasts to contain them.

Hope this helps, Good luck!!!