Question

0 pts

Motility, via flagella, is metabolically expensive for the cell. Microbiologists have noticed that many motile cells have storage polymers in their cytoplasm. Also while not all motile cells are Gram negative, the majority are. What role would storage polymers and a Gram negative cell structure play in motility?

A high concentration of protons is maintained where in the prokaryotic cell and why?

In the periplasm where protons can cross the cell membrane (in response to a proton gradient) and enter the cell's cytoplasm

Outside of the outer membrane in order to establish a high to low concentration with the cell's periplasm where ATP is made

In the cytoplasm to be able to support ATP production by the mitochondria

In the cell wall to facilitate active nutrient transport across the wall

For each of the following pairs, predict whether you would expect them to co-occur in the same cell at the same time or not. Explain your answer.

Gas vesicles and glycocalyx

Storage polymers and glycocalyx

Sex pilus and gas vesicles

Answer 1

1. Motility is a energy consuming process and it require high amount of ATP to do their function. The stored polymer
in the cytoplasm undergoes glycolysis and produce lot of ATP molecules. This ATP are used by the flagella for motility.

2. In the periplasm where protons can cross the cell membrane (in response to a proton gradient) and enter the cell's cytoplasm.
The H+ ions stored in the periplasm of the cell and it has high concentration gradient compare to cytoplam. So, it moves from periplam to cytoplasm to produce ATP from ATP synthetase. Because bacterial cells do not have mitochondria for the ATP rpoduction it uses it cell membrane for it purpose.

3. Gas vesicles and glycocalyx are not co-occur beacuse both are different function in the cell. Glycocalyx present in the outside of the cell wall. It is polysaccharides and plays a role in protect bacteria from phagocytosis and desiccation. Gas vesicles helps to buoyancy of cells.

Storage polymers and glycocalyx both co-occur. Both are polysaccharides.

Sex pilus and gas vesicles not co-occur. Both are in different function.