Exam 2: Microbial Cell Structure and Function

Compared to Eukaryotes,Bacteria and Archaea have ________ surface-to-volume ratios,causing ________ nutrient exchange and growth rates.

Some archaea have unique phospholipids in their cytoplasmic membrane that

Using phase contrast microscopy on a wet mount of live cells,you observe motile bacilli moving rapidly and randomly through the field of view,changing directions after a brief tumble and taking off in a different direction.These cells are exhibiting ________ motility.

Bacteria stain as gram-positive or gram-negative because of differences in the cell

Which of the following types of microscopy can be used with live cells?

Porins are channels in the outer membranes of gram-positive Bacteria.

Eukaryotes have ________ in their cytoplasmic membranes,which serve to strengthen and stabilize the membrane and make it less flexible.Many bacteria have similar molecules,known as ________,in their cytoplasmic membranes that have a similar role.

The peptide interbridge crosslinking between peptidoglycan layers is found ONLY in the cell walls of

You are given an electron micrograph of a bacterial cell.In the micrograph you can clearly see three thin layers of different densities surrounding the cell.Based on the micrograph,you can infer that this cell is ________ and would appear ________ after application of the Gram stain procedure.

Both hydrophilic and charged molecules readily diffuse through the cytoplasmic membrane.

Which of the following types of microscopy could be used to visualize the layers of the cell membrane and the cell wall?

You have discovered a new microorganism,but you want to know if it is a eukaryote or a prokaryote.To investigate this question you prepare a slide with a simple stain and view it with a light microscope with a 40X objective lens and 10X ocular lens.You also prepare a control slide using Saccharomyces cerevisiae (a unicellular eukaryote).You can see the cells on your control slide,but you don't see cells when you look at your unknown microorganism.What can you conclude from this experiment?

A bacterial cell is interpreted as gram-positive when it forms purple insoluble crystal violet-iodine complexes within the cell during the Gram stain.

Which of the following statements is FALSE?

The cytoplasmic membrane could best be described as

Some membrane proteins are involved in bioenergetic reactions,while others are involved in membrane transport.

The lipopolysaccharide (LPS)layer is found ONLY in the cell walls of

The morphology of a cell influences its

Some of the intestinal symptoms elicited by pathogens such as Salmonella,Shigella,and Escherichia are due to the presence of

Construct a chart to show at least five major differences between the cytoplasmic membrane and cell wall of bacteria and archaea.What are the implications of these differences?