Microbiology Study Questions Essay

While the other cells appeared translucent, the bacteria types were stained with a purple pigment. While examine this organism, the team discovered that this cell was very “stringy” in comparison to the previous cells. They noticed that the center of a “bacteria blob” appeared darkly colored, mostly likely due to the bacteria cells piling up, while individual strands extending out of the middle. These bacteria cells were very similar to the cheek cells, as both things were messily stacked, unlike the organized layout of the onion cells. Although the biologists could distinguish a cell membrane and a cell wall, they noticed that the cell did not contain a nucleus.

The bacterial cell wall is comprised of glycan strands of repeating disaccharide derivatives N-acetylglucosamine acid and N-acetylmuramic acid attached to a cross-link of amino acids, including L-alanine, D-alanine, D-glutamic acid, and either L-lysine or diaminopimelic acid (DAP). This mesh-like structure is called the peptidoglycan. It serves as an exoskeleton for the bacterial cell and is critical to bacterial cell’s ability to survive environmental conditions [1]. In gram-positive bacteria, the peptidoglycan is the cell’s outermost structure, while in the gram-negative bacteria, this structure is sandwiched between an outer membrane and the inner membrane called the periplasm.

5. A. Fimbriae- hair like Gram-negative bacteria that allows attachment and through that the bacteria is able to colonize.

The cell membrane consists of eight distinctive parts that each have their own unique structure and function. The phospholipid bilayer is an integral part of the cell membrane because it is the external layer of the cell membrane and composes the barriers that isolate the internal cell components and organelles from the extracellular environment. It is composed of a series of phospholipids that have a hydrophobic region and a hydrophilic region. These regions are composed of the hydrophilic heads and the hydrophobic tails of the phospholipids, this organization of the polar heads and nonpolar tails allows the heads of the cell to form hydrogen bonds with water molecules while the tails are able to avoid water. The phospholipid bilayer also has many important functions within the cell, it gives the cell shape, provides protection, and it is selectively permeable which allows it to only let very specific molecules pass through its surface. The phospholipid bilayer is an important structure because it prevents harmful and unwanted molecules from entering the cell and isolates organelles which helps to maintain the internal environmental homeostasis of the cell.

The Gram-positive cell wall is composed of peptidoglycans, a thick layer of protein-sugar complexes taking up 60-90% of their cell wall. Peptidoglycan is composed of two glucose derivatives, N-acetylmuramic acid and N-acetylglucosamine alternated and cross-linked by tetrapeptides that is composed of L-alanine, D-glutamine, L-lysine

22. The two major groups of prokaryotic cells are the _______ and the _______, which diverged early in evolution. archaebacteria; eubacteria

n.d.). Gram-negative bacteria have a cell wall made up of a thin layer of Peptidoglycan, which is covered with an outer membrane of Lipoprotein and Lipopolysaccharide, and a bipolar-staining coccobacillus is an oval shaped bacterial cell with two poles that is in between coccus and bacillus forms (Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, Seventh Edition. 2003.). It is also known as an obligate intracellular pathogen, meaning that it is a microorganism causing disease that is only able to survive in a particular environment or by taking on a particular role. This particular pathogen can only survive when concentrated in blood (Sutyak, Katia. n.d.). This fermentative, motile organism produces a thick antiphagocytic, or a cell that prevents the action of phagocytes, slime layer as it moves (Sutyak, Katia. n.d.). Phagocytes are cells that absorb detrimental microorganisms, unwanted material, and other foreign bodies within the bloodstream and tissues (The American Heritage® Dictionary of the English Language, Fourth Edition, Mifflin, Houghton.

Bunches of spherical shapes (Staphylococci) looks mosaic, Streptobacillus, the veined structure is more pronounced, Vibrio shapes (slightly curved, but not distinctly spiral)

1 - Describe the normal structure and functioning of cell membranes, and explain how they compare to the membranes relating to a specific abnormality in cystic fibrosis?

not survive. The wall of a bacterial cell can fit into two major categories: gram-positive

(It isn’t bacillus!)  Assuming we are on oil, what is the size of one coccus of the

The cytoplasm is the area between the nucleus and the cell membrane. The cytoplasm contains many important structures. This area is basically the main place where you will find structures that help the cells stay alive.

Eukaryotic cells - found in animals, plants and fungi. In eukaryotic cells, the DNA is sectioned off from the cytoplasm in its own membrane compartment called the nucleus.

Cocci has a spherical shape, Bacilli has more of a rod shape, and Spirillum has a spiral shape. They all consist of different gram stains such as Cocci can be gram positive in young organisms and might be gram negative in older organisms. Spirillum is gram negative and Bacilli is gram positive.

In all areas of biology, it is easy to see that structure is related to function. This statement holds true in microbiology as well, the study of microorganisms, including bacteria. One characterizing feature of bacteria is the cell wall, which can generally (although not in all situations) be categorized into one of two categories: either Gram positive or Gram negative. Gram positive bacteria’s cell walls are composed of a large peptidoglycan layer (up to 90% of their cell wall). Within this large peptidoglycan layer, one can find techoic acids, which contribute to the maintenance of cell wall structure, and lipotechoic acids, which attach to membrane lipids. Gram positive bacteria that act as pathogens can also potentially release exotoxins, which can have very dangerous effects on humans. Gram negative bacteria, on the other hand, have a very small layer of peptidoglycan in their cell wall, which is surrounded by an outer membrane. Within the outer membrane, one can find the lipopolysaccharide layer, which is one of the most distinguishing factors of Gram-negative bacteria. It is important to note that Gram negative bacteria fail to possess techoic