Microbiology Study Questions Essay

In chapter 24, we learn about early life and the diversity among it. Peptidoglycan is a polymer that is composed of polysaccharide and peptide chains and is found in bacterial cell walls. The bacterias cell wall sugars cross-link with the peptidoglycan. Gram staining is a method of staining used to distinguish and classify bacterial species into two large groups, gram positive and gram negative. Gram positive bacteria retain a crystal violet color, the cell wall is composed of a thick layer of peptidoglycan.

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

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

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

Eukaryotes include all living animal organisms other than the eubacteria and archaea. The eukaryote has a nucleus membrane that surrounds the nucleus in which the way they defined the

Think on this one! Name the gram stain and shape of the bacteria pictured. Name the genus of the organism pictured. Note the size when determining the

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?

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.

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.

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

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

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.

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.

Prokaryotic Cells All living things are made of cells, and cells are the smallest units that can be alive. Life on Earth is classified into five kingdoms, and they each have their own characteristic kind of cell. However the biggest division is between the cells of the prokaryote kingdom (monera, the bacteria) and those of the other four kingdoms (animals, plants, fungi and protoctista), which are all eukaryotic cells. Prokaryotic cells are smaller and simpler than eukaryotic cells, and do not have a nucleus. Prokaryotic means 'pre-nucleus' and eukaryotic means 'true nucleus'.