Structure of the Bacterial Cell Wall Bacterial cells differ from mammalian cells due to highly developed cell walls outside the cytoplasmic membranes that provide structural integrity and shape to the cell. Bacteria live in dilute aqueous environments, which causes an intracellular pressure equivalent of 10-25 atm. Without the structural support of the cell wall, the cell is susceptible to lysis and osmotic rupture due to osmotic rupture due to turgor pressure. Figure 1: Comparison between gram-positive bacterial cell walls and gram-negative bacterial cell walls. Structural differences in the bacterial cell walls cause bacteria to be subcategorized into gram-positive and gram-negative. Gram-positive cell walls (e.g. Bacillus subtilis, Streptococcus…
The cell wall is only found in plant, bacteria, fungi, algae and other archaea cells. Its main functions are to provide protection and support for the cell. But the cell wall has many other functions as well including intercellular communication, providing shape, they also regulate what gasses can enter each cell. The vacuole hold water in plant cells and the cell wall maintains shape when the vacuole is full. The cell wall also prevents the cell from bursting when the vacuole is fully expanded.…
Plasmolysis is when the cytoplasm of a cell shrinks as a result of an imbalance of water from within the living cell to it’s surroundings. This causes an osmotic flow that leaves the cell to become wrinkled and dry. In the lab we were able to view this transfer of water through the the experiments with the blood samples and with the Elodea plant leaves. When working with the blood samples, three different mixtures with Sodium chloride and distilled water were added. In one sample there was an…
Biological functions: The main biological functions for CRP to determine via its ability to identify pathogens and injured cells of the host and mediate their elimination via activating the complement system and phagocytic cells (Brundish and Baddiley,1968 ; Weiser et al., 1997). CRP binds to microorganisms and mediates their killing to more recent observations of protection against bacterial pathogens in CRP transgenic mice. The most significant evidence has supported the notion that CRP plays…
out of cells can also be due to active transports that use energy from ATP to move substances through the cell membrane against the concentration gradient, from regions of low concentration of that substance into regions of higher concentration. In this part of the lab, the students will examine the diffusion of solute through dialysis tubing, a selectively permeable membrane, to observe why the size of the pores in the dialysis tubing determines which substances can pass through the membrane.…
Cellular Death: Tonicity on Potato Cells Introduction The purpose of this experiment was to test the effects of tonicity on potato cells. During this experiment slices of a potato were placed into beakers containing salt solutions with different concentrations. How will the percentage of salt concentration in solution affect a plant cells water content? This experiment will determine which salt solution concentrate will cause the potato cells to absorb water or lose water. Tonicity in…
because they are large and are composed of thousands of atoms. Each organic molecule consists of a monomer and is created with certain elements. Without these vital organic molecules the cell would not function properly and the cell would not be able to achieve essential processes that helps the survival of the cell. Macromolecules help sustain life.…
and some algal cell walls, in bacteria and in the exoskeleton of invertebrates (Li and Roseman 2004). Lipochitooligosaccharides or Nod factors produced by rhizobia essentially consist of a chitin backbone of 3–5-N-acetylglucosamine residues with N-acyl group attached to the non-reducing sugar and a variety of additional substituents attached to the glucosamine residues (den Hartog et al. 2003). Bacterial peptidoglycan, a polymer of β-1,4-linked N-acetylglucosamine and N-acetylmuramic acid…
Cell Structure and Function: Tonicity and pH Lab Report Assistant Exercise 1: Plant Cells and Osmosis Data Table 1. Potato Masses. Test Tube Solution Initial Mass (g) Final Mass (g) Mass Difference (g) Percent Change in Mass (%) Class Average: Percent Change in Mass (%) (If Available) a Distilled water 2.5 2.8 0.3 12 na b 0.2 M sucrose 2.5 2.7 0.20 8 na c 0.4 M sucrose 2.5 2.4 -0.1 -4 na d 0.6 M sucrose 2.5 2.3 -0.2 -8 na e 0.8 M sucrose 2.5 2.3 -0.2 -8 na f 1.0 M sucrose 2.5 1.7 -0.8 -32 na…
also the growth was stimulated with several concentrations of lead. The maximum growth was recorded in 100 ppm. High concentrations slightly inhibited the fungal growth (Table 40, Fig. 50). Low concentrations of iron (1 ppm - 30 ppm) stimulated the fungus growth. Incrasing iron concentration inhibited the fungal growth to stop it completely with 300 ppm iron (Table 40, Fig. 50). Rome and Gadd, (1987) studied the ability of P. italicum to remove copper from aqueous solution. Heavy metal uptake by…