Enzyme Lab Report

The more acidic a substance is the less oxygen it will produce when going through a chemical reaction. During the Lab “How Do Changes in pH Levels Affect Enzymes Activity”, the researcher conducted an experiment to test the effects that an acidic, neutral, and a base substance will have when combine it with hydrogen peroxide. The data table shows that HCL (acidic substance) barley produced any oxygen at all when it was combining with Hydrogen Peroxide. The pH level for HCL was 2.5; this level indicates that the substance was very acidic. When the H2O and NaOH were tested they produced more bubbles than HCL. NaoH produced a little more bubbles than HCL. The pH that NaoH produced was a 9, which is a base. H2O produced more bubbles than both substances;

The purpose of this experiment was to test which type of sunscreen worked better, spray or lotion. The experiment was conducted by cutting a UV paper into squares and labeling each one with each of the six sunscreen. A small amount of each sunscreen was applied to a square and was taken outside for three minutes to be exposed to the sun. The UV squares were taken back inside to be soaked in water for one minute each. The squares were left to dry for twenty-four hours. Three trials were conducted for each sunscreen. After the twenty-four hours of drying time and for the results to fully come in, immediately it was noticed that the lotions made the UV paper much lighter than the sprays. For all three trials, sunscreen number two, made the UV paper the whitest, meaning it protected the UV paper from sun exposure more.

This research was conducted to see the effects of sunscreen on plants ' lifespan. The hypothesis was that the plants that had sunscreen applied to them would have a shorter lifespan than plants with no sunscreen applied to them and increasing the amount and SPF value of the sunscreen would decrease the lifespan even more. 12 Romaine Heirloom Leaf Lettuce plants were separated into 4 categories and were tested on for a period of 28 days. The 4 categories were: control or no sunscreen, 1/4 teaspoon SPF 30 sunscreen, 1/2 teaspoon SPF 30 sunscreen, and 1/4 teaspoon SPF 50 sunscreen. It was found that the original hypothesis was supported by the data. On average the control plants lived 21 days, the 1/4 teaspoon SPF 30 sunscreen lived 9 days, the 1/2 teaspoon SPF 30 lived 8 days, and the 1/4 teaspoon SPF 50 lived 5 days. This implies that sunlight is a very important factor in plant lifespan. This research could be useful to scientists trying to grow plants on other planets.

In this lab, the organism that we have been working with is the bacterium, Serratia marcescens. S. marcescens is a member of the Enterobacteriaceae family, and tends to grow in damp environments. S. marcescens is an ideal bacterium to work with in the lab because it reproduces quicker than other bacterium. This bacterium produces a special pigment called prodigiosin, which is red in color. The prodigiosin pigment is intensified when S. marcescens is grown at higher densities. During our experiment, temperature, pH, salinity concentration and oxygen requirements were tested on S. marcescens to measure their optimal growth and prodigiosin production.

When reflecting back to experiment 3, Aseptic Technique and Culturing Microbes, I realized the large amount of microorganisms that can be found in everyday life. Many different types are found with in the human body. Theses experiments focused on two types of bacteria. First was Staphylococcus epidermidis, found on the skin, and second was Lactobacillus acidophilus, found in the gastrointestinal tract. Both have similar needs for growth when it comes to temperature, however, different growth environments are used.

“Enzymes are proteins that have catalytic functions” [1], “that speed up or slow down reactions”[2], “indispensable to maintenance and activity of life”[1]. They are each very specific, and will only work when a particular substrate fits in their active site. An active site is “a region on the surface of an enzyme where the substrate binds, and where the reaction occurs”[2].

For this year’s science project, I would like to test the effects of both mineral and commercial sunscreens on human skin and coral reefs. In current news, the island chain and United States’ state, Hawaii is planning on banning common sunscreens for the detrimental effects on the coral reefs. I would like to test the sunscreens for the detrimental effects on human skin as well to answer the common question, “Why should I care?” With this project, I will be able to educate the public on not only the effects of chemicals on marine life, but also on humans as well. Also, determine if there is a way not to wear sunscreen at all and still be protected from the sun’s UV rays.

The lab group conducted three separate experiments to test the effect of ultraviolet radiation on the survival of yeast cells. These experiments are significant because ultraviolet radiation can damage the DNA of human skin cells and eventually lead to skin cancer. The yeast cells were prepared and then exposed to UV for various increments of time. The first experiment was a comparison of a wild type strain versus an unknown type. The hypothesis was that if the unknown yeast has better adapted to ultraviolet radiation, more unknown cells would survive. The wild-type strain survived substantially more than the unknown. The second experiment introduced “protections.” The group covered the yeast samples with a thick black film or a sample of distilled water. More cells under the black film outlasted the cells under the distilled water. The third experiment covered the samples with a thinner, red film or a general sunscreen with SPF 70. More cells covered by the sunscreen lived than those under the red film.

S. marcenscens is an adaptable bacteria found in many different environments including water, soil, gastrointestinal tracts of many animals, but grow particularly well on starchy food sources (Petersen and Tisa, 2013). S. marcenscens when first isolated it was believed to be non-pathogenic, but S. marcenscens is responsible for nosocomial human infections, plant infections, insect and nematode infections, among many more (Petersen and Tisa, 2013). S. marcenscens is opportunistic and is known to cause nearly every possible infection imaginable including, urinary tract infections, upper respiratory infections,

The Functional and Structural Differences of Mutant and Normal Alkaline Phosphatase (AP) Enzymes Taylor Mann, BSCI105, Section 5621, Spring 2015 Abstract Previous research has shown that mutated alkaline phosphatase (AP) is related to hypophosphatemia, a condition that is caused by insufficient amounts of phosphate in the blood and reduced enzyme activity (Keller 2015). Throughout the three completed experiments we observed data from a group of individuals with hypophosphatemia with nearly normal bone density. The state of their condition led us to hypothesize that the abnormal folding pattern of mutant AP causes the enzyme to function most effectively at a different pH than normal AP.

Organisms cannot depend solely on spontaneous reactions for the production of materials because they occur slowly and are not responsive to the organism's needs (Martineau, Dean, et al, Laboratory Manual, 43). In order to speed up the reaction process, cells use enzymes as biological catalysts. Enzymes are able to speed up the reaction through lowering activation energy. Additionally, enzymes facilitate reactions without being consumed (manual,43). Each enzyme acts on a specific molecule or set of molecules referred to as the enzyme's substrate and the results of this reaction are called products (manual 43). As a result, enzymes promote a reaction so that substrates are converted into products on a faster pace (manual 43). Most enzymes are proteins whose structure is determined by its sequence of its amino acids. Enzymes are designed to function the best under physiological conditions of PH and temperature. Any change of these variables that change the conformation of the enzyme will destroy or enhance enzyme activity(manual, 43).

The aim of this experiment is to follow the growth of Serratia marcescens in nutrient broth at 37oCby recording the changes in turbidity (cloudiness) by measuring the absorbance of visible light (600 nm) and also to prove that there is an increase in the cell number and not just in mass during the growth.

There was no difference between the control plates which proves that the lid on the plate serves as significant protection, potentially shielding the bacteria to the mutagenic effects the UV light. All three plates were incubated at 25 degree Celsius. The first Control plate showed lots of red and furry growth and the original pattern of swiping was observed in all the quadrants. The second control plate was also observed to have furry and pigmented red growth in all the quadrants, despite being exposed to UV light due to the plate lid during exposure. The experiment plate showed the most interesting results, in the 10 second UV exposure quadrant the bacteria had red pigmented growth but it is speckled, pinpointed and the original swipes were not observed. Moreover the growth seemed not as furry and robust as the control plates. The quadrant exposed to 20 sec of UV light showed significantly less growth than the 10 sec quadrant and the colonies are pinpointed with several beige colonies in between the red speckles. Original swipe pattern of the bacteria was not observed in this colony. In the quadrant exposed to 30 seconds of UV light, the differences are even more significant as the colonies are few and far in between and only several pinpoint red colonies found with a few beige colonies and some colonies with red centers surrounded by beige. The effects of UV light are very drastic in the 40 second quadrant as the growth is severely diminished with only a

A small amount of research has been conducted on air as a habitat compared to other environments such as soil, water, and sediments (1). Air makes up the atmosphere and is composed of approximately 78% nitrogen, 21% oxygen, .93 % argon, and .038% carbon dioxide (http://www.space.com/17683-earth-atmosphere.html). In addition, air carries dust particles, pollutants and plant grains. Air presents a hostile environment for the sustaining of metabolically active and reproducing microbes. The air is composed of UV radiation, which results in the development of UV light protection in the microbial populations that reside in this environment (1). Due to the conditions of air, microbes that inhabit air are capable of adapting to wider pH ranges. They are also capable of living in a wide range of temperatures due to varying altitudes (1). A majority of microbes that inhabit the air are in the Proteobacteria, Firmicutes, and Actinobacteria phylum. These microbes include, Pseudomonas syringae, Pantoea agglomerans, Propionibacterium acnes, Agrobacterium tumefaciens and Sphingomonas echnoides (2).

In this experiment, I looked at what affect varying environmental variables have on gene expression in bacteria. More specifically, I observed the effect of temperature on the common soil bacteria Serratia marcescens. S. marcescens can appear either red, pink, white, or colorless due to the presence, or the lack, of several specific enzymes within the bacteria that cause the production of the red pigment known as prodigiosin.