Structure of Crab shells The exoskeleton of the crab shells contains three distinct layers namely epicutile, exocuticle and endo cuticle. Generally, the exoskeleton has a high degree of mineralization, typically calcium carbonate as main constituent, in some case calcium phosphate. In exoskeleton, chitin fibrils are wrapped with proteins forms a form of fibers which is assembled further into a bundle of fibers in the exoskeleton. In addition to that, the calcium carbonate in the form of calcite deposited in the chitin–protein matrix. Current status of extraction process of chitosan Most of the chemical based extraction processes for chitosan from grabs shells are involved with harsh chemicals with high concentration and temperature. For …show more content…
Because it remains obscure about binding of proteins with chitin in the crab shells. As a consequence, the deproteinization is a complex process and lack of information of about interaction between proteins and chitin and its chemistry in the literature. Deprotenization by alkali method such as sodium hydroxide is a common method for removal of proteins from the shrimp shells. Based on the literature review, Sodium hydroxide is chosen as a de-protenization agent for this process. This step explains the optimized concentration of sodium hydroxide, contact time and temperature of the deproteinization process of crab shells and its limitations such process problems. De-proteinization Process The demineralized crab shell is washed with deionized water to remove the acidity present in the crab shell. The residual acidity in crab shell is removed by washing with water and otherwise it reacts and neutralize with sodium hydroxide solution which lowers the strength of NaOH solution. The demineralized shells are treated with various concentrations of sodium hydroxide solution, contact times and temperature. The 2 ml of sample from the de-protenized solution is taken every hour and measured the absorbance at 280nm in UV-Visible
A lobster must shed its shell in order to grow. It takes about five to seven years for a lobster to become a legal size harvestable adult. Soft-shell is the term used for a newly molted lobster. A soft-shell lobster has a shell with room for growth. Soft-shell lobsters are not as full of meat because their new shell is larger than the muscle inside the body. The part not filled with its body’s muscle tissue is filled with water. Soft-shell lobsters may look big on the outside, but they have a much lower meat yield on the inside. Most adult lobsters molt from June to September depending upon location and water temperatures.
The yeti crab is an interesting creature when it's around its surroundings. The yeti's association with their bacteria is more developed than its relatives. Each species has its own system, but one has a comb with which it can extract its food from its setae! The radiation of the closely related species seems to have been in the Coenozoic. This means that, 65 million years ago, as mammals began to take over on land, the types of crab represented now by the yetis began taking over hydrothermal vents and similar niches from a lost generation of previous inhabitants.
As shown in Fig. 5, the final pH of the NaClO-NH3 solution after simultaneous removal are 5.4, 6.9, 7.2, 7.5, 8.5, 9.6, 10.7, 11.5 and 12.8 with respect to the initial pH of 5, 6, 7, 8, 9, 10, 11, 12 and 13, from which, an interesting law can be concluded as that if the initial pH is an acidic, the final pH is slightly increased; but if the initial pH is an alkaline, the final pH is declined. NaClO-NH3 is macromolecule compounds with a large inter surface area. It contains abundant functional groups such as hydroxyl (OH), carboxyl (COO), quinone, amino (–NH2), etc, which determines that NaClO-NH3 is a salt of strong base and weak acid, as well the ionization equilibrium and hydrolytic equilibrium would be complicated. When the pH of the NaClO-NH3 solution was acidic, the functional groups such as OH, COO and NH2- would react with H+ to generate the NH3 sediment, resulting in a decrease of inter surface area owing to the block and a great loss of NaClO-NH3, then the NOx removal as well as the duration time was decreased. As for the increase of the final pH in the acidic conditions, this was a result of the consumption of H+ by NaClO. The decrease of the
"Consider the Lobster" an issue of Gourmet magazine, this reviews the 2003 Maine Lobster Festival. The essay is concerned with the ethics of boiling a creature alive in order to enhance the consumer's pleasure. The author David Foster Wallace of "Consider the Lobster” was an award-winning American novelist. Wallace wrote "Consider the Lobster” but not for the intended audience of gourmet readers .The purpose of the article to informal reader of the good thing Maine Lobster Festival had to offer. However, he turn it into question moral aspects of boiling lobsters.
The location is one of the most critical factors to analyze thoroughly because it helps predict whether the sales of the choosing location will be good or not? Although the Boiling Crab is in the growth stage, it still has to focus on new locations that the owner plan to extend to these areas. As I mentioned in the introduction, the owner plans to open the Boiling Crab in four new locations soon.
The independent variable for this experiment is the enzyme concentration, and the range chosen is from 1% to 5% with the measurements of 1, 2, 4, and 5%. The dependant variable to be measured is the absorbance of the absorbance of the solution within a colorimeter, Equipments: Iodine solution: used to test for present of starch - Amylase solution - 1% starch solution - 1 pipette - 3 syringes - 8 test tubes – Stop clock - Water bath at 37oc - Distilled water- colorimeter Method: = == ==
The North American brine shrimp goes through several stages in development before reaching adulthood. The brine shrimp is first encased in a protective capsule within a female brine shrimp’s brood sac (Drewes, C, 2006). Here, egg development rapidly...
From a crab to a barnacle, crustaceans are a diverse group of animals that inhabit much of the world. This lesson will explore what it means to be a crustacean and will also provide some example organisms.
Lighting in tanks of goldfish can alter the pigment of the goldfish in various ways. The corr...
The scientific name given to the blue crab was derived from Latin and Greek: Calli, beautiful; nectes, swimmer; and sapidus, savory. Thus, a literal transition might be the beautiful, savory swimmer. The blue crab is an important and interesting species. The blue crab is a species whose life history involves a complex cycle of planktonic, nektonic, and benthic stages which occur throughout the marine environment in a variety of habitats. The blue crab is one of the more abundant estuarine invertebrates and supports important commercial and recreational fisheries along the Atlantic and Gulf coasts.
A disembodied human head on metal crab legs, known as a crab man, has to battle evil forces to get stem cells that can make him whole again.
The same procedure was done using 10ml of CV and 20ml of sodium hydroxide, both separately diluted to 50ml and added in a large beaker. The absorbance was recorded. In the last trial, 10ml of CV, 10ml of NaOH were diluted to 50ml. Before adding the two mixtures, 1ml of soap was added to the NaOH solution and then poured into a large beaker, along with the CV. Absorbance was recorded and the materials
For the lab experiment for Membrane Damage, we tested the extract pigment and diluted it. When the pH solutions are added, this will cause it to be in a range of absorbance. We used materials as follows. Obtaining a beet we proceeded to cut small individual cubes. We then rinse each cube to remove any damaged pigments with deionized water. Using a blender, we blend the beets with 15 mL of pH 7 DI water. After blending we used cheesecloth to separate the liquid from the solids for easier centrifuge process. Then we put the liquid beet into a centrifuge tube and centrifuge it for 5 minutes at 2500 rpm. We then remove the supernatant into a beaker, and discarded the sediment. Using a 1:4 ratio mixture of the supernatant and deionized water, we made a stock solution. We then tested the stock solution’s absorbance with a spectrophotometer, and place 1 mL of the solution into separate test tubes. Next we added an additional 4 mL of pH solutions in the 2-11 range into each test tube. After mixing, we tested the absorbance for each solution using a spectrophotometer.
In the first study examined, “Effect of Different Salinities on the Survival and Growth of Artemina Spp,” researchers Soundaraparian and Saravanakumar designed an experiment to ascertain the ideal conditions for the growth of brine shrimp, or Artemina. In the Introduction, the scientists note the growing significance of Artemina, as it is now used as live feed for over 85 percent of cultured species around the world. Thus, a demand to grow huge quantities of Artemia has arisen, making this study incredibly relevant.
Chemistry: Acid-Base Titration. Purpose: The objective of this experiment were: a) to review the concept of simple acid-base reactions; b) to review the stoichiometric calculations involved in chemical reactions; c) to review the basic lab procedure of titration and introduce the student to the concept of a primary standard and the process of standardization; d) to review the calculations involving chemical solutions; e) to help the student improve his/her lab technique Theory: Titration was used to study acid-base neutralization reaction quantitatively. In acid-base titration experiment, a solution of accurately KHP concentration was added gradually to another solution of NaOH concentration until the chemical reaction between the two solutions was completed. The equivalence point was the point at which the acid was completely reacted with or neutralized by the base.