Lab Report Food Testing free essay sample

Food Tests Carbohydrates (Sugars and Starches) Reducing Sugars. The reducing sugars include all monosaccharides, Such as glucose and fructose, and some disaccharides, such as maltose. Use 0. 1 – 1% sugar solutions. Test for reducing sugar: Benedicts test: Add 2 cm3 of a solution of the reducing sugar to a test tube. Add an equal volume of benedicts solution. Shake and bring gently to the boil, shaking continuously to minimise spitting. Observation: The initial blue coloration of the mixture turns green, then yellowish and may finally form a brick red precipitate. Basis of test: Benedicts solution contains copper sulphate. Reducing sugars reduce soluble blue copper sulphate containing copper (II) ions (Cu2+) to insoluble red brown copper oxide containing copper (I). The latter is seen as a precipitate. Non- Reducing sugars. Non reducing sugars, the most common non reducing sugars is sucrose, a disacchriade. If reducing sugars have been shown to be absent (negative result in a above test) a brick red precipitate in the test below indicates the presence of a non reducing sugar. We will write a custom essay sample on Lab Report: Food Testing or any similar topic specifically for you Do Not WasteYour Time HIRE WRITER Only 13.90 / page If reducing sugars have been shown to be present, a heavier precipitate will be observed in the following test than with the reducing test if non reducing sugar is also present. Tests for non reducing sugar: Add 2 cm3 of sucrose solution to a test tube. Add 1 cm3 dilute Hydrochloric acid. Boil for 1 minute. Carefully neutralise with sodium hydrogencarbonate (Check with pH paper) Care is required because effervescence occurs. Carry out benedicts test. Observation: As benedicts test. Basis of test: Disaccharide can be hydrolysed to it’s monosaccharade constituents by boiling with dilute hydrochloric acid. Sucrose is hydrolysed to glucose and fructose, both of which are reducing sugars and give the reducing sugar result with the benedicts test. Test for starch: Iodine/potassium iodide test. Add 2cm3 of 1%starch solution to a test tube. Add a few drops of iodine potassium solution. Alternatively add the latter to the solid for of starch. Observation: A blue-black colouration. Basis of test: A polyiodide complex is formed with starch. Test for a lipid: Emulsion test: Add 2cm3 fat or oil to a test tube containing 2cm3 of absolute ethanol. Dissolve the lipid by shaking vigorously. Add an equal amount of cold water. Observation: A cloudy white suspension. Basis of test: Lipids are immiscible with water. Adding water to a solution of the lipid in alcohol results in emulsion of tiny droplets in the water which reflect light and give a white , opalescent appearance. Test for a protein: Biuret test: Add 2cm3 protein solution to a test tube. Add an equal volume of 5% potassium hydroxide solution and mix. Add 2 drops of 1% copper sulphate solution and mix. No heating is required. Observation: A mauve or purple colour develops slowly. Basis of test: A test for peptide bonds. In the presence of dilute copper sulphate in alkaline solution, nitrogen atoms in the peptide chain for a purple complex with copper(II) ions (Cu2+). Buiret is a compound derived from urea which also contains the –COHN- group and gives positive results.

Flatback Sea Turtle Facts

Flatback Sea Turtle Facts Flatback turtles (Natator depressus) live primarily on the continental shelf of Australia and nest only on Australian beaches. Despite their limited range, probably less is known about this sea turtle species than the other six sea turtle species, which are more wide-ranging. Initial classification of flatback turtles led scientists to think they were related to Kemps ridley or green sea turtles, but evidence in the 1980s led scientists to determine that they were a separate, genetically distinct species. Description The flatback turtle (also called the Australian flatback) grows to about 3 feet in length and weighs about 150-200 pounds. These turtles have an olive-colored or gray carapace and pale yellow plastron (bottom shell). Their carapace is soft and often turns up at its edge. Classification Kingdom: AnimaliaPhylum: ChordataClass: ReptiliaOrder: TestudinesFamily: CheloniidaeGenus: NatatorSpecies: depressus (referred to as depressa in the World Register of Marine Species (WoRMS)) Habitat and Distribution Flatback turtles are found in the Pacific Ocean, primarily in waters off Australia and Papua New Guinea and occasionally off Indonesia. They tend to frequent relatively shallow, coastal waters less than 200 feet deep. Feeding Flatback turtles are omnivores that  feed on invertebrates such as jellyfish, sea pens, sea cucumbers, crustaceans and mollusks, and seaweed. Reproduction Flatback turtles nest along the northern coast of Australia, from Western Australia to Queensland. Males and females mate offshore. Mating often results in bites and scratches in the females soft skin, which later heal. Females come ashore to lay their eggs. They dig a nest that is about 2 feet deep and lay a clutch of 50-70 eggs at one time. They may lay eggs every 2 weeks during the nesting season and return every 2-3 years to nest. Although the egg clutch size of flatback turtles is relatively small, flatbacks lay unusually large eggs - even though they are a medium-sized turtle, their eggs are almost as big as those of the leatherback - a much larger species. The eggs weigh about 2.7 ounces. The eggs incubate for 48-66 days. The length of time depends on how warm the nest is, with warmer nests hatching sooner. The baby turtles weigh 1.5 ounces when they hatch and carry undigested yolk, which will nourish them during their initial time at sea. Flatback turtle nest and hatchling predators include saltwater crocodiles, lizards, birds, and crabs. Once they reach the ocean, hatchlings do not go into deeper waters like other sea turtle species but stay in shallow waters along the coast. Conservation The flatback turtle is listed as Data Deficient on the IUCN RedList, and vulnerable under the Australian Environment Protection Biodiversity Conservation Act. Threats include harvesting for eggs, bycatch in fisheries, nest and hatchling predation, entanglement in or ingestion of marine debris and habitat destruction and pollution. References and Further Information Australian Government. EPBC Act List of Threatened Fauna.IUCN Marine Turtle Specialist Group. Flatback Turtle: Natator depressus .Red List Standards Petitions Subcommittee 1996. Natator depressus.  IUCN Red List of Threatened Species.Spotila, James R. Sea Turtles: A Complete Guide to Their Biology, Behavior and Conservation 2004. The Johns Hopkins University Press.SWOT. State of the Worlds Sea Turtles.Waller, Geoffrey, ed. SeaLife: A Complete Guide to the Marine Environment. Smithsonian Institution Press. Washington, D.C. 1996.

Grants Narrative Statement of Need - Fleishhacker Foundation Education Assignment

Grants Narrative Statement of Need - Fleishhacker Foundation Education Program - Assignment Example This essay declares that Boys and Girls Club believe that all children in San Francisco deserve high quality education, which will enable them became responsible citizens of San Francisco in particular, and the Unites States of America in general, in future. Boys and Girls Club prides itself in striving to provide safe environment which is necessary for academic excellence of students; with a special focus on children from low income households in San Francisco. Ensuring that all children from low income households; graduate from high schools and join university and colleges is one of our main desires. This paper makes a conclusion that improving education infrastructure in public schools will enable children from low income households complete education processes successfully. San Francisco Unified School District is one of the largest school districts found in California. The average graduation rate is 66%. An ethnic breakdown of this data reveals a worrying trend in the education sector; African Americans graduation rate is 49%, Latino 48%, Asian 76%, and white 64%. Less than 50% of African and Latino Americans graduated from the high schools in San Francisco. Majority of African Americans and Latino Americans come from low income households; and this explains the high rates of high school drop outs. Low income children cannot afford to study in schools which have all the required academic infrastructures; due to the high fees charged. This calls for a project like ours that will make good education infrastructure accessible to many children as possible.