Natural Indicators
Each year millions of tourists travel to the woods of New England, upstate New York, Wisconsin, and Canada to witness the appearance of brilliant autumn colors. Sugar maples, red oaks, sumac, birch and other trees and shrubs turn from green to bright red, orange, and yellow. The short, cool days of autumn bring an end to the production of chlorophyll (the green light-gathering pigment). As chlorophyll gradually breaks down, the colors of the more stable carotenoid (yellow/orange) and anthocyanin (red/blue/purple) pigments become visible. Some years the leaves of a particular species are bright yellow, while other years they may appear redder or even purple. Although no one can accurately predict the timing or coloration of each year's show, we do know that there is a chemical basis for it.
Anthocyanins (Figure I) are responsible not only for the red and purplish colors of autumn, but also for similar colors in various summer leaves (red cabbage, red lettuce, red plum tree), flowers (roses, hydrangeas, geraniums, bachelor buttons, dark pansies), fruit (cherries, red apples, grapes, tomato, blackberry, blueberry, plum), roots (beets, radishes), bulbs (red onions), and petioles (rhubarb). Anthocyanins are water-soluble and are dissolved in the cell sap rather than bound to the membranes as chlorophyll is. If cell sap in a leaf is very acidic, then anthocyanins make the leaves a bright red color, but if it is less acidic the color may appear purple.
The color of anthocyanin depends on acidity, and thus it may serve as a pH (acid/base) indicator (Figure II). pH is a quantitative measure of the acidity or basicity of solutions. Numerically, the pH of a solution is defined as the negative logarithm (base 10) of the hydronium ion (H3O+) concentration. If the pH is less than 7 the solution is acidic, if it is greater than 7 the solution is basic, and if it is 7 the solution is neutral. The higher the pH, the more basic the solution, and the lower the pH, the more acidic the solution. Figure II illustrates the relationship between color and pH for anthocyanin pigments extracted from red cabbage or other sources.
Since anthocyanins are found in all of the above named organic materials, they are all very useful natural indicators. Natural indicators are better for detecting acids and bases than man made indicators. This experiment utilizes red cabbage juice, red onion juice, blueberry juice, phenolphthalein, bromythol blue, and universal indicator for the indicators and for the acids and bases, uses .
Some sources of error in my experiment can be found mainly in my research of the tropical trees. In the tropical zone and temperate zone, most trees were too tall to reach and examine their leaves. Furthermore, it was hard to get the entire tree within our pictures. Therefore, this caused little information about the large trees in the tropical zone, giving our information less variation. This error was also implemented throughout all the zones. Another source of error was with the light shining upon the leaves. During our experimentation, there were moments in time where the sun was hidden and the sun was shining brightly. Therefore, possibly affecting the color of our leaf color. The sunlight may cause our leaf to look lighter than they possibly are. This could cause false information to compare the leaf colors for each biome.
Photosynthetic pigments work by absorbing different wavelengths of light and reflecting others. These pigments are divided into two categories primary (chlorophyll) and accessory (carotenoids) pigments. Chlorophyll is then divided into three forms a, b, and c (Campbell, 1996). Chlorophyll a is the primary pigment used during photosynthesis (Campbell, 1996). This pigment is the only one that can directly participate in light reactions (Campbell, 1996). Chlorophyll a absorbs the wavelengths of 600 to 700nm (red and orange) along with 400 to 500nm (blue and violet) and reflects green wavelengths (Lewis, 2004). Chlorophyll b has only a slight difference in its structure that causes it to have a different absorption spectra (Campbell, 2004). The carotenoid involved with spinach leaf photosynthesis absorbs the wavelengths of 460 to 550nm (Lewis, 2004). The pigments are carotene and its oxidized derivative xanthophylls (Nishio, 2000). A wavelength is determined by measuring from the crest of one wave to the crest of the next wave. All the wavelengths possible are...
The high rate of absorbance change in blue light in the chloroplast samples (Figure 1) can be attributed to its short wavelength that provides a high potential energy. A high rate of absorbance change is also observed in red light in the chloroplast samples (Figure 1), which can be accredited to the reaction centre’s preference for a wavelength of 680nm and 700nm – both of which fall within the red light range (Halliwell, 1984). Green light showed low rates of photosynthetic activity and difference in change in absorbance at 605nm in the chloroplast samples (Figure 1) as it is only weakly absorbed by pigments, and is mostly reflected. The percentage of absorption of blue or red light by plant leaves is about 90%, in comparison to the 70–80% absorbance in green light (Terashima et al, 2009). Yet despite the high absorbance and photosynthetic activity of blue light, hypocotyl elongation was suppressed and biomass production was induced (Johkan et al, 2012), which is caused by the absorption of blue light by the accessory pigments that do not transfer the absorbed energy efficiently to the chlorophyll, instead direction some of the energy to other pathways. On the other hand, all of the red light is absorbed by chlorophyll and used efficiently, thus inducing hypocotyl elongation and the expansion in leaf area (Johkan et al, 2012).
Stephanie Lindsey the author of the article Autism and Education addresses some serious issues in the education system between the special needs students and the highly gifted students. Stephanie writes the article based off her children and how they are treated in school. Her son has autism, which affects his capability to learn, speak, and to train himself when it comes to bathroom use. Also never being alone in school due to him having a personal aid alongside him with special classes he is treaded with a different type of education. Her daughter on the other hand tests in the 95th percentile nationwide on standardized testing. She’s twelve and her capability of progressing information and taking complex ideas apart and putting them back together to form new thoughts is like no normal twelve year old. She reads entire novels, solves Sudoku puzzles, and also participates in her school
There are multiple types of schools in the United States; especially when it comes to dealing with children with Autism. Some schools do not handle autistic children well. There are multiple reports on how these children are put in isolation from other students in the school. Society frowns upon the mentally disabled, and many people feel as if this should not be. Most psychologists have said that there are no “right” schools for children with autism. However, public schools seem to have more pros, than cons. In public schools, the ratio (for teachers to students) is 1:1. There is special support, just like mainstreaming. Also, Autistic children don’t feel different than other students because the classroom has the same type-of setting and any other class. Just as there are pros, cons seem to follow however. One of the main, and only cons is simply that the parent does not agree with the choices, or setting of the school. The parent might feel the classroom is not adequate for their child.
Microbial pigments have antioxidant activity because of their biological functions.and these pigments are Carotenoid ,naphthaquinone,and Violacein.
The purpose of this lab was to extract chlorophyll and carotenoid pigments from fresh spinach leaves and separate and analyze these pigments using column chromatography and thin layer chromatography. Acetone was used as a polar solvent to dissolve the more polar pigments first (Xanthophylls, chlorophylls), while hexane was used as a nonpolar solvent to dissolve the more nonpolar pigments such as the carotenes. In addition to being used as the polar solvent, acetone was used to remove the spinach components that were not pigments such as cellulose which is insoluble. The column chromatography worked by eluting the nonpolar carotene pigments first because the alumina is polar and doesn’t absorb the nonpolar carotene. The polar components such
This source highlighted different approaches taken by schools, teachers, and aides that work closely with persons with ASD. While states offer equal educational opportunities to students, it is important for the individual to understand what their needs are when choosing a school or program. While mainstreaming students with ASD into normal learning environments can be beneficial to personal development, it can also be damaging if the students is not emotionally prepared. This type of frustration can cause the individual with ASD to exhibit problematic behavior or cause them to develop
The idea of inclusion or mainstreaming has been around the education community for a long time. Both of these ideas involve including students with learning disabilities in regular classrooms to be taught by regular teachers rather than special education teachers. The difference between the two is that inclusion allows for a learning disabled student to be in a classroom for the majority of their day and mainstreaming allows or a learning disabled student to be in a regular classroom for a set amount of time if they have shown that they (the special needs student) can keep the same pace as the students in the regular classroom. Both inclusion and mainstreaming that include special needs students in regular classrooms could easily be modified to help students without learning disabilities to excel at their education. Including students from a lower class level in a higher-class level could benefit both the higher level students as well as the visiting students.
There are many benefits for learning disabled students when placed in an inclusive classroom. Research has shown that students with learning disabilities can be supported in a general education classroom setting for the entire day with academic achievement as high as or higher than those in a separate setting (McLeskey & Waldron, 1998). There are many positive benefits which include improved social skills, stronger peer relationships, enhanced academic performance, and positive feeling about one self.
However, the negative aspects of inclusion have not proven a strong enough point in that the good, which comes from this experience, severely outweighs any doubt of its success. Inclusion of autistic children has shown to be beneficial due to the notion that these 'disabled kids' can attend 'normal' classes with their non-learning disabled peers. By allowing all kids to feel 'normal' we, as a society, stand a chance of making prejudice which we associate the disabled under, cease to exist.
As 10 mL of NaOH was added drop wise, the solution began to have a pink tint. The fuchsia color did not permanently stay until 9mL of NaOH was added. The pH indicator demonstrated when exactly the reaction has neutralized. Because an acid and a base reacted to form water and a salt, the reaction is a neutralization
The number of children that display autistic traits keeps rising and the need for services is at an all-time high. Out of 10,000 children born, 60 to 100 children and families will be affected by autistic spectrum disorder (Gulberg, 2010). Autism is characterized by a lack of connection to other people, even parents, and an avoidance of interpersonal situations (Feldman, 2011). Children with autism also show limited, repetitive and stereotypical patterns of behavior, interest, and activities. Not one child with autism is the same as the next; each child has their own severity and indicators of autism. A child with intellectual disabilities and a gifted child can both be given the diagnosis of being on the autism spectrum, because of the wide range of severities. Many of these children will not attend special schools, but instead be included in the general education population by inclusion. Inclusion has been found to have a number of benefits for children with autism. In addition, negative perspectives have also come into play when discussing autism and inclusion. Furthermore, parents have the right to make decisions for their child on an individual basis.
Four solutions were tested an out of the four only one had a color change, meaning that it had alcohol present. This solution was methanol and of course it would produce a color change because methanol is an alcohol. One solution that should have changed color was solution 4, the base-hydrolyzed aspartame, but it did not produce a color change when aqueous ceric ammonium nitrate reagent. Water and fresh aqueous aspartame are not going to produce a color change because there is no alcohol group in there structure.
One of the most difficult things teachers will face when dealing with Autistic children is their lack of communication skills and inappropriate or nonexistent social skills. In addition to academic instruction children with Autism require instruction in communication techniques and social skills. Kamps et.al. says “A key to accommodating students with autism in public school settings is the provision of social and behavioral programming to develop meaningful participation with nondisabled persons” (p.174).