THE CHEMICAL REACTION THAT TAKES PLACE IN THE BODY AFTER EXERCISE

By increasing your heart rate, raising your core body temperature, boosting oxygen levels and improving cardiac output, exercise triggers several known biochemical reactions. However, as Scientific American magazine explains, "Aside from such macro links and knowledge about the heart rates, blood-oxygen levels and hormonal responses related to exercise, scientists have a relatively cursory understanding of the chemical mechanisms at work in the body during and after physical activity."

Endorphins

One of the most well-documented reactions that take place after working out is the production of endorphins. These nonaddictive, feel-good molecules are polypeptides that bind with neurotransmitters in the brain to reduce pain symptoms. The human body produces at least 20 types of endorphins, which benefit the body in myriad ways. Besides relieving pain, endorphins help reduce stress, boost immunity, slow the aging precess and create a sense of euphoria.

Blood Chemistry

Another known reaction that takes place after working out is a change in your blood chemistry. While exercising, your muscles use oxygen contained within your blood's hemoglobin to convert the glucose in your bloodstream into usable energy. In addition, carbon dioxide and hydrogen are produced during this process. Together, these changes affect your overall blood chemistry and cause your blood's pH level to drop.

Metabolism

Metabolites are small chemicals involved in your metabolic process that increase the more you exercise. Specifically, glycerol, a metabolite that breaks down fatty tissue, increases after exercise in people at all fitness levels. In fact, even after only 10 minutes of exercise, your bloodstream will likely contain more metabolites then when you started. Furthermore, according to Scientific American magazine, consistent exercise may stimulate long-term changes in your metabolism, of which scientists are only barely scratching the surface.

Considerations

Your experience after working out will depend on your own unique body chemistry. For example, the body releases endorphins at a different rate for every individual. It may take some people 10 to 15 minutes of consistent exercise to feel them kick in, whereas others may require 30 minutes or more. In addition, your metabolism often depends on your genetic predisposition, age and body type.

History of the construction of the periodic table

A good reflection to begin the day's work.

Chemical Changes

It's the Fourth of July in Providence, Rhode Island.   Brilliant fireworks are exploding in the night sky.  When you look at the fireworks, you see dazzling sparkles of red, white and blue trickle down in all directions. 
The explosion of fireworks is an example of chemical change.

During a chemical change, substances are changed into different substances.  Another words, the composition of the substance changes.

Physical changes are relatively easy to identify.  If only the form of a substance changes, you have observed a physical change.

Signs of Chemical Changes
How can you tell whether a change is a chemical change? If you think you are unfamiliar with chemical changes,think again.

 A common physical change occurs when matter changes from one phase to another.  When an ice cube melts for example, it becomes liquid water.  The solid ice and liquid water have the same composition.  The only difference is the form. 

Color Changes As in the case of autumn leaves, a change in color is a clue to indicate a chemical change.  Perhaps you have found a half eaten apple that turns brown.  The reason is that a chemical change has o ccurs when food spoils .

You have just witnessed a spectacular chemical change if you have seen the leaves change color in the autumn.

Energy - Absorbed or Released When you bake a cake, energy is absorbed by the batter as it changes   form a runny mix into a cake. Another sign of a chemical change is the release or gain of energy by an object.  Many substances absorb energy to undergo a chemical change.  Energy is absorbed during chemical changes involved in cooking, like baking a cake.

Energy can also be released during a chemical change.  The fireworks that were mentioned above release energy in a form of light that you can see.  You can also see that energy is released when in this movie clip when sodium and chlorine are combined with water.

Odor Changes It only takes one experience with a rotten egg to learn that they smell different that fresh eggs.  When eggs and food spoil, they undergo a chemical change.  The change in odor is a clue to the chemical change .

When you smell an odd order in foods such as  chicken, pork of mayonnaise, you know that the food has undergone a chemical change. You can use this cllue to avoid eating spoiled food and becomin ill.

Production of Gases or Solids The formation of a gas is  a clue to chemical changes.  The bubbles of gas that you observed form when an antacid is dropped into water is an example of change. Another clue that a chemical change has occurred is the formation of a solid.  A solid that separates out of solution during a chemical change is called a precipitate.

As wood burns, it turns into a pile of ashes and gases that rise into air.  After the wood is burned, it cannot be restored to its original form as a log.

Not easily reversed How do physical and chemical changes differ from each other?  Think about ice for a moment.  After ice melts into liquid water, you can refreeze it into solid ice if the temperature drops.  Freezing and melting are physical changes. The substances produced during chemical changes however cannot easily change back into the original substances.

Chemical vs Physical Change

The most important thing for your to remember is that in a physical change the composition of a substance does not change and in a chemical change the composition of a substance does change.

Chemical Reactions Chemical Changes are also called Chemical Reactions.  Chemical reactions involve combining different substances.  The chemical reaction produces a new substance with new and different physical and chemical properties.  Matter is never destroyed or created in chemical reactions.  The particles of one substance are rearranged to form a new substance. The same number of particles that exist before the reaction exist after the reaction.

To create your own chemical change, click on Fireworks.  To find more fun information about firework displays that you seeclick here. 

Consumer fireworks are illegal to possess in Rhode Island, however there are still plenty of opportunities to enjoy a great show.  Although it rarely happens, it is possible that a firework component might fall to the ground without exploding. What do you do?

Education does not change the world: changes to the people that are going to change the world

US Education System: Crying Out for Help

Decades ago, the United States ranked first in the world in the number of young adults who had high school diplomas. As of today, compared to Europe and Asia, 15 year-old students in the U.S. are ranked just above average in reading and science and below average in math. Moreover, according to OECD (Organization of Economic Co-operation and Development) 2009 Program for International Student Assessment, the United States ranked 17^th in reading, 23^rd in science, and 31^st in math.

One of the major issues with our education system is the declining knowledge and understanding of history, geography, grammar, civics and literature. However, in the attempt to solve the education dilemma politicians, community leaders, along with the education community all sing the same old song, “students fails because expectations are not high enough” or “we need more accountability”.  With this lingering tune, the only solutions that they proposed is to pump more money into the education system, so that teachers receive better pay and children are placed in smaller classrooms in order to receive enough attention.

Yet, with such significant changes within our education system the question remains, “Why are our students becoming more and more illiterate each year?” Furthermore, is pumping more money into schools really addressing the problem or is there an unknown secret political agenda? Instead of ‘adding fuel to fire’, these ‘education experts’ should focus on the root of the problem-No Child Left Behind Act.

After taking office in January 2001, former President George W. Bush made education his number one agenda. His first policy proposal was the “No Child Left Behind” Act (NCLB Act). According to the President, he wanted to tackle the growing problem of illiteracy among American children and the low standard of test scores.  His policy addressed three specific ideologies:

1) annual testing for grades 3-8 to ensure that schools are actually teaching children;

2) give parents the choice to find schools that produce results within their district. However, President Bush gave schools specific time-period to improve and if they failed, parents have the option of going to a more successful school by way of a voucher plan;

3) “flexibility for accountability,” which means giving the control back to local and state schools boards. However, it was made clear that federal funding will stop if failing schools fails to improve. The Act’s main purpose is to have every student in America be proficient in reading and math by 2014.

On the surface, the NCLB Act seems like a fresh new start for the American’s education system, but carefully sifting through the act proves otherwise. According to the National Conference of State Legislatures (NCSL), high schools across the nation are receiving a significant amount of attention from both state and federal interest groups. These high schools are being called upon to renew their curriculum, methodology, as well as teacher/student relationship in order to better serve the needs of the students.

Currently, there are a record number of high school graduates who are not adequately prepared for postsecondary education or for the competitiveness of the workforce. According to NCSL, a survey done by Achieve Inc. stated that college instructors estimated that more than 40 percent of high school graduates are not ready for college courses, and up to 30 percent of first-year postsecondary education students take remedial courses upon entering college.  In the same survey, employers estimated that 45 percent of high school graduates lack the skills to advance beyond entry-level jobs.

At this time, the Obama Administration claims that the NCLB Act shines light on achievement gaps and increased accountability for high-need students; however, it encourages states to lower their standards and narrow their curriculum to focus mainly on test scores instead of student growth and gains. The goal of the Obama Administration is to find a way to give states and districts flexibility to develop solutions locally under the NCLB Act to address their educational challenges while protecting children and holding schools accountable for better preparing young people for college and careers.

It is extremely clear that the NCLB Act is not practical and it is also clear that over the last decade the federal education policies that are being introduced are leading our education system down a destructive path that has severely impacted the traditional public school system. Our education system is desperately crying out for help; to solve this problem America needs to attack the root-the different non-functional education program of the federal government, e.g., the NCLB Act. If it does not work, get rid of it. It is about time the government takes the political agenda out of education, and return back to the traditional education system where students actually learn skills such as reading, writing, science and math that prepare them for college or careers.

 

fuente:http://aspanational.wordpress.com/2011/10/12/us-education-system-crying-out-for-help/

A reflection about Freire!

In class, last Friday, we were reflecting on the pedagogy of the oppressed of Paulo Freire and Valeria R and S Adriana came to an idea of our reflection: We agree with Freire, because we thik that the education is a tool to change our minds and the way to act.
As teachers, we must promote the development of critical thinking. The reason of this is to reach a social compromise!