Measurements

Our assignment this week for our chemistry blog was to make a prezi in prezi.com, which is a fun website to make presentations, about measurements. This week in class, we learnt how to use significant figures and do all sorts of math problems using them. If you want to check my prezi presentation about measurements and significant figures, click the link below! 

Measurement Prezi

Stressed Bacteria Stop Growing

I read an article called "Stressed Bacteria Stop Growing" which was published by the University of Massachusetts Amherst. This article tells us that it has been discovered that stress is very bad for organisms. Experiments tested in the University of Massachusetts Amherst and MIT, have discovered results that if the mechanism of an organism is releasing stress or is exposed to very hot or cold temperatures, cells within the organism will stop growing.

Stressful conditions cause proteins in the cell to change shape or be misfolded and stop working.

“Bacteria deal with stress by destroying proteins. Specifically, we've shown that certain kinds of bacteria respond to high temperatures by destroying proteins needed for DNA replication. Therefore, they stop growing. The signal for this destruction turned out to be the buildup of proteins that were misfolded because of the stress."

Cells grow in stable and favorable conditions which means that your DNA is replication but in stressful conditions, cells prevent the start of replication and instead change their priorities to protection.

Cells, including bacteria, contain various proteins. Molecules that help cells create chemical reactions are needed. The shape of the proteins determine what job they do within an organism. So therefore, if proteins bend out of their shape in stressful conditions, they will no longer be able to do their job and will stop working and growing.

There have been decades of study for this and scientists didn’t understand the molecules that cells use to send information about surrounding conditions affected the reproduction machinery.

“Jing Liv, a graduate student researcher in the UMass Amherst

shows that in the bacteria Caulobacter, can help defend against the effects of stress by cutting up and destroying small amounts of misfolded proteins.”

However, when the enxyme finds too many proteins that are bent out of shape, it will eliminate other protein that wasn’t damaged, then deleting all functioning proteins to complete the DNA replication process.

As the replication process begins to stop, the cells obviously stop growing. When the stress is over, the number of affected proteins drops and then cells start growing again.

Chien says, "In this way, bacteria can respond quickly to stressful, but restart again quickly. Stress and protein misfolding are a universal part of life, so understanding how simple bacteria deal with this kind of stress will help us understand how our cells do as well."

In conclusion, cells put under stressful conditions and environments will bend the proteins inside them into unnatural shapes and those proteins will not be able to perform their vital functions and therefore will stop every chance of the cell ever growing.

Source: University of Massachusetts Amherst. "Stressed bacteria stop growing: Mechanism discovered."ScienceDaily, 15 Aug. 2013. Web. 18 Aug. 2013. <http://www.sciencedaily.com/releases/2013/08/130815172202.htm 

Why Is Safety Important?

This week in Chemistry class, we have learnt how to be successful in the lab by being safe. Ms. Fogler has taught us a few rules on how to be safe in the chemistry lab. These rules are very important to our class because they will not only keep us safe, they will keep our classmates and teachers safe too. Safety in the lab is very important so our experiments are successful and we are able to develop our chemistry skills.

Some rules that Ms. Fogler has taught us are:

•   No horseplay, jokes, or pranks in the lab.

•   Food, drink, or gum are not allowed.

•   Keep science room clean and organized.

•   Notify the teacher immediately of any accidents or unsafe conditions.

•   Safety goggles must be worn at all times.

•   Contact lenses are not allowed in the lab because various fumes may accumulate under the lens and cause injuries or blindness.

•   Never taste anything or smell the source of any vapor or gas, instead waft it toward you to sample the smell. 

•   Know the chemicals you are using. Check the label on the bottles twice before taking anything from it.

•   Keep any flammable reagents away from open flames.

•   Always pour acids into water, if you pour water into acid, it will splatter all over and and cause the water to explode in steam.

•   If chemicals get into your eyes, flush in the eyewash for 15 minutes.

•   Never point a test tube to yourself or your lab partners. 

•   Beware of hot glass--it looks exactly like cold glass.