Brown Fat Cells - On page 36, Dr. Moalem describes several ways in which our bodies our able to generate and preserve heat in order to survive in colder temperatures. Dr. Moalem specifically describes a heat-generating tissue called brown fat. Brown fat cells are able to convert heat on the spot unlike regular fat cells which store blood sugar for future energy. This relates to BIG IDEA 2 (biological systems utilize free energy and molecular building blocks to grow, reproduce, and to maintain dynamic homeostasis) since the brown fat cells are utilizing glucose (C6H12O6) in the bloodstream and converting it into heat in order to maintain homeostasis with the body’s temperature.
First, describe similarities and differences between regular fat cells and brown fat cells. Then describe the process in brown fat cells are able to utilize the glucose in the bloodstream. Describe the necessary reactants and products of the process.
Finally, we learned earlier that our bodies go through a process called cellular respiration in order to break down glucose. Determine if there is a relationship between the process that occurs within the brown fat cells and cellular respiration.
Faith Teodoro (fteodor4@students.d125.org)
There are many similarities and differences between brown fat cells and normal fat cells. Some similarities include that both are fat cells with a small amount of cytoplasm, a small nucleus, and mostly lipid droplets. Both have the function of a fat cell, which is to store fatty acids, carbohydrates, or sugars that are meant to be metabolized at some point. As it says on page 36, a major difference between the two types of fat cells is that brown fat cells convert blood sugar directly into heat immediately whereas a normal fat cell would just store the energy for it to be broken down to use at a later time. The reason why is because brown fat cells have several lipid droplets in each cell, rather than one large one in white fat cells, and are full of mitochondria. The mitochondria use fatty acids to make heat energy for the body. Another difference is that white fat cells are much more common in the human body compared with brown fat cells. In normal humans, babies have the most brown fats cell because their bodies are developing white fat cells and the brown fat cells help insulate the body when it is new.
ReplyDeletehttp://science.howstuffworks.com/life/cellular-microscopic/fat-cell2.htm
Brown fats cells also tend to have more capillaries surrounding them because more oxygen and blood flow is needed to power its many mitochondria. Brown fat cells are activated by adrenaline or thyroid hormones when temperatures get extremely cold. Different from white fat cells, which need insulin to bring glucose and fatty acids to them, brown fat cells get blood sugar directly to them and can break down the glucose immediately. The reactants of this process is very similar to cellular respiration where glucose is obviously needed, as well as oxygen to power the mitochondria. The products of the process are also similar, being carbon dioxide from the mitochondria and then heat in the form of ATP.
http://www.livescience.com/6728-mysteries-brown-fat-revealed.html
http://diabetes.diabetesjournals.org/content/58/7/1482.full
http://www.sciencedaily.com/releases/2013/03/130314124611.htm
Cellular respiration and the process that brown fat cells use are very similar in how both processes use glucose and oxygen as reactants to their processes. Both processes most likely both use glycolysis, the Krebs cycle, and the electron transport chain to make the necessary ATP for functioning. The process of brown fat cells is just a more specific form of cellular respiration. In the end, products still are ATP, carbón dioxide, and water.
(Jenny S. Li - jesli4@students.d125.org)
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ReplyDeleteBrown and regular fat cells have many similarities and differences. The biggest difference between normal fat cells and brown fat cells is the high number of iron containing mitochondria brown fat cells have. This is what causes the brown fat cell to be brown. Also the brown fat cells have many smaller lipid droplets. Normal fat cells have a single lipid droplet. Since brown fat cell has a greater need for oxygen than most tissues, it contains many more capillaries than normal fat cells. The brown fat cells releases chemical energy to produce heat as a defense to cold, whereas normal fat cells are specialized for the storage of excess energy. Brown fat are polygonal shaped and have round nuclei, and normal fat cells don’t have a certain shape and have flattened nuclei. But, despite the differences both the fat cells have, there are a few similarities in the developmental origins and physiological functions. Both cells share a similar transcription cascade that controls the process of fat differentiation. (http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2857670/) Also, both have the basic functions of storing fatty acids, carbohydrates, and sugars. They both are held in a framework of collagen fibers, and are filled with lipid. (http://www.sportsci.org/encyc/adipose/adipose.html)
ReplyDeleteBrown fat is especially important in small mammals in cold environments and animals that hibernate because of its ability to release stored energy as heat. The brown fat cells have a special protein, mitochondrial uncoupling protein, which allows the cell’s mitochondria to uncouple oxidative phosphorylation and utilize substrates to generate heat instead of unnecessary ATP. (http://www.vivo.colostate.edu/hbooks/pathphys/misc_topics/brownfat .html) Brown fat cells get blood sugar directly to them, unlike normal fat cells, where they can break down glucose right away. The reactants and products of the process of both cells are pretty much the same. Both require oxygen and glucose as a reactant and release heat and CO2. In normal fat cells, ATP would be formed, but brown fat cells generate heat instead. (http://www.livescience.com/6728-mysteries-brown-fat-revealed.html)
There is definitely a relationship between the brown fat cells and cellular respiration. They go through the same process of cellular respiration as other fat cells do. The only difference is that instead of ATP, the brown fat cells generate heat. They go through the basic process of glycolysis, bridge reaction, krebs cycle, and ETC. This process relates to Big Idea #2 because the animals are utilizing the free energy and heat released by the brown fat cells to maintain body temperature and homeostasis in the body. They are using the glucose in the bloodstream and converting it to heat, as Faith put it.
Pranathi Merneedi (pmernee4@students.d125.org)