1. 1. In your own words, explain: What is cellular
respiration? What is basic process of cellular respiration? What is the
purpose? Which organisms on the planet utilize cellular respiration?
Cellular respiration is the conversion of glucose and oxygen to energy in the form of ATP. This process consists of three stages: glycolysis, the citric acid cycle, and electron transport. In glycolysis, one glucose molecule is converted into 2 Pyruvic acid molecules. Before the next stage can occur, these resulting molecules must first be converted into Acetyl CoA. This Acetic acid then enters the citric acid cycle, where NADH and FADH2, along with a by-product of CO2, are produced. Finally, NADH and FADH2 from the previous stage transfer electrons to the electron transport chaduction, producing H2O. H+, which was pumped across the membrane when NADH and FADH2 transfered electrons, goes through an ATP synthase, which generates ATP. The purpose of cellular respiration is to convert food into a form of energy--ATP--that organisms can use. Both plants and animals utilize cellular respiration.
2. Explain what makes bread rise and beer bubble.
The fermentation of yeast is what causes bread to rise and beer to bubble. Yeast ferments sugar and other foods when it is in an anaerobic environment in order to stay alive. During the fermentation process, the yeast “burps” CO2, this is what causes the bread to rise and also causes the bubbles in beer. The fermentation also produces ethyl alcohol as a waste produce, which is burned off when bread is baked, and is what gives beer its alcohol content.
I love to bake bread and I have tried to create a sourdough starter several times, but have never been happy with the taste of the bread. After watching the Alton Brown clip, I did a bit of research online and I believe I may have found out what my problem has been with the sourdough starters. It is the bacteria in the sourdough that gives the bread its distinctive flavor. I have always used commercial yeast to make my starter, and I found out that commercial yeast contains more yeast than bacteria. Also, in commercial yeast, both the yeast and the bacteria feed on the same type of sugars, and as there is more yeast than bacteria, the yeast thrive while the bacteria do not, so the bacteria do not have a chance to add their flavor to the dough. The wild yeast cannot metabolize the sugars in flour, but the bacteria needs this sugar to grow, therefore there is a better balance of yeast and bacteria when wild yeast is used, which results in a better tasting sourdough. I plan to attempt to make a starter using wild yeast in the next few weeks. I hope I am successful!
Here is the website where I found my information on the sourdough starter: http://www.exploratorium.edu/cooking/bread/recipe-sourdough.html
Fungus of the Week: The "Bird's Nest Fungi"
Scientific name: Cyathus olla
Order: Nidulariales (Class Basidiomycetes)
Common name: Bird's Nest Fungi
Photo courtesy of Wayne's Word
I have chosen to highlight this particular fungus because of its unique shape and because of the interesting way in which it reproduces.
This tiny fungi which has the appearance of a miniature bird's nest is only about 5mm in diameter, which is smaller than a penny. Bird's Nest fungi have been found to grown in North America and in New Zealand.
Bird's Nest fungi are saprophytes, which means they decompose organic materials to obtain nutrients. Because of this, they are found to grow on decaying wood and other organic debris.
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| Photo courtesy of Wayne's Word
The nest portion of the fungi, which are called "peridia" collect rainwater and function as "splash cups". When the raindrops hit the surface of the nest, the eggs of the fungi, called "periodoles" are thrown up into the air, eventually landing on leaves, branches, etc. Once they have landed, the spores from the eggs disperse and germinate, creating "mycelia", which is how the fungi reproduces.
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To find out more about this interesting little fungi, check out these websites:
Roseann, the fungus you chose to research is fascinating! It's very interesting how the fungus shoots the little eggs into the air in order to reproduce. I also enjoyed your description of cellular respiration. After reading everyone's definition of cellular respiration I feel like an expert!
ReplyDeleteRoseann, what a unique mushroom. It is so amazing how a plants unique abilities allow it to grow and reproduce in in a way that benefits it. I was thinking that in a way the bird's nest fungi uses rainfall as an indicator of when it is the best time to attempt reproduction. When the rain splashes them out of the nest and onto new land it is also providing the plant with some of the material it needs to survive and is during a time of year where there is plenty of moisture available. I don't know if that is why the birds nest fungi acts the way it does, but I think it interesting to examine how an organism's life history benefit it.
ReplyDeleteBen
Thank you for your comments, Megan and Ben. Isn't nature amazing? Living things are so complex, aren't they? Ben you make a very good point about rain being an indicator as to the best time for the bird's nest fungi to reproduce. It makes perfect sense as the "baby" fungi needs water to grow.
ReplyDeleteReply to blog posts 3-18-12.
ReplyDeleteHi Brittany. I enjoyed reading about the honey mushroom. I read your source for the mushroom, and it says that the taste is mild to bitter and the odor is sweet. I wonder if this means that this mushroom is edible? Not that I have any plans to go and find some to try it out--I have to admit that wild mushrooms scare me and I would not ever attempt to eat any!
I also liked your explanation of yeast for baking bread and making beer. I have never made beer, but I do love to bake and it is very interesting to me to find out more about what makes my bread rise.
Hi Jamie. I love the picture of the mushrooms! They looked to me just like the mushrooms you see pictured in fairy stories--when I read through your sources I found out that is exactly what they are, and one of the web sites said that they sometimes called Fairy Toadstools. It seems they are common in the UK; I wonder if any grow in the US or in CA? I also found it interesting that people used to think that this mushroom was poisonous to flies.
When I showed the picture of this mushroom to my daughter, the first thing she said was that the caterpillar in Alice in Wonderland was sitting on this type of a mushroom, so of course I had to go find a picture, and she was right, he is sitting right next to one! http://t0.gstatic.com/images?q=tbn:ANd9GcSrAFY62AFgDvjOs4Sxn7AgrG0mCJQsKAGrQnylGnqzt_DHn4pZ2f8U4Hox-Q.
Hi Alisha. I love the mushroom that you chose for your blog post this week! I had no idea that the ring grows from one organism under the ground. Put your mushroom together with Jamie's fairy toadstools and we are all ready for a fairy story!
Roseann,
ReplyDeleteWhat a great point on why your sourdough bread didn't have the flavor. I too have tried to make my own sourdough bread with inadequate results. I had not known that commercial yeast had more yeast than the bacteria needed for the flavor. Using your sourdough site above, I'm going to give it another try at making the sourdough bread. I'll let you know how it turned out!
Rosanne,
ReplyDeleteIsn't it amazing these exist and we have little to no knowledge of their existence? According to the University of Wisconsin article, Bird's Nest Fungi (Bird’s Nest Fungi. Amy Gibbs and Brian Hudelson, UW-Madison Plant Pathology.http://pddc.wisc.edu/factsheets/Low%20Color%20PDF%20Format/Birds%20Nest%20Fungi.pdf. Access 18 Mar 2012). "Bird’s nest fungi are not harmful to living plants and control of these fungi is typically not necessary. In fact, bird’s nest fungi can be fascinating organisms to observe when you find them in your yard. On occasion, bird’s nest fungi can be a nuisance, particularly when the “eggs” stick to objects such as houses or cars where they are difficult to remove."
I did not realize these fungi could be difficult. However, as with many fungi species they recommend reducing moisture to control growth. It appears "moisture" is the key component to most fungi.
Syndi