question archive 1) Create a chart (like the one below) and include one example in each box to describe how these two kingdoms contain members that can be both helpful and harmful Kingdom fungi : Kingdom protista: helpful: helpful: harmful: harmful: 2
1) Create a chart (like the one below) and include one example in each box to describe how these two kingdoms contain members that can be both helpful and harmful Kingdom fungi : Kingdom protista: helpful: helpful: harmful: harmful: 2
Subject:BiologyPrice: Bought3
1) Create a chart (like the one below) and include one example in each box to describe how these two kingdoms contain members that can be both helpful and harmful
Kingdom fungi : Kingdom protista:
helpful: helpful:
harmful: harmful:
2. Read the article entitled Pasteur and Yeasts (PDF version) and then answer the following questions in sentence form. You will use the information from this article as well as material covered in your lessons in order to answer the questions.
a) Which microorganism is responsible for the production of wine and how does this happen? (2 marks)
b) Early studies of enzymes were done in order to better understand what commercial process? (1 mark)
c) What was the name of the problem facing the wine industry? (1 mark)
d) What did Louis Pasteur conclude about from his experiments regarding the conditions required for fermentation to occur? (1 mark)
e) In Liebig's experiments, why did the yeast cells not ferment sugar after he boiled them? (1 mark)
f) What microorganism is responsible for souring the wine and why does this happen? (2 marks)
g) Early biotechnology has been used throughout history to make wine, bread, milk, antibiotics, chocolate, vinegar, and cheese. Briefly define the term "biotechnology". (1 mark)
ARTICLE
?Pasteur and Yeasts
The word enzyme means "in yeast". Most of the early studies on enzymes and their actions were attempts to understand the alcoholic fermentation by which wine is made. As early as 1785 the Academy of Florence offered a prize for a theory of fermentation that could be applied to keeping wine in better condition while was transported. However, no real light was shed on the subject until the French wine industry asked Louis Pasteur to investigate the condition "l'amer" that destroyed large quantities of the best Burgundy wine every year. From his experiments, Pasteur concluded that fermentation occurred only when living yeast was present. Liebig, and influential chemist, thought otherwise and performed many experiments in which he killed yeasts cells by boiling them and then tested them to see if they would ferment sugar. They would not, and enzymes, also called "ferments", came to be considered as catalysts that would not function outside a living cell. We know that enzymes can function outside cells and that Liebig. in boiling the yeasts cells, had also denatured the enzymes so that they could no longer function. Pasteur discovered that I'amer which turned wine sour, was caused by bacteria. Microscopic examination showed that the wine turned sour when it contained more bacteria than yeast cells. L'amer could be prevented by greater cleanliness, including sulfur sterilization, which is now standard practice in many winemaking steps. Pasteur also showed why it is important to exclude air during fermentation: wine yeast produce alcohol under anaerobic conditions, but if oxygen is present, bacteria that convert alcohol into acetic acid will outcompete the wine yeast, and will the wine into vinegar turn. Pasteur loved good wines and devoted marly years to studies of their fermentation and aging. His book Erudes sure le Vin, published in 1866. revolutionized winemaking, giving it a scientific basis for the first time.
