cellular respriation and fermentation

9. Explain how a change in the volume of the gas pocket was used as a measurement of the rate of fermentation

.CO2 is a by-product of respiration and fermentation. The apparatus set-up in this experiment is designed to capture gas produced by fermentation in the top of the inverted test tube. The gas cannot escape out of the sides of the vial because the tube is inverted and water is place between the tube and vial as a seal. The amount of gas that accumulates is an indirect measurement of the rate of fermentation. One can measure the length of the gas column and compare this measurement to other tubes to get a relative rate -- greater the rate, the more gas accumulated.

1. What is the difference between monosaccharides, disaccharides and polysaccharides? Give examples.

1. What is the difference between monosaccharides, disaccharides and polysaccharides? Give examples.A monosaccharide is composed on one simple sugar (exs. glucose, fructose and galactose). A disaccharide is composed of two simple sugars bonded together (exs. maltose = glucose + glucose, lactose = glucose + galactose, sucrose = glucose + fructose). A polysaccharide is lots of saccharides bonded together (exs. starch = lots of glucose, cellulose = lots of glucose - starch and cellulose have different configurations).

2. Compare potential energy & kinetic energy. Give an example an example of each.

2. Compare potential energy & kinetic energy. Give an example an example of each. • PE - stored energy - example - energy stored in candy bar • KI - energy of motion - example - energy released when you eat a candy bar

3. How is chemical energy of form of potential energy

3. How is chemical energy of form of potential energy. Chemical energy is a form of potential that "sits" between the atoms of a molecule. If the bond is broken, energy is released - kinetic energy.

4. Compare aerobic and anaerobic.

4. Compare aerobic and anaerobic. • aerobic - with or in the presence of oxygen • anaerobic - without or in the absence of oxygen

5. Compare cellular respiration and fermentation.

5. Compare cellular respiration and fermentation. • Both are reactions that convert glucose to ATP. • Cellular respiration is the more efficient of the two producing more ATP than fermentation. • Cellular respiration occurs in an aerobic environment (with oxygen). • Fermentation occurs in an anaerobic environment (without oxygen).

10. How did enzymes affect the results of the first experiment you did in the fermentation lab.

The results of the experiment showed that in general the monosaccharides run faster than the disaccharides or polysaccharides. However, due to the internal structure of simple sugars, or the bond types between more complex sugars, this generality is only a generality. While glucose and galactose look very similar in structure (they are isomers of one another), converting glucose to galactose requires enzymes that apparently are not manufactured by the yeast. Similarly, the bond between the glucose and the galactose molecules making up lactose cannot be broken again because the enzymes required are apparently not manufactured by the yeast. The same reasoning follows for starch and the bonds that hold together its constituent glucose monomers.

6. What is the difference between a facultative anaerobe vs. an obligate anaerobe?

What is the difference between a facultative anaerobe vs. an obligate anaerobe? • facultative anaerobe - an organism that generate ATP via cell respiration in an aerobic environment, but can switch to fermentation if oxygen is not present • obligate anaerobe - can only generate ATP via fermentation in an anaerobic environment

7. What role did yeast play play in the fermentation experiment.

yeast was the study organism

8. During the fermentation lab you looked at how various sugars affected the rate of fermentation in yeast. List the following components of that experiment: • independent variable • dependent variable • control • constants • levels of treatment • replication

• independent variable - various sugars • dependent variable - rate of fermentation • control - tube without sugar • constants - same amount of sugar, yeast and water added, same temperature water bath, etc. • levels of treatment - different types of sugars • replication - each lab bench was a replicate - used all lab benches to get average values