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28 Mar 2018

Starch is digested by amylase. Which of the following statements would be true?

______________________

The digestion of starch by amylase is spontaneous.

The digestion of starch by amylase is endergonic.

Amylase supplies the energy needed for this reaction.

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30 Mar 2018

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I need a good introduction and conlcusion of this experiment below is the expermeint and my results.

In this experiment you will observe the action of the enzyme amylase on starch. Amylase changes starch into a simpler form: the sugar maltose, which is soluble in water. Amylase is present in our saliva, and begins to act on the starch in our food while still in the mouth.

Exposure to heat or extreme pH (acid or base) will denature proteins. Enzymes, including amylase, are proteins. If denatured, an enzyme can no longer act as a catalyst for the reaction.

Benedict's solution is a test reagent that reacts positively with simple reducing sugars like maltose, but will not react with starch. A positive test is observed as the formation of a brownish-red cuprous oxide precipitate. A weaker positive test will be yellow to orange

PRE-LAB:

Add 1g of cornstarch to a beaker containing 100ml of cold distilled water. While stirring frequently, heat the mixture just until it begins to boil. Allow to cool.

PROCEDURE:

1. Fill the 250-mL beaker about ³/₄ full of water and place on the hot plate for a boiling water bath. Keep the water JUST AT BOILING.

2. Mark 3 test tubes A, B and C. "Spit" between 1 and 2 mL of saliva into each test tube.

3. Into tube A, add 2 mL of vinegar. Into tubes B and C, add 2 mL of distilled water. Thump the tubes to mix.

4. Place tube B into the boiling water bath for 5 minutes. After the five minutes, remove from the bath, and place back into the test tube rack.

5. Add 5 mL of the starch solution to each tube and thump to mix. Allow the tubes to sit for 10 minutes, occasionally thumping the tubes to mix.

6. Add 5 mL of Benedict's solution to each tube and thump to mix. Place the tubes in the hot water bath. The reaction takes several minutes to begin.

OBSERVATIONS:

Tube A: Starch + saliva treated with vinegar (acid)

Was the test positive or negative? Negative

What does this indicate? The vinegar stops the action of amylase from catalyzing the starch therefore the solution becomes cloudier. This indicates that vinegar (acids) distort the shape of proteins in the salivary amylase.

Results: The solution turns cloudy.

Conclusion: Acids denature the shape of proteins in the salivary

Tube B: Starch + saliva and water, treated in a boiling water bath

Was the test positive or negative? Negative

What does this indicate? It indicates that when enzymes are exposed to extreme temperature for some time they are denatured and therefore become inactive.

Results: The benedictâs solution retained its color as the reaction did not occur. Extreme temperatures denatures enzymes, therefore when the salivary amylase was introduced to a hot water bath for five minutes the amylase was denture.

Conclusion: Salivary amylase/enzymes when introduced to hot temperatures it is a denatured therefore does not react on the substrate.

Tube C: Starch + saliva

Was the test positive or negative? Positive

What does this indicate? This indicates that the salivary amylase successfully worked on the starch.

Results: The benedictâs solution turned brown as an indication of the presence of sugar.

Conclusions: Salivary amylase acts on starch in favorable conditions, ie is optimum te

Please provide a lab report that explains your procedure, results and conclusions. Remember to include pictures of the lab set-up and results. Also, I want you to expand this initial experiment by proposing and testing (in the form of an additional experiment) a testable hypothesis that involves the above general concept. You will be graded on your use of the scientific method and the creativity/complexity of your experiment. Both the above experimentation and your original experiment may be included together into one experiment

Part II. Enzymes and Digestion

A.) You should have been surprised to read that salivary amylase survives the stomach to enter the small intestine with much of its enzyme activity intact. A) Why were you surprised, i.e., what is the expected fate of proteins in the stomach? B) Try to come up with some general possible explanations as to why salivary amylase doesnât suffer the usual fate of proteins in the stomach.

ii)

B) Pancreatic amylase is absent in all newborn infants. Activity is present at only very low levels during the first 6 months of life, and doesnât begin to reach normal levels until about 9 months of age, yet most infants seem to do just fine without it. Suggest reasons why this is so (include a consideration of the components of the usual diet of newborns).

C) Although the disease is quite rare, malabsorption of dietary starch occurs in individuals with a genetic deficiency in pancreatic a-amylase activity. Although early infancy (until about 9 months of age) is generally unremarkable in these patients, they soon have serious medical problems. What do you think some of the symptoms and/or problems might be? Why?

lavendergiraffe953

Help with Biology. Ive got some of the answers just need somehelp with others and see if what i have is good too.

Effect of enzyme concentration.

Ballon Diameter: (circumference):

TUBE 1: 15.5 cm

TUBE 2: 13.8 cm

TUBE 3: 8.8 cm

What is the enzyme in the experiment? What is the substrate?

Do you expect more enzyme activity if the substrateconcentration is increased or decreased? Explain. The moresubstrate you increase or decrease will cause the enzyme activityto increase or decrease up to a certain point. If you add to itthen it has more molecules to act upon. If you add enough substrateand all the enzymes are being used then it would reach a pointwhere there would be no further activity.

Effect of temperature.

Tube:

Refridgerator:

Temperature (0C): 16 degrees celcius

Ballon Diameter (cm): 17.1 cm

Room Temperature:

Temperature (0C): 28 degrees celcius

Ballon Diameter (cm): 17.1 cm

Boiling Water:

Temperature (0C): 83 degrees celcius

Ballon Diamter (cm): 6.9 cm

What is the enzyme in the experiment? What is the substrate?

How does temperature affect enzyme function? An increase intemperature results in more kinetic energy of the enzyme andsubstrate. It is more likely to collide with the enzyme for areaction to take place. To much heat however can cause the bondswhich holds the enzyme in the very specific shape to break and itwill no longer function (denatured).

What is the function of amylase? What does amylase do to starch?Amylase is a digestive enzyme that acts on starch in food, itbrakes down the starch into smaller carbohydrate molecules. Amylaseis made in two places the salivary glands in your mouth whichstarts the digestive process by breaking down the starch in foodsas you chew and convert that into maltose a smaller carbohydrate.The other place is in the pancrease which completes the digestivecarbohydrate, producing glueclose, a small molecule absorbed intothe blood and carried throughout the body.

Why did you wait 5 minutes before spraying with IKIsolution?

Saliva does not contain amylase until babies are about twomonths old. How could this affect digestion? (Hint: babies do noeat cereal until about 2 months old.) Amylase is needed fordigestion of starches and complex carbohydrates, this makes thefood for babies to not be digested and possibly pass right throughthe babies system and into a diaper. It can also lead to gas andconstipation for the baby. In the case of a high protein food itcould even cause problems with a babies underdeveloped kidneys.Babies are not usually able to eat solid foods until they are 4 to6 months old.