Please Help Im stuck, answer the questions in your own words, and cite your sour
ID: 141470 • Letter: P
Question
Please Help Im stuck, answer the questions in your own words, and cite your sources plzz. Write neat No cursive!!
Read the lessons then Answer the questions at the bottom of the page
Lesson Objectives:
Student will recall the effect of enzymes on biochemical reactions.
Student will summarize the effect of temperature, concentration, and pH on enzymes.
Student will identify ways organisms use enzymes.
Student will be able to give an example of how absence of proper enzymes affects an organism.
Enzymes
Enzymes are protein molecules that work as catalysts for biochemical reactions. Remember, catalysts lower the activation energy of a chemical reaction while not being consumed by the reaction.
Each enzyme is very specific about the conditions (environment) it will work in, and the chemical reaction it will catalyze. There are thousands of different enzymes because each one is so specialized.
An enzyme works on one reactant in a chemical reaction. This reactant is called the substrate. The enzyme lowers the activation energy of the chemical reaction by lowering the energy required to break existing bond(s) in the substrate.
Every enzyme has what is called an "active site", a spot in the protein that is exactly the right size for one sort of chemical to fit. The enzyme binds a substrate at the active site, helps break bonds and releases products that are used in the chemical reaction. The products released from the enzyme are not the products of the overall reaction. They are used by the reaction that can proceed once the enzyme breaks bond(s) in the substrate.
Enzymes are involved in many of the reactions necessary for life. Processes such as digestion, respiration, reproduction, movement, and just a few examples of enzymes are:
Ribbon diagram of human salivary alpha-amylase.
From PDB at http://tinyurl.com/cobda56
Amylase is an enzyme in human saliva that breaks down starches. Starch is the substrate of amylase and it only works as a catalyst for them.
Lactase is the enzyme that helps to break down lactose (milk-sugar). People whose bodies no longer make lactase have problems digesting milk products--the food is useless to them.
Notice the names – Many enzymes have names based upon the substrate they work upon and end with the suffix "-ase".
Without enzymes many reactions would not take place fast enough for an organism to make use of a chemical. There are examples of biochemical processes for which 18 milliseconds in the presence of enzyme that would require 78 million years without it. (“Orotidine 5'-phosphate Decarboxylase." Wikipedia. N.p., n.d. Web. 1 Aug. 2012. <http://en.wikipedia.org>.)
Most reactions in the body happen in chains, where each step depends on a different enzyme. If one enzyme for a step is missing or not working, the end result the organism needs will not be reached. (If lactose can't be broken down into glucose, the body can't use it at all.)
The most important result an enzyme has for an organism is that it speeds up the rate of a reaction. A reaction that might take a year without an enzyme can happen in a millionth of a second if the enzyme is present. Enzymes help to ensure that reactions take place at a useful rate.
Environmental Effects (Homeostasis)
One way to envision an enzyme is as ribbons of protein, folded together to form a sort of nest that perfectly fits the substrate. Some changes can alter the structure of the enzyme which affects how well it works. A few of these include:
As you increase the temperature, reaction rate usually increases. But, each enzyme has a temperature range it works best in. Extremely high or low temperatures may cause irreversible damage to an enzyme (or may denature it, see more on that below)
Substrate concentration: Too little substrate gives the enzyme nothing to work with, so the reactions will be slower. The reaction rate increases as you add more substrate. If you continue to increase the concentration of substrate you reach a point where the rate levels off.
pH: Each enzyme has a specific range of pH values where it works best. These conditions often determine where an enzyme functions in an organism. Conditions that are too acidic or basic can permanently damage (denature) an enzyme, rendering it useless.
Comparison of the optimum pH range for three digestive enzymes
From Mcyjerry at http://en.wikipedia.org/wiki/File:Enzyme_pH.png
When a protein (enzyme) is denatured, the ribbons are moved, so that there is no longer a nice little nest, and the enzyme can't hold the substrate. Denaturation can be caused by other factors, such as chemicals and poison. The important thing to remember is that a denatured enzyme does not function.
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Help me answer these questions im Stuck!! PLzz HELP!! Answer the questions 2, 3, 4, 5
2. A reaction you are monitoring is catalyzed by an enzyme. You start recording data at a low temperature, and gradually increase the temperature (not stopping until you reach the boiling point of water). Describe each of the changes you expect the enzyme to experience while increasing the temperature. How should each of these changes affect the rate of reaction?
Part B
Pepsin and trypsin are two digestive enzymes that break down protein from our food into peptides. Here is a little information about each:
Name
Optimal pH
Optimal Temperature
pepsin
2
37° C (98.6° F)
trypsin
8
37° C (98.6° F)
One of these enzymes breaks down proteins in the stomach, the other in the small intestine.
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3. Using this information and what you learned this lesson, which of these enzymes breaks down dietary proteins in the stomach? Explain how you reached this conclusion.
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4. Using this information and what you learned this lesson, which of these enzymes breaks down dietary proteins in the small intestine? Explain how you reached this conclusion.
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5. Would your answer for question #3 be able to break down dietary fat in the stomach? Explain why it would, or would not be able to using concepts from this lesson.
Student will recall the effect of enzymes on biochemical reactions.
Student will summarize the effect of temperature, concentration, and pH on enzymes.
Student will identify ways organisms use enzymes.
Student will be able to give an example of how absence of proper enzymes affects an organism.
Products Enzyme changes shape slightly as substrate binds Active site Substrate entering active site of enzyme Products leaving active site of enzyme Enzyme/sub strate Enzyme/products complex complexExplanation / Answer
As mentioned in the lesson each enzyme has a temperature in which it works well . It is called as the optimum or optimal temperature and is Usually somewhere around the normal temperature of the body in case of human enzymes . So when you slowly increase the temperature the rate of reaction will increase . This happens because the kinetic energy increases leading to increase binding of enzyme to substrate as with the increase of kinetic energy the rate of ramdom collision of molecular increases hence increasing the binding as enzymes bind to Substrate by random collision . However as the temperature goes above the optimal temperature then bonds weaken and the shape of enzyme is not maintained and it gets denatured this decreasing the rate of reaction and ultimately reaction is stopped.
Just like temperature there is the concept of optimal pH where an enzyme will have a range of pH where is works best at . The pH in the stomach is 1.5-3.5 due to gastric acid so Pepsin will act in the stomach breaking down dietary proteins.
The pH of small intestine is 6-8 due to presence of bicarbonate ions. Therefore trypsin will act there similarly.
Different enzymes have different substrates as mentioned in the lesson and each acts on it’s specific substrate only . Using this concept pepsin won’t be able to break down dietary fat.