List some factors explaining an enzymes rate of reaction?

Question

Please do me proud this is for a mid term and I cant find the right answer in the text.

Answer 1

In any explanation in a text of the rates of reaction of enzyme catalyzed reactions, there will nearly always be discussions of things that affect those rates.

For example, the concentration of the substrate, the amount of the enzyme, the temperature, the pH of the solution, the presence of activators and inhibitors of the enzyme.

While there are others, these are just a few of the things that affect enzymes rates.

Answer 2

Heat: If the temp is less than the enzyme's optimal temp, the molecules will move slower and therefore provide less reactions. If the temp is SLIGHTLY higher, the molecules will move faster and provide more reactions. If the temp is a lot higher, the enyzmes will denature (lose their specific shape and function), and there will be less, if any, reactions.

Inhibitors: There are inhibitors that block the substrate from entering the enzyme. Noncompetitive inhibitors bind to the allosteric site, which is not the active site (not where the substrate binds to). This will change the shape of the enzyme because the molecule will change it's shape to snugly fit around the inhibitor. Since the shape has been changed, the substrate cannot enter the enzyme and less, if any, reactions will be made. Competitive inhibitors bind to the actual active site (where the substrate binds to), preventing the substrate to enter. Less, if any, reactions will be made. Irreversible inhibitors permanently bind to the site and the enzyme won't work anymore. Not all inhibitors are irreversible.

pH: The pH needs to be the optimal temp in order for the enyzme to function. If the pH is too extreme (high or low), the enzyme will denature (lose it's specific shape and function), thus preventing the enzyme from acting.

Answer 3

Salt Concentration:
Most enzymes can not tolerate extremely high salt concentrations. The ions interfere with the weak ionic bonds of proteins. As usual there are exceptions such as the halophilic (salt loving) algae and bacteria.

Effects of Temperature:
All enzymes work within a range of temperature specific to the organism. Increases in temperature generally lead to increases in reaction rates. There is a limit to the increase because higher temperatures lead to a sharp decrease in reaction rates. This is due to the denaturating (alteration) of protein structure resulting from the breakdown of the weak ionic and hydrogen bonding that stabilize the three dimensional structure of the enzyme. The optimum temperature for human enzymes is between 35 and 40 °C. The average temperature for humans is 37 °C. Human enzymes start to denature quickly at temperatures above 40 °C. Bacteria found in the hot springs of Yellowstone National Park have optimum temperatures of 70 °C. Temperature loving bacteria are called thermophilic. Denaturating of enzymes, regardless of the cause, leads to the death of the cell.
Effects of pH:
Most enzymes are sensitive to pH and have specific ranges of activity. All have an optimum pH. The pH can stop enzyme activity by denaturating (altering) the three dimensional shape of the enzyme by breaking weak bonds such as ionic, and hydrogen. Most enzymes function between a pH of 6 and 8; however pepsin in the stomach works best at a pH of 2 and trypsin at a pH of 8. Bacteria that thrive at lower pH values are said to be acidophilic (acid loving).

Enzyme Saturation:
Increasing the substrate concentration increases the rate of reaction (enzyme activity). However, enzyme saturation limits reaction rates. An enzyme is saturated when the active sites of all the molecules are occupied most of the time. At the saturation point, the reaction will not speed up, no matter how much additional substrate is added. The graph of the reaction rate will plateau. It can be increased if more enzyme is added.] concentration can inactivate an enzyme. Typical enzymes are active in salt concentrations of 1-500 mM.

Answer 4

limiting factor in any enzymatic reaction is the amount of SUBSTRATE... not the amount of Enzyme. Enzymes will work until there is no substrate left to change. Above answers are all correct, just adding the substrate Concentration as another answer!