khan academy enzymes
In the graph above, which letter represents the activation energy (EA\text E_{\text A}EAE, start subscript, A, end subscript) of a reaction without an enzyme and why?
X; the activation energy (EA\text E_{\text A}EAE, start subscript, A, end subscript) is greater in an uncatalyzed reaction
Which of the following is true regarding enzymes?
Enzymes are reusable.
Pepsin is an enzyme found in the human stomach that breaks down protein. Pepsin will not break down starch. Which statement best explains this observation?
Enzymes only work for specific substrates.
What is one way to increase the rate of the reaction?
Increase the enzyme concentration
Amylase is an enzyme found in saliva that breaks down starch. The enzyme is currently functioning at its optimal pH of 7777 and optimal temperature of 32∘C32\,^\circ \text{C}32∘C32, space, degree, C. Which of the following could result in an increase in the reaction rate?
Increasing substrate concentration
How does an enzyme influence a chemical reaction?
It speeds up the reaction rate.
The table below shows three enzymes found in the human body and the pH of their locations. Enzyme Body part pH Ptyalin Mouth 6.5 - 7 Pepsin Stomach 1.0 - 3.0 Trypsin Small intestine 7.5 - 9.0 How will the activity of pepsin change after it moves with the food from the stomach to the small intestine?
It will slow down because the environment is too basic.
Which of the following is true regarding the structure of enzymes?
The active site is where the enzyme binds with the substrate.
In the graph above, what might cause a reaction that originally proceeds through the path of X to change and proceed through the path Y?
The addition of a catalyst
Some species of bacteria can live in hot springs. Their cells contain enzymes that function best at temperatures of 70∘C70\,^\circ \text{C}70∘C70, space, degree, C or higher. How will the enzymes in these bacteria most likely change if the temperature is lowered to 45∘C45\,^\circ \text{C}45∘C45, space, degree, C?
The enzymes will not catalyze reactions as efficiently.
The active site of an enzyme is damaged, leaving it nonfunctional. How would this change to the enzyme's function be best described using the graph above?
The reaction originally proceeded through the path of Y, but now proceeds through the path of X.