Question

enzymes are proteins that have a very specific shape... a change in the shape of an enzymes active site will affect how well the enzyme can catalyze a reaction. the two main factors which affect enzyme activity are covered below.

key factors that affect enzyme activity

temperature
sketch below the line youd expect to see for the relationship between temperature and enzyme activity

graph with enzyme activity (y - axis), temperature (°c) x - axis, 40 marked

affect on enzyme activity
words to use: stomach, vibrate, optimum, shape, active, increases, time, denatured, high, acidic, kinetic, decreases

1.) initially as temperature increases, enzyme activity also ______. this is because the enzyme molecules gain more ____ energy and are more likely to successfully collide with the substrate molecules. this leads to more enzyme - substrate complexes being formed and therefore more product is formed in a given ______. the optimum temperature of enzymes in our body is about 40°c.

2.) however, after a certain temperature (about 45°c) the bonds within the enzyme molecule that keep its shape, begin to ______ so violently that they break. this results in the enzyme losing its shape, including the active sites shape. this is called denaturation. as the substrate can no longer fit into the ____ site, the activity of the enzyme dramatically ____. once all the enzyme molecules are ______ the enzyme activity will completely cease.

ph
sketch below the lines youd expect to see for pepsin (optimum ph 2) and amylase (optimum ph 8)

graph with enzyme activity (y - axis), ph x - axis, 7 marked

all enzymes have an ______ ph that their activity will be highest at. as the ph increases or decreases either side of the optimum ph the enzymes activity will decrease. eventually when the ph becomes too low or high for the enzyme it will denature and lose its ____ just like with ____ temperatures. most enzymes in our body work best at around ph 8. however there are some exceptions. pepsin, found in our ____ has an optimum ph about ph 2, which is very ______.

Explanation:

Temperature Section Fill - in - the - Blanks

Step 1: First blank in Temperature part (enzyme activity change with temperature increase)

As temperature increases initially, enzyme activity should increase because kinetic energy of enzyme molecules increases. So the first blank: \(\boldsymbol{\text{increases}}\)

Step 2: Second blank in Temperature part (energy type)

Enzyme molecules gain more kinetic energy. So the second blank: \(\boldsymbol{\text{kinetic}}\)

Step 3: Third blank in Temperature part (time for product formation)

More product is formed in a given time. So the third blank: \(\boldsymbol{\text{time}}\)

Step 4: Fourth blank in Temperature part (bond movement)

Bonds begin to vibrate violently. So the fourth blank: \(\boldsymbol{\text{vibrate}}\)

Step 5: Fifth blank in Temperature part (site for substrate)

Substrate can no longer fit into the active site. So the fifth blank: \(\boldsymbol{\text{active}}\)

Step 6: Sixth blank in Temperature part (enzyme activity change after denaturation start)

Enzyme activity dramatically decreases. So the sixth blank: \(\boldsymbol{\text{decreases}}\)

Step 7: Seventh blank in Temperature part (enzyme state after all denatured)

Once all enzyme molecules are denatured, activity ceases. So the seventh blank: \(\boldsymbol{\text{denatured}}\)

pH Section Fill - in - the - Blanks

Step 1: First blank in pH part (optimum pH)

All enzymes have an optimum pH. So the first blank: \(\boldsymbol{\text{optimum}}\)

Step 2: Second blank in pH part (enzyme structure lost)

Enzyme loses its shape. So the second blank: \(\boldsymbol{\text{shape}}\)

Step 3: Third blank in pH part (temperature condition for denaturation)

Just like with high temperatures (since high temp causes denaturation too). So the third blank: \(\boldsymbol{\text{high}}\)

Step 4: Fourth blank in pH part (location of pepsin)

Pepsin is found in our stomach. So the fourth blank: \(\boldsymbol{\text{stomach}}\)

Step 5: Fifth blank in pH part (pH nature of pepsin's optimum)

pH 2 is very acidic. So the fifth blank: \(\boldsymbol{\text{acidic}}\)

Temperature - Enzyme Activity Graph Sketch Explanation

The graph of enzyme activity vs temperature should be a curve that first increases with temperature, reaches a peak (optimum) around \(40^{\circ}\text{C}\), and then decreases sharply after around \(45^{\circ}\text{C}\) as enzymes denature.

pH - Enzyme Activity Graph Sketch Explanation (Pepsin and Amylase)

• For Pepsin (optimum pH 2): The curve should peak at pH 2, and decrease as pH moves away (both increase or decrease from 2).
• For Amylase (optimum pH 8): The curve should peak at pH 8, and decrease as pH moves away (both increase or decrease from 8).

Final Answers for Fill - in - the - Blanks (Temperature Section in order)

1. increases, 2. kinetic, 3. time, 4. vibrate, 5. active, 6. decreases, 7. denatured

Final Answers for Fill - in - the - Blanks (pH Section in order)

1. optimum, 2. shape, 3. high, 4. stomach, 5. acidic

(For the graph sketches, the description above gives the general shape and key points to draw)

Answer:

Temperature Section Fill - in - the - Blanks

Step 1: First blank in Temperature part (enzyme activity change with temperature increase)

As temperature increases initially, enzyme activity should increase because kinetic energy of enzyme molecules increases. So the first blank: \(\boldsymbol{\text{increases}}\)

Step 2: Second blank in Temperature part (energy type)

Enzyme molecules gain more kinetic energy. So the second blank: \(\boldsymbol{\text{kinetic}}\)

Step 3: Third blank in Temperature part (time for product formation)

More product is formed in a given time. So the third blank: \(\boldsymbol{\text{time}}\)

Step 4: Fourth blank in Temperature part (bond movement)

Bonds begin to vibrate violently. So the fourth blank: \(\boldsymbol{\text{vibrate}}\)

Step 5: Fifth blank in Temperature part (site for substrate)

Substrate can no longer fit into the active site. So the fifth blank: \(\boldsymbol{\text{active}}\)

Step 6: Sixth blank in Temperature part (enzyme activity change after denaturation start)

Enzyme activity dramatically decreases. So the sixth blank: \(\boldsymbol{\text{decreases}}\)

Step 7: Seventh blank in Temperature part (enzyme state after all denatured)

Once all enzyme molecules are denatured, activity ceases. So the seventh blank: \(\boldsymbol{\text{denatured}}\)

pH Section Fill - in - the - Blanks

Step 1: First blank in pH part (optimum pH)

All enzymes have an optimum pH. So the first blank: \(\boldsymbol{\text{optimum}}\)

Step 2: Second blank in pH part (enzyme structure lost)

Enzyme loses its shape. So the second blank: \(\boldsymbol{\text{shape}}\)

Step 3: Third blank in pH part (temperature condition for denaturation)

Just like with high temperatures (since high temp causes denaturation too). So the third blank: \(\boldsymbol{\text{high}}\)

Step 4: Fourth blank in pH part (location of pepsin)

Pepsin is found in our stomach. So the fourth blank: \(\boldsymbol{\text{stomach}}\)

Step 5: Fifth blank in pH part (pH nature of pepsin's optimum)

pH 2 is very acidic. So the fifth blank: \(\boldsymbol{\text{acidic}}\)

Temperature - Enzyme Activity Graph Sketch Explanation

The graph of enzyme activity vs temperature should be a curve that first increases with temperature, reaches a peak (optimum) around \(40^{\circ}\text{C}\), and then decreases sharply after around \(45^{\circ}\text{C}\) as enzymes denature.

pH - Enzyme Activity Graph Sketch Explanation (Pepsin and Amylase)

• For Pepsin (optimum pH 2): The curve should peak at pH 2, and decrease as pH moves away (both increase or decrease from 2).
• For Amylase (optimum pH 8): The curve should peak at pH 8, and decrease as pH moves away (both increase or decrease from 8).

Final Answers for Fill - in - the - Blanks (Temperature Section in order)

1. increases, 2. kinetic, 3. time, 4. vibrate, 5. active, 6. decreases, 7. denatured

Final Answers for Fill - in - the - Blanks (pH Section in order)

1. optimum, 2. shape, 3. high, 4. stomach, 5. acidic

(For the graph sketches, the description above gives the general shape and key points to draw)