Enzymes in Biology Quiz

Study Notes

Amylase breaks down starch into reducing sugars.
Iodine solution is used to test for the presence of starch.
Iodine solution turns blue-black in the presence of starch.
The time it takes for the iodine solution to stop turning blue-black indicates the rate of amylase activity.
Measuring the rate of enzyme activity involves measuring the time for a reaction to occur.

All enzymes have an optimum temperature at which they work best.
The rate of enzyme activity increases as the temperature rises until it reaches the optimum temperature.
Above the optimum temperature, the rate of enzyme activity decreases.
Enzymes become denatured at high temperatures, losing their shape and function.
The optimum temperature for enzymes in baby food is 37°C.

The pH of a solution affects the shape of the enzyme and its active site.
Each enzyme has an optimum pH at which it works best.
The optimum pH for amylase is 6.
The pH value tested that is closest to the optimum pH for amylase is the pH at which it is most active.

Pepsin breaks down proteins.
Gastric proteases are found in the stomach.
The optimum pH for gastric protease would be acidic because it is found in the stomach.

Other factors besides temperature that can affect the rate of enzyme activity include:
- pH
- Substrate concentration
- Enzyme concentration
- The presence of inhibitors

Pancreatic cancer can lead to weight loss as it affects production of digestive enzymes.
Enzyme specificity is critical in digestion as certain enzymes are required to break down specific types of food.

Thermophilic bacteria are a type of bacteria that can survive high temperatures.
Thermophilic bacteria produce enzymes that are stable at high temperatures.
Enzymes from thermophilic bacteria can be used in biological washing powder.
Using enzymes from thermophilic bacteria can improve the cleaning performance of biological washing powder.
Measuring absorbance using a colorimeter is an advantage over a visual color change method because it can be done more accurately.

The concentration of protein can be measured using a colorimeter.
The absorbance value on a colorimeter gives an indication of how much light passed through the solution.
The higher the absorbance, the darker the colour.
The graph shows that the concentration of protein is almost the same in the solution both at 10 °C and 30 °C after 1 minute.
The concentration of protein at 80 °C after 1 minute is different, which suggests the protease might be denatured at this temperature.
The enzymes in biological washing powder are denatured at temperatures above 45 °C.