An enzyme sample contains 24 mg protein per mL. Twenty µL of this sample in a standard incubation volume of 0.1 mL catalysed the conversion of substrate X to product Y at a rate of 1.6 nmol per minute. Calculate the velocity in terms of:
a) µmol per minute
b) µmol per litre per minute
c) µmol per mg protein per minute
a) 1.6 µmol per minute
b) 16 µmol per litre per minute
c) 0.067 µmol per mg protein per minute
To calculate the velocity in terms of µmol per minute, we need to convert the rate from nmol per minute to µmol per minute.
a) To convert nmol to µmol, divide the rate by 1000.
1.6 nmol/min ÷ 1000 = 0.0016 µmol/min
Therefore, the velocity is 0.0016 µmol per minute.
b) To calculate the velocity in terms of µmol per litre per minute, we need to convert the volume to litres.
0.1 mL = 0.1/1000 = 0.0001 L
Now, we divide the rate by the volume in litres to get the velocity in terms of µmol per litre per minute.
0.0016 µmol/min ÷ 0.0001 L = 16 µmol/L/min
Therefore, the velocity is 16 µmol per litre per minute.
c) To calculate the velocity in terms of µmol per mg protein per minute, we need to convert the protein concentration to µg per mL and then calculate the velocity.
Given that the enzyme sample contains 24 mg protein per mL, we can convert this to µg per mL by multiplying by 1000.
24 mg/mL × 1000 = 24000 µg/mL
Now, we convert the sample volume from µL to mL by dividing by 1000.
20 µL ÷ 1000 = 0.02 mL
Finally, we divide the rate by the product of protein concentration and sample volume to get the velocity in terms of µmol per mg protein per minute.
0.0016 µmol/min ÷ (24000 µg/mL × 0.02 mL) = 0.00000333 µmol/mg/min
Therefore, the velocity is 0.00000333 µmol per mg protein per minute.
To calculate the velocity in different terms, we need to convert the given values and adjust the units accordingly. Let's solve each part step by step:
a) µmol per minute:
Given: Rate = 1.6 nmol per minute
We need to convert nmol to µmol:
1 µmol = 1000 nmol
So, 1.6 nmol = 1.6 / 1000 µmol = 0.0016 µmol
Therefore, the velocity in terms of µmol per minute is 0.0016 µmol per minute.
b) µmol per litre per minute:
Given: Standard incubation volume = 0.1 mL
We need to convert mL to L:
1 L = 1000 mL
So, 0.1 mL = 0.1 / 1000 L = 0.0001 L
Now, we can calculate the velocity in terms of µmol per litre per minute:
0.0016 µmol per minute / 0.0001 L = 16 µmol per litre per minute
c) µmol per mg protein per minute:
Given: Protein concentration = 24 mg per mL
We need to convert mL to L:
1 L = 1000 mL
So, 1 mL = 1 / 1000 L = 0.001 L
Now, we can calculate the velocity in terms of µmol per mg protein per minute:
0.0016 µmol per minute / (24 mg * 0.001 L) = 0.0667 µmol per mg protein per minute
Therefore, the velocity is:
a) 0.0016 µmol per minute
b) 16 µmol per litre per minute
c) 0.0667 µmol per mg protein per minute