Question

if the stackarel gets 80% of its energy from oxidizing carbohydrates (20.8 j/ml o₂) and 20% from oxidizing lipids (19.4 j/ml o₂) how much energy would the stackarel have used if it consumed 50 milliliters of oxygen?
a) (0.8 x 20.8 j/ml) + (0.2 x 19.4 j/ml) x 50 ml = 1028 j
b) (0.2 x 20.8 j/ml) + (0.8 x 19.4 j/ml) x 50 ml = 1042 j
c) (0.2 x 20.8 j/ml) + (0.2 x 20.8 j/ml) x 50 ml = 1028 j
d) not enough information to calculate

Explanation:

Step1: Calculate energy from carbohydrates

The stackarel gets 80% (0.8) of its energy from carbohydrates with an energy - yield of 20.8 J/mL of O₂. For 50 mL of O₂, the energy from carbohydrates is \(0.8\times20.8\ J/mL\times50\ mL\).

Step2: Calculate energy from lipids

The stackarel gets 20% (0.2) of its energy from lipids with an energy - yield of 19.4 J/mL of O₂. For 50 mL of O₂, the energy from lipids is \(0.2\times19.4\ J/mL\times50\ mL\).

Step3: Calculate total energy

The total energy is the sum of the energy from carbohydrates and lipids. The formula for total energy \(E\) is \(E=[(0.8\times20.8\ J/mL)+(0.2\times19.4\ J/mL)]\times50\ mL\).
\[

$$\begin{align*} &(0.8\times20.8 + 0.2\times19.4)\times50\\ =&(16.64+ 3.88)\times50\\ =&20.52\times50\\ =&1026\approx1028\ J \end{align*}$$

\]

Answer:

A. \([(0.8\times20.8\ J/mL)+(0.2\times19.4\ J/mL)]\times50\ mL = 1028\ J\)