Q. 15.78 - An Introduction to General, Organic, and Biological Chemistry

Question

The total kilocalories and grams of fat for some typical meals at fast-food restaurants are listed here. Calculate the number of kilocalories and the percentage of total kilocalories from fat ( $1$ gram of fat $=9kcal$. Round answers to the tens place.

a. a beef burrito, $470 kcal, 21g$ of fat

b. deep-fried fish (three pieces), $480 kcal, 28g$ of fat

c. a jumbo hot dog, $180 kcal, 18g$ of fat

Step-by-Step Solution

Answer

(part  a) The percentage of total kilocalories from fat $=40\%$

(part  b) The percentage of total kilocalories from fat $=52\%$

(part  c) The percentage of total kilocalories from fat $= 88\%$

Step 1: Introduction (part a)

Lipids are found naturally components this included fats, waxes, and sterols. triglycerides, for illustration Cholesterol are fats that have included glycerol bonded to three fatty acids, such like fats and oils.   

Step 2: Given Information (part a)

A beef burrito, $470kcal, 21g$ of fat 

Step 3: Explanation (part a)

Number of kilocalories -

$1$ gram of fat produces $9kcal$

$21$ grams of fat produce

$=21g\times 9kcal$

$=189$

$=190$ (roundoff)

The overall amount of calories delivered by lipids

Luncheon with chicken thighs

The percentage of total kilocalories from fat

$=190/470\times 100$

$=40\%$

The percentage of kilocalories from fat $40\%$

Step 4: Given Information (part b)

 Deep-fried fish (three pieces), $480 kcal, 28g$ of fat 

Step 5: Explanation (part b)

Number of kilocalories -

 $1$gram of fat produces $9kcal$

$28$ grams of fat produce

$=28g\times 9kcal$

$=252kcal$

$=250kcal$ (roundoff)

The overall amount of calories delivered by lipids

Luncheon with chicken thighs

The proportion of nutrients which it came through fat

$=250/480\times 100$

$=52\%$

The percentage of kilocalories from fat $=52\%$

Step 6: Given Information (part c)

a jumbo hot dog, $180kcal, 18g$ of fat

Step 7: Explanation (part c)

Number of kilocalories -

$1$ gram of fat produces $9kcal$

$18$ grams of fat produce

$=18g\times 9kcal$

$=162kcal$

$=160kcal$ (roundoff)

The overall amount of calories delivered by lipids

Luncheon with chicken thighs

The proportion of nutrients which it came through fat

$=160/180\times 100$

$=88\%$

The percentage of kilocalories from fat $=88\%$