Chapter 17 - The Energy Content of Food

Question 1

body uses glucose for energy in preference to what?

Answer 1

fats and proteins

Question 2

cellular respiration

Answer 2

process by which cells obtain energy using glucose as the primary energy source

Question 3

aerobic respiration

Answer 3

requires oxygen and is main source of energy for human body

Question 4

anaerobic respiration

Answer 4

doesn’t require oxygen and yields less energy although it can be faster than aerobic respiration

Question 5

energy content

Answer 5

measure of the energy released by food on combustion

Question 6

energy value

Answer 6

energy available to body from a nutrient

Question 7

calorimetry

Answer 7

experimental method by which heat energy released by combustion of a fuel or a food, or another chemical reaction is measured

Question 8

calorimeter

Answer 8

instrument designed to measure energy changes in a reaction

Question 9

ways to reduce heat loss in calorimetry

Answer 9

lid on.
insulate beaker.
place insulation around burning food

Question 10

energy content equation

Answer 10

ec = energy transferred to water / change in mass of food

Question 11

solution calorimeters

Answer 11

reaction takes place in solution.

with accurately known volume of water

Question 12

limitations of coffee cup calorimeter

Answer 12

polystyrene cup absorbs some heat

Question 13

use of stirrer in calorimeter

Answer 13

ensure temp of water is uniform

Question 14

use of electric heater in calorimeter

Answer 14

used for calibration

Question 15

bomb calorimeters

Answer 15

reaction occurs in sealed, fixed volume vessel.

used for reactions with gases

Question 16

calibration factor

Answer 16

amount of energy that is required to change the temperature of water within a calorimeter by 1 degree.
CF = E (VIt or n x delta H) / delta T

Question 17

electrical calibration

Answer 17

known quantity of thermal energy is released and the rise in temperature of water measured.
E = V x I x t

Question 18

chemical calibration

Answer 18

chemical reaction releases known quantity of thermal energy is performed and rise in temp is measured.
E = n x delta H

Question 19

calculating energy content of food

Answer 19

E = CF x delta T.
ec = E / m (food combusted)