<< Chapter < Page Chapter >> Page >

Natural sciences

Grade 4

Energy and change

Module 31

Food as a source of energy


To discuss and describe food as a source of energy

[lo 1.1, 1.2, 1.3]

We have to take in food to obtain energy, and eat enough to keep going for long enough. If we do not eat enough, our bodies will not remain warm and we will not have enough energy to do our daily work. To remain healthy, we have to follow a balanced diet. It is possible to know whether you eat correctly and get enough to eat by studying the information on the boxes, packets, bags and tins in which food is bought to find out how much energy per volume is contained in the foodstuff. The quantity that is eaten is measured in kilojoules.

Some of the energy that animals obtain from the food that they eat is stored in their muscles. Those muscles are able to use the energy to do work.

In early times, people used the energy of their own muscles to do work, like gathering food, tilling their fields and building shelters. They made simple implements to help them use this energy more efficiently and to work better. The first tools were made of wood and stone, but when people discovered how to melt down metals, they used metal to make better and stronger tools.

They also discovered that they could use animals to work faster and better and get more work done, as one ox is able to do the work of eight grown men.

Animals were used to transport people and goods, to pull the ploughs in the fields and to pump water from below the ground to irrigate the fields.

Work out a balanced diet by examining the labels on different containers in which food is packed.

  • Learners must be divided into three groups: Group 1 must determine the kilojoules value of breakfast; Group 2 the kilojoules value of lunch; and Group 3 the kilojoules value of supper.
  • Each group must then report their findings concerning the value of the specific meal with regard to the energy requirement for the day.



The learner will be able to act confidently on curiosity about natural phenomena, and to investigate relationships and solve problems in scientific, technological and environmental contexts.

Assessment Standard

We know this when the learner

  • plans investigations;
  • leads investigations and collects data;
  • evaluates data and provides feedback on observations.



This assignment involves research. Help the learners to plan their research, to collect information, to draw conclusions and to communicate their findings.

Questions & Answers

what is variations in raman spectra for nanomaterials
Jyoti Reply
I only see partial conversation and what's the question here!
Crow Reply
what about nanotechnology for water purification
RAW Reply
please someone correct me if I'm wrong but I think one can use nanoparticles, specially silver nanoparticles for water treatment.
yes that's correct
I think
what is the stm
Brian Reply
is there industrial application of fullrenes. What is the method to prepare fullrene on large scale.?
industrial application...? mmm I think on the medical side as drug carrier, but you should go deeper on your research, I may be wrong
How we are making nano material?
what is a peer
What is meant by 'nano scale'?
What is STMs full form?
scanning tunneling microscope
how nano science is used for hydrophobicity
Do u think that Graphene and Fullrene fiber can be used to make Air Plane body structure the lightest and strongest. Rafiq
what is differents between GO and RGO?
what is simplest way to understand the applications of nano robots used to detect the cancer affected cell of human body.? How this robot is carried to required site of body cell.? what will be the carrier material and how can be detected that correct delivery of drug is done Rafiq
what is Nano technology ?
Bob Reply
write examples of Nano molecule?
The nanotechnology is as new science, to scale nanometric
nanotechnology is the study, desing, synthesis, manipulation and application of materials and functional systems through control of matter at nanoscale
Is there any normative that regulates the use of silver nanoparticles?
Damian Reply
what king of growth are you checking .?
What fields keep nano created devices from performing or assimulating ? Magnetic fields ? Are do they assimilate ?
Stoney Reply
why we need to study biomolecules, molecular biology in nanotechnology?
Adin Reply
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
what school?
biomolecules are e building blocks of every organics and inorganic materials.
anyone know any internet site where one can find nanotechnology papers?
Damian Reply
sciencedirect big data base
Introduction about quantum dots in nanotechnology
Praveena Reply
what does nano mean?
Anassong Reply
nano basically means 10^(-9). nanometer is a unit to measure length.
do you think it's worthwhile in the long term to study the effects and possibilities of nanotechnology on viral treatment?
Damian Reply
absolutely yes
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit Reply
Privacy Information Security Software Version 1.1a
Got questions? Join the online conversation and get instant answers!
Jobilize.com Reply

Get the best Algebra and trigonometry course in your pocket!

Source:  OpenStax, Natural sciences grade 4. OpenStax CNX. Sep 18, 2009 Download for free at http://cnx.org/content/col11096/1.1
Google Play and the Google Play logo are trademarks of Google Inc.

Notification Switch

Would you like to follow the 'Natural sciences grade 4' conversation and receive update notifications?