I/GCSE Biology - Energy

In this post, we'll talk about the energy in I/GCSE Biology. Let's get started! 😆

• Nearly all organisms are ultimately dependant on energy from the SUN.
• Energy from the sun enters the food chain when green plants absorb light in order to PHOTOSYNTHESIS.
• By the process of photosynthesis, organic compounds like glucose are made from carbon dioxide and water using this energy.
• Plants only absorb a small percentage of the sun’s energy for this process; this energy is stored in the chemicals which make up the plants’ cells.

In I/GCSE Biology, it's important to memorize the following points!

Energy is transferred between organisms in an ecosystem:

• When organisms are eaten
• When dead organisms and waste materials are fed on by decay organisms. There are two types of decay organism:

1. DECOMPOSERS such as bacteria and fungi break down the dead materials and use the energy stored inside.

2. DETRITIVORES include animals such as earthworms and woodlice. These consume the DETRITUS (dead plants or animals and their waste), breaking it down into smaller particles that other detritivores and decomposers can use

In I/GCSE Biology, it's commonly asked in the exam!

In a food chain only around 10% of the energy is passed on to the next level. A large proportion of the energy is:

• Loss to the environment as heat
• Excreted as waste products
• Trapped in indigestible materials such as bones, cellulose and fur

As less energy is transferred at each level of the food chain, the number of organisms at each level gets smaller.

The percentage of energy efficiency can be calculated using the formula

And we're done with this topic! Well Done!

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Drafted by Alyssa (Biology)

References:

1. "What is photosynthesis?", https://www.science-sparks.com/wp-content/uploads/2020/04/Photosynthesis-Diagram-1024x759.jpg
2. "4.1 Species, Communities and Ecosystems", https://www.mrgscience.com/uploads/2/0/7/9/20796234/published/decomposers-vs-detritivores-800x400.jpg?1504978681
3. "Q2 Page 260 - What is the role of decomposers", https://d1avenlh0i1xmr.cloudfront.net/0a96df12-a39d-46ad-b408-15e6038f137d/decomposers---teachoo.jpg
4. "Heterotrophs", https://ib.bioninja.com.au/_Media/detritivores_med.jpeg
5. "Flow of energy and Ten percent law", https://img.brainkart.com/extra3/oD7tyCN.jpg
6. "Boardworks Science", https://slideplayer.com/slide/12683912/76/images/4/How+is+energy+efficiency+calculated.jpg