Heterotrophy (Vardui Khorikyan)

Vardui Khorikyan

SED 525S/L

Demonstration

Title: Unleash the Yeast!: The demonstration of how yeast is heterotrophic.

Principle(s) Investigated: Heterotrophy, Autotrophy, Photosynthesis, Mitochondria, Chloroplast

Standards: Seventh Grade – Focus on Life Science – Cell Biology

d. Students know that mitochondria liberate energy for the work that cells do and that chloroplasts capture sunlight energy for photosynthesis.

Materials:

· Holt, Rinehart and Winston. Holt Science & Technology: Whiz-Bang Demonstrations. Texas: Holt, Rinehart and Winston: A Harcourt Classroom Education Company.

· Yeast

· Sugar

· Warm water

· Bottle

· Balloon

· Funnel

Procedure:

· Put 250mls of warm water in a clear container, which can be plastic or glass.

· Using a funnel to avoid mess, add about 120mls of sugar to the water and mix well.

· Add 2 packets of yeast and quickly put a balloon over the top of the bottle.

· Observe changes.

· Discuss changes.

· Lecture about animals, plants, heterotrophy, autotrophy, mitochondria, chloroplasts, and photosynthesis.

Student prior knowledge: Students prior knowledge comes from their knowledge of getting their own energy from eating food.

Explanation:

A heterotroph is that cannot create its own food for energy and growth. In contrast with an autotroph, such as a plant, which can use the process of photosynthesis to create their own food. There are different types of heterotrophs: photoheterotrophs and chemoheterotrophs. Photoheterotrophs, such as green and purple bacteria, produce ATP (adenosine triphosphate: chemical energy transport within cells for metabolism) from light and use organic compounds to build structures. This concept can be related to the processes of the mitochondrion in a cell. Mitochondria is the power-house of a cell, which produces most of the cell’s supply of energy, ATP.

Questions & Answers:

1. What is produces during the heterotrophic process of yeast consuming sugar?

Carbon Dioxide and alcohol are produced.

2. What is an autotroph?

An autotroph is an organism that produces organic compounds from inorganic molecules using energy from sunlight through photosynthesis or from inorganic chemical reactions through chemosynthesis.

3. What is the function of chloroplast?

Chloroplasts are organelles in plants that conduct the process of photosynthesis.

Applications to Everyday Life:

1. This principle can be used to explain in more detail how we get our energy from the food we eat.

2. It can also be applied to food science in the manner of exploring which foods create more energy.

3. What is yeast used for in our everyday life? Where can we find natural living yeast?

Photographs:

Cut and paste the following link: http://lh3.ggpht.com/_ioinZ7OgaII/TP6TXTlvFwI/AAAAAAAAK1w/hJbyVk85QGs/s512/xphoto2.JPG

Videos: http://www.youtube.com/watch?v=okGmexVC2_o

References

· Holt, Rinehart and Winston. Holt Science & Technology: Whiz-Bang Demonstrations. Texas: Holt, Rinehart and Winston: A Harcourt Classroom Education Company

· www.wikipedia.org