Cellular Respiration

Transpiration of oxygen and water out of the stomata of leaves was evident in the plants found in the outdoor classroom this week.  Sixth graders placed a plastic bag around a leaf and left it for 24 hours.  When they returned to check on the project, most students found between 2.5 and 5 ml of water in their bag. This process proved that cellular respiration had taken place in the cells of the chosen plant.  

In cellular respiration, the mitochondria in cells convert small glucose molecules into energy, carbon dioxide, and water. This process is the other half of the energy cycle. Photosynthesis and cellular respiration are the two processes in the energy cycle. 

Students also completed a chromatography investigation where they took leaves from some of the green plants and placed them in alcohol.  After allowing the chlorophyll to break down, they placed a filter into the solution to separate the chlorophyll from the other colors in the leaf.  The fall leaf colors have been in the leaves throughout the growing season, we have not been able to see them because of the chlorophyll.  When plants start to go dormant for the winter, the chlorophyll breaks down and the other colors begin to show. 

Students were able to study the leaves at both the macro and micro scale by using the digital microscope with an ipad. 

How Do Cells Function?

How do you explain the ways cells contribute to the function of living organisms?  In an effort to promote the basic understanding of the role of cells in body systems and how those systems work to support the life functions of the organism, students have been completing experiments and modeling the cell organelle functions. 

Students placed raw eggs into five different solutions to see if the solution would pass through the barrier of the shells to affect the circumference of the egg.  Both quantitative and qualitative data were taken over a five day period to record changes in the egg.  Students inferred that the process of osmosis allowed some of the substances to pass through the shell and increase the size of the egg.   Students included a control egg that was not placed into any solution.  This was offered as evidence that it was the solutions that were affecting the egg size.  Constant variables that should stay the same were also identified to make sure that the experiment was a fair test.

Students then moved to the outdoor classroom to make cell models out of materials found outside.  The cell membrane was represented with a plastic bag and the cytoplasm that the materials were placed into was made of corn syrup.  Students then explained which biotic factors they chose to represent the organelles and why they were chosen.

Life Comes From Life!

Sixth graders have been studying cells and cell theory in Science.  They have created models, group diagrams, and microscope slides of real specimens from the outdoor classroom wetland.

The conclusions they have drawn support the cell theory.

All organisms are made up of cells.  Some are multicellular and some are unicellular. The cells allow the organisms to carry out the functions of life. All cells come from existing cells.

In Technology class, students are looking at the cells from the macro scale.  They are collaborating with google shared documents over the systems of the body and preparing presentations to share with classmates.