Today’s lesson Introduction to photosynthesis Photosynthesis 1 lab

Photosynthesis

Photosynthesis All cells need energy to grow Some living things eat other things to get energy (consumers) Where do we get our energy? Food Some living things produce their own food (producers) Like plants! This process is called photosynthesis

Photosynthesis Plants use sunlight as a source of energy to turn carbon dioxide and water into carbohydrates (sugars) and oxygen. Energy comes from the sun Water is pulled in by the roots from the ground Carbon dioxide is absorbed from the air through the leaves

CO2+ water + solar energy → sugar + O2 Photosynthesis CO2+ water + solar energy → sugar + O2 This is how we get the oxygen we breathe!

Conducting Experiments

Next little while Over the next couple of classes we will be conducting a few experiments related to photosynthesis Labs 1 and 2 we will do together After that you will be doing an evaluation based on these labs (lab 3) So you need to know what you’re doing and how we conduct experiments!

Variables Variables: the factor that we are changing to see if it has an effect on our experiment Many things can affect the outcome of an experiment so to see if a particular factor (or change) causes an effect we try to only change one thing at a time (the variable) We want to compare the changed situation to the non-changed situation (the control) We call this controlling the experiment

Example I want to know if plants grow better with music. How would I test this? Have 2 groups of plants: Group 1: let grow without music Group 2: let grow with music Which is the control group? Group 1 – no change

Photosynthesis I Lab

CO2+ water + solar energy → sugar + O2 Photosynthesis CO2+ water + solar energy → sugar + O2 This is how we get the oxygen we breathe!

Today’s lab Purpose: Show that plants require carbon dioxide in order to photosynthesize Hypothesis: If test tube A is carbonated water and test tube B is tap water, then test tube ____ will have more bubbles because ____ ____ ____ ____ ____ ____ ____ ____

Today’s lab Analysis: Which test tube is the control? Test tube B (tap water) – regular condition 3. Which test tube is the variable? Test tube A (carbonated water) – treatment, we changed the regular condition

Today’s lab Procedure: Take 2 test tubes. Label them A and B. Fill test tube A with 40ml of carbonated water Fill test tube B with 40 ml of tap water Be SUPER careful not to contaminate the water or it will mess up your results! Take 2 pieces of Elodea (100 mm long) and place 1 in each test tube Install a lamp 100 mm away from the test tubes Count the number of bubbles of oxygen that are produced during 5 min Record the data Repeat 10 min, 15 min and 20 min.

Today’s lab Cleanup Test tube A Dump the water from test tube A into the sink Then use water from beaker A to rinse out the test tube and rinse off the Elodea Put the Elodea back in the beaker with the other Elodea for test tube A Put the test tube back in the bin for A Test tube B Dump the water from test tube B into the sink Then use water from beaker B to rinse out the test tube and rinse off the Elodea Put the Elodea back in the beaker with the other Elodea for test tube B Put the test tube back in the bin for B

DON’T LOSE THE LAB Report Draw the setup Fill in your results table Answer all the questions (Analysis & Conclusion) You have to show me your work before you leave! DON’T LOSE THE LAB