Focus Question: What do plants need in order to make

food?Living Systems 3-1A

Food Chain• What is a food chain?

– Example of a food chain?

• What are the animals that eat other animals called?

• What are the animals that eat plants called?

• What about animals that eat both plants and other animals?

• What role do all the organisms that eat plants and animals play in the ecosystem?

• What role do plants play in the ecosystem?

• What does it mean to be a producer in the ecosystem?

Cells and Energy• All cells need energy to do the things they

need to do. They get their energy from _____– Food

• Plants make the food they need to keep their cells alive. – Phloem delivers the food to all the cells– Plants also use this food to grow

• The whole plant is made out of food produced by the plant.

• When an animal eats a plant, the plant becomes food for the animal.

• What is the food produced by plants made of?

• Where does the matter come from?

• What kinds of raw materials do plants use to make food?

Making Food• Two students learned that plants make food.

– If it is true, then the food should have mass.– Plants should gain mass if they are producing

food.

• Decided to do an experiment to find out.– Read about the experiment and analyze the

results.

• Open textbook to pg 111 - read Making Food

Making Food Experiment• Question

– Experiment question is about what plants need in order to make food.

– If the experiment answers that question, you should have a pretty good idea about what food is made of.

• Design– Set up 6 trays of beans in exactly the same way.– In experiments B-F, they eliminated one of the factors in

the environment.– Copy the design data into the table on your worksheet

• Data– Transcribe the measured data to the data table on

the notebook sheet.

• Results and Conclusions– Work in table groups to record your results.– What do the results mean?– What conclusions can you draw from the results?

Analyze Results• Do plants gain mass when they have no water?• Do plants gain mass when they have no light?• Do plants gain mass when they have no nitrogen?

• Do plants gain mass when they have no oxygen?

• Do plants gain mass when they have no carbon dioxide?

• Do plants gain mass from the sand they grow in?• What variables must be present for plants to make food?• Where does the mass of the produced food come from?

• Review conclusions and make any needed changes or additions to your statements.

Photosynthesis• Experimental results showed that beans

grown in an environment with water, carbon dioxide, and light increased in mass. – The increased mass was food

• Form of food produced by plants is sugar.

• Process that makes sugar is called photosynthesis.

• Photosynthesis happens in green cells (chlorophyll).

Photosynthesis Equation

• 6CO2 + 12H2O C6H12O6 + 6H2O + 6O2

• 6 molecules of carbon dioxide (6CO2) combine with 12 molecules of water (12H2O)

• Forms 1 molecule of sugar (C6H12O6), 6 molecules of oxygen (6O2), and 6 molecules of water (6H2O)

• Sugar molecule is made from the six carbon atoms in the six carbon dioxide molecules, six of the twelve oxygen atoms in the carbon dioxide molecules, and twelve hydrogen atoms from the water molecules.

• Leftover oxygen atoms form six molecules of oxygen gas, which are released into the air.

Energy• Food-producing reaction happens only

when energy from light is present.– No light : No food production

• Photosynthesis– Photo means light– Synthesis means put together from parts

• Because this reaction only happens when light is present, equation should include light energy– Usually sunlight or solar energy

Revised Equation• 6CO2 + 12H2O + Solar Energy C6H12O6 + 6H2O+ 6O2

• Energy from the Sun changes into chemical energy in sugar during photosynthesis.– Energy powers cells– Makes it possible for them to do things they

need to do– When you run, think, feel, or see, you are using

solar energy to do it.

Chemical Energy• Sugar can then be changed chemically into

all kinds of other substances.– Starches, fats, and proteins

• When you think of human food, usually think of carbohydrates, fats, and proteins.– All made out of sugar– Have to change back into sugar through

digestion before our cells can use them

Vocabulary• Food

– The source of energy and building materials for living cells

• Photosynthesis– A chemical process in which cells produce energy-

rich sugar molecules and release oxygen & water

• Fats and Proteins– Groups of nutrients that provide energy and building

blocks for growth and development

• Starches– Chemicals produced by plants to store food

Vocabulary• Mass

– A quantity of matter

• Molecule– A particle made of two or more atoms– A sugar molecule is made of carbon, hydrogen, and

oxygen

• Sunlight– Solar energy, light from the Sun

Content• What is Photosynthesis?

• Photosynthesis is the process in which sugar (food) is made from carbon dioxide, water, and solar energy, and oxygen is released.

• What is the chemical formula for Photosynthesis?

• 6CO2 + 12H2O + Solar Energy � C6H12O6 + 6H2O + 6O2

Photosynthesis Reading• What is sugar?

• What raw materials do plants need to build sugar molecules?

• Where do these raw materials come from?

• What is the role played by chlorophyll?

• What are the products of photosynthesis?

• Where do they go?

• Where do plants produce food?

• You run on solar energy. How is that possible?

Photosynthesis Game• Table Group - 2 teams/elbow partner

• Each team has board & atom bag

• Group has a spinner circle

• Rules – – Team 1 spins. Build molecule according to

result on spinner circle. Repeat Team 2– When all molecules at top & light are done,

move atoms to the bottom – draw both formulas in notebook

• First team to make sugar – wins!

• Make notes – what are challenges?