Photosynthesis There are different types of energy Remember

Photosynthesis

There are different types of energy • Remember: Energy is the ability to cause a change • The type of energy that comes from the sun is LIGHT ENERGY • Light energy can’t give plants the energy they need to perform processes – like making new cells and reproducing • CHEMICAL ENERGY is energy that comes from breaking apart molecules and is the type of energy all living things use

Why photosynthesize? • Plants have no way to get chemical energy (or food) because they do not eat • So they need to MAKE a molecule they can break down to get chemical energy • They make molecules for energy (food) during photosynthesis • Let’s look at how this works:

Capturing Light Energy • Plants have chloroplasts • Chloroplasts contain lots of chlorophyll which absorbs the sun’s light energy • Chloroplasts reflect green light, which makes them look green

Photosynthesis LIG CARBON DIOXIDE WATER GLUCOSE HT OX N E YG

Photosynthesis Reaction O O O 6 CO 2 + 6 H 2 O C C C O O O H O H H OH HO H HOH H O H LIGHT C 6 H 12 O 6 + 6 O 2

Photosynthesis Reaction 6 CO 2 + 6 H 2 O The molecules before the arrow are called the REACTANTS because they are reacting to form something new. C 6 H 12 O 6 + 6 O 2 The molecules after the arrow are called the PRODUCTS because they are what has newly formed.

What are the REACTANTS in photosynthesis? 1. Carbon dioxide and oxygen 2. Oxygen and glucose 3. Water and glucose 4. Carbon dioxide and water

What are the PRODUCTS in photosynthesis? 1. Carbon dioxide and oxygen 2. Oxygen and glucose 3. Water and glucose 4. Carbon dioxide and water

Plants make sugar to get ENERGY • All living things need energy to carry out life processes • That energy comes from GLUCOSE and is broken down for energy in the mitochondria

Getting energy • The process of breaking down glucose (sugar) to get energy is called CELLULAR RESPIRATION • It is the exact opposite reaction of photosynthesis AT OXYGEN W ER GLUCOSE CARBON DIOXIDE CHEMICAL ENERGY

What are the REACTANTS in cellular respiration? 1. Carbon dioxide and oxygen 2. Oxygen and glucose 3. Water and glucose 4. Carbon dioxide and water

What are the PRODUCTS in cellular respiration? 1. Carbon dioxide and oxygen 2. Oxygen and glucose 3. Water and glucose 4. Carbon dioxide and water

How does water and Carbon dioxide get into the plant? • Water is absorbed by the ROOTS • Carbon dioxide enters through tiny holes on the underside of the leaf called STOMATA

STOMATA • Oxygen will leave through the stomata • Sometimes water can also leave through the stomata • When more water leaves the stomata than is absorbed by the roots, the plant wilts • The process of water leaving the stomata is called transpiration

Why are plants important? • Plants can make their own food! (Change light energy into chemical energy) – no animal can do that • This makes plants the beginning of every food chain

Why else are plants important? • One of the products of photosynthesis is OXYGEN – which every living thing needs for cellular respiration • In other words, the oxygen given off by plants allows all other living things to get energy Oxygen Carbon Dioxide

Assignment: • Create a song/rap/poem/story with a friend that contains the following information. 1. ) Process of Photosynthesis 2. ) Reactants of Photosynthesis 3. ) Products of Photosynthesis **You must each have the song/rap/poem or story written down in your composition book to receive credit.