Photosynthesis Life from Light and Air Do now

Photosynthesis: Life from Light and Air Do now: Where in the cell does photosynthesis happen? What do plans need to grow? Regents Biology 2006 -2007

Plants are energy producers ▪ Like animals, plants need energy to live ◆ unlike animals, plants don’t need to eat food to make that energy ▪ Plants make both FOOD & ENERGY animals are consumers ◆ plants are producers ◆ Regents Biology

How do plants make energy & food? ▪ Plants use the energy from the sun to make ATP energy ◆ to make sugars ◆ ▪ glucose, sucrose, cellulose, starch, & more sun ATP sugars Regents Biology

Using light & air to grow plants ▪ Photosynthesis using sun’s energy to make ATP ◆ using CO 2 & water to make sugar ◆ Happens in chloroplasts ◆ allows plants to grow ◆ makes a waste product ◆ ▪ oxygen (O 2) (ATP) = used to build the sugar carbon sun + water + energy → glucose + oxygen dioxide 6 CO 2 + 6 H 2 O + sun → C 6 H 12 O 6 + 6 O 2 energy Regents Biology

What do plants need to grow? ▪ The “solar power plant” for making energy & sugars ◆ chloroplast ▪ Fuels CO 2 sunlight ◆ carbon dioxide ◆ water Make ATP! Make sugar! I can do it all… And no one even notices! sun ◆ ▪ The Helpers ◆ enzymes H O 2 Regents Biology ATP enzymes sugars

Chloroplasts are only in plants cells animal cells plant cells Regents Biology

Chloroplasts absorb sunlight & CO 2 Leaf CO 2 Leaves sun Chloroplasts in cell Chloroplasts contain Regents Biology Chlorophyll Chloroplast make ENERGY & SUGAR

So what does a plant need? ▪ Bring In light ◆ CO 2 ◆ H 2 O ◆ leaves ▪ Let Out ◆ stem O 2 ▪ Move Around ◆ sugars roots 6 CO 2 + 6 H 2 O + light → C 6 H 12 O 6 + Regents Biology energy 6 O 2

How do plants get water? ▪ Water evaporates from ▪ ▪ the stomates in the leaves This motion pulls water up from roots Like with a straw, more water is pulled up tree from ground Regents Biology

Stomates & Guard Cells ▪ Function of stomates ◆ ◆ ◆ Lets CO 2 in Lets O 2 out Lets H 2 O out ▪ gets to leaves for photosynthesis ▪ Function of guard cells ◆ open & close stomates guard cell stomate Regents Biology

Guard cells & Homeostasis ▪ Homeostasis ◆ keeping the internal environment of the plant balanced ▪ Stomates open ◆ let CO 2 in ▪ needed to make sugars ◆ let H 2 O out ▪ needed for photosynthesis ◆ let O 2 out ▪ get rid of waste product ▪ Stomates close ◆ if too much H 2 O is evaporating Regents Biology

Xylem carry water up from roots Regents Biology

Phloem: food-conducting cells Regents Biology ▪ carry sugars around the plant wherever they are needed ✓ new leaves ✓ fruit & seeds ✓ roots

How are they connected? Photosynthesis carbon sun + water + energy → glucose + oxygen dioxide 6 CO 2 + 6 H 2 O + light → C 6 H 12 O 6 + 6 O 2 energy Respiration glucose + oxygen → carbon + water + energy dioxide e C 6 H 12 O 6 + 6 O 2 → 6 CO 2 + 6 H 2 O + ATP Regents Biology