Photosynthesis: Life from Light and Air 2006-2007
Energy needs of life All life needs a constant input of energy get their energy from eating others eat food = other organisms = make energy through get their energy from self make energy through
Photosynthesis carbon dioxide + water + energy glucose + oxygen 6CO 2 + 6H 2 O + light C 6 H 12 O 6 6O 2 energy + This is the equation you are used to seeing, but this is not the whole story
Chemical Energy and ATP Energy can be found in many forms The chemical fuel used by cells to store and release energy is ATP is made of adenine, ribose (carbohydrate) and three phosphate groups
Storing Energy is a compound like ATP with one less When a cell has energy available, it can store small amounts of energy by adding a phosphate group to ADP to make ATP
Releasing Energy Energy stored in ATP is released by breaking the bonds between the Cells use ATP to power activities like ADP is like a battery, while ATP is like a fully charged battery ready to do work.
ATP ATP is not good for storing large amounts of energy long-term. Cells only have a small amount of ATP (enough to last for a few seconds) Cells generate ATP from like
Check Point What is the difference between ATP and ADP?
Photosynthesis using pictures
How do plants live? collect sun energy make ATP use ATP for energy use CO 2 as carbon for new sugars build sugars glucose, cellulose, starch build all other organic molecules proteins, lipids, carbohydrates, DNA store energy for future use starch in seeds & roots
Photosynthesis Actually 2 separate reactions use sunlight make energy (ATP) use ATP use CO 2 make sugars (C 6 H 12 O 6 ) ADP Energy building reactions Sugar building reactions sun ATP CO 2 sugar
Light and Pigments Plants absorb the sun s energy with light absorbing molecules called The plant s main pigment is called Chlorophyll absorbs blue, violet, and red light and reflects green light Chlorophyll is found in the of plant cells
Leaf Chloroplasts Leaf CO 2 Chloroplasts Chloroplast Chlorophyll
Reactions of Photosynthesis
Reactions of photosynthesis Take place in the chloroplast Photosynthetic membranes called contain clusters of chlorophyll and other pigments called Space outside the thylakoid membranes Granum is a stack of thylakoids
Energy Building Reactions H 2 O + light ATP O energy + 2 sunlight H 2 O Energy Building Reactions ATP O 2
Light Reactions Require Produce and 1.Light strikes chlorophyll 2. in chlorophyll absorb the energy from the light 3.Excited electrons are passed to NADP + 4.Electrons are passed to the which is a series of molecules in the thylakoid membrane
Light reactions 5. As electrons are passed from one molecule in the ETC to the next they give off energy, which is used to make ATP 6. Electrons lost by are replaced by splitting water, a process called
Sugar Building Reactions CO 2 + ATP C 6 H 12 O 6 + ADP ADP ATP CO 2 Sugar Building Reactions sugars C 6 H 12 O 6
Sugar Building Reactions (Calvin Cycle) Don t require Uses from the light reactions to make The Calvin cycle uses molecules of to produce a single 6-carbon sugar molecule
Factor Affecting Photosynthesis 1. A shortage of can slow or stop photosynthesis 2. : photosynthesis depends on enzymes that work best between O C and 35 C. Temperatures out of this range may damage the enzymes and slow photosynthesis. 3. Intensity of : increasing light intensity increases the rate of photosynthesis
Putting it all together CO 2 + H 2 O + light C 6 H 12 O 6 O energy + 2 sunlight H 2 O Energy Building Reactions ADP ATP CO 2 Sugar Building Reactions O 2 sugars C 6 H 12 O 6
So what does a plant need? Bring In Let Out Move Around leaves roots shoot 6CO 2 + 6H 2 O + light C 6 H 12 O 6 6O energy + 2
Leaf Structure photosynthesis O 2 H 2 O CO 2 O 2 H 2 O CO 2
Stomates guard cell stomate
Xylem
Phloem: food-conducting cells
Putting it all together Making a living leaves = solar collectors photosynthesis stomates = gases in & out roots take in water from soil pulled up by leaf evaporation roots take in from soil
How are they connected? Respiration glucose + oxygen carbon + water + energy dioxide C 6 H 12 O 6 + 6O 2 6CO 2 + 6H 2 O + ATP Photosynthesis carbon dioxide + water + energy glucose + oxygen 6CO 2 + 6H 2 O + light C 6 H 12 O 6 6O energy + 2
Energy cycle sun Photosynthesis CO 2 H 2 O O 2 Cellular Respiration The Great Circle of Life! Where s Mufasa? ATP
The poetic perspective All of the solid material of every plant was built out of thin air All of the solid material of every animal was built from plant material air Then all the cats, dogs, mice, people & elephants are really strands of air woven together by sunlight! sun
Any Questions?? 2006-2007