Obtaining NutrientsObtaining Nutrients

I.I. We need plants to fulfill life We need plants to fulfill life processes such as digestion, processes such as digestion, breathing, blinking, etc. breathing, blinking, etc.

I.I. Autotrophs Autotrophs (producers) (producers)

Need Need sunlightsunlight

II.II. Heterotophs Heterotophs (consumers) (consumers)

Need Need foodfood

PhotosynthesisPhotosynthesis

• Uses light Uses light energy to energy to construct simple construct simple sugarssugars

• Occurs in Occurs in chloroplasts of chloroplasts of plantsplants

6CO2 + 12H2O + light energy ---> C6H12O6 + 6O2 + 6H2O

Or carbon dioxide + water + light energy ---> glucose + oxygen + water

http://static.howstuffworks.com/gif/irrigation-photosynthesis.gif

How do Plants do this?How do Plants do this?

• A photon of light strikes A photon of light strikes pigment (pigment (chlorophyll in chlorophyll in thylakoidsthylakoids) causing an ) causing an electron in an atom to electron in an atom to become excited.become excited.

• The excited (energized) The excited (energized) molecule can pass the molecule can pass the energy to another energy to another molecule or release it in molecule or release it in the form of light or heat. the form of light or heat.

• Electrons are repeatedly Electrons are repeatedly gained or lostgained or lost

Light ReactionsLight Reactions

• Light reactions Light reactions require light and require light and take place in the take place in the thylakoid membranethylakoid membrane. .

• They They convert ADP convert ADP and NADPand NADP (electron (electron carriers) into ATP carriers) into ATP and NADPH (energy and NADPH (energy released) needed to released) needed to produce glucose in produce glucose in the dark reactions. the dark reactions.

Thylakoid

Grana

Chlorophyll in plants Chlorophyll in plants absorb light most efficientlyabsorb light most efficiently

Dark ReactionsDark Reactions

• No light is needed. No light is needed. The plant uses the The plant uses the energy of ATP and energy of ATP and NADPHNADPH produced produced during the light during the light reactions to create reactions to create sugar.sugar.

• Takes place in the Takes place in the stroma (jelly like stroma (jelly like substance in the substance in the chloroplast)chloroplast)

Cellular RespirationCellular Respiration

• The process in the The process in the mitochondriamitochondria where simple where simple sugars are “burned” to produce sugars are “burned” to produce energy (in the form of ATP).energy (in the form of ATP).

• Occurs in PLANTS AND Occurs in PLANTS AND ANIMALS!ANIMALS!6O2 + C6H12O6 -->  6H2O + 6CO2 + energy

OR oxygen + glucose water + carbon dioxide + energy (ATP)

How it worksHow it works

• Glycolysis, Krebs and Glycolysis, Krebs and then the Electron then the Electron Transport ChainTransport Chain

• Mostly takes place in Mostly takes place in the mitochondria the mitochondria which supply all of which supply all of the usable energy for the usable energy for Plants (autotrophs) Plants (autotrophs) and Animals and Animals (heterotrophs). (heterotrophs).

http://fig.cox.miami.edu/Faculty/Dana/krebs.jpg

Leaf StructureLeaf Structure

– Cuticle Cuticle – – thick, waxy thick, waxy coat (cutin)that coat (cutin)that protects plant from protects plant from loss of water and loss of water and penetration by disease penetration by disease – part of the epidermis– part of the epidermis

– EpidermisEpidermis – – on the top on the top and bottom layer of and bottom layer of the leaf (skin), the leaf (skin), protects leaf tissueprotects leaf tissue

– Palisade LayerPalisade Layer – – the the dense upper layer that dense upper layer that contains the contains the chloroplastschloroplasts

– Stomata Stomata – – opening in opening in the leaf the leaf (most in lower (most in lower epidermis)epidermis)

– Spongy LayerSpongy Layer – – lower layer that lower layer that contains more air contains more air space and space and chloroplastschloroplasts

• Guard CellsGuard Cells – – protect the protect the openings called openings called the stoma in the the stoma in the leaf and regulate leaf and regulate the passage of the passage of water, oxygen, and water, oxygen, and carbon dioxide carbon dioxide through the lethrough the le

Vein Vein – – through petiole (part through petiole (part attached to stem)attached to stem)

Xylem – Xylem – transports water, transports water, minerals and hormonesminerals and hormones

Phloem – Phloem – transports sugar, transports sugar, oxygen and hormonesoxygen and hormones

ChloroplastsChloroplasts - - to produce glucoseto produce glucose from carbon dioxide and water from carbon dioxide and water by using light energy.by using light energy.

• Chlorophyll – Chlorophyll – green pigment green pigment required to convert light energy required to convert light energy into chemical energyinto chemical energy

• Grana – Stack of coins/pancakesGrana – Stack of coins/pancakes• Thylakoid– flattened membranes Thylakoid– flattened membranes

sacssacs• Stroma – cytoplasm of chloroplastStroma – cytoplasm of chloroplast

Enzymes in PlantsEnzymes in Plants• Remember, Autotrophs make their own Remember, Autotrophs make their own

organic nutrients (simple sugars). How do organic nutrients (simple sugars). How do plants do this?plants do this?

• Enzymes speed the necessary chemical Enzymes speed the necessary chemical reactions and give organisms the ability to reactions and give organisms the ability to control how much, where, and when these control how much, where, and when these reactions occur Glucose is coupled together reactions occur Glucose is coupled together into starch in the roots of plants for storage.into starch in the roots of plants for storage.

– The enzyme for this reaction is called: The enzyme for this reaction is called: SucraseSucrase• The chemical reaction that occurs is a The chemical reaction that occurs is a

Dehydration SynthesisDehydration Synthesis, draw the structures , draw the structures of two glucose molecules being joined to of two glucose molecules being joined to create a disaccharide.create a disaccharide.