Bellringer – 9/23/14 1) Draw the following leaf and fill in the blanks for the 5 arrows. 2) In what organelle does photosynthesis take place? 3) Try and write the FULL and BALANCED equation for photosynthesis

Photosynthesis: Life from Light and Air AQUAPONICS

All organisms need energy Like animals, plants need energy to live Unlike animals, plants don’t need to eat food to make that energy Plants make their own energy –animals are consumers –plants are producers

Autotrophs vs. Heterotrophs  Autotroph  Obtain their organic material from inorganic sources  They are producers of the biosphere  Heterotrophs  Obtain their organic material from other organisms  They are consumers of the biosphere

The Process That Feeds the Biosphere  Photosynthesis  the process that converts solar energy into chemical energy  What organisms?  Plants and other autotrophs  Plants form the base of most food chains

 Plants, some bacteria and algae are photoautotrophs  Use energy of sun to make organic molecules from H 2 O and CO 2  Some worms and bacteria are chemoautotrophs  Use energy from chemicals to make organic molecules 2 Types of Autotrophs

 Photosynthesis  Occurs in plants, algae, certain other protists, some prokaryotes They feed not only themselves, but the entire living world. (a) On land, plants are the predominant producers of food. In aquatic environments, photosynthetic organisms include (b) multicellular algae, such as this kelp; (c) some unicellular protists, such as Euglena; (d) the prokaryotes called cyanobacteria; and (e) other photosynthetic prokaryotes, such as these purple sulfur bacteria, which produce sulfur (spherical globules) (a) Plants (b) Multicellular algae (c) Unicellular protist 10  m 40  m (d) Cyanobacteria 1.5  m (e) Purple sulfur bacteria Figure 10.2

The Equation for Photosynthesis  When plants convert the energy of sunlight into chemical energy stored in the bonds of carbohydrates  Photosynthesis is summarized by this Overall chemical equation 6 6 CO H 2 O + Light energy  C 6 H 12 O O 2

Using light & air to grow plants 6CO 2 6H 2 O C 6 H 12 O 6 6O 2 sun energy   glucose + oxygen carbon dioxide sun energy + water + (ATP) – using sun energy to make glucose – Then use glucose to generate ATP – using carbon dioxide from air & water from roots to make sugar – Takes place in chloroplast – allows plants to grows and do work – makes a waste product oxygen

Chloroplasts: The Sites of Photosynthesis in Plants  The leaves of plants-THEY’RE GREEN!!  major sites of photosynthesis, also occurs in stems.

Chloroplasts  Stroma  Dense fluid within chloroplast  Dark reaction occurs here  Thylakoids  Membranous sac (or “coin”) in stroma  Light reactions occur here  Grana (granum = singular)  Stack of thylakoids (“coins”)

The Nature of Sunlight  Light  a form of electromagnetic energy, which travels in waves and particles (called photons)  Wavelength  distance between crests of waves  Determines type of electromagnetic energy (wavelength & energy are inversely proportionate)  wavelength,  energy

 The Electromagnetic Spectrum  The entire range of electromagnetic energy, or radiation  Visible light is only a small part of the spectrum Gamma rays X-raysUVInfrared Micro- waves Radio waves 10 –5 nm 10 –3 nm 1 nm 10 3 nm 10 6 nm 1 m 10 6 nm 10 3 m nm Visible light Shorter wavelength Higher energy Longer wavelength Lower energy

Color we SEE = color most reflected by pigment; other colors (wavelengths) are absorbed  BLACK  all colors are reflected

How do the light reactions capture solar energy?  Photosynthetic Pigments  molecules that absorb visible light  different pigments absorb different wavelengths of light  Many different pigments used in light reactions of photosynthesis

Primary vs. Accessory Pigments  Primary Pigment  Chlorophyll a (most abundant)  Accessory (Antennae) Pigments  Chlorophyll b  Anthocyanins  Xanthophylls  Caratenoids

Photosynthetic pigments Primary pigment = chlorophyll a –takes direct part in light reactions Accessory pigments protect chlorophyll a from UV light damage absorb light at wavelengths that are not absorbed by chlorophyll a Transfer energy to chlorophyll a  help broaden the absorption spectrum for photosynthesis (act as “antennae”)

The Two Stages of Photosynthesis: A Preview The Light reactions NEEDS LIGHT Occurs in Thylakoids The Calvin cycle DOES NOT NEED LIGHT A.K.A- Dark Reactions Occurs in Stroma

The Light Reactions  Occur in the grana (& thylakoids)  Convert solar energy to chemical energy  Chlorophyll absorbs solar energy  Splits water  release O 2 (a by-product)  produce ATP and NADPH (chemical energy)

The Calvin Cycle  Occurs in the stroma (gel of chloroplast)  Forms SUGAR (glucose) from carbon dioxide  Carbon fixation occurs (CO 2  organic carbon)  Uses ATP for energy and NADPH to carry electrons

What do plants do with the glucose? Use it! – They can use cellular respiration to break glucose down and make ATP (cellular energy) Store it! – They can string together lots of glucose molecules to form starches (stored energy) or cellulose (strong fibers that support cell walls)

An overview of photosynthesis H2OH2O CO 2 Light LIGHT REACTIONS CALVIN CYCLE Chloroplast [CH 2 O] (sugar) NADPH NADP  ADP + P O2O2 ATP

Basics of Photosynthesis 2 Phases Light reactions happen in the thylakoid Dark reactions happen in the stroma Inputs to Dark Reaction? Outputs of Dark Reaction? Inputs to Light Reaction? Outputs of Light Reaction?

Photosynthesis This is the equation you are used to seeing, but this is not the whole story… + water + energy  glucose + oxygen carbon dioxide 6CO 2 6H 2 O C 6 H 12 O 6 6O 2 light energy  +++