Photosynthesis

Title :

Photosynthesis

Author :

Kim Foglia & Kelly Reidell

Number of slides:

18

Slideshow :

Content transcript :

Photosynthesis:

Life from Light and Air

Energy needs of life

* All life needs a constant input of energy

* Heterotrophs (Animals)

* get their energy from “eating others”

* eat food = other organisms = organic molecules

* make energy through respiration

* Autotrophs (Plants) 

* produce their own energy (from “self”)

* convert energy of sunlight

* build organic molecules (CHO) from CO2 

* make energy & synthesize sugars through photosynthesis

Plant structure 

* Obtaining raw materials

* sunlight

* leaves = solar collectors

* CO2

* stomates = gas exchange

* H2O

* uptake from roots

* nutrients

* N, P, K, S, Mg, Fe… 

* uptake from roots

Chloroplasts

Plant structure 

* Chloroplasts

* double membrane

* stroma

* fluid-filled interior

* thylakoid sacs

* grana stacks

* Thylakoid membrane contains

* chlorophyll molecules

* electron transport chain

* ATP building molecule

Photosynthesis

* Light reactions

* light-dependent reactions

* energy conversion reactions

* convert solar energy to chemical energy

* ATP & NADPH

* Calvin cycle

* light-independent reactions

* sugar building reactions

* uses chemical energy (ATP & NADPH) to reduce CO2 & synthesize C6H12O6

Light reactions

* Electron Transport Chain 

* uses electrons to pump hydrogens

* proteins in organelle membrane 

* electron acceptors

* NADPH

* pumps H+ to

make ATP

Light Reaction

* ETC uses light energy to produce

* ATP & NADPH

* go to Calvin cycle

* Light drives the process

* enzyme extracts electrons from H2O & supplies them to chlorophyll

* splits H2O

* O2 released to atmosphere

* and we breathe easier!

      The Calvin Cycle

  Life from Air

Remember what it means to be a plant…

* Need to produce all organic molecules necessary for growth

* carbohydrates, lipids, proteins, nucleic acids 

* Need to store chemical energy (ATP) produced from light reactions

* in a more stable form 

* that can be moved around plant

* saved for a rainy day

In the light reactions…

* Convert solar energy to chemical energy

* ATP

* NADPH

* What can we do now?

From Light reactions to Calvin cycle

* Calvin cycle 

* chloroplast stroma

* Need products of light reactions to drive synthesis reactions

* ATP

* NADPH

Photosynthesis summary

* Light reactions

* produced ATP

* produced NADPH

* consumed H2O

* produced O2 as byproduct

* Calvin cycle

* consumed CO2

* produced Glucose (sugar)

* regenerated ADP

* regenerated NADP

Putting it all together

Energy cycle

Chloroplasts are only in plants