AP Biology
Korzeniewski
Name_______________________________
Date___________________Per_________
Metabolism Notes #5 – Photosynthesis
Objectives:


Be able to explain the process of photosynthesis.
Observe the relationship between photosynthesis and cellular respiration.
Key Vocabulary
Heterotrophs
Autotrophs
Thylakoid Membrane
Photosystem I
Stomates
Chlorophyll
Photosystem II
Chloroplast
Light Reactions
Chlorophyll a
Stroma
Calvin Cycle
Chlorophyll b
Thylakoid Sacs Grana stacks
NADPH
RuBisCo
G3P
C3 Photosynthesis
Photosynthesis Part 1– Life from Light and Air
Energy needs of life

All life needs a constant input of energy
o _________________________________
 get their energy from “eating others”
 eat food = other organisms = ___________________
 make energy through ____________________
o ___________________________________
 produce their own energy (from “self”)
 convert energy of sunlight
 build ____________________________________
 make energy & synthesize sugars through __________________
How are they connected? Write the two reactions and the relationship between them:
What does it mean to be a plant

Need to…
o ___________ light energy
 transform it into chemical energy
o __________ light energy
 in a stable form to be moved around the plant or stored
o need to get ______________________________________
 _____________________________
o produce all ___________________ needed for growth
 carbohydrates, proteins, lipids, nucleic acids
Plant structure
o
Obtaining raw materials
o _____________
 ______________ = solar collectors
o _______________
 ________________= gas exchange
o _________________
 uptake from ________________
o ___________________
 N, P, K, S, Mg, Fe…
 uptake from ______________
Plant structure


Chloroplasts
o double membrane
o stroma
 fluid-filled interior
o thylakoid sacs
o grana stacks
Thylakoid membrane contains
o chlorophyll molecules
o electron transport chain
o ATP synthase
 H+ gradient built up within thylakoid sac
Photosynthesis
o
o
Light reactions
o light-dependent reactions
o _________________________________________________
 convert solar energy to chemical energy
 ATP & NADPH
Calvin cycle
o light-independent reactions
o ________________________________________________________
 uses chemical energy (ATP & NADPH) to reduce CO2 & synthesize C6H12O6
Light reactions
o
o
o
_________________________________________________
o like in cellular respiration
proteins in organelle membrane
___________________________________________
o ___________________________________
o proton (H+) gradient across inner membrane
 find the double membrane!
o ATP synthase enzyme
ETC of Respiration:

Mitochondria transfer ___________________________________________________
o Use electron carrier _________________
ETC of Photosynthesis:

Chloroplasts transform __________________________________________________
o Use electron carrier _________________
The ATP that “Jack” built … Copy this slide:
Pigments of photosynthesis

Chlorophylls & other pigments
o embedded in thylakoid membrane
o arranged in a “photosystem”
 collection of molecules
o structure-function relationship
A Look at Light

The spectrum of color
o Shorter wavelength ------------------------____________________
o Higher energy
------------------------_____________________
Light: absorption spectra

Photosynthesis gets energy by absorbing wavelengths of light
o chlorophyll a
 absorbs best in red & blue wavelengths & least in green
o accessory pigments with different structures absorb light of different wavelengths
 chlorophyll b, carotenoids, xanthophylls
Photosystems of photosynthesis
o
2 photosystems in thylakoid membrane
o collections of chlorophyll molecules
o act as light-gathering molecules
o Photosystem II
 _____________________________
 P680 = absorbs 680nm wavelength red light
o Photosystem I
 ______________________________________
 P700 = absorbs 700nm wavelength red light
ETC of Photosynthesis


ETC uses __________________________ to produce
o ______________________________________
 go to Calvin cycle
PS II absorbs light
o excited electron passes from chlorophyll to “primary electron acceptor”
o need to replace electron in chlorophyll
o enzyme ______________________________________ supplies them to chlorophyll
 ___________________________________
 combines with another O to form O2
 _____________________________________________
 and we breathe easier!
Photosynthesis summary
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Where did the energy come from?_____________________
Where did the electrons come from? _______________________
Where did the H2O come from? _________________________
Where did the O2 come from? __________________________
Where did the O2 go? ___________________________
Where did the H+ come from? _______________________
Where did the ATP come from? ________________________
What will the ATP be used for? __________________________
Where did the NADPH come from? ____________________________
What will the NADPH be used for? _______________________________
Photosynthesis Part 2: The Calvin Cycle ---- Life from Air
Remember what it means to be a plant…


Need to _______________________ necessary for growth
o carbohydrates, lipids, proteins, nucleic acids
Need to store ____________________________________________
o in a more stable form
o that can be moved around plant
o saved for a rainy day
Light reactions
o
o
Convert solar energy to chemical energy
o ATP ______________
o NADPH _____________________
What can we do now? _______________________________________
How is that helpful?
o
Want to make C6H12O6
o synthesis
o How? From what?
What raw materials are available?
Carbon Fixation: Copy slide diagram:
From CO2  C6H12O6
o
o
o
o
CO2 has very ____________________
o ____________________
C6H12O6 contains a lot of chemical energy
o ____________________
Synthesis = endergonic process
o put in a lot of energy
Reduction of CO2  C6H12O6 proceeds in many small uphill steps
o each catalyzed by a specific enzyme
o using _____________________________
From Light reactions to Calvin cycle
o
o
Calvin cycle
o chloroplast stroma
Need products of light reactions to drive synthesis reactions
o ATP
o NADPH
To G3P and Beyond!
o
o
o
________________________________
o __________________________
o energy rich ______________________
o __________________________”
G3P is an important intermediate
G3P
  _______________  carbohydrates

_____________  phospholipids, fats, waxes

_____________   proteins

_____________   DNA, RNA
RuBisCo
o
Enzyme which fixes carbon from air
o ribulose bisphosphate carboxylase
o the most important enzyme in the world!
 it makes life out of air!
o definitely the most abundant enzyme
Accounting

The accounting is complicated
o 3 turns of Calvin cycle = 1 G3P
o _____________________________
o ___________________________________
o 6 CO2  1 C6H12O6 (6C)
o __________________________________
o any ATP left over from light reactions will be used elsewhere by the cell
Photosynthesis summary
o
Light reactions
o produced ATP
o produced NADPH
o consumed H2O
o produced O2 as byproduct
o
Calvin cycle
o consumed CO2
o produced G3P (sugar)
o regenerated ADP
o regenerated NADP
Putting it all together:
o
Plants make both:
o ______________
 ___________________
o ____________________
Energy cycle: Explain “The Great Circle of Life”
Summary of photosynthesis
o
o
o
o
o
o
o
o
o
o
Where did the CO2 come from? _____________________
Where did the CO2 go?___________________________
Where did the H2O come from?____________________________
Where did the H2O go?_________________________________
Where did the energy come from? __________________________
What’s the energy used for?______________________________
What will the C6H12O6 be used for?______________________________
Where did the O2 come from?_______________________________
Where will the O2 go?_______________________________
What else is involved…not listed in this equation?_______________________-
Supporting a biosphere
On global scale, photosynthesis is the most important process for the continuation of life on Earth
o
o
each year photosynthesis…
o ______________________________
o _________________________________
heterotrophs are dependent on plants as food source for fuel & raw materials
The poetic perspective…
o
o
All the solid material of every _____________ was built by sunlight out of thin air
All the solid material of every ____________ was built from plant material