Transcript 8. Photosynthesis

8. Photosynthesis
http://www.science.siu.edu/plant-biology/PLB117/JPEGs%20CD/0076.JPG
http://www.youtube.com/watch?v=sQ
K3Yr4Sc_k
Energy and Life
WHAT DO CELLS USE ENERGY FOR ?
ACTIVE TRANSPORT
Na+ - K + PUMP
Endocytosis
Exocytosis
WHAT DO CELLS USE ENERGY FOR ?
Movement
Synthesis of
biomolecules
Reproduction
Meiosis: http://www.tokyo-med.ac.jp/genet/anm/
Cilia: http://www.sk.lung.ca/content.cfm?edit_realword=hwbreathe
Replication: http://www.beyondbooks.com/lif71/4c.asp
Transcription:http://www.wappingersschools.org/RCK/staff/teacherhp/johnson/visualvocab/mRNA.gif
Translation:
ATP
ONE SPECIAL KIND of NUCLEOTIDE
is used by cells to store and transport
ENERGY
ATP
CELLS USE ATP TO STORE and RELEASE
ENERGY
3 PHOSPHATE
____
GROUPS
Adenosine triphosphate
ATP = __________________________
ATP can change into ADP
2 PHOSPHATE
____
GROUPS
Adenosine diphosphate
ADP = __________________________
ATP releases
energy stored
in a high energy
chemical bond by
removing the
phosphate and
becoming ADP
ATP
ADP + ____ +
→ ____
Cells ________
STORE energy by adding the
phosphate back on to ADP to make ATP.
The energy to do this comes from
FOODS like _____________
GLUCOSE
____________
It’s like recharging the battery !
ADP + ___ + ________
ATP
→ ___
Autotrophs
_____________ can make
their own food using
energy from sunlight.
Ex: Green plants,
a few bacteria
Heterotrophs
__________________ get
energy by consuming
other organisms
Ex: Animals, fungi,
most bacteria
Photosynthesis
Photosynthesis
• a metabolic pathway that converts light
energy into chemical energy.
• is the process by which plants, some bacteria,
and some protists use the energy from
sunlight to produce sugar.
Photosynthesis
Photosynthesis


Method of converting sun energy into chemical
energy usable by cells
Autotrophs: self feeders, organisms capable of
making their own food
–
–
Photoautotrophs: use sun energy e.g. plants
photosynthesis-makes organic compounds (glucose)
from light
Chemoautotrophs: use chemical energy e.g.
bacteria that use sulfide or methane
chemosynthesis-makes organic compounds from
chemical energy contained in sulfide or methane
Photosynthesis

Photosynthesis takes place in specialized
structures inside plant cells called chloroplasts
–
Light absorbing pigment molecules e.g. chlorophyll
Chloroplasts containing chlorophyll.
Chloroplast
Chloroplast
Chlorophyll
Visible Spectrum
Photosynthetic Pigments
6H2O + 6CO2  C6H12O6 + 6O2
(water) + (carbon dioxide) + (light)  (sugar) + (oxygen)
Leaves and
Photosynthesis
24
How Leaves Work
Pearson Education Inc; Publishing as Pearson Prentice Hall
LIGHT-DEPENDENT REACTIONS
See an animation about the
ELECTRON TRANSPORT CHAIN
SEE A MOVIE
ATP SYNTHASE
IN ACTION
http://www.stolaf.edu/people/giannini/flashanimat/metabolism/atpsyn1.sw
http://www.stolaf.edu/people/giannini/flashanimat/metabolism/photosynthesis.swf
Noncyclic Electron
Pathway
27
Light Reactions:
28
Light-dependent Reactions

Overview: light energy is absorbed by
chlorophyll molecules-this light energy excites
electrons and boosts them to higher energy
levels. They are trapped by electron acceptor
molecules that are poised at the start of a
neighboring transport system. The electrons
“fall” to a lower energy state, releasing energy
that is harnessed to make ATP
Energy Shuttling


Recall ATP: cellular energy-nucleotide based
molecule with 3 phosphate groups bonded to it,
when removing the third phosphate group, lots of
energy liberated= superb molecule for
shuttling energy around within cells.
Other energy shuttles-coenzymes (nucleotide
based molecules): move electrons and protons
around within the cell
NADP+, NADPH
NAD+, NADP
FAD, FADH2
Light-dependent Reactions




Photosystem: light capturing unit, contains chlorophyll,
the light capturing pigment
Electron transport system: sequence of electron
carrier molecules that shuttle electrons, energy released
to make ATP
Electrons in chlorophyll must be replaced so that cycle
may continue-these electrons come from water
molecules, Oxygen is liberated from the light reactions
Light reactions yield ATP and NADPH used to fuel the
reactions of the Calvin cycle (light independent or dark
reactions)
Calvin Cycle (light independent or
“dark” reactions)



ATP and NADPH generated in light reactions
used to fuel the reactions which take CO2 and
break it apart, then reassemble the carbons into
glucose.
Called carbon fixation: taking carbon from an
inorganic molecule (atmospheric CO2) and
making an organic molecule out of it (glucose)
Simplified version of how carbon and energy
enter the food chain
Calvin Cycle Reactions:
Overview of C3 Photosynthesis
• A cyclical series of reactions
• Utilizes atmospheric carbon dioxide to
produce carbohydrates
• Known as C3 photosynthesis
• Involves three stages:
• Carbon dioxide fixation
• Carbon dioxide reduction
35
• RuBP Regeneration
CALVIN CYCLE
(also called _________________________)
LIGHT INDEPENDENT
DOES NOT
LIGHT
____________
require ____________
Happens in _________
between thylakoids
STROMA
NADPH donates _______________
Hydrogen + electrons
ATP donates _________________
ENERGY
CO2 donates ______________
Carbon & oxygen
to make __________
GLUCOSE
http://www.estrellamountain.edu/faculty/farabee/biobk/BioBookCHEM2.html
Calvin Cycle
CO2 Enters the Cycle
Energy Input
5-Carbon
Molecules
Regenerated
6-Carbon Sugar
Produced
Sugars and other compounds
Concept Map
Section 8-3
Photosynthesis
includes
use
to produce
takes place in
take place in
of
uses
to produce
Concept Map
Section 8-3
Photosynthesis
includes
Lightdependent
reactions
Calvin cycle
use
take place in
Energy from
sunlight
Thylakoid
membranes
to produce
ATP
NADPH
O2
takes place in
Stroma
uses
ATP
NADPH
of
to produce
Chloroplasts
High-energy
sugars
Photosynthesis Overview
40
Harvesting Chemical Energy




So we see how energy enters food chains (via
autotrophs) we can look at how organisms use
that energy to fuel their bodies.
Plants and animals both use products of
photosynthesis (glucose) for metabolic fuel
Heterotrophs: must take in energy from outside
sources, cannot make their own e.g. animals
When we take in glucose (or other carbs),
proteins, and fats-these foods don’t come to
us the way our cells can use them