ATPATP

Why do we use it for Energy?Why do we use it for Energy?

ATP: Adenosine TriphosphateATP: Adenosine Triphosphate

Consists of Adenosine + 3 PhosphatesConsists of Adenosine + 3 Phosphates Highly unstable moleculeHighly unstable molecule 3 phosphates each highly negative repel each other 3 phosphates each highly negative repel each other

(like the wrong end of a magnet)(like the wrong end of a magnet) Hence a phosphate group is removed through Hence a phosphate group is removed through

hydrolysis energy is released (-7.3 kcal/mole) and hydrolysis energy is released (-7.3 kcal/mole) and breaks down into the more stable molecule ADP. breaks down into the more stable molecule ADP.

ATP: Pictures

Where does the Negativity come from? Oxygen

Oxygen

I thinkhe’s a bitunstable…don’t you?

How does ATP store energy?How does ATP store energy?

PO–

O–

O

–O PO–

O–

O

–O PO–

O–

O

–OPO–

O–

O

–O PO–

O–

O

–OPO–

O–

O

–O PO–

O–

O

–O PO–

O–

O

–O

Each negative POEach negative PO44 more difficult to add more difficult to add a lot of stored energy in each bonda lot of stored energy in each bond

most energy stored in 3rd Pi = releases energy ∆G = -7.3 kcal/mole

3rd Pi is hardest group to keep bonded to molecule

Bonding of negative PBonding of negative Pi i groups is unstablegroups is unstable spring-loadedspring-loaded PPi i groups “pop” off easily & release energygroups “pop” off easily & release energy

Instability of its P bonds makes ATP an excellent energy donor

AMPAMPADPATP

Can’t store ATP good energy donor,

not good energy storagetoo reactivetransfers Pi too easilyonly short term energy

storage carbohydrates & fats are

long term energy storage

ATP / ADP cycleATP / ADP cycle

A working muscle recycles over 10 million ATPs per second

Whoa!Pass me

the glucose(and O2)!

ATP

ADP Pi+

7.3 kcal/mole

cellularrespiration

PHOTOSYNTHESIS

..

CAPTURING THE ENERGYIN LIGHT

The process by which organisms obtain energy directly from sunlight is called photosynthesis.

6CO2 + 6H2O → C6H12O6 + 6O2

ENERGY FOR LIFEPROCESSES

Autotrophs: Plants, Algae, Autotrophs: Plants, Algae, and some Bacteria.and some Bacteria.

Autotrophs store energy in various organic compounds, primarily carbohydrates.

Photosynthesis involves a complex series of chemical reactions: Biochemical Pathway

Products used in cellular Products used in cellular respiration.respiration. The Basic

BiochemicalPathway

LIGHT ABSORPTION INCHLOROPLASTS

Light Reactions or Light Dependent Reactions

They begin with the absorption of lightin chloroplasts.

OverviewOf the

Light Reaction

CHLOROPLASTSCHLOROPLASTS

LIGHT AND PIGMENTS

chlorophylls

accessory pigments

carotenoids

LIGHT REACTIONSLIGHT REACTIONS

1.1. ELECTRON TRANSPORT ELECTRON TRANSPORT CHAIN: PHOTOSYSTEMS II CHAIN: PHOTOSYSTEMS II AND IAND I

2.2. RESTORING RESTORING PHOTOSYSTEM IIPHOTOSYSTEM II

3.3. CHEMIOSMOSISCHEMIOSMOSIS

Photosystem

I & II

ELECTRON TRANSPORT CHAINELECTRON TRANSPORT CHAIN

RESTORING PHOTOSYSTEM IIRESTORING PHOTOSYSTEM II

CHEMIOSMOSISCHEMIOSMOSIS

PUTTING IT ALL TOGETHERPUTTING IT ALL TOGETHER

Review of theLight Reaction

With AllDetails!

Photosynthesis AnimationPhotosynthesis Animation

http://www.stolaf.edu/people/giannini/http://www.stolaf.edu/people/giannini/flashanimat/metabolism/photosynthesis.swfflashanimat/metabolism/photosynthesis.swf

LIGHT INDEPENDENT LIGHT INDEPENDENT REACTIONSREACTIONS

KNOWN AS THE KNOWN AS THE CALVIN CALVIN CYCLECYCLE..

COCO2 2 IS FIXED INTO ORGANIC IS FIXED INTO ORGANIC COMPOUNDS: CARBON COMPOUNDS: CARBON FIXATION.FIXATION.

THREE MAJOR STEPS, WHICH OCCUR WITHIN THE STROMA.

Calvin

Cycle

How do Plants

CaptureCO2?

RATE OF PHOTOSYNTHESIS