1. Making energy!
ATP

2. The energy needs of life
Organisms are energy absorbing systems
What do we need energy for?
synthesis
building biomolecules
reproduction
movement
active transport
temperature regulation
Which is to say… if you don’t eat, you die… because you run out of energy.
The 2nd Law of Thermodynamics takes over!

3. The first law of thermodynamics states that energy can be transformed, i.e. converted from one form to another, but cannot be created or destroyed.
Light energy to chemical energy
Chemical energy to mechanical energy
The second law of thermodynamics states that this conversion of energy cannot occur without some loss of energy.

4. Where do we get the energy from?
Work of life is done by energy coupling
use catabolic (breaking) reactions to fuel anabolic (building) reactions
energy + +
energy + +

5. ATP Living economy Fueling the body’s economy
eat high energy organic molecules
food = carbohydrates, lipids, proteins, nucleic acids
break them down
catabolism = digest
capture released energy in a form all processes in the organism can use
Need a universal energy currency
a way to pass energy around
need a short term energy storage molecule
ATP

6. Build once, use many ways
ATP
Adenosine Triphosphate
modified nucleotide
nucleotide = adenine + ribose + Pi  AMP
AMP + Pi  ADP (uncharged battery)
ADP + Pi  ATP (charged battery)
Marvel at the efficiency of biological systems!
Build once = re-use over and over again.
Start with a nucleotide and add phosphates to it to make this high energy molecule that drives the work of life.
Let’s look at this molecule closer.
Think about putting that Pi on the adenosine-ribose ==>
EXERGONIC or ENDERGONIC?
How efficient!
Build once, use many ways
high energy bonds

7. How does ATP store energy?
I think he’s a bit unstable… don’t you?
How does ATP store energy? P O– O –O P O– O –O P O– O –O P O– O –O P O– O –O
ADP
AMP
ATP
Each negative PO4 becomes more difficult to add
a lot of stored energy in each bond
most energy stored in 3rd Pi
3rd Pi is hardest group to keep bonded to molecule
Bonding of negative Pi groups is unstable
spring-loaded
Pi groups “pop” off easily & release energy
Not a happy molecule
Add 1st Pi  Kerplunk! Big negatively charged functional group
Add 2nd Pi  EASY or DIFFICULT to add? DIFFICULT takes energy to add = same charges repel  Is it STABLE or UNSTABLE? UNSTABLE = 2 negatively charged functional groups not strongly bonded to each other So if it releases Pi  releases ENERGY
Add 3rd Pi  MORE or LESS UNSTABLE? MORE = like an unstable currency • Hot stuff! • Doesn’t stick around • Can’t store it up • Dangerous to store = wants to give its Pi to anything
Instability of its P bonds makes ATP an excellent energy donor

8. How does ATP transfer energy?+
ATP
ADP
ATP helps all reactions occur in two ways:
ATP  ADP
releases energy & can fuel other reactions
Phosphorylation
released Pi can transfer to other molecules
destabilizing the other molecules or changing the shape, allowing the reaction to occur
How does ATP transfer energy?
By phosphorylating
Think of the 3rd Pi as the bad boyfriend ATP tries to dump off on someone else = phosphorylating
How does phosphorylating provide energy?
Pi is very electronegative. Got lots of OXYGEN!! OXYGEN is very electronegative. Steals e’s from other atoms in the molecule it is bonded to. As e’s fall to electronegative atom, they release energy.
Makes the other molecule “unhappy” = unstable. Starts looking for a better partner to bond to. Pi is again the bad boyfriend you want to dump.
You’ve got to find someone else to give him away to. You give him away and then bond with someone new that makes you happier (monomers get together).
Eventually the bad boyfriend gets dumped and goes off alone into the cytoplasm as a free agent = free Pi.

9. An example of Phosphorylation…
Building polymers from monomers
need to destabilize the monomers
phosphorylate! H OH C H HO C
enzyme C H OH HO O +
H2O +
ADP C H OH
enzyme C H P
Monomers  polymers
Not that simple!
H2O doesn’t just come off on its own
You have to pull it off by phosphorylating monomers.
Polymerization reactions (dehydration synthesis) involve a phosphorylation step!
Where does the Pi come from? ATP +
ATP C H P H HO C + C H O + Pi

10. Another example of Phosphorylation…
The first steps of cellular respiration
beginning the breakdown of glucose to make ATP
glucose
C-C-C-C-C-C C H P
ATP 2
Enzyme 1
ADP 2
Enzyme 2
These are the very first steps in respiration — making ATP from glucose.
Fructose-1,6-bisphosphate (F1,6bP)
Dihydroxyacetone phosphate (DHAP)
Glyceraldehyde-3-phosphate (G3P)
1st ATP used is like a match to light a fire…
initiation energy / activation energy.
The Pi makes destabilizes the glucose & gets it ready to split.
fructose-1,6bP
P-C-C-C-C-C-C-P
DHAP
P-C-C-C
G3P
C-C-C-P

11. A working muscle recycles over 10 million ATPs per second
ATP / ADP cycle
Can’t store ATP
too reactive
transfers Pi too easily
only short term energy storage
carbohydrates & fats are long term energy storage
ATP
respiration
7.3 kcal/mole
ADP P +
A working muscle recycles over 10 million ATPs per second

12. Going back some months….
What is the ultimate source of energy for all living organisms?
What is the name of organisms that can capture the energy from that source?
What are the critical products they make that all other life depends upon?
Can you name 5 structures on that type of organism that help it do the job?

13. Check for Understanding
1. What do the first two laws of thermodynamics say about energy.
2. List five processes of life that require energy.
3. I eat a slice of greasy, yummy pizza. My stomach takes it and anabolizes/catabolizes it.
4. How does ATP become ADP? What is released when that happens?
5. Does your body use a form of sugar or ATP to store energy?

14. Parts of a plant
Four basic parts
leaves
stems
roots
flowers

15. Internal Stem Structure
phloem- vascular tissue, carries manufactured foods down.
Xylem- vascular tissue, carries water and minerals up.

16. Roots Usually underground functions: anchor plant and hold upright
absorb water and minerals form soil and conduct to stem
store food, & propagation

17. Leaves the food factory of the plant
produce the food used by the plant or stored for later use
Move to expose maximum surface area to perpendicular angle with sunlight

18. Shape and size of leaves
Each species leaf is distinctive from all others.
Location usually dictates size of leaves due to resource availability.

19. Internal leaf structure
epidermis
skin of the leaf
single layer of cells
protects leaf from loss of too much moisture (cuticle = wax layer)

20. Guard Cells & Stomata
open and close the small pore on the underside of the leaf

21. Stomates
allow the plant to breathe and transpire

22. Chloroplasts
contain chlorophyll

23. PHOTOSYNTHESIS

24. Photosynthesis is TWO Steps
Light Dependent Reactions
Light splits water at the Thylakoid to produce ELECTRONS AND ATP
Light Independent Reactions (Dark Rxns)
The Calvin cycle uses the electrons and ATP to turn Carbon Dioxide into SUGARS