1. The chemical activities of the cell.
Cell Metabolism
The chemical activities of the cell.
Most conversations of metabolism are focused on “fast” or “slow” metabolisms …. the rate!

2. Anabolic Pathways “Anabolism”
Pathways that consume energy, building complex molecules from smaller ones.
Example: Photosynthesis

3. Catabolic Pathways “Catabolism”
Pathways that break down complex molecules into smaller ones, releasing energy.
Example: Respiration

4. Energy and ATP

5. Energy Gives the ability to do work.
Most common forms of energy
Kinetic: energy of motion
Potential: stored energy
Activation: energy required to start a reaction

6. Energy of action or motion.
Kinetic Energy
Energy of action or motion.

7. Stored energy or the capacity to do work.
Potential Energy
Stored energy or the capacity to do work.

8. Energy needed to convert potential energy into kinetic energy.
Activation Energy
Energy needed to convert potential energy into kinetic energy.
Activation Energy
Potential Energy

9. Why do cells need energy?
To Do Work……..
The “work” cell’s need to do to stay alive is called the
“Life functions”.
The Life functions are:
Grow
Develop
Reproduce
Respond to Stimuli

10. 1st Law of Thermodynamics
Energy can be transferred and transformed, but it cannot be created or destroyed.
Also known as the law of Conservation of Energy.

11. 2nd Law of Thermodynamics
Each energy transfer or transformation increases the entropy of the universe.

12. Entropy is a measure of disorder…
Entropy is a measure of disorder…. In order to keep order you must apply energy.

13. How do living organisms overcome Entropy?
Question?
How do living organisms overcome Entropy?
By using energy from the environment or external sources (e.g. food, light).

14. The portion of a system's energy that can perform work.
Free Energy
The portion of a system's energy that can perform work.

15. Free Energy G = H - TS G = free energy of a system
H = total energy of a system
T = temperature in oK (Kelvin)
S = entropy of a system

16. Chemical Reactions Are the source of energy for living systems.
Are based on free energy changes.
Most energy lost is in the form of HEAT.

17. Reaction Types and Energy
Exergonic: chemical reactions with a net release of free energy.
Endergonic: chemical reactions that absorb free energy from the surroundings.

18. Exergonic/Endergonic

19. Exergonic - Respiration Endergonic - Photosynthesis
Biological Examples
Exergonic - Respiration
Endergonic - Photosynthesis

20. All living cells use ATP as their energy source
ATP is Adenosine Triphosphate
Made of:
- Adenine (nitrogenous base)
- Ribose (pentose sugar)
- 3 phosphate groupst

21. ATP
3 Phosphate Groups

22. The ATP Cycle ATP ADP + P + Energy

23. ATP in Cells A cell's ATP content is recycled every minute.
Humans use close to their body weight in ATP daily.
No ATP production equals quick death.

24. Adding a phosphate group to a molecule.
Phosphorylation
Adding a phosphate group to a molecule.
The phosphate group adds “energy” to the molecule for chemical reactions.

25. ATP
ATP energizes other molecules by transferring phosphate groups to them….. The process is called phosphorylation.

26. Phosphorylation

27. ATP is produced in the cytosol and the mitochondria.
ATP Production
ATP is produced in the cytosol and the mitochondria.