1. 3.3. NUTRITION AND ENERGY SYSTEMS
IB SEHS

2. Starter What distinguishes animal cells versus plant cells?
Where does respiration occur?

3. Learning Objectives Everyone will be able to
Identify the different parts of the mitochondrion.
2. Define and understand respiration
3. Explain the loss and gain of phosphate in an adenosine molecule

4. The Animal Cell

5. Mitochondrion Ultrastructure
Energy provision
Only site where oxygen is used
Location: All cells, but red cells
Ultrastructure shown right

6. The Energy currency, ATP
ATP is the energy currency
Adenosine TriPhosphate is a molecule created from biochemical energy in organic molecules by catabolic reactions.

7. Cell Respiration
Cell respiration is the controlled release of energy in the form of ATP from organic compounds in cells

8. Energy metabolism: ATP
ATP connects anabolic and catabolic reactions.
Ingested food  stored as fats or glycogen  Catabolism  ATP Energy

9. ATP role in muscle contraction
Actin and myosin use ATP to drive contraction
Muscle fibers have sufficient ATP for only 2 seconds of contraction. The rest comes from catabolic reactions that generate ATP
ATP + H2O ADP + P + Energy  Contraction

10. Anaerobic Energy Systems Creatine Phosphate System
CP is another high energy molecule BUT cannot be used directly. It´s a check we need to first cash into ATP.
During exercise, after spending our 2 sec worth of ATP, CP helps re-synthesizing ATP, giving energy for up to first 20 sec to muscles

11. Creatine Phosphate System goes both ways
The ATP-CP system can go both ways.
During exercise, first 20 sec, ATP is re-synthesized
At rest, ATP can be used to refill our store of PCr in the muscle
REST < >EXERCISE

12. Anaerobic Energy Systems Lactic Acid System
Anaerobic Glycolysis LOCATION: CYTOPLASM of all cells
Glucose  ATP + pyruvate
Limited supply of oxygen or mithocondria leads to Pyruvate Lactate + 2 ATP
Lactic Acid System is quick and ideal of hard exercise

13. Anaerobic Energy Systems Lactic Acid System
Is the Lactic Acid System an ideal system for an elongated period of hard exercise?
Interpret and comment on the following graph

14. Aerobic Energy Systems
Location: MITOCHONDRIA
Electron transport chain in the inner membrane
Krebs Cycle in the matrix
β-oxydation in the matrix

15. Aerobic Energy Systems
Glucose Oxydation
Pyruvate  acetil CoA Krebs Cycle in the matrix
H+ ions released  ELECTRON TRASPORT CHAIN ENERGY AS ATP

16. Aerobic Energy Systems
Fat Oxydation
Free fatty acids enter the matrix  β-oxydation  Acetil CoA  Krebs Cycle  H+  Electron transport chain  Energy as ATP
Fat CANNOT
BE USED
ANAEROBICALLY,
unlike glycogen

17. STARTER
Discuss in pairs what is the determiant factor for cells to use one energy system or another. Explain in detail.

18. What Energy System is this one? What is the limitant factor?

19. THE BIG QUESTION
How does the elenctron tranport chain help the cell synthesizing ATP?

20. INDIVIDUAL ACTIVITY YOU HAVE RECEIVED A MUSCLE CELL (LONG WHITE PAPER)
DRAW A DIAGRAM, INCLUDING CELL MEMBRANE, CYTOSOL AND MITHOCONDRION WITH DETAIL, IN WHICH THE THREE METABOLIC PATHS ARE SHOWN: ANAEROBIC LACTIC ACID, GLUCOSE AND FATTY ACID OXYDATION. INCLUDE MAIN REACTIONS ONLY
BE READY TO EXPLAIN YOUR CELL.

21. Oxygen Deficit and Excess Post-Exercise Oxygen Consumption (EPOC)
Start of exercise Oxygen need > oxygen supply: O2 DEFICIT  ATP, PCr and anaerobic glycolysis activate quicker!
After exercise  Oxygen supply greater than needed: EPOC or O2 DEBT  offset consequences of anaerobic metabolism, repair of tissue, myoglobin oxydation, etc.

22. Oxygen Deficit and Excess Post-Exercise Oxygen Consumption (EPOC)
Analyze and comment on the following graph:

23. Contribution of the Energy Systems during exercise
High intensity exercise  high rate of ATP needed Fast metabolism  PCr (20 sec) and Lactic Acid System
Longer & Slower exercise  Aerobic metabolism: Glucose and Fat oxydation (slowest one)
Glucose (anaerobic and aerobic) metabolism is key across all intensities of exercise.

24. Contribution of the Energy Systems during exercise

25. Different types of exercise and energy systems contribution