3. Enzymes and Glycolysis

4. Talk about it
Essentially, burning oil and cellular respiration are the same reaction. Why do you think there are so many reactions that need to take place in cellular respiration? Basically, why don’t we just burn all the gas at once, rather than use a little bit of gas at a time to run our cars? (If you didn’t know, our cars run because little explosions of the gas occur, forcing the pistons out which allows it to turn the wheels)

5. Controlled release of energy

6. Why does the combustion of sugar release energy?
Electrons move to a more stable state, just like energy is released as someone sleds down a hill to a more stable state.

7. Glycolysis Chart
Page 168

8. Glycolysis How could this break down into two identical units?
Show how yeast undergo glycolysis. Talk about how glycolysis is the only thing that organisms could use to make energy when there was no oxygen in the atmosphere

9. What you should know about glycolysis
Why there are 10 reactions rather than just 1
The specificity of enzymes
How much ATP is used and given off
What the initial molecule is and what you end with.

10. Look at pg 168
Find the Enzymes!

11. Enzymes Usually proteins Catalyze reactions
Have an active site (where substrates bind)

12. Activation energy
Amount of energy needed to start an exergonic reaction

13. Enzymes lower the activation energy barrier

14. How enzymes lower activation energy barrier
Holds substrates together
Stresses the bonds between substrates
Serves as a pocket of a different chemical environment
May temporally bind to the substrates and then go back to its original form

15. Conditions that affect the rate of reactions
Enzyme and substrate concentration pH
Temperature
The presence of an inhibitor

16. Rates of reactions with enzymes
Reaction speeds up until all enzymes active sites are full

17. Conditions that affect reaction rates

18. Regulation of Enzymes Inhibition Activation Fig 8.19 Competitive
Allosteric (noncompetitive inhibition)
Activation
Fig 8.19

19. Enzymes fluctuate between inactive and active form

20. Feedback mechanisms
Ex. ATP binds as an allosteric inhibitor while ADP functions as an activator
So… When ATP is abundant, it slows down catabolism, when ADP is present then it speeds up catabolism
Find 1 feedback mechanism on pg 168

21. What you should know about glycolysis
Why there are 10 reactions rather than just 1
That each reaction has a specific enzyme
That four ATP are produced but two are required… so net of 2 ATP produced
Initial molecule is 6 carbon sugar and you end up with a 3 carbon sugar.

22. Online Tutorials
nt/chp06/ html
and nt/chp06/ html