1. Enzymes Enzymes are Proteins
Enzymes are Catalysts- substances that speed up reactions without being altered in the process
Enzyme names end in “ase”

2. Chemical Reactions and Energy
During chemical reactions bonds are broken and formed – energy is released or absorbed
Chemical reactions that release energy often occur on their own, or spontaneously.
Chemical reactions that absorb energy will not occur without a source of energy.

3. The Direction of Spontaneous Reactions (and what it takes to go the other way)
Energy and Enzymes
4/22/2017
G. Podgorski, Biol. 1010

4. Where do we get Energy from?
Every organism must have a source of energy to carry out the chemical reactions it needs to stay alive.
Plants get their energy by trapping and storing the energy from sunlight in energy- rich compounds.
Animals (Humans) get their energy when they consume plants or other animals.

5. Activation Energy
Every Chemical reaction – even the ones that release energy and occur on their own need a push – something to get going
Activation energy is the energy required to get going, to get a reaction started

6. Enzymes lower the Activation Energy
Enzymes speed up the reaction

7. Enzymes bind to substrates at their active site (lock and key model).
Substrate(s) – reactants of the chemical reaction
1 Enzyme – 1 substrate – 1 chemical reaction

8. A Fit between and enzyme and a substrate is
critical and
precise

9. How enzymes work

10. ENZYME DEFICIENCY AND HEALTH
Energy and Enzymes
4/22/2017
ENZYME DEFICIENCY AND HEALTH
Most genetic disorders are due to a deficiency in enzyme function.
This archival photo shows three children with the enzyme deficiency that causes phenylketonuria.
G. Podgorski, Biol. 1010

11. PKU test for newborns
A phenylketonuria (PKU) test is done to check whether a newborn baby has the enzyme needed to use phenylalanine in his or her body. Phenylalanine is an amino acid that is needed for normal growth and development.
If a baby's body does not have the enzyme that changes phenylalanine into another amino acid called tyrosine, the phenylalanine level builds up in the baby's blood and can cause brain damage, seizures, and mental deficiencies.

12. Enzyme Activity is Often Regulated
Energy and Enzymes
4/22/2017
Enzyme Activity is Often Regulated
Feedback inhibition - a common form of enzyme regulation in which the product inhibits the enzyme.
When you have enough product you want to stop the reaction – product
inhibits enzyme.
G. Podgorski, Biol. 1010

13. INHIBITION: NON-COMPETITIVE -an inhibitor binds to a site other than the active site which causes a change in the active site

14. INHIBITION: COMPETITIVE - an inhibitor binds to the active site preventing the enzyme from binding to the substrate

15. Brain Teaser You have 10 locked doors and only 1 key that unlocks
all the doors. It takes 1 min to unlock each door.
We are going to 'measure'
how efficient you are by
counting the unlocked doors/time.

16. Efficiency:
10 doors in 10 min
You find 1 more key and get a friend to help you.
Efficiency:
10 doors in 5 min
You recruit a total of 9 friends with keys to help you.
Efficiency:
10 doors in 1 min

17. Your friends bring their friends, and they bring their
friends. You end up having 20 people with 20 keys.
Efficiency:
1 min, there are only 10 doors.

18. Enzymes
PART 2

19. Enzymes Part II Enzymes are proteins and have a specific shape
Shape of Proteins can be affected by different environmental factors – temperature, pH, solute concentration, etc.
If the shape is disrupted – the enzyme will not work

20. Enzyme Shape determines Enzyme specificity
In the same way that a key fits into a lock, so a substrate is thought to fit into an enzyme’s active site. The enzyme is the lock, and the reactant is the key. + + ↔ ↔

21. Enzyme Shape
The shape of an enzyme is very important because it has a direct effect on how it catalyzes a reaction.
An enzyme’s shape is determined by the sequence of amino acids in its structure, and the bonds which form between the atoms of those molecules.
Different types of enzymes have different shapes and functions because the order and type of amino acids in their structure is different.

22. The rate of enzyme-catalyzed reactions depends on several factors
The rate of enzyme-catalyzed reactions depends on several factors. What are some of these?
Factors that affect the rate of a reaction include:
temperature
substrate concentration pH
surface area
enzyme concentration
pressure.
All enzymes work best at only one particular temperature and pH: this is called the optimum.
Different enzymes have different optimum temperatures and pH values.

23. Temperature and pH effect enzyme action
Enzymes - Activity
Temperature and pH effect enzyme action

24. Temperature and pH effect enzyme action
Enzymes - Activity
Temperature and pH effect enzyme action

25. The acidic (pH <4) and hot (>80°C) springs in Yellowstone National Park contain LIFE

26. Ice contains LIFE

27. “Weird” Life forms – extreme conditions
Life at Extreme conditions means that enzymes in these organisms can work at extreme conditions

28. PCR – Polymerase Chain Reaction
Taq Polymerase – an enzyme isolated
from a microbe living in hot springs.
Its discovery has revolutionized Science: Biology, Medicine, Forensics