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• An _______________ is a __________________ that functions as a ______________ to

________________________________________________________ in the body.

• Continuously recycled.

• _______________________________: speed up rates of reactions inside the cytoplasm.

• They _______________ the rate of _____________________ in the body.

• They lower ______________________________ (energy needed to get a reaction started)

• They weaken chemical bonds so molecules can be ___________ or ___________________ by the

body.

• Highly specific-

____________________________________________________________________________________

• Specific terminology-

o Substrate-

______________________________________________________________________________

______________________________________________________________________________

______________________________________________________________________________

o Active Site-

______________________________________________________________________________

______________________________________________________________________________

______________________________________________________________________________

o Product-

______________________________________________________________________________

______________________________________________________________________________

______________________________________________________________________________

• Many enzymes have an ________________ ending.

o Some examples:

� Sucrose (table sugar) Sucrase

� Lipids Lipase

� Amylose Amylase -in human saliva, helps break down starch

� Lactose Lactase

� Catalase breaks down hydrogen peroxide in eukaryotic cells

� DNA helicase unzips the double stranded DNA molecule for replication

� DNA polymerase enzymes that create DNA molecules by assembling nucleotides.

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Step 1- ______________ binds to the ____________ at the ________________________.

Step 2- The _______________ is changed by the ______________ and converts the _____________ into

____________________.

Step 3- ____________________ are released into the body.

Step 4- Once the _____________ are released, the ________________________ is ready for another molecule

(substrate) to bind to,

Step 5- The process is _________________________, it never stops.

The model can be called the “Enzyme Substrate Complex” OR the

“Lock and Key Model”

The shape of the active site (“the lock”) determines which substrate (“the key”) will “fit” into the enzyme.

Lowers activation

energy so that the

product can form

and the chemicals

can spontaneously

break apart.

B i o c h e m i s t r y N o t e s

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1. Temperature

• As ________________________________, kinetic energy increases, and

______________________________________________________________________. The

more they move around, the higher the probability that an ____________________ and a

________________________ will ________________________________and react.

• Enzymatic reactions _________________________ with an

________________________________________________________________.

• TOO HOT-

______________________________________________________________________________

• TOO COLD-

______________________________________________________________________________

• OPTIMAL TEMPERATURE-

______________________________________________________________________________

2. pH

• Work best at a certain pH.

• ______________________________________________________________________________

• TOO low or TOO high the enzyme will _________________________________________

• Optimal ph =_______

• Example of an exception:

______________________________________________________________________________

______________________________________________________________________________

3. Concentration of Enzyme or Substrate

• If enzyme concentration is low, the reaction is slow.

As the enzyme

concentration increases,

the rate of reaction

increases.

As the substrate increases,

the reaction increases up

to a certain point (enzyme

is limited).

B i o c h e m i s t r y N o t e s

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ATP= ________________________________________________

Macromolecule: _____________________________

Organelle: __________________________

Main Function: _________________________________________________________________________

Comes from: ____________________________________________________________________________

Structure: Made up of adenine, ribose, and three phosphates.

Differences

ATP ADP • 3 phosphates

• High energy

• 2 phosphates

• Low energy

Third bond is very weak.

When phosphate is

removed, energy is released

and ATP becomes ADP,

Adenosine Diphosphate.

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• Fats store the most energy.

o 80 % of the energy in your body.

o About 146 ATP molecules from a triglyceride.

• Proteins are the least likely to be broken down to make ATP because they have so many

different functions.

o Amino acids are not usually needed for energy.

o About the same amount of energy as a carbohydrate.

• Carbohydrates are the molecules most commonly broken down to make ATP.

o Not stored in large amounts.

o Up to 36 ATP is created from one glucose molecule.

Of course it all starts with photosynthesis and then organisms take it in via cellular respiration.

What if there isn’t any sunlight?

Chemosynthesis:

__________________________________________________________________________________________________

__________________________________________________________________________________________________

Where does this occur? ____________________________________________________________________________

phosphate removed

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Review Questions- complete the review questions. Try not to use your notes!

1. Explain in your own words, what is occurring in the ATP / ADP cycle.

__________________________________________________________________________________________________

__________________________________________________________________________________________________

__________________________________________________________________________________________________

2. Describe two functions of catalysts in chemical reactions.

__________________________________________________________________________________________________

__________________________________________________________________________________________________

3. The substrate is also known as the _________________ in a chemical reaction.

4. List three ways in which enzymes can be altered.__________________________________________________

5. Some organisms live in very hot or very acidic environments. Would their enzymes function in a person’s cells? Why

or why not?

__________________________________________________________________________________________________

__________________________________________________________________________________________________

__________________________________________________________________________________________________

6. Suppose that the amino acids that make up an enzyme’s active site are changed, how might this change affect the

enzyme?

__________________________________________________________________________________________________

__________________________________________________________________________________________________

7. What is the main function of ATP? _______________________________________________________________

8. How do we obtain ATP? _________________________________________________________________________

9. Which organic molecule is used by the body as a good source of long term energy storage? ____________

10. Proteins are composed of a chain of ____________________________.

11. Label the diagram.