Download Catalase

Welcome!
AP Biology Warm ­ Up; Friday September 26, 2012
Catalase Period 2
Catalase is a common enzyme found in nearly all living organisms exposed to oxygen. It catalyzes the decomposition of hydrogen peroxide to water and oxygen. It is a very important enzyme in reproductive reactions. Likewise, catalase has one of the highest turnover numbers of all enzymes; one catalase molecule can convert millions of molecules of hydrogen peroxide to water and oxygen each second.
Catalase is a tetramer of four polypeptide chains, each over 500 amino acids long. It contains four porphyrin heme (iron) groups that allow the enzyme to react with the hydrogen peroxide. Catalase was first noticed in 1818 when Louis Jacques Thénard, who discovered H2O2 (hydrogen peroxide), suggested its breakdown is caused by an unknown substance. In 1900, Oscar Loew was the first to give it the name catalase, and found it in many plants and animals. In 1937 catalase from beef liver was crystallised by James B. Sumner and Alexander Dounce and the molecular weight was worked out in 1938.
In 1969, the amino acid sequence of bovine catalase was worked out. Then in 1981, the three­dimensional structure of the protein was revealed.
What does hydrogen peroxide (H2O2) decompose into? How is it possible for catalase to cause hydrogren peroxide to decompose more rapidly? Under which conditions does catalase work best? How can we model the activity of catalase? Why does catalase work better under some conditions than others?
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Welcome!
AP Biology Warm ­ Up; Friday September 26, 2012
Catalase Period 4
Catalase is a common enzyme found in nearly all living organisms exposed to oxygen. It catalyzes the decomposition of hydrogen peroxide to water and oxygen. It is a very important enzyme in reproductive reactions. Likewise, catalase has one of the highest turnover numbers of all enzymes; one catalase molecule can convert millions of molecules of hydrogen peroxide to water and oxygen each second.
Catalase is a tetramer of four polypeptide chains, each over 500 amino acids long. It contains four porphyrin heme (iron) groups that allow the enzyme to react with the hydrogen peroxide. Catalase was first noticed in 1818 when Louis Jacques Thénard, who discovered H2O2 (hydrogen peroxide), suggested its breakdown is caused by an unknown substance. In 1900, Oscar Loew was the first to give it the name catalase, and found it in many plants and animals. In 1937 catalase from beef liver was crystallised by James B. Sumner and Alexander Dounce and the molecular weight was worked out in 1938.
In 1969, the amino acid sequence of bovine catalase was worked out. Then in 1981, the three­dimensional structure of the protein was revealed.
What does hydrogen peroxide (H2O2) decompose into? How is it possible for catalase to cause hydrogren peroxide to decompose more rapidly? Under which conditions does catalase work best? How can we model the activity of catalase? Why does catalase work better under some conditions than others?
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AP Biology
1. Warm ­ Up /Mystery Question ­ 10
2. Review Test ­20
3. Lecture Chapter 1 ­15
4. Chemistry Review ­30
5. Worksheet/Activity ­20
Announcement
Week 5 Assignments due today
Week 6 Assignments due one week from today
Please pay $15 Lab Fee! ­ Due today. 3
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Review Test
Period 2 mean 89.48%
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Review Test
Period 4, mean 85.8%
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Chapter 1 Listen and record notes as we move through the brief lecture.
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Chapter 2
http://www.youtube.com/watch?v=tpJ3asv3XMY
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Student Notes
Chapter 2 Notes: The Chemical Context of Life
Maer: ________________________________________________________________.
I.
Elements: ________________________________________________________ _____________________________________________________________________
A. 25 are essenal
B. 4 make up 96% of living maer 1. ________________
2. ________________
3. ________________
4. ________________
C. Most of remaining 4% are:
1. ________________
2. ________________
3. ________________
4. ________________
D. ________ elements‐ required by an organism in ny amounts eg)Iron
II. Atom: _______________________________________________________________.
A. Subatomic parcles:
1. ___________‐ heavy, in nucleus, charge is 0
2. __________ ‐ heavy, in nucleus, charge is +
3. ___________‐ light, orbing nucleus, charge is –
B. Atomic #‐ # of ___________ (defines element)
C. Mass #‐ # of protons + ____________ aka‐ atomic weight
D. Isotoopes: ______________________________________________________ _______________________________________________________________
eg) ___________________
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B. _________________ unit of measure for subatomic parcles (1 dalton = 1 proton)
___________: What is the atomic weight of Oxygen – 16?
III. Energy Levels of Elccons A. 1st energy level‐ closest to nucleus
lowest energy level
holds ___ electrons
B. 2nd energy level‐
holds ___ electrons
C. Chemical properes of an atom depend on # of _____________ in outermost shell ____________________________________.
*Know‐ HONC!
eg) Hydrogen
Element #1
Mass #1
eg) Oxygen
Element #8
Mass #16
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Exit Questions
What are the three parts of an atom? Where are these parts to an atom found?
Reminders
Announcement
Study Guide due Today
Work on Week 6 Assignments!
Please pay $15 Lab Fee!
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Attachments
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