User:Eric Martz/Hemoglobin Quiz
From Proteopedia
(Difference between revisions)
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- | { | + | {Molecular oxygen binds directly to, and is released from |
|type="[]"} | |type="[]"} | ||
- | + | + | - alpha helices |
+ | - oxygen atoms | ||
+ | + histidine amino acids | ||
+ | - cysteine amino acids | ||
+ | + iron atoms | ||
+ | - magnesium atoms | ||
|| | || | ||
- | { | + | {Heme groups are held |
|type="[]"} | |type="[]"} | ||
- | + | + | + in alpha chains |
+ | + in beta chains | ||
+ | - between alpha and beta chains | ||
+ | - in gamma chains | ||
|| | || | ||
- | { | + | {More than half of the atoms in heme are |
|type="[]"} | |type="[]"} | ||
- | + | + | + carbon |
+ | - oxygen | ||
+ | - nitrogen | ||
+ | - sulfur | ||
|| | || | ||
- | { | + | {Hydrogen bonds |
|type="[]"} | |type="[]"} | ||
- | + | + | - are covalent bonds |
+ | + are non-covalent bonds | ||
+ | - form between two hydrogen atoms | ||
+ | + stabilize the main chain conformation in alpha helices | ||
|| | || | ||
- | { | + | {Each chain in the hemoglobin molecule contains |
|type="[]"} | |type="[]"} | ||
- | + | + | - multiple beta strands |
+ | + multiple alpha helices | ||
+ | - a hydrophilic core | ||
+ | + a hydrophobic core | ||
+ | + one pocket to hold one heme | ||
+ | - one pocket to hold two hemes | ||
|| | || | ||
- | { | + | {An amphipathic alpha helix is one that |
|type="[]"} | |type="[]"} | ||
- | + | + | - occurs only in sickle disease |
+ | - occurs only in the de-oxy form of hemoglobin | ||
+ | - is hydrophilic on both sides | ||
+ | + has a hydrophilic side and a hydrophobic side | ||
+ | - is hydrophobic on both sides | ||
|| | || | ||
- | { | + | {Amino acids with hydrophobic sidechains are present mostly |
|type="[]"} | |type="[]"} | ||
- | + | + | + where they do not contact water |
+ | - on the surface of the protein molecule | ||
+ | - in order to bind molecular oxygen | ||
+ | + buried in the center of the protein molecule | ||
+ | - in separate helices from the helices of hydrophilic amino acids | ||
|| | || | ||
- | { | + | {Salt bridges |
|type="[]"} | |type="[]"} | ||
- | + | + | + form when oppositely-charged amino acid sidechains contact each other |
+ | - form when positively charged amino acid sidechains contact each other | ||
+ | - form mostly in the core of the molecule | ||
+ | + form mostly on the surface of the molecule | ||
+ | - are covalent bonds | ||
|| | || | ||
+ | |||
+ | {Histidine amino acids | ||
+ | |type="[]"} | ||
+ | - have oxygen in their sidechains | ||
+ | + have nitrogen in their sidechains | ||
+ | + have carbon in their sidechains | ||
+ | + bind tightly to Fe++ | ||
+ | + help to bind molecular oxygen | ||
+ | |||
+ | Oxygen binding | ||
+ | |type="[]"} | ||
+ | + is partly to a histidine sidechain nitrogen | ||
+ | + moves the iron in heme | ||
+ | + changes the conformation of hemoglobin | ||
+ | + is stronger at the higher pH in the lungs | ||
+ | + causes some salt bridges to separate | ||
+ | + is decreased by diphosphoglyceric acid | ||
+ | |||
+ | Sickle hemoglobin | ||
+ | |type="[]"} | ||
+ | +is advantageous in some parts of the world | ||
+ | +shortens the lifetime of red blood cells | ||
+ | +impairs blood flow | ||
+ | +is caused by a mutation that changes a single amino acid | ||
+ | +causes severe disease only in homozygotes | ||
+ | +polymerizes into fibers due to hydrophobic interactions | ||
+ | |||
</quiz> | </quiz> |
Revision as of 20:15, 16 September 2018
Hemoglobin Quiz
You will get immediate feedback when you click Submit. The quiz below is offered to accompany the interactive tutorial Hemoglobin Molecular Structure.