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Friday, October 14

  1. page (a) About enzymes edited ... *catalyst: a substance which makes a chemical reaction go faster (without changing itself). A …
    ...
    *catalyst: a substance which makes a chemical reaction go faster (without changing itself). A catalyst can be used over and over again without getting used up
    WHAT IS THE ACTIVE SITE?
    ActiveActive site is
    http://academic.brooklyn.cuny.edu/biology/bio4fv/page/active_.htm <-- there is a really good animation on this link which describes what active site is.
    {Lock-and-key_model.jpg} Diagrams like this are often called 'lock and key models' because of the way the substrate fits into the enzyme.
    Without enzymes, why would so many reactions be so slow?
    Enzymes are an absolute necessity to live. Without enzymes, you wouldn't be able to breathe, swallow, drink, eat, or digest your food.
    
    "The catalysts of biochemical reactions are enzymes and are responsible for bringing about almost all of the chemical reactions in living organisms. Without enzymes, these reactions take place at a rate far too slow for the pace of metabolism."
    Enzymes are highly specific in terms of what they act upon and what they do.
    This specificity and what the enzyme does is made possible by their structures
    Enzymes make it easier for a reaction to take place.
    Enzyme substrate will bind to a special area of the enzyme
    called the active site
    Enzymes are very specific to with reaction they catalyze and also the substrates which are involved in the reactions. They specify because of the substrate and the reaction. They can only catalyze the transformation of a specific group of substrates which all have either the exact of similar structure.
    An example of specificity: The characteristics of the enzymes of hydrophilic and hydrophobic layers allow the plasma membrane to form. Enzymes specificity is responsible for creating shapes that complementary.
    For complementary shapes, think of it as a handshake model (what was formerly called the lock & key model). The specific shapes allow the objects to function.
    + Video of the lock and key model
    http://www.youtube.com/watch?v=EiMBsgNZh-M
    + There are four types of specificity:
    Absolute specificity, linkage specificity, group specificity and stereochemical specificity.
    Vocabulary:
    Catalyst:
    A substance, usually used in small amounts relative to the reactants, that modifies and increases the rate of a reaction without being consumed in the process.
    Substrate: The material or substance on which an enzyme acts.
    +Such an interaction would be structurally incorrect. Each enzyme has its own substrate (or set of substrates, which are closely related compounds with high structural similarity). Its specificity allows it to catalyze certain reactions with similarities.
    Enzyme pepsin and enzymes on the membrane of mitochondria:
    The enzymes on the membrane of the mitochondria (located in the inner membrane) make ATP.
    Enzyme pepsin are released by cells in the stomach (and the small intestines) which are responsible for breaking down food proteins into peptides. Pepsin degrade proteins into polypeptides, which are then broken down into amino acids, dipeptides and tripeptides.

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    6:29 am

Thursday, October 13

  1. page (c) Enzymes & activation energy edited Activation energy and enzymes: - Activation Activation energy is ... are formed. Enzymes a…

    Activation energy and enzymes:
    - ActivationActivation energy is
    ...
    are formed.
    Enzymes are proteins that catalyze chemical reactions.
    Enzymes use
    How do enzymes speed up reaction?
    A catalyst is a substance that speeds up the rate of a chemical reaction, but is chemically unchanged at the end of a reaction. This process is known as Catalysis.
    Calalysts work by lowering the activation energy of the reaction.

    Catalysts offer an alternate path for the reaction to occur
    Lower the activation energy required for recants to form products
    Catalysts are not changed by reactions(and also not change the reaction, but only speeds it up) and so can be used again
    
    {ch06c1.jpg} 
    

    
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    6:50 am
  2. page (c) Enzymes & activation energy edited Activation energy and enzymes: ... up the reaction. How Enzymes reaction (Enzymes lowers th…

    Activation energy and enzymes:
    ...
    up the reaction.
    How Enzymes
    reaction (Enzymes lowers the activation energy neede to start up a reaction).
    How do enzymes
    speed up reaction:
    - Catalysts
    reaction?
    Catalysts
    offer an
    ...
    to occur
    - Lower

    Lower
    the activation
    ...
    form products
    - Catalysts

    Catalysts
    are not
    
    {ch06c1.jpg} 
    
    (view changes)
    6:35 am

Tuesday, October 4

  1. page (c) Enzymes & activation energy edited ... - Activation energy is the amount of energy needed to get the reactants to the transition stat…
    ...
    - Activation energy is the amount of energy needed to get the reactants to the transition state, in which bonds are broken and new bonds are formed. Enzymes use less activation energy and so speed up the reaction.
    How Enzymes speed up reaction:
    - Catalysts offer an alternate path for the reaction to occur
    - Lower the activation energy required for recants to form products
    - Catalysts are not changed by reactions(and also not change the reaction, but only speeds it up) and so can be used again

    
    {ch06c1.jpg} 
    (view changes)
    7:22 am
  2. file ch06c1.jpg uploaded
    7:19 am
  3. page (c) Enzymes & activation energy edited cc Activation energy and enzymes: - Activation energy is the amount of energy needed to get th…
    cc
    Activation energy and enzymes:
    - Activation energy is the amount of energy needed to get the reactants to the transition state, in which bonds are broken and new bonds are formed. Enzymes use less activation energy and so speed up the reaction.
    How Enzymes speed up reaction:
    

    (view changes)
    6:53 am

Sunday, October 2

  1. page (b) Enzyme models edited ... (2) Write 4-5 really good sentences to describe this process. (3) How does the induced fit m…
    ...
    (2) Write 4-5 really good sentences to describe this process.
    (3) How does the induced fit model of enzyme activity differ from the lock & key model? (You need to think for yourselves for this one)
    {http://waynesword.palomar.edu/images/enzyme5.gif}
    The active site on the enzyme attaches to a substrate molecule (such as a disaccharide) forming an enzyme-substrate complex. While attached to the substrate, the enzyme causes a weakening of certain chemical bonds in the substrate molecule, resulting in a breakdown (hydrolysis) of the substrate into two smaller product molecules (such as two monosaccharides). The enzyme is unaltered during the reaction and is free to catalyze the breakdown of another substrate molecule
    

    (view changes)
    9:23 pm
  2. page (a) About enzymes edited ... WHAT IS THE ACTIVE SITE? Active site is basically where the substrate combins with the enzym…
    ...
    WHAT IS THE ACTIVE SITE?
    Active site is basically where the substrate combins with the enzyme and where the catalyst (the sped up reaction) occurs.
    ...
    site is.
    {Lock-and-key_model.jpg} Diagrams like this are often called 'lock and key models' because of the way the substrate fits into the enzyme.

    Without enzymes, why would so many reactions be so slow?
    Enzymes are an absolute necessity to live. Without enzymes, you wouldn't be able to breathe, swallow, drink, eat, or digest your food.
    
    ...
    of metabolism."
    

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  3. page (a) About enzymes edited WHAT ARE ENZYMES? ... living things. "Without enzymes, our guts would take weeks and …

    WHAT ARE ENZYMES?
    ...
    living things.
    "Without enzymes, our guts would take weeks and weeks to digest our food, our muscles, nerves and bones would not work properly and so on - we would not be living!"
    http://www.purchon.com/biology/enzymes.htm
    ...
    getting used upup
    WHAT IS THE ACTIVE SITE?
    Active site is basically where the substrate combins with the enzyme and where the catalyst (the sped up reaction) occurs.
    http://academic.brooklyn.cuny.edu/biology/bio4fv/page/active_.htm <-- there is a really good animation on this link which describes what active site is.
    Without enzymes, why would so many reactions be so slow?
    Enzymes are an absolute necessity to live. Without enzymes, you wouldn't be able to breathe, swallow, drink, eat, or digest your food.
    
    "The catalysts of biochemical reactions are enzymes and are responsible for bringing about almost all of the chemical reactions in living organisms. Without enzymes, these reactions take place at a rate far too slow for the pace of metabolism."
    

    (view changes)

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