Key Concepts - Week 9 - Enzymes Flashcards
Enzymes are powerful _________
catalysts
All reactions pass through a _____________ on the reaction pathway
transition state
Enzyme active sites bind the…?
transition state of the reaction more tightly than the substrate
Enzyme active sites bind the transition state of the reaction more tightly than the substrate.
By doing so, enzymes stabilize the ___________ & lower the…?
transition state
activation energy of the reaction
What are enzymes? What do they do? (4 points)
What are the Two basic types of enzyme-catalysed reactions?
Essentially all enzyme-catalysed reactions are_______.
REVERSIBLE
Label the cofactor, catalytic site, coenzyme, apoenzyme, and holoenzyme on a drawing of an enzyme
Define COFACTORS
are non-protein components (e.g. metal ions)
Define COENZYMES
- Organic molecules (contain Carbon)
- Commonly vitamins or derivatives
- Involved in catalysis such as to assist in 4. chemical group transfer
- Often at the active site and aide recognition, attracting or repelling a substrate or product
- If the coenzyme is tightly bound to the protein such as through covalent interaction it is known as a PROSTHETIC GROUP
Define APOENZYME
is a protein without a prosthetic group (inactive)
Define HOLOENZYME
Enzyme with cofactors or coenzymes attached that is ready to catalyse a reaction (active)
Activation energies are ALWAYS _________.
positive
At a higher temperature, there are less molecules required to overcome…?
the activation energy compared to the lower temperature.
In addition to temperature, the pH of a reaction can also…?
affect the enzyme catalysed reaction.
T/F: Substrates bind to the enzyme via weak forces (non-covalent associations)
H-bonds, van der Waals and ionic interactions
Sometimes also by hydrophobic interactions
True
What are other factors of enzyme regulation?
Enzymes are __________ that are essential to our cells to facilitate…?
proteins (or ribozymes)
reactions fast enough to sustain life
Enzymes often has the suffix “_____” and are classified into groupings based on what chemical reactions they faciliate
ase
Enzymes have ___________, they are specific and can be regulated
catalytic power
The reaction rate is proportional to the concentration of reactant molecules with the transition-state energy (3 points, 2 sub points)
Selectivity of an enzyme is dependent on…? Grouping of selected amino acids in the ________ structure of the protein.
The active site of the protein
tertiary
Regulation occurs in a variety of ways. List them:
Label the type of reversible inhibition
