Exam 2 - Intro to Enzymes Flashcards
An enzyme that is inactive due to the absence of a cofactor or prosthetic group is a….
Apoenzyme
A catalytically active enzyme-cofactor or enzyme-prosthetic group complex is a …..
Holoenzyme
A small organic molecule (coenzyme) or metal ion that is required for enzyme activitiy is called a….
Cofactor
A cofactor that is covalently associated with an enzyme is a….
Prosthetic group
What is the difference between the substrate binding site and the active site?
- Substrate Binding site
- area of the enzyme that binds specificity with substrate
- Active Site
- region of enzyme that caralyzes the reaction
- Or the specific amino acid residues in the substrate binding site
A control site not within the active or substrate binding site is called the….
Allosteric Site
Can an allosteric, effector, molecule increase or decrease the reaction rate?
- It can do both - increase or decrease the reaction…it depends.
What are the 6 classifications of enzymes?
- Oxidoreductase
- Transferase
- Hydrolase
- Lyase
- Isomerase
- Ligases
What are our examples of an Oxidoreductase?
-
Oxidase and Reductase
- transfers electrons, usually reversible
-
Dehydrogenase
- Moves electrons, Look for reducing cofactors like - NAD, NADP, FAD
-
Oxygenase or Hydroxylase
- Moves Oxygen around
- Peroxidase
-
Catalase
- Used in reactive oxygen systems
This type of enzyme transfers functional groups to a substrate - 2 substrates = 2 products.
Transferase
What are common groups transferred by transferases?
Acyl
Amino
Methyl
Glycosyl (sugar)
Phosphate (kinases)
What does a transamerase do? What classification of enzyme would this be?
- Moves Amino acids
- EC 2
- This enzyme basically works in the reverse of a condensation reactions, transferring the donor group to water
- 1 subtrate = [] products
- Hydrolase
- 2 products
Phosphoprotein phosphatase is a specific enzyme that does what….?
- specific hydrolase that removes phosphate groups.
What are the 7 types of Hydrolases, and what does each do?
- Esterase - acts on esters
- Glycosidase - reverses glycosyl transfers
- Peptidase - reverses peptidyltransferase
- Thiolase - acts on something attached to acetyl-CoA
- Lipase - Acts on phospholipid or fatty acid…BUT not on free cholesterol
- Deaminase - Removes a Nitrogen group
- Nuclease - Exonuclease (DNAP, RNAse, DNAase)
Lyases
- EC []
- Carbon covalently linked to what types of molecules… [] [] [] []
- May add groups to double []
- May form double bonds by [] removal
- May [] or [] water, ammonia, carbon dioxide
- [] substrate = 2 products
- EC 4
- N, O, S, P
- Double Bond
- Group removal
- add or remove
- 1 substrate
What are 5 examples of a lyase?
- Decarboxylase
- Synthase (or Lyase….)
- Lyase
- Aldolase
- Hydratase
- This classification of enzyme forms C-C, C-S, C-O, C-N by condensation reactions coupled to ATP cleavage
- EC []
- Referred to as []
- Ligases
- EC 6
- synthetase
What are the 3 examples of Ligases?
- Synthetase
- Carboyxlase
- Ligase
- T4 DNA-ligase
Isomerase
- Transfers groups [] a molecule
- EC []
- May alter position of double []
- May alter position on a [] molecule
- May alter position of an [] group
- 1 substrate = [] product
- within
- EC 5
- Double bond
- chiral
- attached group
- 1 product
This classification of enzyme is also called an “intramolecule lyase”…
isomerase
What are some examples of isomerases and what do they do?
- Epimerase
- changes connection of molecules on a chiral center when the molecule has >1 chiral centers
- Racemase
- Changes connection if the molecule only has 1 chiral center
- Mutase
- Can move around a functional group
A reaction order describes how many [] must interact to form products
reactants
What are the different “ordered” reactions?
- 1st order
- 2nd order
- 3rd order, very rare
- Zero Order
- Pseudo 1st Order
