M2: Enzymatic Reactions Flashcards
1
Q
enzymes overview
A
- proteins that help maintain equilibrium in the cell by accelerating (catalyzing) biological reactions
- not consumed/destroyed in reaction, so they can be detected in lab tests
- only catalyze their specific chemical reaction
2
Q
naming of enzymes (usually)
A
“substrate - ase”
3
Q
substrate
A
molecule that an enzyme acts upon (aka molecule going through the chemical reaction)
4
Q
catalase
A
- increases speed of hydrogen peroxide (H2O2) decomposition into H2O + O
- protects cell from oxidative damage by reactive oxygen species (ROS)
- cell would die without it
5
Q
lipase
A
- catalyzes lipid breakdown
- essential for metabolism in absence of glucose
6
Q
protease
A
- catalyzes protein breakdown
- essential whenever we eat
7
Q
6 major categories of enzymes
A
- Hydrolases
- Isomerases
- Ligases
- Lyases
- Oxidoreductases
- Transferases
8
Q
Hydrolases
A
catalyze hydrolysis (addition of water to break chemical bonds)
9
Q
Isomerases
A
- promote intramolecular rearrangements by changing bonds w/in molecule –> create different molecule with same formula
- eg: AB –> BA
10
Q
Ligases
A
- cause molecules to form covalent bonds
- e.g. A + B –> AB
11
Q
Lyases
A
- cause bonds to break w/out hydrolysis or oxidation
- e.g. AB –> A + B
12
Q
Oxidoreductases
A
- catalyze electron transfer from reductant (electron donor) to oxidant (electron acceptor)
- e.g: A- + B –> A + B-
13
Q
Transferases
A
- transfer a functional group from one molecule to another
- e.g: Ab + C –> A + Cb
14
Q
how enzymes work (4 steps)
A
- substrate binds to active site on enzyme molecule
- enzyme converts substrate
- enzyme releases converted substrate
- reaction resets (enzyme can be used again)
15
Q
hydrolysis
A
addition of water to break chemical bonds
eg: AB + H2O –> AOH + BH
