L4 Flashcards
What three factors determine of a chemical reaction? And how does this effect it’s rate?
- Activation energy - energy that must be overcome for chemical reaction to continue
- Concentration - substrate increases = increase reaction until enzyme hits saturation
Increase enzyme = increase rate of reaction
- Temperature - increase temp = speed up molecule movement ; slow down = low temp
What does activation energy mean?
The kinetic energy required for 2 colliding molecules to react
How to enzymes increase the rate of reactions?
Lower activation energy
How do enzymes differ from Catalyst? What do enzymes names tend to end with?
Enzymes = biological catalyst found w/in cells of the body
- names end in “ase”.
Describe the characteristics of an enzyme (6)
- increase reaction rate (lowering activation energy)
- Not chemically altered
Can be reused - doesn’t change chemical reaction.
- made of protein
- regulate cellular metabolism
Specificity
Each unique enzyme has one unique substrate
Saturation
Maximal rate of substantiate converted to product ( reaching its max amount)
Cofactors
Metals (cu+, zn+)
Coenzymes
Organic molecules
- derived from water soluble vitamins (b’s)
Function of an enzyme and its mechanism
Function = chemical reaction speeds up
Mechanism = decrease activation energy for Chemical reaction
How are enzymes regulated. And why is regulation important
- Allosteric regulation - regulation of enzyme by binding substrate to site other than active site
- Covalent Modulation - (phosphorylation) adding of phosphate
- Proteolytic cleavage - enzyme is released in an inactive form (zymogen)
- Genetic control of synthesis - cells make enzymes that are not currently present
Allosteric regulation
regulation of enzyme by binding substrate to site other than active site
Activation + inhibition
Able to turn on/off
Covalent modulation
Aka phosphorylation ( adding of phosphate)
- turns protein on
Proteolytic cleavage
enzyme is released in an inactive form (zymogen)
Genetic control of synthesis
Cells make enzymes that are not currently present
Ex) pregnancy = lactation ( producing milk)
Males during puberty
Isoenzyme
Enzyme with same active site & substrate
How are isoenzymes the same and how are they different?
Same - same active site & substrate
Different - have a few different amino acids (which help distinguish which organ)
Describe how enzymes are used in diagnosis
They have different amino acids therefore, if you took a sample of each and compared it to the “diseased” one you will find the correct enzyme it belongs to and organ
Where is the defect when an enzyme is lacking/ dysfunctional?
End product ( excessive accumulation of intermediates)
Significance in pH optimum? What happens at extremes?
Enzymes have maximum activity at specific pH
On either side of that enzyme activity deceases ( not at its optimum or favorable amount)
Significance of Temperature optima? What happens if it’s at extremes?
- temperature optima = favorable temperature (98..6)
If above optima, enzymes will denature (unfold) slowing enzyme activity until fully denatured
If optima is below optima, molecules will slow down movement decreasing collision rate, therefore decreasing enzyme activity
Explain how an enzyme can cause 2 substrates to join creating only one product
Substrates bind to enzyme ➡️ shape change bringing molecules closer together (electrons interact) ➡️ electrons interacting = covalent bond / new Chemical (product) formed
Explain how an enzyme with one substrate can produce 2 products
Degradation- strain / breakdown of a chemical
Substrate binds to enzyme➡️ cause shape change putting stress onto covalent bond ➡️ breaking bond due to extreme stress
