Flashcards in Biology Class 1 Deck (45)
Exergonic vs Endergonic
Exergonic (-) - energy is exiting system
Endergonic (+) - energy is added to system
Endothermic vs Exothermic
Endothermic (+ΔH) - inputting heat
Exothermic (-ΔH) - liberating heat
What are two ways enzymes can be turned on or off?
2. Allosteric Activator - turns on
Allosteric Inhibitor - turns off
What does Vmax depend on?
1. Type of enzyme
What is Km
[S] required for 1/2 of Vmax
As affinity for [E] and [S] increases = Km decreases
Binds at the active site
Vmax will stay the same
Km will increase
Binds at the allosteric site
Vmas will decrease
Km will stay the same
Binds at ES complex
Vmax will decrease
Km will decrease
Binds at allosteric site
Vmax will decrease
Km will decrease (if binded to ES complex) or increase (if binded to enzyme alone)
9 essential amino acids that cannot be synthesized by adult humans & must be obtained from diet
Purpose of reaction coupling
- Allows for generation of products that would not normally be formed spontaneously
- Reaction coupling allows for a spontaneous process to drive a nonspontaneous process to make the overall reaction spontaneous
- As this is affecting a thermodynamic property, it is unlikely to have an impact on kinetics (reaction rates would not increase, but would be limited by the slow reaction)
What is a direct enzymatic regulation?
- Protein hydrolysis, phosphorylation/dephosphorylation, allosteric activity (even downstream) NOT modification of transcription factors
What happens when a molecule covalently links to an enzyme site?
This would be known as an irreversible inhibitor; negligible enzyme activity
How is dietary fat broken down?
Dietary fat is broken into 2 fatty acids and 1 monoglyceride prior to absorption. Due to the activity of lipase, triglycerides are broken down into two fatty acids and a monoglyceride before absorption and ultimate reassembly into a triglyceride in the enterocyte.