C-3 Flashcards
(37 cards)
What do enzymes do and how do they work?
catalyze reactions so they occur at a biologically relevant rate (by having a substrate attach to their active site)
How are enzymes regulated?
inhibition - turn off when don’t need
activation - turn on when you need it
holoenzymes vs apoenzymes
complete enzyme vs part of one
exoenzymes vs endoenzymes
extracellular (outside cell) vs intracellular (inside cell)
Give examples of when cells might use endo- and exo- enzymes
for breaking or building bonds (?)
oxidoreductases
transfer electrons; both exergonic and endergonic
transferases
Transfer functional groups; endergonic
hydrolases
break molecules with water (hydrolysis); exergonic
lyases
break molecules without water (lysis); exergonic
isomerases
rearrange molecules into isomers; can be both exergonic and endergonic
synthetases/ligases
link larger molecules together using ATP as an energy source; endergonic
synthases
synthesize molecules without ATP; endergonic
polymerases
polymerize monomers of nucleotides into chains; endergonic
Catabolic and Anabolic reactions
breaking down vs building
Exergonic and Endergonic reactions
release energy (catabolism) vs require energy (anabolism)
Oxidation and Reduction reactions
• Include NAD+ and NADH in your discussion of redox: which is the reduced form?
losing electrons vs gaining electrons; oxidation loses electrons to give to NAD+ and stored to make NADH (reduced form)
ATP synthesis
making ATP as a chemical energy source (endergonic)
Aerobic respiration (glycolysis, pyruvate oxidation, Krebs/TCA cycle, electron transport chain/ETC)
- glycolysis: break sugar in half and oxidize to make pyruvate (2 NADH, 2 ATP, 2 pyruvate)
- pyruvate oxidation by stripping pyruvate of carbon (2 CO2, 2 NADH, 2-carbons)
- Krebs cycle: cycle 2-carbon molecules and rearrange to make NADH and ATP (4 CO2, 2 ATP, 2 FADH2, 6 NADH)
- ETC: losing electrons and H+ to convert to ATP by chemiosmosis and oxidative phosphorylation (very end product to complete glucose oxidation = water)
Anaerobic respiration (glycolysis, pyruvate oxidation, Krebs cycle, ETC)
same but doesn’t use oxygen - makes ATP from glucose instead
Fermentation
catabolic pathway;
recycle NADH generated during glycolysis; NADH -> NAD+ (oxidize NADH) for cell to keep running glycolysis (anaerobic process so ATP is made from glucose); only make 2 ATP from glycolysis
Photosynthesis
using light energy to produce glucose from CO2 and H2O (6 H2O, 6 CO2, 18 ATP, 12 NADH to produce 1 glucose)
substrate
Reactants in an enzyme-catalyzed reaction (fits into enzyme)
active site
The portion of the enzyme that binds to and acts upon the substrate
activation energy
the minimum amount of energy it takes to get a chemical reaction started