C-3 Flashcards
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
reversible inhibition - noncompetitive
substrate and inhibitor are not competing for the same site – they can look nothing alike because they are trying to sit in different places on the enzyme (allosteric site- binds to change active site shape so no one can bind there)
reversible inhibition - competitive
substrate and inhibitor are directly competing to sit in the same active site of an enzyme
irreversible inhibition
permanently binds the active site of the enzyme
feedback inhibition
When an end-product itself is used to turn off an enzyme
oxidative phosphorylation
synthesis of ATP by ATP synthase and the electron transport chain
Substrate-Level phosphorylation
synthesis of ATP by coupling the direct transfer of a Phosphate group from a substrate to ADP
what is not a product of fermentation
glucose
order of least ATP produced
pyruvate oxidation
krebs
ETC anaerobic
ETC aerobic
T/F molecular O2 can’t be a terminal electron acceptor in anaerobic respiration
true
T/F anaerobic respiration is more efficient and makes less ATP than aerobic respiration
false
T/F anaerobic respiration can use nitrate as a terminal electron acceptor
true
T/F anaerobic respiration is different than aerobic but it does use ETC of sorts
true
T/F organisms that do anaerobic respiration do live in aerobic places
false
