Exam 3: lecture 9 Flashcards
What is ATP?
Adenosine Triphosphate
phosphoanhydride bonds: linked the 3 phosphates tgt to each other
- the 1st bond holds the most energy
phosphoester bond: the 3rd bond closest to adenosine
ribose: 5 carbon sugar at the 2’ carbon
H: @1’ carbon
hydrolysis: ATP –> ADP + Pi + energy (endergonic)
synthesis: ADP + Pi–> ATP (exegonic)
common:
ATP: most commonly used “$5”
GDP
*know structure
apoenzyme
protein portion- incomplete & inactive enzynme
coenzyme
cofactor(nonprotein protion)
often a catiion
holoenzyme
whole active enzyme along with the coenzyme- ready for substrate to bind
substrate will bind to alter shape
the structure of NAD+ and its oxidation and reduction
structure:
1 adenine
2 ribose
linked by pyrophosphate bridge
NAD+—reduced—> NADH (loses an e-: gain an H+)
NADH (H carrier) —oxidized–> NAD+ (gains an e-: loses an H+)
carrier molecule:
NAD:carry a hydrogen
how do inhibitors interfere with substrate binding?
competitive inhibitor: bind to the active site, blocks substrate from binding directly
noncompetitive inhibitor: bind to an allosteric site, causing the enzyme to alter shape-> prevent substrate from binding indirectly
how do enzymes get to the most energy?
functions by proximity
enzymatic pathway: how to lead to Feedback Inhibition
path way starts when substrate binds to enzymes to form intermediate products through a series of pathway
once there is enough products needed, the end products bind to the allosteric site of the first enzyme to shut down the pathway—> Feedback inhibition (enzyme activity is inhibited by the enzyme’s end product)
(end products acts as a noncompetitive inhibitor)
Factors that influence enzyme activity
1) temp
2)pH
lysosomal enzyme: most active at pH 5
basophile: basic environment
thermus aqauticus: live in the vents of the ocean (close to boiling temp)
3) substrate concentration: as substrate increases, enzyme activity increases but hits a plateau bc there’s only a certain # of active sites (activity is limited by active sites)
Redox reactions
hydride (alcohol)—oxidation (dehydrogenase)break—> NAD+
NAD+ + 2H(& e-) —-reduction (add+putting tgt)—-> NADH + H
how is NADH & energy involved in chemiosmosis?
membrane: high H+ concentration
inside inner mitochondria membrane: low H+ concentration
electron carrier: NADH donate e- to the ETC, where H+ pumps into the membrane with a lot of H+ (gradient)
ATP synthase: uses the gradient energy pum H+ from a high-> low concentration to make ATP
how is ATP involved in substrate-level phosphorylation
the substrate carries a P with it
bind to the enzyme where theres already ADP
—> ATP
Equation for Cellular Respiration + rearrangements of H atoms (redox )
C6H12O6 (glucose) + 6O2——> 6CO2 (Carbon dioxide) + 6H2O (water) + ATPs (energy)
C6H12O6 —oxidation (loss of H)—> 6 CO2
6O2—-reduction (gain of H)—-> 6 H20
overview of cellular respiration+ location
- glycolysis: glucose–> pyruvic acid
location: cytoplasm (cytoplasmic fluid) - krebs cycle
location: mitochondria matrix - ETC
location: inner membrane of mitochondria
glycolysis: steps + products
overview:
glucose—-> 2 pyruvic acid (2x 3 carbon)
(2ADP+ 2Pi—–> 2 ATP)
(2NAD+—–> 2 NADPH+2H)
preparatory phase (energy investment):
step 1: OOOOOO—(ATP–>ADP)—> OOOOOO+P (glucose 6-phosphate)
step 2: glucose 6-phosphate—-> fructose 6-phosphate
(to get mirror image molecules (2 copies of the same thing)
step 3: fructose 6-phosphate—-(ATP—>ADP)—-> fructose 1, 6-phosphate (P+OOOOOO+P)
step 4: fructose 1,6-phosphate—-(hydrolytic reaction)—> glyceraldehyde 3-phosphate (G3P)
phosphorylation stage (payoff where ATP is generated)
step 5: G3P—-(NAD+–reduced—>NADH)—–> 1, 3-biphosphoglycerate
step 6: 1,3 biphosphoglycerate —(ADP–>ATP)—-> 3 phosphoglycerate
step 7: 3 biphosphoglyerate—(ADP–>ATP)—> pyruvate
happens twice-once w each 1,3 biphosphoglycerate made.
4 total made
2 net
the conversion of pyruvic acid to acetyl CoA
location: cytosol–> mitochondria
pyruvic —–coenzyme A(take it into mitochondria—> Actyle coa
-remove carbon (CO2) is taken out
nad+—> NADH + H+ (generated when carbon is redoxed)
total nadh: 4
the krebs cycle
dpendent on oxygen present
CoA is removed, only Aetyl enters the cycle
acetyl—> citric acid
citric acid—–> a-ketoglutaric acid (5 carbon)
CO2 leaves cycle as a gas
NAD+ —->NADH+ H+
a-ketoglutaric acid (5 carbon)—-> succinic acid
NAD+ —-> NADH+ + H+
ADP+P —-> ATP
succinic acid—-> fumarate
fumarate——-> malic acid
FAD—-> FADH2
malic acid——> oxaloacetic acid
NAD+ —-> NADH+ + H+
total atp used: 6 atp
net: 4 atp
The process of ETC
location: inner mitochondria membrane
NADH——> NAD+ + H+
e- are released and bind to H- go through electron carriers of the ETC
this energy is used to pump H+ out where theres a high concentration H+
ATP synthase uses it to create ATP
at the end of the chain, reduced 1/2 O2 bind with 2H+ to make h2o
O2 is the final electron acceptor
The process of ETC
location: inner mitochondria membrane
NADH——> NAD+ + H+
e- are released and bind to H- go through electron carriers of the ETC
this energy is used to pump H+ out where theres a high concentration H+
ATP synthase uses it to create ATP
at the end of the chain, reduced 1/2 O2 bind with 2H+ to make h2o
O2 is the final electron acceptort
the effects of five poison on the ETC & chemiosmosis
Rotenone: 1 step weher NADH—-> NAD+
Cynanide, carbon monoxide: the last step of ETC where O2 cant bind with 2h+ to make water
DNP: H+ are no longer able to diffuse through+ no ATPs
Oligomycin: prevent H+ to go down ATP synthase
A tally of ATP yield
glycolysis: 2 ATP (by substrate-level phosphorylation)
0-2 ATP (used for shuttling electrons from nadh made in glycolysis
krebs cycle: 2 ATP (by substrate-level phosphorylation) (each actyle coa)
ETC & chemiosomosis: about 34 ATP (by cheiosmotic phosphorylation)
total: 38+2=40 atp
net:36-38 atp
10 NADH
2 FADH2
anaerobic respiration + examples
an attempt to make atp with O2
a. alcoholic fermentation
b. lactic acid fermentation
anaerobic respiration: alcoholic fermentation
glucose —-> 2 pyruvic acid
2 nad+ ——> 2nadh
2adp+p——>2atp
2 pyruvic acid —–>ethanol
2 nadh + H+—-> 2nad+
2 co2 is released
heterolactic
makes much more than just lactic acid
homolactic
only produces lactic acid
anaerobic respiration: lactic acid fermentation
glucose —-> 2 pyruvic acid
2 nad+ ——> 2nadh
2adp+p——>2atp
2 pyruvic acid—–2 lactic acid
2 nadh + H+—-> 2nad+
no co2 is released
