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
