TEST 3 Flashcards
cellular respiration equation
C6H12O6 + 6O2 –> 6CO2 + 6H2O
24 electron redox reaction
what does glucose breakdown during glycolysis?
2 pyruvate
reactions that are used to capture energy during cellular respiration?
-substrate level phosphorylation
-oxidative phosphorylation
pyruvate
3 carbon molecule
where does glycolysis occur
in the cytoplasm
every intermediate compound between glucose and pyruvate is what
phosphorylated
keeps the intermediate inside the cell
kinase function
transfers phosphoryl group from high energy molecule
isomerase function
catalyzes the interconversions of isomers
glyceraldehyde 3 phosphate
&
dihydroxyacetone phosphate
glyceraldehyde 3 phosphate - used directedly in glycolysis
dihydroxyacetone - not used in glycolysis turned into glyceraldehyde 3 phosphate by isomerase
glyceraldehyde 3 phosphate turns into what
13 bisphosphoglycerate
only added another phosphate group
dehydrogenase
catalyzes redox reactions by tranfering electrons to electron acceptor
mutase
catalyzes intramolecular shift of a chemical group
Net reaction for glycolysis
Glucose + 2Pi + 2ADP + 2NAD -> 2 pyruvate + 2ATP + 2NADH +2H + 2H2O
how many electrons are transfered in glycolysis
4 electrons
how many molecules of CO2 is produce in glycolysis
0
is O2 used in glycolysis
no
What other molecules serve as reactants in glycolysis
ADP Pi NAD+
what created this change?
kinase
what created this change?
isomerase
what created this change?
kinase
what created this change?
aldolase
what created this change?
isomerase
what created this change?
dehydrogenase
what created this change?
kinase
where does the TCA cycle take place
inside the mitochondrial matrix for eukaryotes
inside the cytoplasm for prokaryotes
fates of pyruvate
lactate
acetyle CoA
acetaldehyde then ethanol
what occurs in the pyruvate to ethanol fermentation pathway?
-regeneration of NADH to NAD+ to keep glycolysis going to generate ATP
what occurs in the pyruvate to lactate pathway?
-regeneration of NAD+ from NADH to continue glycolysis
what occurs in the pyruvte to acetyle CoA pathway?
–regeneration of NADH from NAD+
-attaches CoA group to Acetyl group from pyruvate
-o2 is needed to
gluconeogenesis
-synthesis of glucose from noncarbohydrate precursors
-occurs in liver, small amts in kidneys
-maintains glucose concentration in blood
-thermodynamically unfavorable
oxaloacetate is only used where
gluconeogenesis
TCA cycle
after turning oxaloacetate into phosphoenolpyruvate what are the reactions that take place to get back to the start of glycolysis?
The exact same reactions that occured in glycolysis occur in gluconeogenesis after the creation of phosphoenolpyruvate but rather in the reverse direction
in gluconeogenesis once fructose 1,6 bisphosphate is created what then occurs?
a phosphatase is introduced to cleave off 1 of the phosphates to get back to glucose
net gluconeogenesis reaction
2 pyruvate + 4ATP + 2GTP +2NADH + 2H + 6H2O = glucose + 4ADP + 2GDP + 6 Pi + 2NAD+
6 nucleotide triphosphates required to turn an energetically unfavable process into a favorable process
∆G=-38kJ/mol
cori cycle
-glycolysis then gluconeogenesis
-done to allow muscle to generate ATP in the absence of oxygen
overall glycolysis byproducts
2 ATP
2 NADH
overall TCA cycle byproducts
NADH FADH2 GTP
conversion reactants and products of pyruvate to acetyl coA
reactants: uses CoA and NAD
products: Acetyl CoA and CO2 and NADH
prothetic groups of Acetyl CoA
TPP
lipoamide
FAD
TPP function
oxidative decarboxylation of pyruvate
lipoamide function
transfers acetyl group to CoA group
FAD function
regenerates oxidized form of lipoamide
Takes away hydrogens, reduces the sulfurs in lipoamide
where does the conversion of pyruvate to acetyl CoA occur?
eukaryotes- in the matrix of the mitochondria
after pyruvate what must be present?
O2
once pyruvate is converted to acetyl CoA what are its characteristics?
its irreversible
net products from pyruvate to acetyl CoA that isn’t carbon related
2 NADH
4 electron transfer
net products of glycolysis that isn’t carbon related
2 ATP
2NADH
1st halve of TCA cycle
oxidize carbon to CO2
2nd halve of TCA cycle
regenerate oxaloacetate (which is the starting material)
synthase
catalyzes the linking of 2 molecules
oxygen and TCA Cycle
indirectly needed
needs NAD+ and FAD which require 02 to regenerate
1st step of TCA cycle
binding of acetyl CoA to Oxaloacetate
bound by synthase
what created this?
synthase
what created this?
dehydrogenase
what created this?
dehydrogenase
succinate hydrogenase
same as complex 2 in electron transport chain
direct link between TCA cycle and electron transport chain
per glucose products from glycolysis to TCA cycle
4 CO2
6NADH
2FADH
2GTP or 2 ATP
how many acetyl per glucose?
2
how many products per glucose in TCA cycle
2 ATP
6 NADH
2FADH2
4CO2
glyoxylate cycle purpose
use acetyl CoA to create glucose
creates excess oxaloacetate to create glucose
used in plants and microorganisms
where are electron transport chain enzymes found
inner mitochondrial membrane
H pumped from matrix into inner mitochondrial membrane
electron gradient in mitochondria
charge gradient
3-4 H+ needed for ATP
complex 1 hydrogens get transported where
to Q pool protein
complex 4
-has oxygen come through into the inner mitochondrial membrane during oxidative phosphorylation
-Cytochrome c oxidase
-oxidizes electrons from cytochome c to O2 the final electron acceptor
-4 e- pumped into intermembrane space per O2
-2 e- pumped per 2 H+ per NADH
-copper is found in complex 4
Negative reduction potential
Reduced form of substance, lower affinity of electrons than H2
wants to be oxidized
Positive reduction potential
Oxidized form of substance has higher affinity
for electrons than does H 2
wants to be reduced
location of TCA cycle in eukaryotes and prokaryotes
eukaryotes: in the mitochondrial matrix
prokaryote: in the cytoplasm
Pyruvate dehydrogenase catalyzes the conversion
of pyruvate to acetyl-CoA. What products are created in this?
NADH
CO2
CoA contains what functional organic group
that binds acetyl groups
thiol / sulfur group
only step in TCA cycle that directly creates ATP
succinyl CoA to succinate
aconitase
4 iron 4 sulfur cube complex
has 2 functions- catalyzes convertion of citrate to isocitrate and creates protein with iron
complex 3
Cytochrome C
Oxidoreductase
transfers 4e- into intermembrane space per NADH
complex 2
Succinate
Oxidoreductase
transfers electrons from succinate to FADH2
no H+ pumped across membrane
complex 1
NADH:Ubiquinone (Q)
Oxidoreductase
turns NADH into NAD + 2e-
pumps 4 H+ into intermembrane space per NADH
Coenzyme Q
ubiquinone
small
diffuses through membrane
isoprenoid tail (hydrophobic keeps it imbedded in membrane)
cytochrome
-all contain heme groups
-has different properties depending on surrounding protein environment
cytochome C
-water soluble protein, can diffuse from complex 3 to complex 4
electron transport chain overall NADH H pumped into cell
10
electron transport chain overall FADH2 H pumped into cell
6
ATP synthase / complex 5
imbedded in membrane = F0 subunit
innermembrane subunit = F1 subunit
as protons flow through intermembrane protein, it rotates a rotor 120 degrees
Step 1. bind ADP and Pi
Step 2. bind ATP
Step 3. release ATP
gamma subunit of ATP synthase
bound to several alpha and beta subunits
bound differently to each subunits
PMF casuses three active sites to sequentially charge function, rotation of the c ring and gamma subunit driving the interconversion of these 3 forms
is energy needed to release or bind ATP
release
subunit T
bind ATP
subunit O
release ATP
ATP produced per NADH
2.5 ATP
ATP produced for each FADH2
1.5 ATP
link reaction between glycolysis and TCA cycle products
2 NADH
2 pyruvate to 2 acetyl CoA
electron transport chain can be uncoupled from TCA cycle
brown fat uncouples the reaction
generates heat
has protein that lets protons into the matrix without creating ATP
photosynthesis definition
transformation of electromagnetic energy to chemical
energy
light reactions
oxidation of water to produce O2 coupled to the
reduction of NADP+ to make NADPH
light independent reactions (dark reactions)
fixation of CO2 (using
ATP and NADPH) to make carbohydrates
chlorophylls do what
absorb the energy of a light of a specific wavelength
when an electron absorbs a photon of light
-it goes into an excited state from ground state
-when the photon is released the electron releases heat
-when it releases the elctron it can transfer the energy to a nieghboring molecule called exciton transfer
photoinduced charge separation
-Excited electron moves to a
nearby molecule
-This results in a positive charge
on the initial molecule and a
negative charge on the
acceptor molecule
chloroplasts utilize what mechanisms of energy transfer
resonance energy transfer
and
photoinduced charge separation
photosystem 2
light harvesting complex
-takes light into photosystem 2 via resonsance energy
-Excitation of special pair chlorophyll
molecules transfer electrons to
pheophytin (Ph) and then to
plastoquinone
-electrons replaced by water
Plastoquinone
-mobile electron
carrier
-H + for reduction to
QH 2 taken from
stroma (contributes
to H + gradient-
higher in thylakoid
lumen)
Water oxidizing complex
has manganese center
takes water and oxidizes it for its hydrogens to help with photosystem 2
what are the potential fates of pyruvate?
conversion to acetyl CoA
conversion into lactate along with NAD+ byproduct
conversion to ethanol with NAD+ and CO2 byproduct
both ethanol and lactate recreate NAD to continue glycolysis to product more ATP
aerobic linking reaction between pyruvate and acetyl CoA
pyruvate + NAD + CoA ⟶ acetyl CoA +
CO2 + NADH
however there are 2 pyruvate per glucose so the real equation is this
2 pyruvate + 2NAD + 2CoA ⟶ 2acetyl CoA + 2CO2 + 2NADH
cytochrome B6f
where electrons are transfered after PS2 and before PS1,
links photosystem to and photosystem 1 via plastocyanin
moves H+ into lumen
does not absorb light energy only transfers electrons
doesnt create ATP
PS1
energy from reaction center passed to the special pair of chlorophyll molecules in photosystem 1 via resonance energy transfer
excitation of special pair of chlorophyll molecules transfer electrons to quinone, the Fe-S cluster then ferredoxin
electrons backfilled by electrons from plastocyanin
reduced ferredoxin is oxidized w the reduction of NADP+ to NADPH by the enzyme ferredoxin-NADP+ reducatase
without NADP+ what happens?
H2O is not oxidized
light reaction products
NADPH & ATP
NADPH carries how many electrons to get to NADP+
2 electrons
O2 per NADPH
.5 mols of O2 per 1 mol of NADPH
2H20 -> O2 + 4H+ how many electrons produced
4
Manganese cluster
directly oxiedizes water
Photosystem 1 oxidizes what
plastocyanin
Definition and How calvin cycle was found
ATP and NADPH produced in the light reactions used to reduce CO2 to glucose
attached radioactive CO2 and stopped the process at different stages and identified radioactive compounds
stages of calvin cycle
1) Fixate Co2 to 3-phosphoglycerate
2) Reduction of 3-phosphoglycerates to hexose sugars
3) Regeneration of ribulose 5-phosphate
rubisco in calvin cycle
enzyme helps compounds in calvin cycle to attach CO2
very inefficient catalyzes wrong reaction 25% of the time
step 1 of calvin cycle requires what
Co2 & 1 ATP
step 2 of calvin cycle requires what
-2 ATP & 2 NADPH
-it requires 2 of each because the last step of step 1 creates 2 reactants to continue on in the cycle
step 3 of calvin cycle requires what
not much, mostly the same as gluconeogenesis
Reactants overall for calvin cycle per CO2
3 ATP
2 NADPH
1 CO2
CO2 needed per calvin cycle to make 1 glucose
6 CO2 to make 1 glucose
overall reactants for calvin cyle to make 1 glucose
6 CO2
18 ATP
12 NADPH
gluconeogenesis uses what molecule that glycolysis doesnt
oxaloacetate
the cori cycle uses what to create what
lactate to create glucose
in gluconeogenesis when fructose 1 6 bi phosphate is converted to frcutose 6 phosphate what enzyme is used
a phosphatase
in the link reaction where pyruvate is converted to acetyl coA what are the byproducts?
CO2 and NADH
how many ATP are generated per Acetyl CoA in the TCA cycle?
10 ATP
Complexes 1 2 3 all have what in common
Fe-S cluster
what are electrons transfered to directly after the PS2?
plastoquinone
in light dependant reactions where are electrons obtained and given?
H2O to NADPH
what molecules in the gluconeogenesis/glycolysis have higher phophoryl transfer ATP
phosphoenolpyruvate and 13bisphosphoglycerate
how many nucleoside triphosphates are required in gluconeogenesis
2
what do humans lack as a metabolism cycle?
glycoxylate cycle
what does the glycoxylate cycle do
converts acetyl coA to oxoaltetate
complex 4 has what as cofactors?
Cu2+ and cytochome hemes
complex 4 does what redox reactions
oxidizes cytochrome C and reduces O2
sucrose
disaccaride composed of 2 monomers
glycogen synthesis starts with what
creating UDP glucose
linkages in glycogen
alpha 1 4, branched alpha 1 6
different enzymes are needed to create the different linakges
glycogen synthesis
-glucose has a phosphate group added
-glucose then has UTP added creating UDP glucose + PPi (2 phosphate groups)
unphosphorylated - active
phosphorylated -inactive
alpha 1 4 linkage enzyme
glycogen synthase
unphosphorylated- regulated through phosphorylation when
alpha 1 6 linkage enzyme
-branching enzyme
-can cleave chains and attach it further up the chain for branching, which allows each chain to extend further
-branches every 10 residues
-generally transfers around 7 glucose residues
starch
polymer of glucose for storage in plants
synthesized using ADP glucose not UDP
branches every 30 residues
glycogen degredation enzyme
glycogen phosphorylase
glycogen chain + P = glucose 1 phosphate + glycogen chain
catalyzes sequential removal of glucose residues
enzymes involved in breaking down glycogen
debranching enzyme- required to cleave alpha 1 6 linkages
has the following 2 enzymes within the debranching enzyme
transferase- shifts block of 3 glucosyl residues from one outer branch to another branch
a16 glucosidase- hydrolyzes ⍺1,6 bond- the free glucose molecule
then phosphorylated by hexokinase
pentose phosphate pathway
Offshoot of glycolysis- glucose-6-
phosphate as a starting point
How non-phototrophs can make
NADPH
source of 5 carbon sugars (helps in nucleotide synthesis)
cost: No ATP/NADH made through glycolysis or TCA cycle
2 phases of pentose phosphate pathway
1 oxidative generation of NADPH
2 nonoxidiative conversion of sugars
NADPH function
breakdown electron donor
anabolic
NADH function
build up electron donor
catabolic
pathway from PS2 to PS1
pheophytin
plastoquinone
cytochrom B6F
plastocyanin
how many electrons per complex 1
4 electrons
how many electrons per complex 3
4 electrons
how many electrons per complex 4
2 electrons
pentose phosphate pathway is needed for what
NADPH production and biosynthetic reactions
glyceraldehyde 3 phosphate
3 carbon molecule
NADH is what ATP equivalent
2.5 ATP
FADH2 is what ATP equivalent
1.5 ATP equivalent
what are byproducts of the link reaction per pyruvate
1 CO2 1 NADH
ATP is produced on the final reaction to the intermediate to pyruvate
no answer
electrons are transferred to after PS1
plastoquinione then iron sulfur cluster then ferrodoxin
what happens to ferrodoxin
reduced ferredoxin is oxidized w the reduction of NADP+ to NADPH
how many ATP are produced in gluconeogenesis
2 ATP
