tricky concept stuff to remember Flashcards
Proteins that function in the cytosol do not contain ____________ and
therefore remain there after they are synthesized
sorting signals
signal sequences are recognized by _____ _____ _____
complementary sorting receptors
The lysosomal enzymes go directly to the ______
lysosome
A ______ plot can predict transmembrane domains.
hydropathy
If the negative charges on electrons are relatively far from the positive charges then that means they have ______ ________ energy
high potential
What is the free energy equation
delta G = G(products) - G(reactants)
If delta G < 0, the reaction is spontaneous
If delta G > ), the reaction is not spontaneous
ATP is cleaved by ______
hydrolysis
ATP being cleaved by hydrolysis is _______-
spontaneous
Why do many spontaneous reactions occur slowly?
- spatial orientation of reactants
- high activation energy
How does a cell increase the probability that enzymes will encounter their substrates?
compartmentalization
When reatants bind to the active site, the R-groups stabilize the ______ state and lowers the activation energy
transition
The __________ takes the double reciprocal of the Michaelis-Menten equation, which conveniently follows the equation of a line (y = mx + b).
Lineweaver-Burk
What is the Lineweaver-Burk equation
1/V = (Km/ Vmax)(1/ concentration S) + 1/ Vmax
If an inhibitor is _________, it will decrease reaction rate when there’s not much substrate, but can be “out-competed” by lots of substrate. That is, the enzyme c
competitive
If an inhibitor is _________, the enzyme-catalyzed reaction will never reach its normal maximum rate even with a lot of substrate.
noncompetitive
The lower the _____ value for a given enzyme and substrate, the lower the
substrate concentration range in which the enzyme is effective (higher affinity
Km
binds directly to active site
- requires more substrate to reach Vmax
- Vmax same, but Km changes (Km apparent is higher, indicating lower affinity
to substrate)
competitive inhibition
Binding Site: The inhibitor can bind to either the free enzyme or the
enzyme-substrate complex.
- Effect on Kinetics: The maximum reaction rate (Vmax) decreases, but the
Michaelis constant (Km) remains unchanged. This is because the inhibitor
affects the enzyme’s activity regardless of whether the substrate is
bound.
- Mechanism: The inhibitor binds to an allosteric site (a site other than the active
site), causing a conformational change in the enzyme that reduces its
activity
noncompetitive inhibition
______ reactions drive ATP production
redox
all c-c and c-h bonds in glucose are _____ in cellular respiration
oxidized
oxidation or reduction
- drop in potential energy
- more stable
-spontaneous
-exergonic
oxidation
cellular respiration redox produces _______ energy which is used to drive molecular motors that use _______ energy to produce ATP
electrical, mechanical,
The reactants and products of glycolysis
R: glucose, P: 2 pyruvate, 2 ATP
What is the electron carrier for glycolysis?
NADH
The reactants and products of pyruvate processing
R: pyruvate
P: Acetyl-CoA, 2 CO2
What is the electron carrier for pyruvate processing?
NADH
The reactants and products of citric acid cycle
R: Acetyl- CoA
P: CO2, 2 ATP
What is the electron carrier for citric acid cycle?
NADH, FADH2
What two processes are referred to as oxidative phosphorylation?
ETC and ATP synthase
glucose is reduced to ___
CO2
glycolysis occurs where?
cytoplasm and outer membrane of mitochondria
pyruvate processing and citric acid cycle occur where?
inner membrane of mitochondria
What happens at complex 1 of ETC
NADH goes to NAD+, oxidized
What happens in complex II of ETC
FADH2 is oxidized to FAD
What happens in complex III
redox reactions
What happens in complex IV?
O2 is reduced to H2O
______ is the last electron acceptor in the ETC
oxygen
With ATP synthase, protons flowing through F0 is ______ energy
kinetic
With ATP synthase, the spinning of the turbine is ______ energy
mechanical energy
______ energy in ATP synthase changes the shape of F1 which causes the ADP+ Pi reaction to be catalyzed
mechanical
________ has a net yield of 2 ATP, because 4 ATP are produced but 2 ATP are invested
glycolysis
______ starts with an “investment phase”. that adds phosphate groups to 6- carbon sugars and uses 2 ATP.
glycolysis
If _______ is depleted in your muscles during strenuous exercise, this happens….
The ETC backs up because electrons can no longer leave it by reducing an electron acceptor (O2).
NADH and FADH2 build up because there is nowhere for the electrons they carry to go when the ETC is backed up.
Glycolysis stops because no NAD+ is available — it has all been reduced to NADH.
ATP production stops.
oxygen
When oxygen is depleted, cellular respiration resumes because _______ is processed to feed the citric acid cycle and ETC
pyruvate
during catabolism, energy is ______, which is then used for cellular functions or stored for later use
released
___________enables the segregation of enzymes involved in different metabolic pathways, regulating cellular processes.
compartmentalization
feedback inhibition acts at the ______ ________step of the pathway, meaning the first step that’s effectively irreversible.
first committed
_____ is necessary for muscle
contraction and signals an increased
demand of energy
Ca 2+
Metabolic pathways never come to equilibrium (ΔG ≠ 0)
because _______ is required to perform work
free energy
The _________ absorb most of the violet-blue and orange-red wavelengths, but reflect green and yellow wavelengths, which is what we see.
chlorophylls
Water and oxygen are there because when electrons are excited out of pigments in ___, the pigment molecules become so oxidized that they pull electrons out of the O-H bonds in water, releasing protons (H+) and molecular oxygen (O2).
PSII
The mass of trees mostly comes from ____
CO2
Is this in photosynthesis or cellular respiration?
- carbon atoms are oxidized
-oxygen atoms are reduced
cellular respiration
Is this photosynthesis or cellular respiration?
- carbon atoms are reduced
- oxygen atoms re oxidized
photosynthesis
Is this in cellular respiration or photosynthesis?
-electron carriers are oxidized
-electron carriers are reduced
BOTH
When _______ absorbs a photon, an electron is bumped into a higher energy orbital
chlorophyll
Excited electrons transfer ______ through photosystems until the energy is trapped in a special pair of chlorophyll molecules
energy
________ ________ _______ describes how energy is
transferred from an excited
donor molecule to an acceptor
molecule without the transfer of
electrons themselves
Resonance energy transfer
(RET)
The Calvin cycle uses ___ and ______ from the
light-dependent reactions to fix carbon into 3-carbon sugar
ATP and NADPH
put this in order..
Ribosome binds to the translocator
Cleavage of the protein by signal peptidase
Translation pauses
Completion of translation and translocation
SRP binds to the ER signal sequence
Protein translation begins
SRP binds SRP Receptor and translation resumes
Ribosome binds mRNA
ER signal sequence is synthesized
ER Signal sequence binds to the channel of the translocator
The translocator plug moves out of the aqueous channel
Translocation of the protein through the translocator begins
What are the functions of the signal recognition particle?
bind the Er signal sequence
bind the SRP receptor
pause translation by the ribosome
What types of proteins go through cotranslational translocation?
secreted proteins, membrane bound, lysosomal
What types of proteins go through post-translational translocation?
proteins targeted to mitochondria, chloroplast, peroxisome, nucleus
In general, a ______-_____ _____ directs its following segment in the protein to the
cytosolic side of the membrane.
stop-transfer signal
Since the n-terminus is
extracellular, the n-terminus of the protein will be in the ______ of the ER during translation
lumen
What two reactions does pyruvate kinase couple?
a. Removing a phosphate group from an intermediate called phosphoenolpyruvate
(PEP) to form another intermediate called pyruvate.
b. Addition of a phosphate group from ADP to form ATP
Reaction b is highly non-spontaneous, but the overall reaction catalyzed by pyruvate
kinase is spontaneous.
What are the steps of the krebs cycle?
Acetyl CoA- 6 carbon- citrate- alpha ketogularate- succinare-oxaloacetate
In the krebs cycle what is the carbon order?
2- 6 - 5 - 4
In what transitions is NAD reduced in the krebs cycle?
citrate–> alpha ketogularate
alpha ketogularate–> succinate
succinate–> oxaloacetate
In what transitions is FAD reduced in the krebs cycle?
succinate–> oxaloacetate
________ are sorting organelles that recieve transport molecules from the plasma membrane and Golgi apparatus to other destination such as the vacuale or plasma membrane
endosomes
________ _______ form when a membrane bugles out and pinches off, and they merge with another membrane to release their cargo
transport vesicles
signal recognition particle (RNA-protein particle) pauses _______
translation
Is the SRP generic?
Yes
Where does the ribosome become attach in the cotranslational translocation?
translocator channel
What happens to the SRP when the ribosome becomes attached to the translocator channel?
The SRP is removed`
What protein cleaves the signal sequence?
signal peptidase`
After the protein has been translocated and the signal sequence cleaved the _____ ______ moves back into position to close the channel
translocator plug
In regulated secretion, proteins are packaged and stored; only secreted in response to a ________ signal
specific
In the rough ER: lysosomal enzyme is synthesized and a (carbohydrate )_________ is added
mannose
Protein is packaged into a vesicle and transported to the cis-Golgi
network. Mannose is ________ on the sixth carbon of the
mannose tree by sequential activity of 2 enzymes,
phosphorylated
(resulting in
mannose-6-Phosphate (M6P)
Where does the M6P bind to?
the M6P receptor in the golgi
What is the pH of the endosome?
low
Endosome matures into _____
lysosome
How is the low pH of the lysosome maintained?
H+ ATPase
