Test 3 Review Flashcards
After isolating the rough ER, you purify. What would you expect from the rough ER? A: soluble secreted protiens B:ER membrane proteins C:Neither D: Both A and B
A: soluble secreted protiens
B:ER membrane proteins
Which of the following states about vesicle budding from Golgi Apparatus is false?
A: Clathrin molecules are important for binding to and selecting cargoes for transport
B:Adaptins interact with clathrin
C:Once vesicle budding occurs and the vesicle comes into close proximity with the target membrane, clathrin molecules are released from the vesicle
D: Clathrin molecules act at the cytosolic surface of the Golgi membrane
A: Clathrin molecules are important for binding to and selecting cargoes for transport
Which of the following statements is true?
A: The signal sequence on mitochondrial proteins are nomally C-terminal
B: Most mitochondrial proteins are not imported from the cytosol but are synthesized inside the mitochondria
C: Chapterone proteins in the mitochondria facilitate the movement of proteins across the outer and inner mitochondrial membranes
D: Mitochondrial proteins cross the membrane in their native, folded state
C: Chapterone proteins in the mitochondria facilitate the movement of proteins across the outer and inner mitochondrial membranes
Glucogenesis refers to?
The synthesis of glucose from small molecules like pyruvate
Useful energy is obtained by cells when?
sugars are broken down by glycolysis, citric acid cycle, and oxidative phosphorylation
What is the name of the specialized junction between neuron and target cells?
synapses
T/F
Each of the three respiratory enzyme complexes includes metal atoms tat are tightly bound to protiens
true
The localization information for protein signaling in a eukaryotic cell is contained in _______ of the proteins.
amino acid sequences
Proteins enter the nucleus in their ______ forms.
folded
Proteins that remain in the cytosol don’t contain a ________.
signal sequence
The proteins transported in to the ER by _______ in their _____ forms.
protein translocators
unfolded
What drives the production of ATP from ADP and Pi by ATP synthase?
A proton gradient
The drug dinitrophenol (DNP) makes the inner mitochondrial membrane permeable to hydrogen ions. When added to mitochondria DNP does?
decreases production of ATP and affect the PH gradient across the membrane
Which component of the electron transport chain is required to combine the electrons with molecular oxygen?
Cytochrome C oxidase
What is a characteristic or measurment used to study the action potentials?
effects of a depolarizing stimulus
Which of the following statements about the endoplasmic reticulum is true?
A: The ER is the major site of new membrane synthesis in the cell
B: Proteins are to be delivered to the ER are synthesized on the ribosome of the rough ER
C: Neither
D: Both A and B
Both A and B
What is the order through which a protein destined for the plasma membrane travels?
Er> Golgi>Plasma membrane
Which of the following statements about the unfolded protein response (UPR) is false?
A: Misfolded proteins bind to receptors that stimulare the production of a transcription regulator
B: Activation of UPR results in chaperon production of more chaperon proteins
C:Actications of the UPR results in the transcript. Regulator translocation to nucleus
D: None of the above
None of the above
T/F
In secretory cells the regulated and constitutive pathways of exocytosis diverge the trans golgi network. A constitutive secretory pathways is one that operates only when extracellular signal stimulates their secretion
False
What is the role of the nuclear localization sequence in a nuclear protein?
A: it is bound by cytoplasmic nuclear receptor proteins that direct the nuclear protein to the nuclear pore
B: It is a hydrophobic sequence that enables the protein to enter the nuclear membranes
C: It aids in protein unfolding so that the protein can threat through nuclear pores
D: It prevents the protein from difffusing out of the nucleus through nuclear pores
it is bound by cytoplasmic nuclear receptor proteins that direct the nuclear protein to the nuclear pore
N-linked oligosaccharides on secreted gylcoproteins are attached to
A: The cytosolic face of the ER
B: The serine or threonine residue in the growing polypeptide chain
C: The NH2 of an asparagine residue in the growing polypeptide chain
D: None of the above
The NH2 of an asparagine residue in the growing polypeptide chain
ATP molecules produced in the cytosol and glucose being converted to pyruvate are both what parts of oxidative phosphorylation?
Neither are part
During an action potential which of the following actions does not help return membrane to its resting potential?
opening of voltage gated Na+ channels
Most proteins destined to enter the ER are:
A: Transported across the membrane after synthesis is complete
B: Synthesized on ribosomes bound to ER membrane
C: Begin to cross membrane while still being synthesized
D: Both B and C
Both B and C
- Synthesized on ribosomes bound to ER membrane
- `Begin to cross membrane while still being synthesized
(During ATP synthesis) In chemiosmosis useful energy is harnessed by the cell from the movement of _____________ across the inner mitochondrial matric _______ its concentration gradient.
Protons; down
T/F The enzyme that catalyzes the last irreversible reaction in glycolysis (STEP 10) yeilding a molecule each of ATP and pyruvate is called hexokinase.
False
-> The actual molecule is called pyruvate kinase
Which of the following protein familes are involved in directing transport vesicles to the target membrane?
A: Snares
B: Rabs
C: Tethering proteins
D: All of the above
All of the above
Which of the following statements concerning the ER signal sequence and/or the SRP is true?
A: THe SRP binds to the exposed ER signal sequence and to the ribosome, thereby slowing protein synthesis by the ribosome
B: The SRP-ribosome complex binds to an SRP receptor in the ER membrane
C: The SRP gets released, passing the ribosome to a translocation channel in the ER membrane
D: All of the above
All of the above
Describe events involved in propagation of an action potential?
A: An initial influx of Na+ though a small cluster of channels causes local depolarization of the membrane
B: Local depolarization causes nearby NA+ channels to open
C: Channels in depolarized regions of membrane are inactivated until the resting membrane potential is reestablished
D: All of the above
All of the above
Experimental Evidence supporting chemiosmotic hypothesis was gathered by using artificial vesicles containing a protein that can pump protons in one direction across the vesicle membrane to create a protein gradient. What protein is it?
Bacteriorhodopsin
What mechanism does the inhibitory neurotransmitter prevent the postsynaptic cell from firing an action potential?
By opening Cl- channels
The mitochondrial ATP synthase consists of several different protein subunits. Which subunit binds to ADP +P and catalyzes the synthesis of ATP as a result of conformational change?
F1 ATPase Head
Pyruvate is an important metabolic intermediate that can be converted into several other compounds, depending on which enzyme is catalyzing the reaction. Which of the following cannot be produced from pyruvate in a single enzyme-catalyzed reaction?
A: Lactate B: Oxaloacetate C: Alanine D: All of the Above E: None of the Above
None of the above
What is the final ATP count during glycolysis?
3
Final ATP of pyruvate oxidation of acetyl CoA
5
Final ATP of complete acetyl CoA oxidation?
15
Total ATP production?
30
What are the functions of lysosomes
degradation of worn out organelles
What is the function of the smooth ER?
steriod hormone synthesis
What is the function of the golgi?
modify secreted proteins
What is chemiosmotic coupling?
The linkage of electron transport, proton pumping and ATP sunthesis
What intracellular membrane bound structure contain both their own DNA and RNA?
mitochondria
In an area of high ATP ultilization, what membrane bound organelle might you find there? AKA-> By a cardiac muscle cell
mitochondira
What are the 4 seperate compartments of mitochondria?
Matrix, Inner membrane, Outer membrane, Intermembrane space
Hundred of Enzymes are located in this space, such as the enzymes required for oxidation of pyruvate and fatty acids for the citric acid cycle. What section of the mitochondria is this? A:Matrix B: Inner membrane C: Outer membrane D:Intermembrane space
Matrix
This space is folded into numerous cristae and contains proteins that carry out oxidative phosphorylation, including ATP synthase and the electron transport chain. What section of the mitochondria is this? A:Matrix B: Inner membrane C: Outer membrane D:Intermembrane space
Inner membrane
Containing large channel-forming proteins called porins, what section of the mitochondria is this? A:Matrix B: Inner membrane C: Outer membrane D:Intermembrane space
Outer membrane
This space contains several enzymes that use the ATP passing out of the matric to phosphorylate other nucleotides. What section of the mitochondria is this?
Intermembrane space
NADH donates it’s high energy electrons to?
the electron transport chain
The chemiosmotic mechanism for ATP synthesis is called?
oxidative phosphorylation
Protons are pumped across the inner mitochondrial membrane as the net product of this is?
3 NADH
1 FADH
1 GTP
2 CO2
The three respiratory enzyme complexes that perform proton pumping, in the order in which they receive electrons are?
NADH dehydrogenase complex
cytochrome c reductase complex
cytochrome c oxidase complex
Each respiratory enzyme complex contains ______ and other chemical groups that act as stepping stones to facilitate the passage of electrons.
metal ions
What two things serve as carriers that ferry electrons from one respiratory enzyme complex to another?
Ubiquinone and cytochrome C
What is the net equation for the process of energy conservation?
2NADH+O2-> 2NAD+ + 2H2O
How does NADH dehydrogenase accept electrons from NADH?
in the form of a hydride ion
What does proton motive force do?
pulls H+ back accross the membrane
What makes of the large force in the electrochemical H+ gradient?
the membrane potential
What is the large, multisubunit protein embedded in the inner mitochondrial membrane
ATP synthase
T/F
ATP synthase can operate in reverse, using the energy of ATP hydrolysis to pump protons “uphill” against electrochemical gradient across the membrane
True
What are F1 and F0 and what do they have to do with ATP synthase?
F1 is the stationary head of the multiunit protein
F0 is the rotating portion
F1 can do what when detatched from the from the F0 part of the complex?
carry out the reverse reaction
The high energy electrons donated by NADH and FADH after passing along the electron transport chain eventually combine with what?
O2 to form H2O