细胞生物学(厦门大学) 中国大学MOOC答案2024版100分完整版

4、 Which of the four classes of ATP-powered pumps share overall similarity: several subunits, the same general organization, and a similar function in being H+ transporters?

答案: F-class pumps and V-class pumps

5、 How does inhibition of the Na+/K+ ATPase increase the force of heart muscle contraction?

答案: It increases cytosolic Na+ and therefore decreases Ca2+ export

6、 Channel proteins (such as the voltage-gated Na channel) transport ions much faster than carrier proteins (such as the Na-K pump), but they cannot be coupled to an energy source; therefore, transport mediated by channels is always passive.

答案: 正确

7、 The resting membrane potential of a typical animal cell arises predominantly through the action of the Na-K pump, which in each cycle transfers 3 Na ions out of the cell and 2 K into the cell, leaving an excess of negative charges inside the cell.

答案: 错误

8、  The concentration gradient for a charged solute and the membrane potential constitute the _______ gradient for that solute.
答案: electrochemical

9、 Over expression of the ____ in human cancer cells can make these cells simultaneously resistant to a variety of chemically unrelated cytotoxic drugs that we widely used in cancer chemotherapy.
答案: Multidrug-resistance transport protein

10、 In the epithelial cells of the gut Na+-linked symporters in the apical (absorptive) domain of the plasma membrane and Na+-independent transport proteins in the basolateral domain bring about the _______ of absorbed solutes.
答案: Transcellular transport

Cellular Energetics

1、 Where does glycolysis takes place?

答案: Cytosol

2、 Where is the electron transport chain found in plant cells?

答案: Thylakoid membranes of chloroplasts

3、 Energy released by the electron transport chain is used to pump H+ ions into which location?

答案: Mitochondrial intermembrane space

4、 Inside an active mitochondrion, most electrons follow which pathway?

答案: Citric acid cycle –> NADH –> electron transport chain –> oxygen

5、 Which do the catabolic products of fatty acid breakdown enter into the citric acid cycle?

答案: Acetyl CoA

6、 Brown-fat mitochondria uncouple oxidative phosphorylation to produce____

答案: Heat

7、 During ATP synthesis, protons move “down” their electrochemical gradient through  the F0 complex of ATP synthase

答案: 正确

8、 The outer mitochondrial membrane is derived from the bacterial plasma membrane

答案: 错误

9、 ____ is a lipid soluble molecule that acts to shuttle electrons within the mitochondrial inner membrane
答案: CoQ
分析：Coenzyme Q

10、 The energy released by the passage of electrons along the respiratory chain is stored as an_____ across the inner mitochondrial membrane.
答案: proton motive force
分析：electrochemical gradient

Moving Proteins into Membranes and Organelles

1、 Type I membrane proteins have all of the following properties except

答案: internal signal-anchor sequence

2、  Many peroxisomal matrix proteins are imported as

答案: folded proteins

3、 GPI-anchoring serves a special function, especially in polarized epithelial cells because this modification serves to target proteins to the

答案: Plasma membrane

4、 Glycosylation, a post-translational modification to proteins, occurs in the

答案: ER

5、  Protein sequences for targeting to mitochondria is located at

答案: the N-terminus of the precursor protein.

6、 Mitochondrial signal peptides are amphipathic α helical structures with positively charged amino acid one side and negatively charged amino on the other side.

答案: 错误

7、 In mammalian cells the import of proteins into the ER begins before the polypeptide chain is completely synthesized-that is ,it occurs co-translationally.

答案: 正确

8、 The fate of proteins synthesized in the cytosol depends on their amino acid sequence, which can contain _____ that direct their delivery to locations outside the cytosol.
答案: signal

9、 The _____at which the inner and outer mitochondrial membranes appear to be joined are thought to be the sites at which import into the matrix occurs.
答案: contact site

10、 The signal peptide is guided to the membrane of the ER by at least two components:a ___ ,which binds to the signal peptide in the cytosol, and the _______,which is located in the ER membrane . 
答案: SRP