Question

We have come across several systems in which the effective concentration of one component is modified to overcome the normal effect of a concentration gradient. This is characteristic of all of the following systems EXCEPT: a. Glucose uptake into the cytoplasm b. Use of G3P in glycolysis c. Calcium control in sarcoplasmic reticulum d. Binding of the SRP to the rough endoplasmic reticulum e. The c4 mechanism in photosynthetic plants
2.. Which of the following ions listed below is directly necessary for sarcomere contraction? a. Na+ and Mg++ ions b. Ca+ and Mg++ ions c. Na+ and K+ ions d. Na+ and Ca++ ions e. Ca+ and K+ ions

3.What kind of glycosylation occurs in the golgi? a. N-linked b. asparagine linkage c. D-linked d. O-linked e. glycosylation does not occur in golgi at all, only occurs in the ER.

4.Which of these choices about import proteins is TRUE? a. Import proteins bind their cargo in the nucleus, after which they are able to interact with the nuclear pore complex and pass through its channel b. Interaction with Ran-GTP inside the nucleus causes a conformational change in the importin that causes it to dissociate from its cargo c. The importin and Ran-GTP complex translocates to the cytoplasm, where RanBP helps hold the complex together d. The hydrolysis of GTP to GDP occurs in the nucleus. e. The Ran-GDP produced stays in the cytoplasm after binding with NUTF2.

Answer 1

Answer:

1.  E

2.  B

3.  A

4.  B

Explanation:

1

In the C4 mechanism in photosynthetic plants , Glucose converts to glucose 6 phosphate(G3P to dihydroxy phosphate).

2

Ca+ and Mg++ ions

Calcium ions result in movement of troponin and tropomyosin on their thin filaments.

In return of tropomyosin to actin binding site, Mg++ complex formed with ATP

3

N-linked glycosylation take place in the endoplasmic reticulum and/or in  the Golgi apparatus.  The N-glycosylation pathway in the ER modifies a multitude of proteins at one or more asparagine residues with a unique carbohydrate structure that is used as a signalling molecule in their folding pathway.

4.

Importin proteins typically do bind their cargo in the cytoplasm, after which they are able to interact with the nuclear pore complex and pass through its channel. Once inside the nucleus, interaction with Ran-GTP causes a conformational change in the importin that causes it to dissociate from its cargo.