Question

1. Once glucose enters a cell, it it ‘phosphorylated' in order to

Select one:

a. trap it inside the cell

b. raise its free energy (G)

c. tag it for entry into mitochondria

d. remove protons (H+)

e. A and B

2. Energy transfers always make heat energy and more disorder. This tendancy toward more disorder refers to

Select one:

a. entropy

b. a heat sink

c. the big bang

d. e=mc squared

e. heat equilibrium

3. According to the current model, an enzyme binding to its target molecule is most like

Select one:

a. a square peg in a round hole, because the enzyme can bind to a variety of target molecules

b. a lock fitting a key, because the pocket where the enzyme fits its specific target molecule is precise, and rigid

c. a hand fitting a doorknob, because the enzyme folds around its target molecule, squeezing it

d. an electric pencil sharpener, because inserting the target molecule into the enzyme causes the enzyme to cut it

4. Which cell structure is INCORRECTLY matched with its function?

Select one:

a. Rough ER: Synthesis of membrane proteins

b. Smooth ER : Assembly of new membranes

c. Lysosome : Digestion of ‘food' substances taken into cell

d. Golgi body : Receives, modifies, and exports

e. Central vacuole : Physical support

5. Which of these are NOT features of microtubules?

Select one:

a. Assists in cell support and movement

b. Controls cell locomotion by cilia and flagella

c. Made of tubulin proteins

d. Are the thickest cytoskeletal fiber

e. Needed to form durable structures like hair and fingernails

Answer 1

Ans 1 When glucose enters the cells via glucose transporters, there is a chance for them to leave the cell. when it get phosphorylated it will go back because the plasma membrane generally lacks transporters for phosphorylated sugars and this disqualifies glucose from leaving through glucose transporters, and it got trapped in the cell.

Hence option A trap it inside the cell is correct

Ans-2 the tendency toward more disorder refers to entropy. hence option a is correct

Ans-3 The current model is also known as induce fit model says that enzymes can undergo a change in conformation when they bind substrate molecules, and the active site has a shape complementary to that of the substrate only after the substrate is bound

hence option C saying a hand fitting a door knob because the enzyme folds around its target molecule, squeezing it is correct because hand can fit a door knob of different shapes

Ans-4 Function of lysosome is breakdown of ingested substances,cell macromolecules, and damaged organelles for recycling not digestion of ‘food' substances taken into cell hence option C is correct

Ans-5 Features of microtubules are, assists in cell support and movement, controls cell locomotion by cilia and flagella,made of tubulin proteins,  are the thickest cytoskeletal fiber

but the durable structure like hair and finger nails is made up of -keratin hence this is not the feature of microtubule option e is correct