Question 1

Which of the following best describes the role of a catalyst in a chemical reaction?

Accepted Answer

It lowers the activation energy, allowing the reaction to proceed faster without being consumed.

Question 2

Which of the following is the correct definition of a substrate in an enzymatic reaction?

Accepted Answer

The molecule upon which an enzyme acts.

Question 3

What type of bond forms between carbohydrate monomers to create polysaccharides?

Accepted Answer

Glycosidic bond

Question 4

Which of the following best describes the function of monosaccharides in the cell?

Accepted Answer

They are the primary source of immediate energy for cellular processes.

Question 5

A student adds iodine to a starch plate and observes a blue-black coloration. What does this indicate?

Accepted Answer

The presence of starch in the plate.

Question 6

Which of the following best explains why human saliva was used in the amylase experiments?

Accepted Answer

Saliva contains amylase, which breaks down starch into maltose.

Question 7

What is the expected result when 2% starch is mixed with commercial amylase and incubated at 37°C for 10 minutes, then tested with DNS reagent?

Accepted Answer

A color change, indicating the presence of maltose.

Question 8

Which of the following best describes substrate specificity in enzymes?

Accepted Answer

Enzymes only bind to molecules with similar shapes to their active site.

Question 9

If a starch plate shows a clear zone after adding iodine, what does this indicate about amylase activity?

Accepted Answer

Amylase digested the starch in that area, so no starch is present.

Question 10

Which of the following is a correct comparison between starch and cellulose?

Accepted Answer

Both are composed of glucose monomers, but starch has $$\alpha-$$glycosidic bonds while cellulose has $$\beta-$$glycosidic bonds.

Question 11

Which of the following best describes a positive control in an experiment testing for sugar production using DNS reagent?

Accepted Answer

A sample containing known maltose and DNS reagent.

Question 12

Why is it important to incubate samples at 37°C for 10 minutes during the amylase activity experiment?

Accepted Answer

To provide optimal temperature for amylase activity, mimicking human body conditions.

Question 13

Which of the following best differentiates between quantitative and qualitative data?

Accepted Answer

Quantitative data is numerical and measurable; qualitative data describes characteristics or categories.

Question 14

What is the monomer of many polysaccharides such as starch and cellulose?

Accepted Answer

Glucose

Question 15

Which of the following best describes what happens to the DNS reagent in the presence of maltose?

Accepted Answer

It turns orange or red, indicating the presence of reducing sugar.

Question 16

A student wants to calculate the concentration of maltose in an unknown sample using a standard DNS curve. Which of the following steps is correct?

Accepted Answer

Measure the absorbance of the unknown, then use the standard curve equation $$y = mx + b to $$solve for $$x ($$concentration).

Question 17

Which of the following best describes the relationship between ATP, amylase, starch, maltose, and glucose in cellular respiration?

Accepted Answer

Amylase breaks down starch into maltose, which is further broken down into glucose; glucose is then used in cellular respiration to produce ATP.

Question 18

Which of the following is true about the detection of amylase activity using iodine and DNS reagent?

Accepted Answer

Iodine detects the presence of starch, while DNS detects the presence of reducing sugars like maltose.

Question 19

Which of the following best describes a negative control in an experiment testing for sugar production?

Accepted Answer

A sample containing only buffer and DNS reagent.

Question 20

Which of the following statements about enzyme active sites is correct?

Accepted Answer

The active site is the region of the enzyme where the substrate binds and the reaction occurs.

Unit 5 Review – Enzymes, Carbohydrates, and Experimental Design (General Biology)

Study Guide - Practice Questions