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Biological Molecules Practice Test



Multiple Choice
Identify the choice that best completes the statement or answers the question.
 

 1. 

Character of four organisms are shown in the table below.
mc001-1.jpg
Which organism is characterized as a prokaryote?
a.
1
c.
3
b.
2
d.
4
 

 2. 

Which of these characteristics best describes the difference between eukaryotic and prokaryotic cells?
a.
Eukaryotic DNA has deoxyribose, and prokaryotic DNA has ribose.
c.
Eukaryotic cells reproduce asexually, and prokaryotic cells reproduce sexually.
b.
Eukaryotic DNA is free floating in the cell, and prokaryotic DNA is in a nucleus.
d.
Eukaryotic cells are usually larger and more complex than prokaryotic cells.
 

 3. 

Which of these molecules is a nucleic acid?
mc003-1.jpg
mc003-2.jpg
a.
A
c.
C
b.
B
d.
D
 

 4. 

Why do animals need a regular supply of carbohydrates?
a.
to provide body structure
c.
to regulate the body’s water supply
b.
to control cell reproduction
d.
to provide a source of cellular energy
 

 5. 

Lipids are often found in plant and animal cell vacuoles.  Compared to lipids in cell membranes, what is the main function of lipids found in vacuoles?
a.
provide cell structure
c.
supply cell genetic information
b.
store energy for cell functions
d.
remove waste materials from the cell
 

 6. 

A student tested different foods for the presence of carbohydrates and proteins.  The student’s observations are shown in the table.
mc006-1.jpg
Which substances contained only carbohydrates?
a.
Potato and Apple
c.
Chicken broth and apple
b.
Potato and Yogurt
d.
Chicken broth and potato
 

 7. 

The  table below shows the results on four unknown substances from compositional tests for biological macromolecules.
mc007-1.jpg
Which unknown substance is most likely primarily composed of protein?
a.
Unknown 1
c.
Unknown 3
b.
Unknown 2
d.
Unknown 4
 

 8. 

The enzyme amylase begins reacting with starch during the chewing of food.  When the food enters the stomach, amylase is no longer active and starch decomposition stops.  When the food leaves the stomach and enters the small intestine, starch decomposition continues.  Why is amylase inactive in the stomach?
a.
The pH of the stomach is not optimum for amylase.
c.
The temperature of the stomach is too low for amylase to function.
b.
The concentration of sugar is great and inactivates amylase.
d.
The amylase has been degraded by the reaction with the starch molecules.
 

 9. 

Enzymes are catalysts.  How do enzymes increase the reaction rate?
a.
transfer inhibitors away from reactants
c.
transfer substrates to ribosomes
b.
provide a site for substrates to react
d.
provide energy to reactants
 

 10. 

The diagram below shows a macromolecule.
mc010-1.jpg
What is one of the functions of this macromolecule?
a.
energy storage
c.
regulating cellular functions
b.
structural support
d.
controlling immune responses
 

 11. 

The diagram below show the structure of glucose and fructose molecules.
mc011-1.jpg
What structure makes glucose and fructose carbohydrates rather than lipids?
a.
These molecules contain fewer oxygen atoms than hydrogen atoms.
c.
These molecules contain double-bonded oxygen atoms.
b.
These molecules contain no double-bonded carbon atoms.
d.
These molecules contain no carboxylic acid groups.
 

 12. 

Which macromolecule has a structure made up of an amino acid chain?
a.
carbohydrate
c.
protein
b.
nucleic acid
d.
lipid
 

 13. 

A student tests for the presence of biomolecules in four unknown liquids. The results of the tests are in the table.
mc013-1.jpg
What is the most reasonable conclusion why unknown 4 displayed all negative results?
a.
This unknown contained lipids
c.
This unknown contained distilled water
b.
This unknown contained proteins
d.
This unknown contained simple carbohydrates
 

 14. 


Students tested four unknown solutions for the presence of biomolecules. The results are shown in the table below.
mc014-1.jpg
Which unknown tested positive for simple sugars?
a.
Unknown 1
c.
Unknown 3
b.
Unknown 2
d.
Unknown 4
 

 15. 

There are reagents that identify the presence of specific organic compounds.  Which result indicates the presence of starch?
a.
Iodine turns black.
c.
Biuret reagent turns purple.
b.
Iodine turns brick red.
d.
Biuret reagent turns yellow.
 

 16. 

Students are testing for organic compounds in unknown liquids.  a students adds Sudan IV to an unknown liquid and observes a red color disperse through the liquid.  What organic compound does this identify?
a.
carbohydrate
c.
nucleic acid
b.
lipid
d.
protein
 

 17. 

Students compared the activity rate of pepsin and trypsin, two enzymes. Pepsin is found in the stomach and trypsin is found in the small intestine. The data collected are illustrated in the graph. Based on the data, students made conclusions about the activity of the two enzymes.

mc017-1.jpg

Which conclusion could not be determined based on the information in the graph?
a.
Pepsin and trypsin have an optimal pH for activity.
c.
Pepsin is active only at a pH around 3, and trypsin is active only at a pH around 9.
b.
Pepsin and trypsin are most active at different pH ranges.
d.
Pepsin is most active in an acidic environment, and trypsin is most active in an alkaline environment.
 

 18. 

Enzymes assist in chemical reactions in cells. The diagram below shows a reaction with and without and enzyme.

mc018-1.jpg

Which statement correctly describes the relationship between enzymes and chemical reactions?
a.
The amount of product increases without an enzyme.
c.
The rate of reaction increases without an enzyme.
b.
The activation energy decreases with an enzyme.
d.
The type of product changes with an enzyme.
 

 19. 

Amino acids are a structural component of which macromolecule?
a.
lipids
c.
carbohydrates
b.
proteins
d.
nucleic acids
 

 20. 

When Benedict’s solution is added to an unknown substance and then heated in a hot water bath, the solution turns an orange-brown color.  This indicates the presence of which molecule?
a.
lipids
c.
carbohydrates
b.
proteins
d.
nucleic acids
 

 21. 

How does the reduction in activation energy by an enzyme affect a chemical reaction?
a.
The products are not stable.
c.
Less energy is gained from the reaction.
b.
The reaction proceeds at a faster rate.
d.
The reaction is less efficient when the enzyme is present.
 



 
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