Download CHapter 2b Practice problems answers

Chapter 2b Extra Practice1. All organic compounds contain _carbon, hydrogen, and oxygen____________.
2. Without __energy_________, organisms could NOT maintain homeostasis, carry out chemical reactions, make their
own food.
3. The ability to move or change matter is _____ energy _______________.
4. All living things require a source of __ energy __________________ to carry out their life activities.
5. The starting materials for chemical reactions are called _____reactants_______________, while the new substances
that are formed are called ___products_________________.
6. The energy needed to start a chemical reaction is called ______activation energy___________.
7. A chemical reaction can be sped up by adding a substance called a(n) __enzyme__________________, which
lowers the amount of activation energy required to start the reaction.
8. The portion of an enzyme molecule into which a specific substrate can fit is called the _active site__.
9. Trypsin is a(n) _protein_________________ that aids in digestion by helping to break down the foods we eat.
10. Foods that are high in fiber most likely come from __carbohydrates_______.
11. _ATP________ stores energy for cells to use in the bonds between its phosphate bonds.
12. Olive oil and fish oil are examples of __saturated_____________ fatty acids.
13. Lipids that are solid at room temperature are __unsaturated________________ fats.
14. DNA and RNA are made up of _nucleotides________, which contain a sugar, a base, and a phosphate group.
15. Protein folding is determined by the sequence of the _amino acids_____.
16. Examples of __protein___________ in your body include collagen and hemoglobin.
17. Monosaccharide, glycogen, cellulose are terms is associated with _carbohydrates____.
18. The speed of a chemical reaction is increased by an __enzyme___________.
19. _Nucleic Acids_________ stores heredity information
20. Two carbohydrates that store energy are __cellulose________________, which is produced by plants to store energy,
and ___glucose__________________, which is produced by animals to store energy.
21. In nucleotides, the letters A, T, C, and G represent __nucleic acids___.
22. A substrate attaches to the _active site__ of an enzyme.
23. Temperature and _pH________ can affect enzyme activity.
24. _Lipids_______________ a class of organic compounds that includes fats, steroids, and waxes.
25. The building blocks of proteins are __amino acids______________; carbohydrates are
__monosaccharides_____________; nucleic acids are ___nucleotides_________; and lipids are __lipids_____ and _fatty
acids___.
26. __Carbohydrates________________ provides temporary storage of energy for cells.
27. __Enzymes____________ reduce the activation energy of chemical reactions.
SOL Questions
28.
The graph to the right represents the relationship between pH and the rate of enzyme
action for two enzymes, X and Y. Which statement best describes this pattern of
enzyme action?
a. As the pH increases from 2.5 to 3.5, the rate of action of enzyme X decreases.
b. At a pH of 5.5, the rate of action of enzyme X is the same as that of enzyme Y.
c. As the pH increases from 10 to 11, the rate of action of enzyme Y increases.
d. At a pH of 7.0, the rate of action of enzyme Y is less than that of enzyme X .
29.
This graph to the right shows that
a. pepsin is less effective at low pH than trypsin.
b. trypsin is not effective at a high pH.
c. pH affects the activity rate of enzymes differently.
d. more enzymes are present at a higher pH.
30.
According to the graph, addition of the enzyme
amylase causes the reaction to —
a. speed up
b. slow down
c. take in heat
d. give off heat
.
Base your answers on questions 31-34 on the organic compounds represented below and your knowledge of biology.
A.
B.
C.
D.
31.
32.
Which compound represents the basic unit of both a DNA molecule and an RNA molecule? _A______
Which compound contains both an amine group and a carboxyl group? __B_________
33.
Which macromolecules are made up of repeating units of molecule D?
a. proteins and nucleic acids
c. fats and oils
b. hemoglobin and enzymes
d. starch and cellulose
34.
Which food contains the highest percentage of the type of molecule represented by C?
a. butter
b. bread
c. table sugar
d. lettuce
35.
Lactase is an enzyme that breaks down Lactose in cells. It accomplishes this because of its
structure. What part of the enzyme is involved in catalytic activity?
a. Binding pocket
b. Pleated sheet
c. Quaternary structure
d. Active site
36.
Enzymes only work with specific substrates because each substrate —
a. actively interferes with other substrates around it
b. has a specific activation site for enzyme attachment
c. can only use a specific ionic bond with the enzyme
d. destroys its specific enzyme
Use the following terms for these 2 diagrams: Substrate, product, enzyme, active site, enzyme-substrate, complex
37. On the basis of the above graph, at which temperature did the catalase exhibit the greatest activity? _40______
38. Why did the activity of catalase decrease as the temperature continued to increase above 40oC? __________
____Because the enzyme can not work at temperature that high and still be effective_________________