1.
Without enzymes, the chemical reactions in the body would
A
occur too slowly to support life processes.
B
require a different pH.
C
occur at much the same rate as they do with enzymes.
D
none of these
Loading practice questions
20 practice sets · Page 1 of 1
Without enzymes, the chemical reactions in the body would
occur too slowly to support life processes.
require a different pH.
occur at much the same rate as they do with enzymes.
none of these
Which term most precisely describes the cellular process of breaking down large molecules into smaller ones?
catalysis
catabolism
anabolism
none of these
Which organic molecule below is most closely related to nucleic acids?
nucleotides
sugars
chains
none of these
Which organic molecule below is most closely related to lipids?
nucleotides
amino acids
chains
none of thes
Which of these is a difference between DNA and RNA?
DNA contains thymine; RNA contains uracil.
In DNA, adenine pairs with guanine; in RNA, adenine pairs with thymine.
DNA consists of five different nucleotides; RNA consists of four different nucleotides.
none of these
Which of the following describe(s) some aspect of metabolism?
A, B, and C
synthesis of macromolecules
breakdown of macromolecules
control of enzyme activity
Which of the following are nitrogenous bases of the pyrimidine type?
none of these
thymine and guanine
cytosine and uracil
guanine and adenine
Which of the following are nitrogenous bases of the purine type?
none of these
guanine and adenine
uracil and cytosine
cytosine and guanine
What name is given to the reactants in an enzymatically catalyzed reaction?
none of these
products
substrate
EA
The structural feature that allows DNA to replicate is the
none of these
twisting of the molecule to form an á helix.
sugar-phosphate backbone.
complementary pairing of the nitrogenous bases.
Nucleic acids include
none of these
glucose and glycogen.
lipids and sugars.
DNA and RNA.
In the double helix structure of nucleic acids, cytosine hydrogen bonds to
none of these
ribose.
guanine.
adenine.
If an enzyme solution is saturated with substrate, the most effective way to obtain an even faster yield of products is to
none of these
add more of the enzyme.
heat the solution to 90 degree Centigrade.
add an allosteric inhibitor.
If an enzyme is added to a solution where its substrates and products are in equilibrium, what would occur?
none of these
The reaction would change from endergonic to exergonic.
Additional product would be formed.
Nothing; the reaction would stay at equilibrium.
How can one increase the rate of a chemical reaction?
none of these
Add a catalyst.
Increase the entropy of the reactants.
Decrease the concentration of the reactants.
Enzymes that break down DNA catalyze the hydrolysis of the covalent bonds that join nucleotides together. What would happen to DNA molecules treated with these enzymes?
none of these
The phosphodiester bonds between deoxyribose sugars would be broken.
The two strands of the double helix would separate.
The pyrimidines would be separated from the deoxyribose sugars.
Choose the pair of terms that correctly completes this sentence: Catabolism is to anabolism as .........is to ............
none of these
exergonic; endergonic
work; energy
DNA and RNA.
According to the first law of thermodynamics,
A and B only
the universe loses energy because of heat production.
systems rich in energy are intrinsically unstable and will give up energy with time.
energy can be neither created nor destroyed.
A model of enzyme action is the
none of these
active site model.
activator action model.
induced fit model.
A double-stranded DNA molecule contains a total of 120 purines and 120 pyrimidines. This DNA molecule could be comprised of
none of these
240 adenine and 240 cytosine molecules.
120 thymine and 120 adenine molecules.
240 guanine and 240 thymine molecules.