Exam 1 Quizes Flashcards
(149 cards)
The best studied GAG is ____, which is secreted by cells in the lungs and other tissues in response to injury.
heparin
Although animals don’t synthesize starch, they possess an enzyme that readily hydrolyzes it. This enzyme is known as ___.
amylase
“Most often such chains are found covalently attached to lipids and proteins, converting them into glycolipids and glycoproteins.” In this sentence “chains” refer to ____.
oligosaccharides
Solid shortening, such as margarine are formed from ____ by chemically reducing the double bonds.
unsaturated vegetable oils
Not all biological polysaccharides consist of glucose monomers. An example of this is ___.
chitin
Which of the following has a carboxyl group?
A) acetic acid
B) ethyl alcohol
C) ethane
D) ethyl mercaptan
acetic acid
Which of the following is an example of a multiprotein complex?
A) myosin
B) myoglobin
C) pyruvate dehydrogenase
D) hemoglobin
E) actin
pyruvate dehydrogenase
Secondary structure is stabilized by ___. Tertiary structure is stabilized by an array of ____.
-hydrogen bonds
-non covalent bonds
Which of the following amino acid contains a sulfhydryl functional group?
A) proline
B) glycine
C) alanine
D) N-acetyglucosamine
E) cysteine
cysteine
The most widespread and important posttranslational modification is the reversible addition of a phosphate group to the following amino acids, EXCEPT ______.
lysine
Which of the following proteins constitute the machinery for biological movements?
A) antibodies and toxins
B) hormones and growth factors
C) membrane receptors and transporters
D) contractile filaments and molecular motors
E) enzymes and structural cables
contractile filaments and molecular motors
In the hemoglobin molecule of a person with sickle cell anemia, a nonpolar valine residue is present where a charged ___ is normally located.
glutamic acid
Vitamins and their derivatives often function as _____ in enzyme-catalyzed reactions.
cofactors
Which of the following is NOT true about enzymes?
A) They accelerate the rate at which a favorable reaction proceeds
B) They supply energy for a chemical reaction.
C) They are required only in small amounts.
D) They are not altered irreversibly during the course of a reaction.
E) They can participate repeatedly in individual reactions.
They supply energy for a chemical reaction.
One way to increase the reaction rate is to ____.
A) increase the energy of the reactants
B) increase the energy of the enzyme
C) increase the energy of the transition state
D) increase the activation energy
increase the energy of the reactants
The part of the enzyme molecule that is directly involved in binding the substrate is termed the ____.
active site
Which of the following will NOT accelerate a chemical reaction?
(Select 3)
A) increasing the reactivity of the substrate
B) stabilizing the the transition state
C) lowering the entropy of the substrate
D) increasing entropy of substrate
E) stabilizing the substrate
F) decreasing reactivity of substreate
stabilizing the substrate
increasing entropy of substrate
decreasing reactivity of substreate
The catalytic constant, which is the simplest measure of catalytic activity of an enzyme can be calculated from the ____.
maximal velocity
Which of the following is NOT true about enzymes?
A) They are not altered irreversibly during the course of a reaction.
B) They are required only in small amounts.
C) They can participate repeatedly in individual reactions.
D) They have no effect on the thermodynamics of the reaction.
E) They determine the ratio of products to reactants at equilibrium.
They determine the ratio of products to reactants at equilibrium.
Which of the following is not a noncovalent interaction?
A) hydrogen bond
B) peptide bond
C) ionic bond
D) hydrophilic interaction
E) hydrophobic interaction
peptide bond
The maximum number of molecules of substrate that can be converted to product by one enzyme per unit time is called ____.
turnover number
Which of the following is true?
A) The higher the delta G (i.e more positive), the faster the rate of reaction.
B) The magnitude of delta G informs us only of the difference in the free energy between the beginning state and equilibrium.
C)The magnitude of delta G is totally dependent on the time it takes to reach equilibrium.
D)The lower the delta G (i.e more negative), the faster the rate of reaction.
The magnitude of delta G informs us only of the difference in the free energy between the beginning state and equilibrium.
The term enzyme is generally reserved for ____ catalysts, while the term ____ is used for RNA catalysts.
A) inorganic, cofactor
B) protein, ribozyme
C) organic, coenzyme
D) DNA, ribosome
protein, ribozyme
Which of the following is NOT true about enzymes?
A) They can participate repeatedly in individual reactions.
B) They are not altered irreversibly during the course of a reaction.
C) They do not supply energy for a chemical reaction.
D) They are required only in small amounts.
E) They determine whether a reaction is thermodynamically favorable or unfavorable.
They determine whether a reaction is thermodynamically favorable or unfavorable.