Biochemistry

For an enzyme reaction obeying Michaelis-Menten kinetics the horizontal part of a v versus S plot is ...

For an enzyme reaction obeying Michaelis-Menten kinetics the horizontal part of a v versus S plot is ...

For an enzyme reaction obeying Michaelis-Menten kinetics the horizontal part of a v versus S plot is indicative of:
 a. a first-order reaction with respect to substrate
 b. a second-order reaction with respect to substrate
 c. a mixed

crownlessking   53   1 Reply

hellokristi4

Malonate (-OOC-CH2-COO-) can depress operation of the tricarboxylic acid cycle by:

Malonate (-OOC-CH2-COO-) can depress operation of the tricarboxylic acid cycle by:

Malonate (-OOC-CH2-COO-) can depress operation of the tricarboxylic acid cycle by:
 a. competitively inhibiting succinate dehydrogenase
 b. complexing with an essential metal ion factor
 c. complexing with acetyl-CoA
 d. favoring

ahh_risa   45   1 Reply

elizabethxo1

A non-competitive inhibitor of an enzyme catalyzed reaction causes:

A non-competitive inhibitor of an enzyme catalyzed reaction causes:

A non-competitive inhibitor of an enzyme catalyzed reaction causes:
 a. an increase in both the apparent Km and Vmax
 b. a decrease in the apparent Km and Vmax
 c. no change in the apparent Km and a decrease in apparent Vmax
 d.

motee   46   1 Reply

DR.BREEEEEE

In the presence of a competitive inhibitor the initial rate of an enzyme catalyzed reaction depends ...

In the presence of a competitive inhibitor the initial rate of an enzyme catalyzed reaction depends ...

In the presence of a competitive inhibitor the initial rate of an enzyme catalyzed reaction depends upon:
 a. the substrate concentration
 b. the inhibitor concentration
 c. the relative affinities of inhibitor and substrate
 d.

Random   67   1 Reply

canelo

Two enzymes within a single organism that catalyze the same chemical reaction but have catalytically ...

Two enzymes within a single organism that catalyze the same chemical reaction but have catalytically ...

Two enzymes within a single organism that catalyze the same chemical reaction but have catalytically distinct subunits are called:
 a. apoenzymes
 b. antipodes
 c. coenzymes
 d. enantiomorphs
 e. isozymes

adamsnaya   46   1 Reply

dthomas18

Heterotropic effectors of allosteric proteins:

Heterotropic effectors of allosteric proteins:

Heterotropic effectors of allosteric proteins:
 a. always influence the protein to form more of the R state
 b. always influence the protein to form more of the T state
 c. always cause increased binding of the substrate to an enzyme

rachelkimq   45   1 Reply

kpennies

One of the basic assumptions of the symmetry model of the allosteric behavior of proteins is that in ...

One of the basic assumptions of the symmetry model of the allosteric behavior of proteins is that in ...

One of the basic assumptions of the symmetry model of the allosteric behavior of proteins is that in the absence of ligand:
 a. The two states (R and T) of the allosteric protein are in equilibrium.
 b. There are equal concentrations of th

crownlessking   46   1 Reply

garroghuu

Diisopropylfluorophosphate (DIFP) irreversibly inactivates proteases such as trypsin and ...

Diisopropylfluorophosphate (DIFP) irreversibly inactivates proteases such as trypsin and ...

Diisopropylfluorophosphate (DIFP) irreversibly inactivates proteases such as trypsin and chymotrypsin by reacting with:
 a. the carboxyl side chain of a glutamic acid residue
 b. the coenzyme
 c. the N-terminal amino acid
 d. the

sarah_verduzco1   45   1 Reply

Mulatta

A number of the digestive enzymes are synthesized in an inactive form and are only activated in the ...

A number of the digestive enzymes are synthesized in an inactive form and are only activated in the ...

A number of the digestive enzymes are synthesized in an inactive form and are only activated in the duodenum. These inactive precursor forms are termed:
 a. zymogens
 b. substrates
 c. coenzymes
 d. trypsins
 e. proteosomes,

starrlite81   43   1 Reply

Beehappy2

In the serine proteases, the formation of an acyl-enzyme intermediate is indicative of:

In the serine proteases, the formation of an acyl-enzyme intermediate is indicative of:

In the serine proteases, the formation of an acyl-enzyme intermediate is indicative of:
 a. the susceptibility of such enzymes to inhibition by diisopropylfluorophosphate
 b. the participation of an aspartic acid residue at the active site

Abessesen   32   2 Replies

Abessesen

In the mechanism of the aspartic proteases:

In the mechanism of the aspartic proteases:

In the mechanism of the aspartic proteases:
 a. Both aspartic acid residues at the active site are always protonated.
 b. Both aspartic acid residues at the active site are always deprotonated
 c. One aspartic acid residue at the acti

Brooke.catlin   38   1 Reply

jjdjd j

The compound diisopropylfluorophosphate (DIFP) is a potent inhibitor of the proteolytic enzyme ...

The compound diisopropylfluorophosphate (DIFP) is a potent inhibitor of the proteolytic enzyme ...

The compound diisopropylfluorophosphate (DIFP) is a potent inhibitor of the proteolytic enzyme chymotrypsin. It permanently inactivates the enzyme by forming a covalent complex with a _____ residue at the active site
 a. serine
 b. proline

hessar3   71   1 Reply

NILLABRO

The inhibition of chymotrypsin by diisopropylfluorophosphate (DIFP) involves:

The inhibition of chymotrypsin by diisopropylfluorophosphate (DIFP) involves:

The inhibition of chymotrypsin by diisopropylfluorophosphate (DIFP) involves:
 a. the transient electrostatic interaction of the inhibitor with positively charged residues at the active site
 b. reversible competitive inhibition of substra

yjuhen   66   1 Reply

P.liania

One of the reasons that enzymes are such efficient catalysts is that:

One of the reasons that enzymes are such efficient catalysts is that:

One of the reasons that enzymes are such efficient catalysts is that:
 a. The energy level of the enzyme-transition state complex is much higher than for an uncatalyzed reaction.
 b. Enzymes can lower the activation energy for the reaction

mdlc0516   49   1 Reply

dalveixes

The affinity of hemoglobin for oxygen is increased by:

The affinity of hemoglobin for oxygen is increased by:

The affinity of hemoglobin for oxygen is increased by:
 a. a higher H+ concentration in the surroundings
 b. an increase in the organic phosphate level in red cells
 c. an increase in the CO2 concentration in the surroundings
 d.

ahh_risa   53   1 Reply

haylsm112

2,3-bisphosphoglycerate lowers the affinity for oxygen of hemoglobin by:

2,3-bisphosphoglycerate lowers the affinity for oxygen of hemoglobin by:

2,3-bisphosphoglycerate lowers the affinity for oxygen of hemoglobin by:
 a. binding preferentially to deoxyhemoglobin
 b. binding preferentially to oxy-hemoglobin
 c. stabilizing oxy-hemoglobin by cross-linking the beta chains
 

lacoya15   58   2 Replies

lacoya15

A characteristic of sickle cell hemoglobin, Hb S, is that it:

A characteristic of sickle cell hemoglobin, Hb S, is that it:

A characteristic of sickle cell hemoglobin, Hb S, is that it:
 a. will not bind oxygen
 b. has abnormal heme groups
 c. contains only alpha globin chains
 d. tends to form aggregates when deoxygenated
 e. contains no heme gr

motee   46   1 Reply

hsprouse

The sigmoidal shape of the oxygen saturation curve for hemoglobin means that:

The sigmoidal shape of the oxygen saturation curve for hemoglobin means that:

The sigmoidal shape of the oxygen saturation curve for hemoglobin means that:
 a. Hemoglobin has a higher affinity for oxygen than does myoglobin.
 b. The affinity of hemoglobin for oxygen is pH independent.
 c. Oxygen binds both to t

MB0727   56   1 Reply

hurricanechris7

In hemoglobin, which is capable of reversibly binding oxygen, the iron atom at the center of the ...

In hemoglobin, which is capable of reversibly binding oxygen, the iron atom at the center of the ...

In hemoglobin, which is capable of reversibly binding oxygen, the iron atom at the center of the heme group is in:
 a. the +3 ferric state
 b. the +3 ferrous state
 c. the +2 ferric state
 d. the +2 ferrous state

alshernandez   50   1 Reply

sara6394

Motor proteins convert chemical energy in the form of ________ into the mechanical energy of motion. ...

Motor proteins convert chemical energy in the form of ________ into the mechanical energy of motion. ...

Motor proteins convert chemical energy in the form of ________ into the mechanical energy of motion.
 a. ATP
 b. a-tubulin
 c. cyclic adenosine monophosphate (cAMP)
 d. glucose

Abessesen   52   1 Reply

yuhiyuhi

Although kinesin and dynein are similar in both form and function, they differ significantly in one ...

Although kinesin and dynein are similar in both form and function, they differ significantly in one ...

Although kinesin and dynein are similar in both form and function, they differ significantly in one key aspect:
 a. the form of energy used for generating motion
 b. the direction in which they move organelles and vesicles in relation to t

mahi   34   2 Replies

mahi

This animal muscle class is the only one that has polynucleated cells:

This animal muscle class is the only one that has polynucleated cells:

This animal muscle class is the only one that has polynucleated cells:
 a. cardiac muscle cells
 b. myoepithelial cells
 c. smooth muscle cells
 d. skeletal muscle cells

hawkins1346   42   1 Reply

alimorey

Release of Ca2+ from the ______________ induces a muscle contraction after Ca2+ binds to the ...

Release of Ca2+ from the ______________ induces a muscle contraction after Ca2+ binds to the ...

Release of Ca2+ from the ______________ induces a muscle contraction after Ca2+ binds to the ____________ component of the troponin complex.
 a. sarcoplasmic reticulum, F-actin
 b. sarcoplasmic reticulum, troponin C
 c. transverse tub

Jnortontruvisio   49   1 Reply

dalveixes

The ATPase activity of the thick filament of muscle fiber is performed by the ________________.

The ATPase activity of the thick filament of muscle fiber is performed by the ________________.

The ATPase activity of the thick filament of muscle fiber is performed by the ________________.
 a. light chain 1
 b. troponin T
 c. myosin heads
 d. myosin tails

mahi   41   1 Reply

Godzilla159

The following observation is a key element in support of the sliding filament model of muscle ...

The following observation is a key element in support of the sliding filament model of muscle ...

The following observation is a key element in support of the sliding filament model of muscle contraction:
 a. The thick and thin filaments' lengths are constant during contraction.
 b. The myosin thick filament expands, while the actin th

ugai_kyut   29   1 Reply

Kanashaea

The opposing orientation of the assembly of the sarcomere allows the shortening of:

The opposing orientation of the assembly of the sarcomere allows the shortening of:

The opposing orientation of the assembly of the sarcomere allows the shortening of:
 a. myosin thick filaments
 b. actin thin filaments
 c. both a and b
 d. nebulin

bubblegum123   25   1 Reply

gidgetlynch@gma

Coupling of ____ and ________ is the link that creates mechanical movement from chemical energy in ...

Coupling of ____ and ________ is the link that creates mechanical movement from chemical energy in ...

Coupling of ____ and ________ is the link that creates mechanical movement from chemical energy in muscle contraction.
 a. ATP hydrolysis, Ca2+ association with troponin C
 b. ATP hydrolysis, actin and myosin association/dissociation

sarah_verduzco1   29   1 Reply

Nickluna@msn.co

The power stroke of the myosin heads during muscle contraction immediately follows __________.

The power stroke of the myosin heads during muscle contraction immediately follows __________.

The power stroke of the myosin heads during muscle contraction immediately follows __________.
 a. ATP hydrolysis
 b. ATP association
 c. ADP release
 d. ADP binding

Random   49   1 Reply

bunique227744

ATP binding to myosin causes ___________ of myosin with actin.

ATP binding to myosin causes ___________ of myosin with actin.

ATP binding to myosin causes ___________ of myosin with actin.
 a. association
 b. polymerization
 c. dimerization
 d. dissociation

Abessesen   65   1 Reply

Godzilla159

The binding of Ca2+ to troponin C increases troponin C interaction with troponin I and decreases ...

The binding of Ca2+ to troponin C increases troponin C interaction with troponin I and decreases ...

The binding of Ca2+ to troponin C increases troponin C interaction with troponin I and decreases troponin I interaction with ____________, which makes myosin-binding sites accessible.
 a. troponin T
 b. myosin
 c. actin
 d. tropo

bubblegum123   80   1 Reply

hennihanadi

Although smooth muscle contraction is dependent on Ca2+, it contains no ___________. ...

Although smooth muscle contraction is dependent on Ca2+, it contains no ___________. ...

Although smooth muscle contraction is dependent on Ca2+, it contains no ___________. Contraction/relaxation is controlled by ______________ of light chain 2.
 a. troponins, phosphorylation/dephosphorylation
 b. troponins, inactivation

Abessesen   28   1 Reply

ABascomb

A non-hydrolyzable analog of ATP would arrest a skeletal muscle contraction at which point?

A non-hydrolyzable analog of ATP would arrest a skeletal muscle contraction at which point?

A non-hydrolyzable analog of ATP would arrest a skeletal muscle contraction at which point?
 a. the low energy conformation of myosin bound to actin
 b. the high energy conformation of myosin bound to actin
 c. myosin head unbound to

lacoya15   37   2 Replies

lacoya15

Catabolic pathways converge to form a few end products. These are:

Catabolic pathways converge to form a few end products. These are:

Catabolic pathways converge to form a few end products. These are:
 a. glucose and fatty acids
 b. amino acids, pyruvate, and glycerol
 c. amino acids, acetyl CoA, and glycerol
 d. water and carbon dioxide
 e. ammonia, water

mahi   27   1 Reply

kburke

The common intermediate of metabolism is:

The common intermediate of metabolism is:

The common intermediate of metabolism is:
 a. glyceraldehyde 3-phosphate
 b. ATP
 c. acetyl CoA
 d. water and carbon dioxide
 e. Catabolism does not have any common intermediates.

jayfro   50   1 Reply

bbebe

In comparing anabolism and catabolism, which of the following statements is true?

In comparing anabolism and catabolism, which of the following statements is true?

In comparing anabolism and catabolism, which of the following statements is true?
 a. The anabolic and catabolic pathways of a given substance usually consist of all the same enzymes, only in reverse of each other.
 b. When a specific enzy

sarah_verduzco1   73   1 Reply

achurch

How is the energy released from catabolism coupled to anabolism?

How is the energy released from catabolism coupled to anabolism?

How is the energy released from catabolism coupled to anabolism?
 a. Catabolism is mostly oxidative; therefore, no energy is released in this process.
 b. Anabolism and catabolism share pathways and transfer energy from each process throug

hawkins1346   72   1 Reply

Lex_Lex21

Anabolic pathways consist mostly of:

Anabolic pathways consist mostly of:

Anabolic pathways consist mostly of:
 a. oxidation reactions
 b. reduction reactions
 c. endothermic reactions
 d. acid-base reactions

jennjenn563   102   1 Reply

ksullivan042197

How are metabolic pathways organized within the cell?

How are metabolic pathways organized within the cell?

How are metabolic pathways organized within the cell?
 a. Enzymes for a given metabolic pathway are localized within distinct cellular compartments or organelles.
 b. Enzymes for a given metabolic pathway are organized in multi-enzyme comp

MB0727   110   2 Replies

MB0727

Which of the following cannot be synthesized by higher organisms?

Which of the following cannot be synthesized by higher organisms?

Which of the following cannot be synthesized by higher organisms?
 a. carbohydrates
 b. lipids
 c. essential amino acids
 d. glucose
 e. All of the above can be synthesized by higher organisms.

kescobar5   34   1 Reply

yuhiyuhi

ATP is produced from: (Multiple Choice)

ATP is produced from: (Multiple Choice)

ATP is produced from:
 a. photosynthesis
 b. catabolism
 c. anabolism
 d. both a and b
 e. both a and c

mdlc0516   39   1 Reply

PrincessAwesome