A protein is found in blood that is secreted by the pituitary gland and acts on the testes, the protein is classified as a/an?
An enzyme that catalyzes phosphorylation of a protein is called a? An enzyme that catalyzes dephosphorylation of a protein is called a?
c. Phosphatase: kinase
d. ligand: active site
A. Kinase: Phosphatase
Which is Not true regarding prostaglandins?
D. NSAIDs stimulate the synthesis of prostaglandins.
In response to falling blood pressure, the nervous system will stimulate the heart to pump harder and increase blood pressure. This is an example of?
A. Extrinsic regulation to accomplish negative feedback
A chemical messenger is released by a cell within the thyroid gland and binds to receptors on other thyroid cells and to receptors on itself. This chemical messenger would be considered?
E. both C & D are correct
Which of the following statements applies to paracrine regulation?
a. Paracrine chemicals are always released directly into the bloodstream.
b.Prostaglandins are paracrine chemicals
c. Paracrine chemicals are released by cells in a tissue and act on cells in the same vicinity
d. A & B
e. B & C
e. both B & C
The hormone insulin causes the transport of glucose into body cells. Its secretion is controlled by a negative feedback system. Which of the following is most likely to be correct?
Increase BGC further
B. An increase in blood glucose concentration will stimulate insulin secretion which will, in turn, lower the blood glucose concentration
C. Both B & C
When a person cuts herself, she has clotting factors in her blood that will be released continuously in an increasing cascade until her blood clots and stops the bleeding, what mechanism caused her blood to clot?
E. Positive feedback
Which of the following can be catabolized to produce ATP by cellular respiration?
D. All of the above
Which of these cell membrane transport mechanisms is subject to saturation limits?
D. Facilitated Diffusion
Which of the following would not increase the rate of simple diffusion across the phospholipid bilayer of the plasma membrane?
A. Greater number of protein carriers
Which substance could cross the plasma membrane directly through the lipid portion?
a. O2 (Oxygen)
d. The protein insulin
e. An Amino Acid
a. O2 (Oxygen)
What is the electrochemical gradient for Na+?
E. Both A & C
Which of the following types of transport is involved in the transepithelial transport of Na+ from the lumen of the intestine into the bloodstream?
E. Both A & C ( Active Transport of Na+
Diffusion of Na+ through a channel)
Predict the effect of placing an RBC in Pure H20
C. Swelling and potential lysis
Which of the following would decrease the rate of an enzyme-catalyzed reaction?
C. Increase the concentration of product
Consider the following reaction: C02 + H20<>H2C03 <> H2C03<>H+ + HC03- When a tissue becomes more active, C02 increases due to the C02 production in?
D. Mitochondria; decreases
Which of the following would increase the saturation rate for an enzyme-catalyzed chemical reaction?
All of the above
B. Increase Enzyme Concentration
Which of the following examples of transport does not require a carrier protein
E. Neither B or D requires a carrier protein
Place the number of the components of a reflex arc in the correct order
(3) Afferent pathway
(5) Integration center
(6) Efferent pathway
3. Afferent Pathway
5. Efferent Pathway
The process of producing glucose from amino acids is termed
Of the gradients listed below, which is the most accurate description of the force that determines the movement of ions across the membrane at resting membrane potential
B. Electrochemical gradient
In facilitated diffusion, a molecule is moved
D. down its concentration gradient with the assistance of a protein carrier molecule, and no ATP is required
Which of these terms describes the variable binding of multiple substrates to an enzyme's active site?
C. Substrate specificity
E. Both B and C
processed by the liver to a less toxic compound.
a waste product of protein metabolism
Glycogenesis refers to the synthesis of__ and occurs in__?
B. Glycogen; the liver
Long-term exposure to high levels of chemical messenger will__ the receptors for that chemical messenger on the target cell?
E. down regulate
Which of the following statements regarding the active transport of substances across cell membrane is correct?
D. all the above
When an enzyme's shape, and therefore its activity is controlled by a ligand loosely and reversibly binding at a regulatory site, it is called?
C. allosteric regulation
Which of the following statements about the transepithelial transport of glucose with sodium(as it is absorbed from the lumen of the intestine to the bloodstream) is true?
D. glucose and sodium both move into the apical surface of the cell
32.which of the following statements about the Na/K pump is false?
B. it transports Na and K in a 3:1 ratio
Which of the following examples of transport requires a carrier protein?
E. both A and C require carrier protein
for an action potential to occur:
be able to identify action potential diagram
D. all of the above are correct
Identify the type of channels involved in Phase (1)?
A. open voltage-gated sodium (Na+) channels
Identify the type of channels primarily involved in phase (2)?
D. open voltage-gated potassium (K+) channels
In a neuron, an action potential originates at the____ and travels along the axon until it reaches the____
D. axon hillock, axon terminal
Hypokalemia will result in
D. Both B and C
(hyperpolarization at rest. difficulty achieving threshold)
Choose the most likely voltage to CLOSE the voltage-gated Na channels in the axon of the neuron.
How can action potentials relay information about the intensity of a stimulus, such as distinguishing between a loud and soft sound? a. due to the frequency of action potential
b. due to the magnitude of each action potential
c. due to the summation of several action potentials
d. due to electronic conduction
e. due to the increasing intensity of graded potentials
a. due to the frequency of action potential
In myelinated axons, voltage-gated sodium and potassium channels would be concentrated in what area?
Which of the following is responsible for restoring the resting electrical gradient (polarized nature) of the plasma membrane after the depolarization phase of an action potential?
C. the opening of voltage-gated K+ channels
The absolute refractory period of a neuron has primarily to do with __
A. the status of the voltage-gated sodium(Na+) channels
Opening gated Na+ channels in a cell membrane would result in
E. Both C and D are true
What type of ion channels are responsible for establishing the resting membrane potential of a cell?
A. leak channels
If the graded potential is at or above threshold once it reaches the of the neuron, an action potential will be generated.
C. axon hillock
Which disorder will cause swelling of brain cells, leading to erratic behavior?
Which of these is most likely to be responsible for a hyperpolarizing graded potential in a cell?
D. Ligand-gated potassium(K+) channels
The cell would be in the relative refractory period when?
A. the voltage-gated sodium (Na+) gates are open
A subthreshold stimulus will not generate an action potential, but a supra-threshold stimulus does generate an action potential. This is an example of?
D. the all or none principle
Movement of what ion is responsible for ever " D" in this figure above?
a. sodium (Na+)
b. potassium (K+)
d. calcium (Ca)
e. Phosphate (P04-)
Action Potentials can be either depolarizing or hyperpolarizing?
When a tissue encounters low oxygen levels, cell within the tissue release chemicals that cause local arteriole dilation. This is an example of intrinsic regulation to accomplish negative feedback?
The primary source of negative charges in the intracellular fluid is presence of chloride ions?
Increasing the concentration of substrate for an enzyme catalyzed reaction will increase the saturation rate?
In the absence of the Na+/K+ pump, the resting membrane potential of a cell would eventually stabilize at (0) mV?
substrate specificity implies multiple possible substrates?
Intracellular and extracellular fluid the have the same ion concentration?
Oxidative phosphorylation takes place in the cytoplasm of a cell?
Hypokalemia will stop the heart due to the inability of cardiac muscle to repolarize after an action potential