BMS 344 FINAL REVIEW (TEST QUESTIONS)

T/F: blood is a connective tissue

true

Vesicular Monoamine Transport (vMAT) Proteins are antiporters responsible for the accumulation of dopamine, norepinephrine, histamine, and serotonin inside synaptic vesicles. vMAT activity requires a pH gradient between the cytoplasm and the vesicle. Carbonyl cyanide-p-trifluoromethoxyphenylhydrazone (FCCP) is a protonophore. Protonophores are capable of disrupting proton gradients by carrying these ions across membranes. What would be the effect of treating dopamine-releasing neurons with FCCP

there will be a build up of dopamine, norepinephrine, etc inside the cell

T/F: protein domains formed by alpha helices wrapping around each other are called coiled-coil structures

true

Microfilaments, composed of F actin, are polar with a plus and minus end. which of the following statements about microfilaments are true?

-microfilaments are most abundant

-positive end pushes out

-positive is ATP and negative is ADP

what structures allow for direct cell to cell communication through cytoplasmic bridges?

gap junctions and connexins

in nervous tissue, there are both neurons and glial cells. which of the following are functions of glial cells?

-non conducting

-insulating

-nourishment

-supportive

The Cytochrome P450, which is heavily involved in drug metabolism and in detoxifying a large number of hydrophobic compounds is a membrane protein located in what subcellular compartment?

smooth ER

T/F: cholesterol is a lipid

true

T/F: the opening of voltage gated Na+ channels allows for the transported ions to accumulate on the side of the membrane with a higher Na+ concentration

false

goes to the side with the higher K+ concentration

which of the following statements about the extracellular fluid compartments are true?

-nearly homogenous

-mainly composed of interstitial fluid

-plasma and interstitial fluid

which of the following statements about enzymes are true?

-speed up rate of reaction

-are not used up in reaction

-do not change equilibrium

-reaction would occur without the enzyme

which of the following statements about diffusion in an open system is NOT true?

diffusion is faster for larger molecules

Keratins are a family of long alpha-helical proteins that come in two classes, Acidic and Basic. Keratins are structurally important in hair and nails. Keratins also form which of the following intracellular features?

intermediate filaments

Although cell membranes have two layers (a lipid bilayer), sometimes called leaflets, some structures in the cell are composed of two lipid bilayers working together. These structures are said to have a double-membrane system that facilitates compartmentation. Which of the following structures have a double-membrane system? Select all correct answers.

mitochondria

nucleus

golgi body

Daniel koshland Jr. proposed the induced fit model for enzyme mediated catalysis. which of the following statements below are true about the induced fit model?

can be regulated by other molecules binding elsewhere than the binding site

which of the following statements is NOT true regarding secondary transport?

does directly use ATP

which of the following represents a positive feedback system

oxytocin with contractions

Cytochrome P450 is a large family of iron (heme)-containing enzymes. These enzymes will transfer electrons from a donor molecule to the heme group and then to oxygen. These reactions are important for the synthesis of steroids and fatty acids, and for the removal and degradation of xenobiotics. The electron transfer reaction of P450 is known as a what?

redox reaction

according to the law of mass balance, which of the following statements is true?

output of water must be equal to the input of water

which of the following membrane proteins are responsible for generating and maintaining the Na+ and K+ concentration gradients across the plasma membrane of most mammalian cells?

sodium potassium pump

membrane potentials are

separation of electrical charges across a membrane

colchicine is a poison that destabilizes microtubules at low concentrations. which of the following processes will be most directly affected by colchicine poisoning?

protein trafficking

motility

cell division

osmosis is the net diffusion of what across a membrane?

water

when a red blood cell is placed in water, it will

burst

a dipole moment results from a brief change in the position of electrons in an otherwise neutral atom. this week effect is responsible for which of the non-covalent interactions?

van der waals

a drop of water tends to form a sphere. which of the following answers are true?

surface tension in the water molecule??

what are the main components of lipid rafts?

sphingolipids

cholesterol

phospholipids

during phagocytosis, the ultimate fate of the phagosome is what?

engulfed by the lysosome

tissues are groups of cells working together to form a common function. which of the following are primary types of tissues?

epithelium

connective

muscle

neural

which of the following factors regarding resting membrane potentials are accounted for in the goldman equation?

ion permeability

ion concentration

charges on the ions

Napthylvinylpyridines are potent inhibitors of the enzyme choline acetyltransferase (ChAT). If these inhibitors are applied to a cholinergic synapse, the predicted effects would include:

paralysis

no muscle cell contraction

The wasp venom β-pompilidotoxin (β-PMTX) slows the inactivation of voltage-gated sodium channels. Which step of the action potential is most likely affected:

repolarization

Ischemic strokes are caused by a reduction in blood flow, and immediately after the decreased blood flow, glutamate builds up causing overexcitation of neurons. Hypothetically, if you wanted to increase glutamate uptake which cell type would you want to increase?

astrocytes

in glucose regulation, the pancreatic beta cells will act as the sensor to start a ________ feedback loop to secrete insulin

direct

T/F: every action potential in a neuron is identical and proceeds to the axon terminals without degradation of the electrical signal

true

When a threshold potential is reached at the axon initial segment, voltage-gated Na+ channels will open leading to a further increase in the membrane potential. This increase will open more voltage-gated Na+ channels, which will further increase the membrane potential. This process is an example of?

positive feedback system

which of the following statements about nicotinic acetylcholine receptors are true?

-allow inflow of sodium

-multisubunit

-do not use second messengers

-undergo a conformational change

the axon initial segment (axon hillock) belongs to with of the following neural zones?

signal integration zone

in the presynaptic active zone, which complex is targeted by both tetanus and botulism neurotoxins?

snare complex

What are the ways that a cell uses to modulate the strength of GPCR signaling?

Desensitization, G protein inactivation, Second messenger degradation, Receptor internalization, Negative feedback, Competition

both autocrine and paracrine signaling are dependent upon which forms of molecular movement?

diffusion

cocaine inhibits the activity of the DAT dopamine transport protein. DAT is responsible for dopamine uptake from the synaptic cleft. what is the effect of cocaine on dopamine neurotransmission in the postsynaptic cell?

increased response due to buildup of dopamine

the integration of graded potentials at the axon hillock that occurs at slightly different times to add together to fire an action potential is called what?

temporal summation

a patient has cushing's disease, caused by too much cortisol. the patient's physician finds that while cortisol and ACTH levels are high, CRH levels are low. the likely source of pathology in the patient is the

anterior pituitary, adenohypophysis

gonadotropin releasing hormone is a trophic hormone. trophic hormones are defined by what feature?

ability to control other hormones

which class of receptors are sometimes held in an inactive state by heat shock proteins until the receptor binds the hormone?

intracellular

which supporting cells produce myelin sheaths that insulate neurons of the peripheral nervous system?

schwann cells

which of the following is the primary excitatory neurotransmitter in the CNS?

glutamate

in an early step in the synthesis of steroid hormones, cholesterol is translocated by the StAR and TSPO proteins to where?

mitochondria

nerve impulses do not travel along myelin-covered regions but jump from one node of ranvier to another node in a process called

saltatory conduction

what hormones are released by the anterior pituitary gland?

prolactin

thyrotropin

adrenocorticotropin hormone

growth hormone

FSH

leutinizing hormone

which of the following statements on the role of RGS proteins in the GPCR signaling is not true

regulated GEF activity

during the ________, the axon is incapable of generating a new action potential, no matter how strong and coincided with depolarization and repolarization phases

absolute refractory period

which of the following is true about indirect cell signaling?

diffusion

contact independent

autocrine, paracrine, endocrine, neural

which of the following cell types have resting and activated phenotypes, produce pro- and anti-inflammatory cytokines, and can phagocytose dead cells

microglia

place the following indirect signaling events in order of occurrence

1) release of chemical messenger from signaling cell into environment

2) transport of chemical messenger through environment to target cell

3) communication of signal to target cell by receptor binding

during the process of agonist-dependent densensitization, which protein is primarily responsible for terminating the GPCRs activation of heterotrimeric G proteins

arrestin

The calcium sensor in the parathyroid gland is the CaSR G-protein coupled receptor. Activation of this receptor occurs when extracellular calcium levels are high and lead to increases in intracellular calcium levels. What would happen to parathyroid hormone (PTH) secretion if you applied an antagonist to the CaSR?

Activation of CaSR leads to an inhibition of release, and the inhibition of CaSR leads to a tonic release of PTH.

In Klinefelter's Syndrome, males with two X chromosomes, and one Y chromosome (47XXY), the patients normally show signs of azoospermia (no sperm in the ejaculate). The endocrine profile of these Klinefelter's Syndrome patients usually shows relatively normal to low levels of testosterone, high levels of both FSH and LH, but undetectable Inhibin. The most likely source of this defect in hormones in these patients is the:

testes

which of the following is not a characteristic of the parasympathetic autonomic nervous system?

-fight or flight

-short pre long post

-preganglia are close to spinal cord

-originate in lumbar or thoracic region

-preganglionic synapses with 10+ postganglionic

what are the two kinds of excitable cells?

neurons and muscles

the driving force for blood flow through the circulatory system is

blood pressure

what is the normal blood pressure measured in the right atrium?

0mm Hg

which of the following is a component of troponin with 4 binding sites for calcium?

troponin C

when the heart makes the lub-dub sounds, what events are responsible for the lub sound?

atrioventricular valves

T/F: the term EC coupling refers to the excitation contraction coupling, whereby a muscle fiber converts the muscle action potential into a contraction of sarcomeres

true

________ is defined as the contraction of a heart chamber and ____________ is defined as the relaxation of a heart chamber

systole; diastole

if a mitochondrion is being transported along a microtubules away from the MTOC, which motor protein would be carrying it?

kinesin

according to Poiseuille's equation, which of the following changed variables would directly or indirectly increase flow?

-increased pressure

-increased radius

-decreased viscosity

-decreased length

during exercise, blood flow shifts from the GI tract to skeletal muscle as a result of increased oxygen demand. which muscle type is mainly responsible for redirecting blood flow?

smooth muscle

which would not cause an increase in blood pressure?

decrease in cardiac output

the vessels that are the main site of variable resistance in the circulatory system, and that contribute to more than 60% of the total resistance, are the

atrioles

which of the following mechanical events would occur due to the T wave?

ventricular diastole/repolarization

which of the following molecules will bind to a myosin head as a part of a sliding filament movement?

ATP

actin

which of the following statements about sarcomeres are true?

repeating segments

contraction

functional units of muscle fibers

striated

Digitalis, a Na+/K+ ATPase pump blocker, is often prescribed to heart failure patients. From your understanding of striated muscle contraction physiology and the role of the Na+/Ca2+ exchanger, taking Digitalis would ___________ the levels of intracellular calcium to ____________the contraction of the heart.

increase; increase

which blood vessel tunica is mainly controlled by the sympathetic nervous system to regulate vasoconstriction and vasodilation of vessels?

tunica media

which are the primary mechanisms that skeletal muscles use for uniform depolarization of a fibers' sarcolemma?

multiple innervations

invaginations

striated muscles are so called because of a repeating pattern of light and dark bands. one repeating unit of the banding pattern is called a

sarcomere

As a clinical pathologist, you receive an unknown muscle sample. You notice that the muscle tissue has a number of distinguishing characteristics, such as branching chains of cells, a single nucleus within the cell, and intercalated discs. Which of the following types of muscle would match your unknown sample?

cardiac muscle tissue

the pericardium provides the heart with which of the following

friction-free environment

autorhythmic myocardium cells express a funny channel with unique properties. which of the following do not describe these F channels?

do not allow sodium inflow

fast depolarization

which of the following statements about calsequestrin are true?

most calcium is bound

release of calcium through SR causes calsequestrin to release calcium

live blood cells are added and dead blood cells are removed from the circulatory system through which blood vessels?

sinusoidal capillaries

what is the term for when actin subunits are being added at one end of a microfilament while being subtracted from the other end, and both occur at the same rate?

treadmilling

which of the following receptors is directly responsible for the release of the greatest amounts of intracellular calcium into muscle and is located on the terminal cisternae of the sarcoplasmic reticulum?

ryanodine receptor

which of the following statements about baroreceptors is not true

sympathetic nervous system

The Beta-adrenergic receptor is located in striated muscle. Beta AR couples to heterotrimeric G(s), which activates adenylyl cyclase . This results in the upregulation of cAMP and Protein Kinase A (PKA) activity. PKA phosphorylates the RYR receptor in muscle, increasing Ca+2 release. The effect of this phosphorylation would be to:

increase muscle contraction

T/F: according to the law of laplace, decreases in transmural pressure will increase the wall stress in a vessel

false

which of the following is found at intercalated discs

gap junctions

desmosomes