Exam 1 Revised Flashcards
Demyelination of neurons in PNS/ Schwann cell defect causes this pathology:
Guillian-Barre
Demyelination of the neurons in the CNS/ Oligodendrocyte defect causes this pathology:
Multiple Sclerosis
Which autoimmune disease causes muscle weakness by antibodies damaging nAChr (nicotinic ACh receptors)?
Myasthenia Gravis
-tx: Neostigmine + Prednisone + possibly plasmapheresis
Which autoimmune disease causes muscle weakness by antibodies attacking voltage gated Ca++ channels on the presynaptic motor nerve terminal?
LEMS
-tx: Neostigmine + chemo/radiation if necessary
A defect with lysosomes can cause this disease:
Tay-Sach’s Disease
Which autosomal recessive disorder involves Cl- ion channel disorder as a result of protein deficiency?
Cystic Fibrosis
True or false: telomerase activity is lower than average in cancerous cells?
false, it is abnormally high
True or false: Hypomethylation of tumor suppressor genes make cancer more likely:
false, HYPERMETHYLATION bc it silences the tumor protective genes
True or false: Hypermethylation of oncogenes can make cancer more likely:
false: HYPOMETHYLATION bc the cancerous gene is less silenced
Which inherited disease is characterized by defective/ leaky ryanodine receptors?
Malignant Hyperthemia
A deceased body will stay contracted due to lack of ATP to release myosin heads from actin on muscle cells after death occurs. This is called:
Rigor Mortis
This condition of the muscle is caused from immobility, poor blood supply, poor nutrition, and less workload:
Atrophy
This condition of the muscle is caused by chronic hemodynamic overload, causing an increase in muscle cell size, increasing size of the organ:
Hypertrophy
This condition of the muscle is caused as a response to injury and increases number of cells:
Ex) good situation- hepatocytes increase after part of liver removed
Ex) bad situation - BPH
Hyperplasia
This condition of the muscle is caused by damage, repair, and regeneration with modifications:
ex) esophageal cells changing after damage from acid reflux to accommodate the environment
Metaplasia
This condition of the muscle is characterized by an abnormal change in shape/ organization of mature cells
ex) achondroplasia in dwarfism
Dysplasia
This condition is caused by autosomal aneuploidy involving trisomy of the 21st chromosome
Down Syndrome/ Trisomy 21
This condition is caused by sex chromosome aneuploidy where the subject has 1 X chromosome:
Turner’s Syndrome
This condition is caused by sex chromosome aneuploidy where the subject has several sex chromosomes (XXY, XXYY, XXXYY)
Klinefelter
Huntington’s Disease and Marfan Syndrome are examples of autosomal dominant conditions. If a mother was heterozygous for this condition and a father was also heterozygous for this condition, what likelihood does their child have of being spared from this condition?
25% chance of not having this condition
Cystic Fibrosis is an autosomal recessive condition characterized by defective Cl- ion channels. If a father expressed this condition and a mother was a carrier, what likelihood does their child have of also expressing this condition?
50% will express this condition
Duchenne’s Muscular Dystrophy is the most common X-linked recessive neuromuscular disease. If a mother possessed 2 of these recessive genes and had a son, what chance does he have of expressing it?
100% because he receives his X chromosome from her.
Name a few conditions that can be caused by increased free radicals in the body:
-Alzheimer’s
-Diabetes Mellitus
-Rheumatoid Arthritis
The insulin gene is impaired in this condition, leading to decreased insulin production:
T1DM
The PPAR-y and glucokinase genes are impaired in this condition, leading to reduced glucose metabolism and insulin resistance:
T2DM
This condition can be autosomal dominant and affects the 13th (BRCA2) and 17th (BRCA1) chromosomes:
Breast Cancer
This neurological condition is inherited from the mother and is caused by a deletion of ~4million base pairs of the long arm of chromosome 15. People affected by this can appear “happy”, ataxic, lack speech, have microcephaly, and have frequent seizures.
Angelman Syndrome
This neurological condition is inherited from the father and is caused by a deletion of ~4million base pairs of the long arm of chromosome 15. People affected by this can appear short and obese. They also experience compulsive behavior and hypogonadism.
Prader-Willi Syndrome
Genomic imprinting is responsible for these 2 conditions linked to developmental delay and intellectual disability:
Prader-Willi and Angelman Syndrome
True or false: Histone acetylation of an oncogene will more likely cause cancer.
true
True or false: histone deacetylation of a tumor suppressor gene will more likely cause cancer.
true
4 functions of epithelial tissue:
-protection
-absorption
-secretion
-excretion
Connective tissue is organized by 3 things:
-consistency
-ground substance
-organization of fibers
Total body fluid = ECF + ICF. What are the 2 components of ECF?
-plasma
-interstitial fluid (ISF)
Which of the fluids is MOST affected by dehydration (pulled from the most):
plasma
Consider the process of a fever causing sweat to be excreted. What is the sensor and effector in this scenario?
-sensor are nerve cells sensing high temp
-effector are sweat glands
True or false: positive feedback (that is useful to the body) is part of an overall negative feedback response.
true
Feed forward is AKA:
adaptive control
Examples of an integral protein channel on a cell membrane:
-channels
-pores
-carriers
Examples of a peripheral protein channel on a cell membrane:
-enzymes
-intercellular signal mediators
More cholesterol in the cell membrane will _ membrane fluidity and permeability but _ flexibility and stability.
decrease, increase
What kind of enzymes do lysosomes contain?
hydrolytic enzymes or hydrolases
What kind of enzymes do peroxisomes contain?
oxidases
True or false: mitochondria generate ATP via ATP hydrolysis,
false, they GENERATE ATP with oxidative phosphorylation and BREAK IT DOWN for energy with ATP hydrolysis
True or false: the nucleolus contains large amounts of DNA and proteins.
false, contains RNA and protein
True or false: glycolysis is anaerobic and generates just a little ATP and does so slowly/ inefficiently.
False, it does generate just a little ATP but its quick and efficient
True or false: the cytoskeleton participates in cell division and mobility with cilia.
true
Ciliary movement requires ATP but also (2 items):
-Ca ++
-Mg ++
True or false: Endocytosis requires a lot of ATP where Exocytosis requires none.
False, they both require ATP
What is the only was large macromolecules can enter the cell?
pinocytosis
True or false: In diffusion, molecules must be water soluble and polarized.
false, must be nonpolarized and lipid soluble
What are the 2 components of typical cellular membranes?
-phospholipids
-cholesterol
True or false: carbohydrates provide “specificity” to a cell membrane.
False, proteins provide specificity and are integral or peripheral
True or false: the cell will use protein as its second choice for making ATP.
False, protein/ amino acids are the last resort
4 components of DNA:
-adenine
-guanine
-cytosine
-THYMINE
4 components of RNA:
-adenine
-guanine
-cytosine
-URACIL
True or false: each nucleotide has a specific pairing (A-C/U, G-T) and is backed by a polypeptide backbone
False: pairings include (A-T/U, G-C) and have a phosphate backbone, not polypeptide
3 uses of ATP:
-membrane support
-synthesis of synthetic compounds
-mechanical work
True or false: ATP production occurs in the nucleus.
false- mitochondria
Basic process of ATP production:
- carbs become glucose, protein becomes AA, fat becomes FA
- glucose + AA + FA = Acetyl Co A
- Acetyl Co A + O2 —(oxidative phosphorylation)—> ATP
True or false: burning fat can happen anaerobically and does so very quickly.
false, burning fat is SLOW and requires O2
ATP must undergo which process to give energy to the body?
Hydrolysis
Which enzyme is required to begin transcription?
RNA polymerase
Where does transcription occur and what is the product?
Nucleus, mRNA
What happens to the RNA before it is sent out of the nucleus?
splicing, removing the introns
What 3 cellular components are required for translation?
-DNA
-AAs
-Ribosomes
Where does translation occur and what product does it make?
cytoplasm at the rough ER and ribosomes, proteins
Which 2 things must happen prior to cells dividing/Mitosis?
-cytokinesis: cytoplasm dividing
-DNA synthesis via DNA polymerase
Which enzyme is required for DNA replication?
DNA polymerase
Which phase does DNA synthesis occur in?
S phase by the S phase activator
True or false: DNA ligase proofreads and fills in gaps in the polypeptide sequence of DNA replication
False!
DNA polymerase proofreads and DNA Ligase fills gaps
Which form of RNA regulated gene expression by binding to complimentary regions of mRNA pre-translation and repressing or promoting degradation of mRNA?
miRNA
Cell growth is determined by (3 items)
-growth factors
-contact inhibition
-cellular secretions (negative feedback)
Telomerase functions by:
adding bases to telomeres to make sure DNA isn’t shortened.
Telomeres function by:
telling cell to stop dividing at the end of DNA
In cancer cells, telomerase activity is high and this can extend the _ phase of the DNA synthesis proces.
S phase
True or false: All mutations cause cancer
false
p53 gene is AKA
tumor suppressor gene
-has t factors
-needs to be ACTIVATED
True or false: DNA is a mononucleotide and has one group of nitrogenous bases.
False, it is a POLYnucleotide and has 4 groups of nitrogenous bases
How can one gene code for more than one protein?
splicing
How many chromosomes does someone with trisomy have?
47
Things that easily/freely pass thru cell membrane:
O2, N, CO2, Alcohols, urea
Things that DO NOT pass easily/freely thru cell membrane:
H2O, ions, glucose, AAs
Which ions are found more in ECF?
-Na+
-Ca++
-Cl-
-Glucose
Which ion is found more in ICF?
K+
What causes the cell membrane to be negative primarily?
K+ Leak Channels
There are leak channels for which 2 ions? Which one more readily leaks through?
NA+ and K+, K+ leaks thru more easily
There are 2 types of Ca++ pumps. One pumps Ca++ out of cell against gradient using ATP. How does the other pump function?
Pumps Ca++ INTO the ER, SR, or mitochondria
At what point will diffusion stop?
When both sides of cell membrane are of = concentration.
True or false: diffusion causes water to move from area of high concentration to low concentration.
False, OSMOSIS, not diffusion
Which 2 processes are considered Passive Transport?
-simple diffusion
-osmosis
True or false: facilitated diffusion is a form of passive transport.
False. It needs the help of a carrier protein
The limit of facilitated diffusion is its _ which is the saturation/ capacity of its binding sites.
Vmax
A diabetic patient urinating glucose would be an example of the limit/ Vmax of _ _.
facilitated diffusion
3 factors that influence rate of diffusion:
-concentration differences
-electrical potential
-hydrostatic pressure differences
ATP is needed to move Ca++ _ the concentration gradient to leave the cell.
against
Tonicity is AKA _ and depends on membrane and solute properties ( _ penetrating solutes)
effective osmotic pressure, excludes penetrating solutes
Osmolarity shows the _ of a solution and without regard to membrane properties.
concentration
Permeant molecules are lipid soluble and readily move thru cell membranes and they are(2 items):
-urea and glycerol
Impermeant molecules have low lipid solubility and don’t readily move thru cell membranes, they are (3 items)
-ions
-glucose
-AAs
Plasma osmolarity=
275-290 mOsm OR ~300mOsm
What is the total osmolarity of this solution?
20mM NaCl + 30mM glucose + 20mM urea
20mOsm Na + 20mOsm Cl + 30mOsm Glucose + 20mOsm Urea = 90mOsm
What is the tonicity of this solution?
20mM NaCl + 30mM glucose + 20mM urea
20mOsm Na + 20mOsm Cl + 30mOsm Glucose —–(not counting urea) = 70mOsm
True or false: Solution A and Solution B are isotonic.
-Solution A (150mM NaCl + 10mM glucose + 10mM glycerol)
-Solution B (150mM NaCl + 15mM Glucose + 5mM Urea)
False. Solution B is hypertonic to Solution A.
-Solution A = 310mOsm (excludes glycerol)
-Solution B = 315mOsm (excludes urea)
True or false: Solution A and Solution B are isosmotic.
-Solution A (150mM NaCl + 10mM Glucose + 10mM Glycerol)
-Solution B (150mM NaCl + 15mM Glucose + 5mM Urea)
True. They are isosmotic.
-Solution A = 320mOsm
-Solution B = 320mOsm
The Na/K ATPase pump is an example of _ active transport.
Primary
The Na/K ATPase pump requires energy because both Na and K are pumped _ their respective gradients.
Against
Which pump is crucial for regulating cellular volume?
Na/K ATPase Pump
The driving force of the Na/K ATPase pump is _ cell volume.
increased
True or False: If Na/K ATPase pump malfunctions, Secondary Active Transport pumps can assist regulating cell volume instead.
False, Secondary Active Transport RELIES on the Na/K ATPase pump to function
Na/K ATPase pump moves K+ _ the cell and Na+ _ the cell.
K+ moves IN, Na+ moves OUT;
More Na outside of cell, so it has to be pumped against diffusion gradient to leave
More K in the cell, has to be pumped against diffusion gradient to come in
True or False: Secondary Active Transport indirectly uses the same energy used from ionic concentration differences (usually Na+’s) from Primary Active Transport.
True
Cotransport AKA Symporters allow for conformational change on the carrier protein responsible for allowing Na+ into the cell to allow _ or _ acids _ the cell as well.
glucose or amino acids, into the cell
Countertransport AKA Antiporters allow for conformational change on the carrier protein responsible for allowing Na+ into the cell to allow _, _, or _ ions to exit the cell like a revolving door.
Calcium, Hydrogen, or Chloride
How do cardiac glycosides like Digoxin increase cardiac contractility?
-inhibits the Na/K ATPase pump which causes more Na+ to stay in cell;
this prevents the antiporter mechanism of Ca++ leaving as more Na+ comes in
Why is the RMP of RBCs/ erythrocytes so close to 0?
RMP to sodium ions is higher than in most cells that have higher affinity with K ions.
Normal Vm (resting membrane potential):
-90 to -70mV
this is because of more K+ leak channels in most cells
Order of highest to lowest Vm:
School Always Needs Some P.E.
Skeletal Muscle
Astrocytes
Neurons
Smooth Muscle
Photoreceptors
Erythrocytes
Skeletal Muscle Vm
-85 to -95mV
Smooth Muscle Vm
-50 to -60mV
Astrocytes Vm
-80 to -90mV
Neurons Vm
-60 to -70mV
Erythrocyte/ RBC Vm
-8 to -14mV
Photoreceptor Vm
-40 (dark) to -70 (light) mV
Na/K ATPase brings _ Na+ ions to ECF and _ K+ ions to the ICF. This helps create a _ charge inside the cell.
3 Na+ ions out for 2 K+ ions in
-creates negative charge
Stages of AP:
1st stage- Membrane is _ and Vm is _ to _.
polarized, -70 to -90mV
Stages of AP:
2nd stage- A stimulus comes and excites cell, Vm becomes more _ due to influx of _. Once the Vm reaches threshold at _, it causes depolarization or _stroke
-Vm becomes more positive due to influx of Na+
-Vm threshold is -55mV causing depolarization or UPSTROKE
Stages of AP:
3rd stage- Na+ channels close and _ channels open, which enter the cell making it more _, but then rapidly diffuse out to make cell more _. This repolarizes the cell membrane during the _stroke.
-K+ channels open to enter cell making it more positive briefly then leave rapidly to make cell negative again
- Repolarization occurs on downstroke
Stages of AP:
After repolarization, sometimes there is overshoot and cell is more negative. The _ pump helps reestablish the concentration gradients after AP has occurred.
Na/K ATPase pump
An AP’s conduction velocity depends on the _ and amount of _.
diameter and amount of myelin
An absolute refractory period happens due to voltage inactivation of Na+ channels which occur on the _stroke, or _.
upstroke, depolarization
A relative refractory period occurs during the _ stroke or _ process but require more stimulus than normal to elicit an AP.
downstroke, repolariztion
True or false: Schwann Cells cover axons and insulate/ speed up AP conduction.
False,
Schwann cells make MYELIN which does this
True or False: Oligodendrocytes make myelin for neurons in the PNS.
False,
CNS not PNS
On Axons, each Node of Ranvier contains _ -gated ion channels.
voltage
True or False: APs occur in the myelin sheaths of neurons
False, APs occur only at Nodes of Ranvier in neuron due to high concentration of Na+ channels located there
When impulses jump along the nerve fiber, increasing velocity and conserving energy, this is called:
Saltatory conduction
Graded potentials are AKA
Local Potentials
Graded potentials are different than APs because:
-no refractory period
-graded = bigger stimulus = bigger response
-summate = mult. stimuli = summed response
-varied response = diff. parts of membrane are influenced differently ( NOT ALL OR NOTHING)
True or false: Graded potentials are most commonly found on voltage gated ion channels on nodes of Ranvier
False,
found on LIGAND gated (not voltage gated) ion channels on DENDRITES (not axons)
True or false: Graded Potentials can give rise to APs
True
ex) like lighting a string on fire that is next to a stick of dynamite
-some parts can fizzle out and not reach dynamite
-if more parts of string catch fire, more likely to grow and spread to dynamite
True or false: APs are mostly found on ligand gated ion channels on dendrites
False
found on VOLTAGE gated (not ligand) ion channels on NODES OF RANVIER on Axons (not dendrites)
Excitability:
Which medication can block ACh channels by competing for binding sites, preventing APs?
Curare (D-tubocurarin)
Excitability:
Which medication can prevent the release of ACh from nerve terminals leading to insufficient stimulus for an AP on skeletal muscles?
Botox
Synapses are either _ or _.
excitatory or inhibitory
Inhibitory Synapses have a _ channel and are found on dendrites on the NT synapse.
Cl-
Inhibitory Synapses cause equilibrium potential to become _ polarized, moving Vm _ to the threshold.
hyperpolarize, farther
Inhibitory Synapses Vm is:
-90mV
Examples of Inhibitory synapses involve:
GABA and Glycine
Inhibitory PostSynaptic Potential (IPSP) _ excitability and makes AP _ likely
depresses, less
Excitatory Synapses are a type of _ potential
graded
The equilibrium potential in excitatory synapses is roughly _mV
0mV, more positive charge
Examples of Exciatory Synapses involve:
Nicotinic ACh Receptors and Glutamate
Excitatory Synapses are more permeable to _.
cations (Na+, K+, Ca++)
-Na and Ca channels are open and K channels are closed so they don’t leave cell.
Each muscle fiber contains _ made of actin and myosin.
MYOFIBRILS
Actin=
thin filament
-I band
-light bands
-attached to Z-discs on the ends, which have sarcomeres in between each z disc
Myosin=
-thick filament
-A band
-dark bands
-heads have ATPase for hydrolysis, needs ATP to move
Sarcomere length @ rest:
2.2 MICRO meters
During muscle contraction, which band is obscured?
I band
Titin is responsible for _ _ which uses NO ATP
passive elasticity
Titin is AKA=
connectin
Drugs that stimulate neuromuscular signaling:
ACh-like drugs and Anti-AChE drugs
Drugs that stimulate the neuromuscular signaling include ACh-like drugs, a few examples would be:
nicotine, carbachol, methacholine
Drugs that stimulate the neuromuscular signaling include Anti-AChE drugs, a couple examples would be:
neostigmine, physostigmine
Drugs that inhibit the neuromuscular signaling:
Curariform drugs and botox
What is happening in Myasthenia gravis?
paralysis, no AP can be generated because antibodies damage nicotinic ACh receptors
What is happening in LEMS?
muscle weakness and paralysis, no AP generated because antibodies damage voltage gated ion channels in presynaptic nerve terminals
Examples of adaptive cellular responses include: (Select all that apply.)
a. Atrophy
b. Dysplasia
c. Hypertrophy
d. Hyperplasia
e. Metaplasia
A,C,D, E
What organs are affected by the type of necrosis that results from either severe ischemia or chemical injury? (Select all that apply.)
a. Lungs
b. Brain
c. Kidneys
d. Muscles
e. Heart
C + E
Current research has determined that chemical-induced cellular injury:
a. Affects the permeability of the plasma membrane.
b. Is often the result of the damage caused by reactive free radicals.
c. Is rarely influenced by lipid peroxidation.
d. Seldom involves the cell’s organelles.
B
Dysplasia refers to a(n):
a. Abnormal increase in the number of a specific cell type
b. True adaptive process at the cellular level
c. Modification in the shape of a specific cell type
d. Lack of oxygen at the cellular level
C
What is an example of compensatory hyperplasia?
a. Hepatic cells increase cell division after part of the liver is excised.
b. Skeletal muscle cells atrophy as a result of paralysis.
c. The heart muscle enlarges as a result of hypertension.
d. The size of the uterus increases during pregnancy
A
During cell injury caused by hypoxia, sodium and water move into the cell because:
a. Potassium moves out of the cell, and potassium and sodium are inversely related.
b. The pump that transports sodium out of the cell cannot function because of a decrease in ATP levels.
c. The osmotic pressure is increased, which pulls additional sodium across the cell membrane.
d. Oxygen is not available to bind with sodium to maintain it outside of the cell.
B
What is the single most common cause of cellular injury?
a. Hypoxic injury
b. Chemical injury
c. Infectious injury d. Genetic injury
A
What type of necrosis is associated with wet gangrene?
a. Coagulative
b. Liquefactive
c. Caseous
d. Gangrene
B
What type of necrosis is often associated with pulmonary tuberculosis?
a. Bacteriologic
b. Caseous
c. Liquefactive
d. Gangrenous
B
What type of necrosis results from ischemia of neurons and glial cells?
a. Coagulative
b. Liquefactive
c. Caseous
d. Gangrene
B
What mechanisms occur in the liver cells as a result of lipid accumulation?
a. Accumulation of lipids that obstruct the common bile duct, preventing flow of bile from the liver to the gallbladder
b. Increased synthesis of triglycerides from fatty acids and decreased synthesis of apoproteins
c. Increased binding of lipids with apoproteins to form lipoproteins
d. Increased conversion of fatty acids to phospholipids
b
What is the most common site of lipid accumulation?
a. Coronary arteries
b. Kidneys
c. Liver
d. Subcutaneous tissue
B
In hypoxic injury, sodium enters the cell and causes swelling because:
a. The cell membrane permeability increases for sodium during periods of hypoxia.
b. ATP is insufficient to maintain the pump that keeps sodium out of the cell.
c. The lactic acid produced by the hypoxia binds with sodium in the cell.
d. Sodium cannot be transported to the cell membrane during hypoxia.
b
During cell injury caused by hypoxia, an increase in the osmotic pressure occurs within the cell because:
a. Plasma proteins enter the cell.
b. The adenosine triphosphatase (ATPase)-driven pump is stronger during hypoxia.
c. Sodium chloride enters the cell.
d. An influx of glucose occurs through the injured cell membranes.
c
Acute alcoholism mainly affects which body system?
a. Hepatic
b. Gastrointestinal
c. Renal
d. Central nervous
d
What is a consequence of leakage of lysosomal enzymes during chemical injury?
a. Enzymatic digestion of the nucleus and nucleolus occurs, halting DNA synthesis.
b. Influx of potassium ions into the mitochondria occurs, halting the ATP production.
c. Edema of the Golgi body occurs, preventing the transport of proteins out of the cell.
d. Shift of calcium out of the plasma membrane occurs, destroying the cytoskeleton.
a
What is a consequence of plasma membrane damage to the mitochondria?
a. Enzymatic digestion halts DNA synthesis.
b. Influx of calcium ions halts ATP production.
c. Edema from an influx in sodium causes a reduction in ATP production.
d. Potassium shifts out of the mitochondria, which destroys the infrastructure.
B
Free radicals cause cell damage by:
a. Stealing the cell’s oxygen to stabilize the electron, thus causing hypoxia
b. Stimulating the release of lysosomal enzymes that digest the cell membranes
c. Transferring one of its charged, stabilized atoms to the cell membrane, which causes lysis
d. Giving up an electron, which causes injury to the chemical bonds of the cell membrane
D
Free radicals play a major role in the initiation and progression of which diseases?
a. Cardiovascular diseases such as hypertension and ischemic heart disease
b. Renal diseases such as acute tubular necrosis and glomerulonephritis
c. Gastrointestinal diseases such as peptic ulcer disease and Crohn disease
d. Muscular disease such as muscular dystrophy and fibromyalgia
A
The loss of the adenosine triphosphate (ATP) during ischemia causes cells to:
a. Shrink because of the influx of calcium (Ca).
b. Shrink because of the influx of potassium chloride (KCl).
c. Swell because of the influx of sodium chloride (NaCl).
d. Swell because of the influx of nitric oxide (NO).
C
Which type of cell adaptation occurs when normal columnar ciliated epithelial cells of the bronchial lining have been replaced by stratified squamous epithelial cells?
a. Hyperplasia
B. Dysplasia
C. Metaplasia
d. Anaplasia
C METAPLASIA
DNA replication requires the enzyme DNA polymerase to:
a. Travel along the single DNA strand, adding the correct nucleotide to the new strand
b. Move along the double strand of DNA to unwind the nucleotides of the double helix
c. Hold the double strand apart while the correct nucleotides are added to the strand
d. Transport the double strand of DNA from the nucleus to the cytoplasm for protein formation
A
A couple has two children diagnosed with an autosomal dominant genetic disease. What is the probability that the next child will have the same genetic disease?
a. One sixth
b. One fourth
c. One third
d. One half
D
When a child inherits a disease that is autosomal recessive, it is inherited from:
a. Father c. Both parents
b. Mother d. Grandparent
C
An X-linked recessive disease can skip generations because:
a. Females are hemizygous for the X chromosome.
b. The disease can be transmitted through female carriers.
c. Mothers cannot pass X-linked genes to their sons.
d. These diseases need only one copy of the gene in females.
B
The part of a membrane protein that extends through the phospholipid bilayer is primarily composed of amino acids that are \nA. highly polar. \nB. negatively charged. \nC. non-polar. \nD. positively charged. \nE. water soluble.
C
The type of movement that is specific and requires carrier molecules and energy is \nA. exocytosis.\nB. facilitated diffusion.\nC. active transport.\nD. endocytosis.\nE. osmosis.
C
In a single sodium-potassium pump cycle, ATP is used with the result that \nA. 3 sodium ions leave and 2 potassium ions enter.\nB. 2 sodium ion enters and 1 potassium ion leaves.\nC. 2 sodium ion leaves and 1 potassium ion enters.\nD. 3 sodium ions enter and 2 potassium ions leave.\nE. sodium and potassium ions enter and water leaves.
A
Which of the following statements is true about smooth muscle?
A. Actin and myosin generate force through the crossbridge cycle.
B. Smooth muscle has more troponin than skeletal muscle.
C. Smooth muscle has the fastest myosin ATPase activity compared to skeletal and cardiac muscle.
D. Smooth muscle receives neural input from the somatic nervous system.
A
Smooth muscle is similar to skeletal muscle in which of the following ways?
A. The mode of entry of calcium into the cytoplasm of the muscle cell
B. Both possess actin and myosin and the mode of entry of calcium into the cytoplasm of the muscle cells
C. The type of calcium-binding molecules they possess
D. Both possess actin and myosin
E. All answers are correct
F. Neuronal regulation
D
During skeletal muscle contraction, thick and thin filaments bind together forming __________.
A. tropomyosin
B. crossbridges
C. myosin heads
D. troponin complex
B
Thick and thin filaments overlap within the __________.
A. Z line
B. H zone
C. A band
D. I band
C
When a muscle is stimulated at a high frequency such that the twitches build on each other, __________ is observed.
A. the size principle
B. fatigue
C. Treppe
D. Summation
E. Recruitment
D
What terminates smooth muscle contraction?
A. Removal of calcium from troponin
B. Removal of calcium from tropomyosin
C. Dephosphorylation of myosin by a phosphatase
D. Dephosphorylation by a kinase
C
There is a high degree of overlap between the action potential and the contractile response in cardiac fibers. Why?
A. The overlap prevents calcium from exiting the cytoplasm by binding to troponin.
B. The overlap permits greater interaction between actin and myosin, resulting in greater movement of the tropomyosin.
C. The overlap allows more calcium into the sarcoplasm, which binds to calmodulin and increases the force of contraction.
D. The overlap prevents summation of cardiac muscle contractions; it is critical that the heart have time to relax and fill with blood before the next contraction.
D
Molecules common to both skeletal and smooth muscle crossbridge cycling include __________.
A. myosin light chain kinase, calmodulin, and actin
B. calmodulin
C. phosphatases
D. myosin light chain kinase
E. actin
F. myosin light chain kinase and actin
E
When an action potential travels along the sarcolemma of a muscle cell __________.
A. DHP receptors in the T-tubule undergo a conformational change and Ca2+ flows down its concentration gradient through the ryanodine receptors
B. voltage sensitive Ca2+ channels in the sarcoplasmic reticulum open, DHP receptors in the T-tubule undergo a conformational change and Ca2+ flows down its concentration gradient through the ryanodine receptors
C. voltage sensitive Ca2+ channels in the sarcoplasmic reticulum open
D. Ca2+ flows down its concentration gradient through the ryanodine receptors
E. Ca2+ pumps in the sarcoplasmic reticulum are activated
F. DHP receptors in the T-tubule undergo a conformational change
B
The troponin complex in thin filaments can bind __________.
A. actin
B. tropomyosin, calcium, and actin
C. myosin
D. tropomyosin
E. calcium
F. tropomyosin and calcium
B
Muscle tension decreases at short muscle lengths because __________.
A. the thin filaments at opposite ends of the sarcomere overlap
B. the thin filaments at opposite ends of the sarcomere overlap and the Z lines come into contact with the thick filaments
C. the number of active crossbridges decreases and the thin filaments at opposite ends of the sarcomere overlap
D. the Z lines come into contact with the thick filaments
E. the number of active crossbridges decreases
F. the series elastic component is stretched
B
When an action potential travels along the sarcolemma of a muscle cell __________.
A. DHP receptors in the T-tubule undergo a conformational change
B. voltage sensitive Ca2+ channels in the sarcoplasmic reticulum open, DHP receptors in the T-tubule undergo a conformational change and Ca2+ flows down its concentration gradient through the ryanodine receptors
C. Ca2+ flows down its concentration gradient through the ryanodine receptors
D. Ca2+ pumps in the sarcoplasmic reticulum are activated
E. voltage sensitive Ca2+ channels in the sarcoplasmic reticulum open
F. DHP receptors in the T-tubule undergo a conformational change and Ca2+ flows down its concentration gradient through the ryanodine receptors
B
As the load on a muscle increases, which of the following also increase(s)?
A. Duration of shortening
B. Latent period
C. Velocity of shortening, latent period, and duration of shortening
D. Velocity of shortening
E. Latent period and duration of shortening
F. Distance shortened
B
After the myosin ATPase hydrolyzes ATP into ADP + Pi, __________.
A. the two products stay attached to the myosin head
B. the two products stay attached to the myosin head, the myosin head is cocked and binds to a different G-actin molecule, ready for the power stroke
C. the myosin head is cocked and binds to a different G-actin molecule, ready for the power stroke
D. the myosin head has nothing bound, ready for the power stroke
B
