Final Exam Flashcards
A scientific study of the effects of drug effectivness should at the very least incldue?
- a comparison or control that gets only a non effective placebo
- a group that gets the drug in an effective dose
The specific aite of large scale ATP synthesis in a eukaryotic cell is the?
Mitichondria
Which of the following is the smallest?
ribosome
virus
protein
mitochondria
bacterium
Protein
Which statement is most accurate about the Kam-Hansen et. al article about migraine treatments?
All statments are correct.
Person
Living vs Non-Living
Laws of Chemistry
Friedrich Wohler
Person
Crude Mircoscope
Cellulae
Robert Hooke
Person
radioisotopes
Pathway for photosynthetic carbon metabolism
Melvin Calvin
Which answer correclty shows the hierarchical naure of cellular structure from simplest to the most complex?
Organic molecules, macromolecules, organelles, a cell
Membranes usually are not permeable to polysaccharides, nucleic acids, and proteins, how are cells able to incorporate these molecules?
Macromolecules are digested in the extracellular space, and their subunits move through transport proteins.
Macromolecules are transported via endocytosis and are digested within the cell
Carbon has four electrons in its outermost quantum energy level orbits, so it usualy can be found with ___ covalent bonds with other atoms. This bonding can lead to long chains, branched chains, or____ formations.
4:ringed
Which of the following biological plymers is mismatched with its monomer?
cellulose-fatty acid
Which of the following is NOT a possible non-covalent interaction?
All-of the above are non-covalent interactions
The process of partial hydrogenation takes vegtable oils and fats and transforms them by?
causing the reduction of double bonds in fatty acid chains, thus making them more dense and melting at higher temperatures.
A secretory cell of the pancrease would likely include all of the following structures and organelles in great quantity EXCEPT?
flagella
A protein with quaternary structure includes most types of covalent and non-covalent bonds and interactions, and also includes?
at least four tertiary protein subunits
Automobile 100 parts and 4 workers, each worker 25 parts then add together
Hierarchical self-assembly
When RNA from a specific strain of tobacco mosaic virus (TMV) is mixed with coat protein from the same strain in a test tube, infectious virions (virus particles) are formed. What is the most reasonable conclusion that could be drawn from this finding?
TMV protein and RNA self-assempbles without any energy or informational input
What gives rise to the cohesiveness of water molecules?
hydrogen bonding
Based on your knowledge of the polarity of water molecules, the solute molecule above is most likely?
Positivley Charged
Fibrous proteins composing hair and silk have extensive____ structure, which allows them to be highly ordered and repetitive.
secondary
Albuterol—Why is it importan fo this drug to consist of only one enantiomeric form, rather than a mixture of enantiomers?
different enantiomers such as the L-form may have different effects or be ineffective.
The structure level of a protein least affected by a disruption in hydrogen bonding is the?
primary level
A protein with tertiary structure may be held together by?
alll of the above
The amino acids above comprise a group of amino acids with _____ R-groups
non-polar
Which of the following molecules has quaternary structure?
hemoglobin
Nucleotides are to nucleic acids as monosaccharides are to?
polysaccharides
Which of the following organelle/structures is NOT generally found in animal cells?
central vacuole
Which of the following is TRUE of plant cells?
Plant cells contain chloroplasts
The smooth endoplasmic eticulum functions primarily in synthesis of?
lipids
The major structura; elements of the cytoskeleton are?
microtubules, microfilaments, and intermediate filamenst
Singer and Nicholson came up with a model of membranes that included?
a model incorperating a phospholipid bylayer and proteins integrated into the lipids.
With regard to the semipermeable nature of the plasma membrane, which of the following would most readily cross without the aid of a transport protein?
Water
Which method below would be best to seperate and determine membrane lipid composition?
Thin Layer Chromotography
The techique that allows various proteins to be seperated from the membrane and differentiaited based on size and charge with electrical current is?
SDS-PAGE
What class of membrane proteins are found only on one side of membranes, but with non-polar portion extending into the bilayers?
integral monotopic
Why do some anaerobic bacteria use an ethanol fermentation, rather than just simply allowing pyruvate to diffuse away from the cell after glycolysis?
b&c
ethanol diffueses out of the cell faster and without a protein transporter
the fermentation also allows for regeneration of NAD+
The statment “The total amount of energy in the universe is constant,” is tenet of?
The first law of thermodynamics
Living organisms increase in complexity as they grow, resuling in a decrease in the entropy of an organism. How does this relate to the second law of thermodynamics?
As a consequence of growing, organisms break down a great number of organic molecules, causing a greater increase of entropy in their enviroment than the decrease in entropy associated with their growth
The Oxygen consumed during cellular respiration is involved directly in which process of event?
accepting electrons at the end of the electron transport chain
Substrate-level phosphorylation occurs_____.
In both the glycolysis and the citric acid cycle
An allosteric inhibitor?
binds at the regulatory site
The phenomenon of an enzyme changing shape to further envelop the substrate when it binds is called?
induced fit
In what way do the membranes of a eukaryotic cell vary?
Certain proteins are unique to each membrane.
HIgh energy molecules in living systems don’t often break down in water soultion, even when they would result in highly exergonic reactions. This is because?
high energy molecules are in a metastable state with relatively high activation energy for reactions to take place.
When transporting large uncharged molecules such as glucose across a membrane, which of teh following is/are false?
ATP directly attaches to the symport moving glucose against gradient.
In some cells, it was noted that water moved faster than could be accounted for by simple diffusion. From this information, which of the following were identified and characterized?
aquaporines
The Na+/K+ pump actively moves?
3 Na+ out & 2 K+ in
Cystic Fibrosis is the result of a malfunction of the cell in transporting which if the following ions?
Cl-
The primary difference between active transport and facilitated diffusion is that active transport is the only one in which?
low [S} is transported to high [S}
The gross output of ATP from glycolysis is_____, whereas the net output of ATP is_______?
4 : 2
Which statement best explains why more ATP is made per molecule of NADH than per molecule of FADH2?
Fewer protons are pumped across the inner mitochondrial membrane when FADH2 is the electron donor than when NADH is the electron donor.
Glucose is transported in the blood stream to cells in all parts of your body. In cells, glucose has four main factors. Which of the following is NOT one of those fates?
Glucose is transformed to sucrose
The tricarboxylic acid cycle is considered amphibolic because
It leads to both the consumption and generation of both carbohydrates and amino acids.
The Cori cycle describes the process of?
Production of glucose in the liver by recycling lactate from skeletl muslce
The site on an enzyme that will bind the substrate is called the?
active site
AN enzyme is ative in the stomach acids of an animal but quickly loses its activity when it enters the intestine. This is an example that some enzymes are?
Sensitive to changes in pH
Bacterorhodopsin absorbes light energy at certan wavelengths in order to?
Transport H+ ions
When short of oxygen, skeletal muscle can use lactic acid fermentation. what usually happens to this lactic acid?
It diffues into the blood and is picked up by liver cells for gluconeogenesis
In cystic fibrosis, why does the lack of ion transport into the mucus of small lung passages lead to congested and infected lungs?
osmosis does not occur into the mucus; thick immovable lung mucus results and bacteria grow.
Both the phosphorylation of itermeditaes and the formation of ATP in glycolysis are examples of?
substrate-level phosphorylation
Beta oxidation of these molecules converts them into acetyl-CoA, which can than enter the Krebs cycle for energy derivation. These are?
Fatty acids
Which of the following is NOT a product of the TCA cycle?
acetyl CoA
The reations at pyruvate dehydrogenase produce all of the following except?
ATP
In eukaryotes, pyruvate is converted to acetyl CoA?
in the mitochondrial matrix
One molecule of NADH produced by glycolysis im a common eukaryotic cell using glycerol-3-P shuttle in aerobic processes evebtually produces?
2 ATP via chemiosmosis
________________ is a type of self tolerance that is induced during the early stages of lymphocyte development.
Connective tissues typically have _____.
relatively few cells and a large amount of extracellular matrix
If you gently bend your ear, and then let go, the shape of your ear will return because the cartilage of your ear contains_____.
elastic fibers
In research on aging (both cellular aging and organismal aging), it has been found that aged cells do not progress through the cell cycle as they had previously. Which of the following, if found in cells or organisms as they age, would provide evidence that this is related to cell signaling?
Growth factor ligands do not bind as efficiently to receptors.
Apoptosis involves all but which of the following?
lysis of the cell
During the course of muscle contraction the potential energy stored in ATP is transferred to potential energy stored in _____.
the myosin head
The release of _____ ions from the sarcoplasmic reticulum is required for skeletal muscle contraction.
Calcium
Myosin heads bind to _____, which they then pull and cause to slide toward the center of the sarcomere.
thin filaments
Of these events, the first to occur when a motor neuron stops sending an impulse to a muscle is _____.
the pumping of calcium ions out of the cytoplasm and back into the sarcoplasmic reticulum
Which of the following statements correctly describes why a series of closely spaced action potentials causes a sustained contraction rather than a series of closely spaced twitches?
When a series of action potentials is closely spaced, there is not sufficient time for Ca2+ uptake into the sarcoplasmic reticulum between action potentials, and Ca2+ remains bound to troponin throughout the series.
Acetylcholine released into the junction between a motor neuron and a skeletal muscle binds to a sodium channel and opens it. This is an example of _____.
a ligand-gated sodium channel
Neurotransmitters affect postsynaptic cells by _____.
I) initiating signal transduction pathways in the cells
II) causing molecular changes in the cells
III) affecting ion-channel proteins
IV) altering the permeability of the cells
I, II, III, and IV
An inhibitory postsynaptic potential (IPSP) occurs in a membrane made more permeable to _____.
potassium ions
Excitatory postsynaptic potentials (EPSPs) produced nearly simultaneously by different synapses on the same postsynaptic neuron can also add together, creating _____
a spatial summation
If you experimentally increase the concentration of K+ inside a cell while maintaining other ion concentrations as they were, what would happen to the cell’s membrane potential?
The membrane potential would become less negative
The point of connection between two communicating neurons is called the _____.
Synapse
The “information receiving” section of a neuron is its _____.
Dendrites
Which of the following is a type of local signaling in which a cell secretes a signal molecule that affects neighboring cells?
paracrine signaling
Hormones are chemical substances produced in one organ that are released into the bloodstream and affect the function of a target organ. For the target organ to respond to a particular hormone, it must _____.
have receptors that recognize and bind the hormone molecule
The receptors for steroid hormones are located inside the cell instead of on the membrane surface like most other signal receptors. This is not a problem for steroids because _____.
steroid hormones are lipid soluble, so they can readily diffuse through the lipid bilayer of the cell membrane
What does it mean to say that a signal is transduced?
The physical form of the signal changes from one form to another.
Adenylyl cyclase has the opposite effect of which of the following?
Phosphodiesterase
Caffeine is an inhibitor of phosphodiesterase. Therefore, the cells of a person who has recently consumed coffee would have increased levels of _____.
cAMP
Put the steps of the process of signal transduction in the order they occur:
- A conformational change in the signal-receptor complex activates an enzyme.
- Protein kinases are activated.
- A signal molecule binds to a receptor.
- Target proteins are phosphorylated.
- Second messenger molecules are released.
3, 1, 5, 2, 4
Why can a signaling molecule cause different responses in different cells?
The transduction process is unique to each cell type; to respond to a signal, different cells require only a similar membrane receptor.
At puberty, an adolescent female body changes in both structure and function of several organ systems, primarily under the influence of changing concentrations of estrogens and other steroid hormones. How can one hormone, such as estrogen, mediate so many effects?
Estrogen binds to specific receptors inside many kinds of cells, each with different responses.
What is apoptosis?
controlled cell suicide
Which of the following describes the events of apoptosis?
The cell’s DNA and organelles become fragmented, the cell shrinks and forms blebs, and the cell’s parts are packaged in vesicles that are digested by specialized cells.
After determining which preparation contained the XFF receptor, you wish to determine the properties of the ligand receptor. Using a radioactive XFF, you wish to determine if the properties are similar to that of epinephrine and the epinephrine receptor. If so, you expect to find the radioactive XFF.
on the cell surface
Synthetic compounds that inhibit receptors by preventing the natural messenger from binding are known as
antagonists.
G protein-adenyl cyclase activity has been shown, in some cases, to be associated with certain diseases. In the case of cholera, which of the following is NOT correct?
The cholera toxin causes the cells of the gut to take in salts and fluids
Kinases and phosphatases are essential in the cell because they
help turn enzymes and other proteins “on and off” through changes in phosphorylation status.
If one homogenizes liver cells, separates the membranes from the cytoplasm, and then adds epinephrine to only the cytoplasmic portion,
none of these
IP3 receptors are associated with
ER membranes
phospholipase C
catalyzes formation of second messenger diacylglycerol (DAG
second messenger associated with prevention of penetration of an animal egg by multiple sperm cells
calcium ions
protein that, when bound with calcium, can be a second messenger
calmodulin
hormones acting over long distances
endocrine hormones
adenylate cyclase
catalyzes formation of cAMP from ATP
pertussis toxin
inhibition of Gi
necessary for the activation of heterotrimeric G proteins
GTP
It would be useful to determine if the mechanism of action for the XFF-XFF receptor is similar to that of estrogen or epinephrine. To test this, you use a nonhydrolyzable analogue of GTP in the reaction mixture. If the mechanism is still similar to that of epinephrine, you would expect the cellular responses would be
prolonged.
You have isolated a factor from the blood of a space alien and named it XFF (for X-files factor). Based on preliminary data, you think that XFF could be one of three compounds normally found in human blood: epidermal growth factor (EGF), epinephrine, or estrogen.
glycogen breakdown
The ________ is a complex network of interconnected filaments and tubules that extends throughout the cytosol, from the nucleus to the inner surface of the plasma membrane
Cytoskeleton
Which of the following is not a function of the cytoskeleton?
passive transport
Microfilaments function in
all of these
One of the following drugs blocks cell division because it stabilizes the microtubules. What is this drug and for what is it used?
taxol; breast cancer
F-actin filaments
are composed of polymerized G-actin monomers wound around each other in a helix.
Actin bundles give shape and support to the ________ found in cells of the small intestine
Microvilli
Critical concentration is
the concentration of tubulin dimers at which assembly is balanced with disassembly
The minus (-) ends of microtubules are often anchored at the ________________ , such that the dynamics associated with microtubules is at the plus (+) ends.
Centrosome
axonemal microtubules
found in cilia and flagella
treadmilling
equal tubulin dimer assembly and disassembly
nocodazole
inhibits microtubule assembly (reversible)
capping protein
prevents loss of subunits
microvilli
increase cellular surface area
nonmotor MAPs
control microtubule organization
________ resist tensile forces and contain keratin to form the protective barrier of the skin
Intermediate filaments
The “9 + 2” pattern of the axoneme is nine ________ of microtubules and two additional microtubules in the center called the ________.
outer doublets; central pair
cytoplasmic dynein
motion toward “minus” end of microtubule
axonemal dynein
activation of sliding in flagellar microtubule
kinesin
motion toward “plus” end of microtubule
myosin II, filament
slides along actin in sarcomere
In relaxed muscle, calcium is found in high concentration in the
sacroplasmic reticulum
All of the following are actin-dependent nonmuscle motility except
translocation of multienzyme complexes
Calcium-calmodulin complexes ultimately mediate the phosphorylation of myosin in which of the following cells?
smooth muscle
During cell crawling, the cell must attach to the substrate upon which it is crawling. One group of attachment proteins is the ________.
integrins
Where does the Calvin cycle take place?
Stroma of the chloroplast
In the Calvin cycle, the enzyme that catalyzes the capture of carbon dioxide and results the formation of 3-phosphoglycerate is?
Ribulose bisphosphate carboxylase/ oxygenase(rubisco).
Location of the chlorophyll based photocenters?
Thylakoids membrane
Location some reactions of photo respiration pathway?
Peroxisomes
Location of sucrose synthesis?
Cell cytoplasm
Location of relatively high proton concentrations?
Thylakoids lumen
The “KDEL” tag, with amino acids Lysine-aspartate-glutamate-leucine at the carboxyl end of a soluble protein, leads to?
The binding to a receptor in the Golgi cis-sacs and vesicles return to the ER.
The addition and modification of mannose-6-phosphate oligosaccharide chains to soluble lysosomal enzymes leads to?
Sorting of enzymes into transport vesicles that eventually form lysosomes
Suppose the thylakoids sacs isolated from chloroplasts were made acidic and the transferred in the dark to a pH 8 solution. What would be likely to happen?
The isolated thylakoids sacs will make ATP
Which of the following is common in both cellular respiration and the light reactions of photosynthesis?
The chemiosmotic formation of ATP
Photorespiration occurs when rubisco enzyme catalyzes the reaction of ribulose bisphophate with?
O2
The continuous release of mucus by the epithelial cells lining the respiratory tract is an example?
Constitutive secretion
List the order in which the protein of these fractions first exhibit radioactivity?
III, II, I, out of the cell
All of the following statements about cellular trafficking are true except?
COPI-coated vesicles move materials from Golgi to the secretory vesicle
Structure that biosynthesis of steroid hormones?
Smooth ER
Structure that degradation of damaged organelles?
Lysosomes
Sorting proteins for export or to specific organelles
Golgi apparatus
Transport to or between various layers of Golgi
Shuttle transition vesicle
Uptake of low-density lipoproteins LDL occurs by?
Receptor-mediated endocytosis?
What are C4 plants more suited to hot climates than C3 plants?
They keep fixing carbon dioxide even when the stomata of the leaf are closed, due to CO2 pump.
The source of most of the O2 gas in the atmosphere is due to oxidation of water by Cyanobacteria, algae and plants.
True
Ultimately, the -66 mV resting potential of many nerve cells is established by what process?
The work of Na+\K+ pumps
A toxin that binds and closes only voltage-gated sodium channels in axons would be expected to
Prevent the depolarization phase of the action potential
One of the first things that happens in post-translational modification of most proteins in the rough ER is?
Addition of carbohydrate chains (glycosylation)
CAM plants keep stomata closed in daytime, and open them at night, thus potentially reducing loss of water. They can do this because they?
Fix CO2 into organic acids like malate held in vacuoles during the night
One of the disadvantages of the C4 pathway is that it requires more_______ to run a carbon dioxide shuttle than the pathway of C3 plants.
More ATP
Peroxisomes have all of the following functions in animal cells EXCEPT?
Fusing with phagocytic vacuoles to digest bacteria?
MS is an autoimmune disease that attacks myelinated nerves and degrades Schwann cells and the myelin sheath around them. This would affect nerve cells by?
All of the above
The order of events in the formation of clathrin-coated vesicles includes all the following steps EXCEPT?
Movement of cell membrane to surround molecules or particles.
The proximal stimulus for secretion of neurotransmitters into the synaptic cleft is in increase in?
Calcium levels
At rest, most cells have relatively high concentrations of________ outside the cell compared to inside the cell, leading to a relatively________ charge inside the cell compared to its environment.
Sodium; negative
You are looking for lysosomes, the enzyme activity you can test for is?
Lipases and protein hydrolases
The faster, salutatory transmission of signals in nerve axons is made possible by?
Nodes of ranvier Myelin sheaths
The “information receiving” section of a neuron is its_____?
Dendrites
The main inputs for the Calvin cycle are_______; the immediate main output carbohydrate is_________?
ATP, CO2, NADPH; G-3-P
Desensitization
A way a cell can adapt.. involves alterations of the receptor that lowers its affinity for ligand or renders it unable to intiate changes in cellular functions. Adapt to permenent changes
Microtubules
Hollow tube with wall
cytoplasmic
orginization
chromosome movement
intracelleular transport
axoemal: Cell motility
Microfilaments
Two interwined chains of F-actin
Muscle contraction
cell locomotion
cytoplasmic streaming
cytokinesis
animal cell shape
intracellular transport
Intermediate filaments
8 protofilaments joined end to end
no knwon polarty
structural support
animal shape
for mation of lamina
strengethin gnerve celss
keeping muscle fibers in register
Name the type of Cell-Cell Junctions
adhesive junction
tight junctions
gap junctions
Tight Junctions
Sealing spaces between cells
actin
gap junctions
exchange of ions and molecules between cells]
channels
adhesion junctions
focal: localized: actin microfilaments
Heidesomsome: Localized: Intermediate filaments
Adherens: Cotionus: actin microfilaments
desmosomes: localized: intermediate filimanets
Extracelluar Matrix
collagens
elstins
GAGS
proteoglycans
Chemotaxos
when a migrating cell moves towards a greater or lesser concentration of a diffusable chemical.
