Exam 3 Flashcards by Aubri Unknown

What is the distinguishing characteristic of a P-type active transport pump?

Question 1 options:

It must be pumped during the cycle.

It must phosphorylate the substance that is being pumped

It must be phosphorylated during the cycle.

It must be deprotonated during the cycle.

It must be protonated during the cycle.

It must be phosphorylated during the cycle.

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Diffusion of uncharged molecules depends on the:

Question 2 options:

Both concentration gradient and electrical gradient

Electrical gradient

Concentration gradient

Neither concentration gradient or electrical gradient

Concentration gradient

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Cystic fibrosis is a genetic disease caused by a defect in a channel for what ion?

Question 3 options:

Sodium

Chloride

Calcium

Potassium

Chloride

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__________ form channels that increase the rate of water movement across the membrane

Question 4 options:

Water conduits

Aquatransporters

Water pumps

Symports

Aquaporins

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What causes the membrane potential to return to a negative value after an action potential has occurred?

Question 5 options:

closing of a voltage-gated K+ channel

opening of a ligand-gated Na+ channel

opening of a voltage-gated K+ channel

opening of a voltage-gated Na+ channel

opening of a voltage-gated K+ facilitated transporter

opening of a voltage-gated K+ channel

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As an action potential is initiated, the membrane is ______. This is caused by the ____ of ____ ions.

Question 6 options:

hyperpolarized, efflux, Na+

hyperpolarized, influx, Na+

depolarized, influx, Na+

depolarized, influx, K+

depolarized, efflux, Na+

depolarized, influx, Na+

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If placed in a hypotonic solution, a red blood cell will:

Question 7 options:

gain water

lose water

not gain or lose water

gain water

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Which part of a neuron conducts impulses toward the cell body?

Question 8 options:

Axon

Dendrites

Terminal knob

Synapse

Dendrites

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Which molecules are likely to be brought into a cell using a transport protein?

Question 9 options:

Nonpolar molecules such as O2 and CO2

Polar molecules such as leucine or glucose

Charged atoms such as calcium ions (Ca+) and sodium (Na+) ions

Steroid hormones

Polar molecules such as leucine or glucose

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Facilitated diffusion is saturable: eventually adding more solute will have no effect on the rate of transport. Why?

Question 10 options:

Higher solute concentrations aggregate & precipitate

All transporter proteins are working at full capacity

Solute collisions prevent them from binding to transporters

High concentrations become toxic to the cell

All transporter proteins are working at full capacity

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Energy input is required for:

Question 11 options:

A. Simple diffusion

B. Facilitated diffusion

C. Osmosis

D. Active transport

B & D

D. Active transport

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Steroid hormones can cross the membrane by ….

Question 12 options:

Facilitated diffusion

Osmosis

Simple diffusion

Endocytosis

Active transport

Simple diffusion

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Which of the following compounds can diffuse across a phospholipid bilayer?

Question 13 options:

All of these

Cl–

Ca2+

glucose

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How do Na+ ions enter a neuron once an action potential is initiated?

Question 14 options:

a ligand-gated Na+ channel

a voltage-gated Na+ channel

an ungated Na+ pump

the Na+/K+-ATPase

a voltage-gated Na+ channel

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A protein pump is required for:

Question 15 options:

Facilitated diffusion

Active transport

Simple diffusion

Osmosis

Active transport

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Paramecium have contractile vesicles that continuously expel water from the cell. This suggests that they live in a(n) __________ environment.

Question 16 options:

Hypotonic

Hypertonic

Isotonic

Hypotonic

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Influx of Na+ into a cell would be:

Question 17 options:

Opposed by concentration gradient, driven by electrical gradient

Opposed by concentration gradient and by electrical gradient

Driven by concentration gradient, opposed by electrical gradient

Driven by concentration gradient and by electrical gradient

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A transport protein is required for:

Question 18 options:

Active transport

B & D

Facilitated diffusion

Osmosis

Simple diffusion

Facilitated diffusion

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What accompanies transport by facilitated transporters and pumps?

Question 19 options:

rigidity

softness

α-helix secondary structure

β-pleated sheet secondary structure

conformational change

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Where is the nucleus located in a neuron?

Question 20 options:

axon hillock

axon

dendrites

cell body

terminal knob

cell body

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What does the sequence of glycosyltransferases in the cell’s cytomembrane system control?

Question 1 options:

the sequence of nucleotides on glycoproteins and nucleotide sugars in the cytoplasm

the sequence of sugars on the oligosaccharide chains of a secretory glycoprotein

the sequence of nucleotides on glycoproteins

the sequence of nucleotide sugars in the cytoplasm

the sequence of sugars on the oligosaccharide chains of a secretory glycoprotein

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Neurotransmitters are released from synaptic vesicles into the synaptic cleft. Specifically at the neuromuscular junction, _____________ is the neurotransmitter released in response to an influx of _________________ into the presynaptic cell (axon terminal).

Question 2 options:

Sodium; calcium

Calcium; sodium

Acetylcholine; sodium

Acetylcholine; calcium

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Which part of a neuron conducts impulses toward the cell body?

Question 3 options:

Dendrites

Terminal knob

Synapse

Axon

Dendrites

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Which of the following happens after the SRP has been released from the signal peptide and the ribosome that has just bound to the translocon?

Question 4 options:

Protein synthesis restarts.

Protein synthesis is temporarily suspended, and ribosomes are released from the translocon.

Ribosomes are released from the translocon.

Ribosomes are conveyed to the SER.

Protein synthesis is temporarily suspended.

Protein synthesis restarts.

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To what amino acid residue of a polypeptide are N-linked oligosaccharide chains attached as that polypeptide enters the RER lumen through the translocon? Question 5 options: asparagine serine aspartic acid threonine arginine

asparagine

Which structure is not part of the endomembrane system? Question 6 options: Golgi apparatus nuclear envelope endoplasmic reticulum chloroplast

chloroplast

A protein is transported in a secretory vesicle and discharges into the extracellular space in a continuous fashion. What type of secretion is this? Question 7 options: unregulated constitutive regulated biosynthetic

constitutive

The smooth endoplasmic reticulum is responsible for all of the following except: Question 8 options: sequestration of calcium ions protein synthesis synthesis of steroid hormones detoxification in the liver

protein synthesis

Asymmetry of cellular membranes is established initially in the: Question 9 options: chloroplast endoplasmic reticulum nucleus mitochondria

endoplasmic reticulum

The signal sequence is found at the N-terminus of secretory proteins and is recognized by: Question 10 options: translocon signal receptor partition signal recognition particle other secretory proteins

signal recognition particle

Where does building the oligosaccharide chain for glycosylation take place? Question 11 options: On a protein carrier On a lipid carrier All of these are correct Directly on the polypeptide Any of these are possible

On a lipid carrier

The first sugars added to dolichol phosphate are: Question 12 options: mannose glucose fructose N-acetylglucosamine

N-acetylglucosamine

Which of the proteins below are NOT made on the membrane-bound ribosomes of the RER? Question 13 options: peripheral proteins attached to the inner surface of the plasma membrane soluble lysosomal proteins enzymes in plant vacuoles proteins of the extracellular matrix all of these are made on membrane-bound ribosomes

peripheral proteins attached to the inner surface of the plasma membrane

Dolichol phosphate ____________. Question 14 options: c) is located in the membrane of the rough ER membrane a) is a sphingolipid b) is responsible for donating a block of carbohydrates to domestic proteins as they enter the RER lumen d) and its attached proteins flip from the leaflet of the RER membrane facing the cytoplasm to the leaflet facing the lumen of the RER

c) is located in the membrane of the rough ER membrane

How do Na+ ions initially enter a post-synaptic neuron after the action potential reaches the synapse of its partner? Question 15 options: a ligand-gated Na+ channel the Na+/K+-ATPase an ungated Na+ pump a voltage-gated Na+ channel

a ligand-gated Na+ channel

How do integral membrane proteins enter the lipid bilayer? Question 16 options: They insert into the membrane from the cytosol after their synthesis is complete. The translocon channel has a side gate that continuously opens and closes, giving each nascent polypeptide segment a chance to partition itself into the lipid bilayer's hydrophobic core. They are inserted into the membrane by BiP during folding The membrane is disrupted and proteins are incorporated during reassembly. They insert into the membrane from the RER lumen after their synthesis is complete.

The translocon channel has a side gate that continuously opens and closes, giving each nascent polypeptide segment a chance to partition itself into the lipid bilayer's hydrophobic core.

What effect does the binding of the signal recognition particle (SRP) to the ribosome and the growing polypeptide chain have on protein synthesis? Question 17 options: Protein synthesis ceases temporarily. No effect on protein synthesis Protein synthesis is terminated Protein synthesis accelerates. Protein synthesis ceases permanently.

Protein synthesis ceases temporarily.

Which of the following is a function associated with the smooth endoplasmic reticulum in at least some cells? Question 18 options: synthesis of steroid hormones detoxification of many organic compounds, like barbiturates and ethanol sequestration of calcium Ca2+ ions within the cisternal space all of these are correct

all of these are correct

The correct order of passage of proteins produced in the biosynthetic pathway is: Question 19 options: endoplasmic reticulum, Golgi complex, plasma membrane, lysosome endoplasmic reticulum, lysosome, Golgi complex, plasma membrane endoplasmic reticulum, lysosome, secretory vesicle, plasma membrane endoplasmic reticulum, Golgi complex, secretory vesicle, plasma membrane endoplasmic reticulum, Golgi complex, plasma membrane, secretory vesicle

endoplasmic reticulum, Golgi complex, secretory vesicle, plasma membrane

How do Na+ ions enter a neuron once an action potential is initiated? Question 20 options: a ligand-gated Na+ channel an ungated Na+ pump the Na+/K+-ATPase a voltage-gated Na+ channel

a voltage-gated Na+ channel

Which of the following is not a mechanism by which organelles maintain their protein composition? Question 1 options: Scavenging of escaped lipids and return back to their home compartment Retention of resident proteins excluded from transport vesicles Retrieval of escaped proteins back to their compartment

Scavenging of escaped lipids and return back to their home compartment

Coated vesicles may be covered by all of the following EXCEPT: Question 3 options: COPI ubiquitin Clathrin COPII

ubiquitin

The current model of movement through the Golgi complex suggests that each cisterna matures from cis to trans and transport vesicles carry Golgi enzymes _____________. Question 2 options: anterograde retrograde from cis to trans to lysosomes

retrograde

Which of the following is not a filamentous structure of the cytoskeleton? Question 6 options: Intermediate filaments Ligamentous filaments Actin filaments Microtubules

Ligamentous filaments

The ____________ functions as a major sorting station, directing proteins to various destinations. Question 4 options: rough ER trans Golgi network Lysosome ribosome

trans Golgi network

Which of the following processes does NOT take place in the Golgi complex? Question 5 options: processing of membrane proteins glycosylation of glycoproteins and glycolipids processing of lysosomal proteins digestion of misfolded proteins

digestion of misfolded proteins

Targeting vesicles to a particular compartment includes the following steps EXCEPT: Question 7 options: coating of vesicles movement of vesicles docking of vesicles tethering of vesicles

coating of vesicles

_____________ residues act as an “address” for delivery of proteins to lysosomes. Question 8 options: ubiquitin Mannose 6-phosphate selenocysteine methionine

Mannose 6-phosphate

What family of proteins is important in recruiting tethering proteins to membrane surfaces of vesicles and target compartments? Question 9 options: Raf Ras Rho Rab

Rab

Which type of coated vesicle moves materials from the ER to the ERGIC and Golgi? Question 10 options: COPI-coated vesicles COPIII-coated vesicles Clathrin-coated vesicles COPII-coated vesicles

COPII-coated vesicles

What protein projects from the A microtubule in a cilium or flagellum, forming an inner and outer arm? Question 11 options: dynein kinesin myosin actin

dynein

How is movement of vesicular-tubular carriers directed from the ERGIC to the Golgi complex? Question 12 options: fast vesicle propulsion a slingshot mechanism random diffusion movement occurs on microtubule tracks

movement occurs on microtubule tracks

Docking vesicles to target compartments relies on ________ proteins in the vesicle membrane. Question 13 options: Rab v-SNARE l-snare MPR t-SNARE

v-SNARE

Microtubules are polymers of tubulin held together by: Question 14 options: Noncovalent bonds Disulfide bonds Adapter proteins

Noncovalent bonds

Kinesins generally move toward the __________ of the microtubule to which they are bound. Question 15 options: plus end 0 end minus end 5'-end

plus end

Molecular motors are powered by: Question 16 options: hydrolysis of ATP condensation of ATP hydrolysis of GDP proton gradient

hydrolysis of ATP

A microtubule is composed of globular proteins arranged in longitudinal rows called _________. Question 17 options: microtubular units microfilaments protofilaments prototubules

protofilaments

Which of the following is not a function of microtubules? Question 18 options: They help to maintain cell shape They support cellular extensions such as axons They pinch cells apart during cytokinesis They position various organelles within the cell They are the moving components of flagella

They pinch cells apart during cytokinesis

The arrangement of microtubules in cilia and flagella is: Question 19 options: 8 + 3 9 + 3 9 + 2 8 + 2

9 + 2

Cilia and flagella are able to move because their microtubules ______________. Question 20 options: shrink and expand longitudinally go through cycles of assembly and disassembly slide over one another expand and contract in diameter

slide over one another

Exam 3 Flashcards

(60 cards)