Exam 2 Problem Roulette Flashcards by Hadley Katzman

Two sugars that differ only in their configuration about a single carbon atom are called?

Epimers

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Which of the following bonds links the monosaccharides in amylose, causing this molecule to naturally form a coil?

Alpha 1 ->4

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What is a lectin?

Proteins that bind specific carbohydrates

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What describes a glycoprotein?

A transmembrane protein that is covalently linked to a unique series of carbohydrates that specifies the cell type

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Which of the following are true about the reactions between monosaccharides and larger polysaccharides?

During starch synthesis, additional monosaccharides are added to amylose via a oxidative reduction reaction

Disaccharide formation proceeds via a condensation reaction that liberates water

A non-reducing sugar has no anomeric carbon available to react

In a glucose disaccharide, the reducing sugar exists in a stable anomeric configuration

Both amylose and amylopectin tend to adopt a coiled tertiary structure

The main factor that contributes to the stability of chitin is the acetylated amino group

-Disaccharide formation proceeds via a condensation reaction that liberates water
-A non-reducing sugar has no anomeric carbon available to react
-Both amylose and amylopectin tend to a adopt a coiled tertiary structure

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Which molecule below is not a glycoconjugate

Heparan Sulfate

Lipopolysaccharides

Hyaluronate

DNA

Integrins

DNA

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What statement about the position of the oxygen atom attached to C5 in monomeric Alpha-D-glucose is correct?

The C5 oxygen is on the same face of the ring as the C6 carbon.

The C5 oxygen is on the opposite face of the ring as the C6 carbon.

None of the other choices is correct

The C5 oxygen is part of an acetal functional group

The C5 oxygen is part of a hemiacetal functional group

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Which of the following does NOT describe a general function of carbohydrates?

Metabolic energy source in biological systems.

Post-translational modifications of extra-cellular proteins.

Signaling hormone

Structural component of bacterial cell walls.

Headgroup component of certain membrane lipids.

Signaling hormone

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Which of the following about cellulose and chitin is FALSE?

The strands stack very tightly, excluding the absorption of water

They are both linear homopolymers

They contain the same kind of glycosidic linkages

The higher order structures for both exclusively comprises parallel strands

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In which of the following locations would you expect to find a high concentration of peptidoglycans?

In starch granules

In the extracellular matrix

In the hard exoskeletons of certain insects

In eukaryotic cell membranes

In gram-positive bacterial cell walls

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Proteoglycans, Glycoproteins, and Glycolipids are collectively known as which of the following?

Glycans

Peptidoglycans

Dextrans

Glycoconjugates

Glycosaminoglycans

Glycoconjugates

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Which of the following Weak Interactions is most important or most influential for homopolysaccharide folding?

Van der Waal’s interactions

Hydrophobic interactions

Hydrogen Bonding

Ionic interactions

Hydrogen Bonding

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Which statement about glycogen is FALSE?

Glycogen is a linear storage molecule used by mammals

Glycogen contains (α1→6) linkages

Glycogen contains (α1→4) linkages

Glycogen is a homopolymer of glucose

Glycogen has many non-reducing ends for each reducing end

Glycogen is a linear storage molecule used by mammals

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When two monosaccharides join to form a disaccharide which of the following is true?

An anhydride is converted to a hydride.

A water molecule is released as an additional product for this reaction.

An acetal is converted to an hemiacetal.

The resulting disaccharide is not a reducing sugar.

The resulting disaccharide is a reducing sugar.

A water molecule is released as an additional product for this reaction.

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Some sugars, such as glucose, which can reduce metals such as iron or copper are called:

Metalloglycosides

Anomeric Sugars

Glycans

None of the above

Reducing Sugars

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An aldohexose that forms a five-membered ring is then called which of the following?

A glucopyranose

A pyranose

An aldopentose

A furanose

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Which of the following does NOT describe a lectin?

A toxin that reversibly binds to complex carbohydrates on the surface of eukaryotic cells

A plant protein with that specifically binds a fungal glycoconjugate

Viral proteins that adhere to sialic acid on the host cell surface

A protein that interacts with the extracellular matrix by hydrogen bonding to specific glycans

A polytopic membrane protein with N-linked glycosylation

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Starch and Cellulose are two of the most abundant polysaccharides in nature. They are both composed of glucose subunits, but with very different structures. Which linkage(s) below is/are present in Starch?

α1 →4 linkages

α1 →6 branches

β1→4 linkages

A and B only

B and C only

A and B only

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From the abbreviated name of the compound Gal(alpha1->1beta)Glc, Which of the following is NOT true? (Gal = galactose, Glc = glucose)

the glucose residue is the beta anomer.

two anomeric carbons were linked to form this compound

the compound is a reducing sugar

there are no hemiacetal groups in this compound

C-1 of glucose is joined to C-1 of galactose by a glycosidic bond.

the compound is a reducing sugar

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What term refers to the interconversion of the alpha and beta anomers of glucose in solution?

Mutarotation

Oxidation/Reduction

Glycosidation

Epimerization

Racemization

Mutarotation

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Which of the following is a purine linked to a phosphate group and a sugar?

Thymidine

Cyclic 3’,5’-cytosine phosphate

Deoxycytidine

Deoxyguanylate

Uridine

Deoxyguanylate

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Which of the following does NOT contribute favorably to the energetics of forming a DNA double helix?

Hydrogen bonds between pairs of nitrogenous bases

Ionic interactions involving the phosphoribose backbone

van der Waals interactions between stacked bases

Cooperativity of the two strands annealing

Bases are hydrophobic relative to the phosphoribose backbone

Ionic interactions involving the phosphoribose backbone

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Which of the following describes a general biological function of nucleotides?

Donor of phoshoryl groups (phosphates) for post-translation protein modification (including regulation).

Component of many important enzyme cofactors

Building block of DNA and RNA

General energy-carrying molecule in biological systems

All these answers are functions of nucleotides.

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Which of the following structures is NOT a permanent change to chromosomal DNA?

Denaturation

Mutation

Thymine-Thymine (cyclobutane) dimer

Deamination

Depurination

Denaturation

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DNA hairpins located exactly opposite each other and on different strands of DNA are called which of the following? H-DNA Inverted repeat Palindrome Cruciform Mirror repeat

Cruciform

Which of the following is primarily responsible for holding the two DNA strands together in a helix? Disulfide linkages Hydrophobic interactions Phosphodiester bonds Hydrogen bonds Glycosidic linkages

Hydrogen bonds

Which of the following is on the 3’ end of a DNA sequence? Amino group Carboxyl of a sugar Hydroxyl of a sugar Phosphate Base

Hydroxyl of a sugar

Which of the following is NOT an example of DNA damage? Cytosine deamination Thymidine dimer formation Guanosine depurination Cytosine methylation

Cytosine methylation

Which of the following are most likely to lead to triplex DNA? Cytosine deamination Wobble base pairing Low pH causing cytosine protonation Palindromic sequences High guanosine content

Low pH causing cytosine protonation

Which of the following is FALSE about phosphodiester linkages? They join the 3' hydroxyl of one nucleotide to the 5' hydroxyl of the next. They are more stable in RNA than in DNA They form the backbone of double helical structure. They are present in both DNA and RNA They are negatively charged at neutral pH

They are more stable in RNA than in DNA

Nucleic acids are characterized by which of the following? Ring resonance that causes absorption of light near 260 nm Formation of helices by DNA but not by RNA A-T rich regions melting at higher temperatures than G-C rich regions Formation of a hairpin by a Palindrome on two strands Sugar and phosphate residues located near the center of the molecule after refolding in aqueous media

Ring resonance that causes absorption of light near 260 nm

Which of the following is on the 5’ end of a DNA sequence? Carboxyl of a sugar Base Amino group Hydroxyl of a sugar Phosphate

Phosphate

Which of the following is NOT a common feature of DNA binding proteins? alpha helices fit perfectly in the major groove DNA binding proteins can recognize specific DNA sequences that are visible within the major groove Slide along the DNA until they find the correct binding site Preferentially recognize single-stranded DNA Tend to have a lot of arginines and lysines

Preferentially recognize single-stranded DNA

Which statement is FALSE? Different fragments of DNA would be expected to have different melting temperatures Depurination and deamination are non-enzymatic mutations RNA and DNA both form Hairpin structures and double-helices Partially denatured DNA could have G-C rich regions that have broken Hydrogen bonds while the A-T regions are intact All of the statements above are TRUE

Partially denatured DNA could have G-C rich regions that have broken Hydrogen bonds while the A-T regions are intact

Which of the following statements about nucleic acid double-helices is FALSE? RNA and DNA adopt essentially identical structures. G-C base pairs are more stable than A-T base pairs. Bases are stabilized in part by aromatic (pi-pi) stacking. The major groove is large enough to accommodate protein secondary structure elements. Negatively charge phosphates are solvent exposed on the outsides of the helix.

RNA and DNA adopt essentially identical structures.

Which of the following is NOT consistent with the Watson-Crick model for the DNA double helix? Base stacking helps stabilize the double helix The two strands run antiparallel to one another. The composition of bases obeys Chargaff's rules Guanosine residues can form tetraplex structure. The sequence of one strand provides a template for duplication of the second strand

Guanosine residues can form tetraplex structure.

You perform a Sanger sequencing reaction. The template strand is: 5’ ATCGAAC 3’ However, you make a mistake and forget to add any dGTP. What is the most likely outcome? You will get a single band representing a 3-nucleotide product in the G lane. You will get a single band representing a 7-nucleotide product in the G lane. You will get two bands representing 1- and 5-nucleotide products in the G lane. You will get a single band representing a 1-nucleotide product in the G lane. You will get no bands in the G lane.

You will get a single band representing a 1-nucleotide product in the G lane.

Consider the following two segments of RNA. Which of the following describes a secondary structure that is likely to be formed? 5’ AUCGCG 3’ 5’ CGCAGAU 3’ Bulge These two segments are not expected to form base pair interactions B-form double helix Hairpin Cruciform

Bulge

Which statement about transcription factor binding to its cognate DNA target is likely true? The minor groove of non-distorted DNA can easily accommodate an alpha-helix for sequence recognition. The transcription factor likely has a significant, positively charged region in its surface which can bind DNA in a NON sequence specific manner. Charge-charge interactions directly between Asp/Glu residues and the phosphate backbone likely contribute to protein-DNA interactions. Recognition of the base pairs by amino acids such as Leu/Ile likely contributes to binding at the correct sequence

The transcription factor likely has a significant, positively charged region in its surface which can bind DNA in a NON sequence specific manner.

What bonds are broken in order to partially Denature double-stranded DNA? Hydrophobic Didulfide Glycosidic Phosphodiester Hydrogen

Hydrogen

Which of the following is NOT an example of RNA secondary structure? Hairpin Internal Loop Palindrome Cruciform Bulge

Palindrome

Which weak interaction is most important in maintaining DNA as a double-helix? Hydrogen bonds Van der Waal’s interactions Ionic interactions Phosphodiester linkages Hydrophobic interactions

Hydrogen bonds

Which of the following is a covalent bond that links elements of the DNA “backbone”? Phosphodiester Ether Peptide Glycosidic Hydrogen

Phosphodiester

What parts of DNA are considered the “backbone”? Nucleoside base Sugar Phosphate A and B B and C

B and C

Movement of water across membranes is facilitated by proteins called _____________, movement of water is allowed by ____________ amino acids in the pore, and selectivity is enforced by the presence of _____________ amino acids at the selectivity filter. hydropermeases, polar, basic annexins, polar, acidic aquaporins, polar, basic aquaporins, polar, acidic aquaporins, hydrophobic, basic

aquaporins, polar, basic

Which of the following principles is consistent with the physical properties of membranes? Lipids in membranes generally move freely (fluidly), both laterally and across the membrane Peripheral proteins associate non-covalently with the polar head groups of lipids Integral proteins span the membrane and associate with only the acyl chains of phospholipids, which stabilizes the proteins in a hydrophobic environment Proteins in membranes are spaced symmetrically between the two layers of the bilayer, but in a manner that varies between membrane types

Peripheral proteins associate non-covalently with the polar head groups of lipids

Which of the following is FALSE concerning the lipids in membranes? Since white blood cells and red blood cells are exposed to essentially the same environment, their membranes would have the same lipid constituents in the same relative proportions. Function, not location. The inner leaflet and the outer leaflet of plasma membranes both contain phospholipids Carbohydrate groups of glycolipids always face the extracellular surface of the plasma membrane Flipases can alter the distribution of lipids on the outer versus inner membrane leaflets

Since white blood cells and red blood cells are exposed to essentially the same environment, their membranes would have the same lipid constituents in the same relative proportions. Function, not location.

Which factor(s) affect the direction in which an ion moves through an ion channel in a membrane? I. the concentration differential across the membrane II. the size and shape of the channel III. the ion selectivity of the channel. IV. the voltage differential across the membrane II and III I and IV I and II All of these I, III and IV

I and IV

Which small molecule is NOT made during an amplification process in cell signaling? diacylglycerol (DAG) cAMP Inositol 1,4,5-trisphosphate (IP3) cGTP Steroid hormone

Steroid hormone

Which of the following proteins that we discussed in class can be studied using patch clamp electrophysiology: Aquaporin GPCR ABC transporter GLUT1 CFTR

CFTR

Which of the following receptors that we discussed in class could be studied using patch clamp electrophysiology? Estrogen receptor Phospholipase C Nicotinic acetylcholine receptor Insulin receptor tyrosine kinase GPCR

Nicotinic acetylcholine receptor

Which of the following is NOT a major component of biological membranes? Carbohydrates All other choices are all major components of biological membranes Polar Lipids Cholesterol Integral proteins

All other choices are all major components of biological membranes

Lateral diffusion rates on cell surfaces can be measured by: glucose transport measurements FRAP experiments single particle tracking of fluorescent lipids patch clamp experiments FRAP and single particle tracking of fluorescent lipids

FRAP and single particle tracking of fluorescent lipids

Which of the following molecules is the least oxidized: Fatty acid Carboxylic acid Glycogen Glucose Carbon dioxide

Fatty acid

The fluidity of a lipid bilayer will be increased by which of the following? Increasing the temperature Substituting Stearic acid (18:0) for Linoleic acid (18:2) Decreasing the number of unsaturated fatty acids Decreasing the temperature Adding alkyl side chains that are longer

Increasing the temperature

Which of the following transport mechanisms permits solute transport down a concentration gradient AND requires a conformational change to translocate each substrate across the membrane? Simple diffusion Ion channel Secondary active transport Facilitated diffusion Primary active transportv

Facilitated diffusion

What is the purpose of the Hydropathy Index (or Plot)? Predicts the charge required to open and close voltage-gate channels. Predicts segments of globular proteins that would fold to the inside to avoid interactions with water. Predicts if channels are Symports or Antiports based on delta E. Predicts the number of solute molecules that pass through a membrane channel per unit of time. Predicts that a segment of a protein may be transmembrane.

Predicts the number of solute molecules that pass through a membrane channel per unit of time.

Which of the following cellular processes typically does NOT involve membrane fusion? Fertilization of an egg by sperm Endocytosis You getting infected with a Fall flu virus Glucose transport into blood from the intestinal lumen Exocytosis (i.e. secretion)

Glucose transport into blood from the intestinal lumen

Match the following cell signaling example with the feature it best exemplifies: Hydrolysis of GTP by Gqa Specificity Modularity Localization Termination Amplification

Termination

A researcher is investigating a potential inhibitor of the GLUT1 glucose transporter protein. They determine that the Vmax for transport is the same with and without the inhibitor present, but the KT for transport is 5 mM glucose without the inhibitor, and 50 mM glucose with the inhibitor. Which statement is most likely true about this inhibitor? None of these other statements is plausible The inhibitor binds GLUT1 in a different location from glucose The inhibitor binds GLUT1 only in the presence of glucose The inhibitor binds covalently to GLUT1 The inhibitor binds GLUT 1 in the same location as glucose

The inhibitor binds GLUT 1 in the same location as glucose

Which of the following membrane processes is responsible for steroid hormone signal transduction across the plasma membrane? Primary active transport Receptor enzymes Gated ion channel Simple diffusion Carrier molecules

Simple diffusion

____________ membrane proteins ___________________ and can be removed from the membrane without disrupting the membrane, while ______________ membrane proteins require detergents and/or organic solvents to remove from the membrane. Peripheral may have functional units on both sides of the membrane integral Integral penetrate deeply into the lipid bilayer peripheral Integral, are usually denatured when released from membranes, peripheral Amphitropic, are generally noncovalently bound to membrane lipids, peripheral Peripheral, are generally noncovalently bound to membrane lipids, integral

Peripheral, are generally noncovalently bound to membrane lipids, integral

Which statement about sterols is FALSE? Cholesterol is the principal membrane sterol. Sterols are soluble in water, but less so in organic solvents such as chloroform. The sterol backbone is the basis for a number of hormones Sterols are found in the plasma membranes of eukaryotic cells. All sterols share a fused-ring structure with four rings.

Sterols are soluble in water, but less so in organic solvents such as chloroform.

You have raised two groups of tadpoles: one group at 15° C, and the second group at 30° C. You then compare the lipid composition of the plasma membranes for the two groups of tadpoles. Which of the following statements best describes the membranes of these tadpoles: The group raised at 15° C has more unsaturated fatty acids, and the group raised at 30° C has more saturated fatty acids. The two groups of tadpoles have identical lipid compositions, but the membranes of the group raised at 30° C are less fluid. The group raised at 30° C has more unsaturated fatty acids, and the group raised at 15° C has more saturated fatty acids. The two groups of tadpoles have identical lipid compositions, but the membranes of the group raised at 15° C are less fluid.

The group raised at 15° C has more unsaturated fatty acids, and the group raised at 30° C has more saturated fatty acids.

What group of lipids serves as the basis for the ABO blood group system? Ether Lipids Sphingomyelins Glycerophospholipids Triglycerides Glycosphingolipids

Glycosphingolipids

Which statement is FALSE regarding the Oleic acid hydrocarbon [18:1(Δ9)]? It has a much lower melting point than steric acid (18:0) All of the above are true statements It can pack tighter together than steric acid due to the higher relative flexibility of its structure It can be classified as an unsaturated lipid molecule There is a single double bond between carbons 9 and 10

It can pack tighter together than steric acid due to the higher relative flexibility of its structure

Triacylglycerols Can sometimes be substituted with a carbohydrate group Are usually planar molecules, which permits their tight packing in cells Provide a means in which to store energy and act as insulators Are composed of a glycerol backbone and 2 fatty acids plus a third group (usually an alcohol) Are the main component of membrane lipids

Provide a means in which to store energy and act as insulators

Match the following cell signaling example with the feature it best exemplifies: Use of SH2 domains to bind phosphotyrosine residues Amplification Integration Modularity Termination Specificity

Modularity

Signal amplification is an important feature of many, but not all, signaling events. Which of the following signaling events do not include amplification? A nuclear hormone receptor that turns gene expression off Ligand binding triggers opening of a calcium channel The insulin receptor signaling cascade I and II only I and III only I only All three signaling pathways include an amplification event I, II, and III

I only

Phospholipases Can produce fatty acids by hydrolysis of an ester bond in a phospholipid Are named according to the specific bond they hydrolyze and not by their substrates Can cleave fatty acids from gangliosides by hydrolysis of diester linkages A and B are both true statements A and C are both true statements

A and B are both true statements

Consider the membrane potential of a typical metabolizing cell. Which of the best mechanisms is the best strategy for the cell to export ammonium (NH4+)? (Assume the concentration of ammonium is equal inside and outside the cell). Simple diffusion H+/ammonium symport H+/ammonium antiport Uniport Ion channel

H+/ammonium antiport

Phospholipase C can use phosphatidylinositol 4,5-bisphosphate (PIP2) as a substrate to produce which of the following molecules that directly causes the release of intracellular calcium? I. Adenosine 3’,5’-cyclic monophosphate (cAMP) II. Diacylglycerol (DAG) III. Inositol 1,4,5-trisphosphate (IP3) IV. Protein Kinase C (PKC) I only IV only II and III II only III only

III only

Which of the following is NOT an example of signal termination? GAPs strongly stimulate GTPase activity causing hydrolysis of the GTP bound to the trimeric G-protein Estrogen production decreases below Kd of its receptor The gate of the nicotinic acetylcholine receptor closes while nicotine remains bound A cell takes up signaling peptides by endocytosis and sends them to the lysosome for degradation Acetylcholine esterase hydrolyzes all of the acetylcholine in the gap junction

The gate of the nicotinic acetylcholine receptor closes while nicotine remains bound

An incorrect feature of G-proteins (Guanine Nucleotide Binding Proteins) is that: They include heterotrimeric proteins as a major subclass They are kinases. They inactivate themselves by hydrolyzing GTP. They include low molecular weight proteins as a major subclass They are active in their GTP bound state.

They are kinases.

Which of the following are structurally most closely related to cholesterol? Tocopherols, like Vitamin E Steroid hormones Eisosanoids Phosphatidylinositols Retinoids, like Vitamin A derivatives

Steroid hormones

What specific class of enzymes hydrolyze the ester bonds of glycerophospholipids? Protein Kinases Sialidases Phosphorylases Phospholipases Phosphatases

Phospholipases

What is the abbreviated nomenclature for a polyunsaturated 22-carbon omega-3,6 fatty acid that contains no other double bonds? 22:2(Δ 16,19) 22:1(Δ 19) 22:2(Δ 13,19) 22:1( Δ 16) 22:2(Δ 13,16)

22:2(Δ 16,19)

Which of the following does NOT describe signal termination? beta-arrestin binds to a GPCR and prevents a trimeric G-protein from accessing its binding site on the GPCR The pancreas stops secreting the insulin, and the level of this hormone in the blood stream drops below the binding constant of the receptor Acetylcholine esterase hydrolyzes acetylcholine in the synaptic cleft Phospholipase C is inactivated and enzymes convert the remaining diacylglycerol to phosphatidic acid GAPs stimulate the trimeric G-protein’s GTPase activity, causing GTP hydrolysis

beta-arrestin binds to a GPCR and prevents a trimeric G-protein from accessing its binding site on the GPCR

Which of the following are phospholipids that contain an ether-linked alkyl group? Cerebrosides Glycosphingolipids Globosides Plasmalogens Sphingomyelins

Plasmalogens

Which of the following statements is FALSE regarding the insulin receptor? Insulin binding causes autophosphorylation on Tyr residues Activated receptors can induce transcription Several steps of the signaling cascade involve phosphorylation, and amplification of the first signal at each step, so there is no requirement for either class of G-protein The receptor changes conformation upon binding of its ligand (insulin). It is a member of the Receptor Enzyme class

Several steps of the signaling cascade involve phosphorylation, and amplification of the first signal at each step, so there is no requirement for either class of G-protein

An example of signal termination is when: Your eyes adjust to a brightened room B-arrestin binds a receptor, leading it to be endocytosed The concentration of the signaling molecule drops below the Kd of the receptor All of these The signal is amplified until there are no more enzymes in the cascade to phosphorylate

The concentration of the signaling molecule drops below the Kd of the receptor

Which of the following is important in developing an electrochemical gradient? Membrane Potential (Vm) Concentration gradient Ka, the Acid-Base Constant A and B only A, B and C are all important in developing an electrochemical gradient

A and B only

What is the accepted minimum number of amino acids required for a portion of a protein to span the lipid bilayer of a membrane? 20 50 100 5 Varies with the size of the R-group, so there is no accepted minimum

A process not involving the fusion of two membranes or two regions of the same membrane is: fertilization of an oocyte by a sperm cell. propagation of the membrane voltage potential in neurons creation of pores between adjacent cells entry of enveloped viruses into cells. release of neurotransmitters at a synapse.

propagation of the membrane voltage potential in neurons

What specific group of lipids have the following properties: long-chain (C14-C36) fatty acids bonded to long-chain (C16-C30) alcohols, chains are usually saturated and unsaturated? Cerebrosides Glycosphingolipids Triacylglycerols Globosides Waxes

Waxes

steroid hormone receptors are different than the other signal transduction mechanisms we talked about because: Their response time is hours-to-days The signal molecules pass through the plasma membrane All of these They don’t make use of second messengers

All of these

We can calculate the energy required to move a charged solute, like bicarbonate, across a membrane using the transport formula, it relates the Transport Constant (GT) to some electrical measurements and the ratio of solute concentrations on either side of the membrane. Which of the following other constants and abbreviations is NOT in that formula? Faraday’s Constant Δψ, in volts Gas Constant Z, the charge of the ion n, the number of ions moved

n, the number of ions moved

Which of the following statements about receptor enzymes is FALSE? Receptor enzyme signaling cascades may include G proteins Some receptor enzymes have tyrosine kinase activity Receptor enzymes may directly catalyze the synthesis of second messengers Receptor enzymes are typically polytopic membrane proteins Integral membrane adenylyl kinases are examples of receptor enzymes

Integral membrane adenylyl kinases are examples of receptor enzymes

Which of the following can induce membrane curvature? The ratio of saturated versus unsaturated fatty acids Peripheral membrane proteins such as BAR domains Monotopic membrane proteins such as caveolin II only II and III only I, II, and III III only I only

II and III only

Which of the following amino acids are likely to contribute to the ligand binding site of a glycerol transporter: Ser, Asn Trp, Tyr Gly, Ala Asp, Arg Ile, Val

Ser, Asn

Which of the following could describe the composition of globoside: 1 sphingosine, 2 fatty acids, 1 glucose 1 Sphingosine, 1 fatty acid, 1 glucose 1 sphingosine, 1 fatty acid, 2 glucose 1 sphingosine, 2 fatty acids, 2 glucose

1 sphingosine, 1 fatty acid, 2 glucose

Many diverse signaling pathways use cAMP as a second messenger. This is an example of the following principle: Modularity Localization Integration Desensitization Termination

Modularity

Which of the following statements is FALSE concerning biological membranes? Aquaporin is a good example of a protein involved in Passive Transport The Chloride-bicarbonate exchanger is best classified as a Symport The inner and outer leaflets of the plasma membrane have different lipids One difference between Primary and Secondary Active Transport is the number of different molecules transported The lipid composition of the plasma membrane is usually significantly different than any intracellular membrane

The Chloride-bicarbonate exchanger is best classified as a Symport

Independently, both insulin and epinephrine signaling lead to an increase in blood glucose levels. However, if both signaling cascades are activated at the same time, insulin signaling decreases epinephrin signaling to prevent blood glucose levels from becoming too high. This is an example of: Modularity Specificity Amplification Termination Integration

Integration

Which of the following is NOT a feature that directly contributes to the Transition Temperature of lipids in membranes? The relative concentration of saturated fatty acids The relative concentration of sterols The relative polarity of fatty acids Only A and B above relate to the Transition Temperature of membrane lipids A, B, and C above all relate directly to the Transition Temperature of membrane lipids

Only A and B above relate to the Transition Temperature of membrane lipids

Which statement about membranes is FALSE? Lipids can freely pass from one leaflet to another in membranes The inner and outer leaflets of membranes differ in lipid and protein compositions. The lipid:protein ratio varies between tissues and organisms. Transport of many solutes requires the action of integral membrane proteins. Individual lipids can move freely in a lateral direction in membranes.

Lipids can freely pass from one leaflet to another in membranes

A cerebroside includes A globoside with 3 or more esterified sugars A phosphate group on carbon 3 A monosaccharide on ceramide Sphingosine plus a long alcohol A repeated disaccharide linked by a short peptide

A monosaccharide on ceramide

Match the following cell signaling example with the feature it best exemplifies: Cyclization of ATP to cAMP Amplification Localization Specificity Termination Modularity

Amplification

Adenylyl cyclase catalyzes the formation of cAMP in direct response to An extracellular messenger Hydrolysis of GTP by a bound G-protein Binding of a GDP-bound G-protein Binding of a GPCR Binding of a GTP-bound G-protein

Binding of a GTP-bound G-protein

Which of the following sphingolipids is not also a glycolipids Ganglioside Globoside Cerebroside Sphingomyelin

Sphingomyelin

Which statement concerning membranes architecture is FALSE? The inner and outer plasma membrane bilayers have an asymmetric distribution of phospholipids Peripheral membrane proteins can be removed without damaging membrane integrity and without removing integral membrane proteins Membranes are impermeable to simple diffusion of charged solutes Carbohydrates are located only on the outer face of the plasma membrane All internal membranes of Eukaryotic cells have the same relative proportions of the various phospholipids

All internal membranes of Eukaryotic cells have the same relative proportions of the various phospholipids

Exam 2 Problem Roulette Flashcards

(102 cards)