biosensors exam 2 homework problems

Find the correct statement about the photometry:

 

It is based on the optical measurement for a range of wavelengths.

 

It is based on the optical measurement for a single wavelength.

 

It must use a spectrometer.

 

It results in a spectrum curve.

It is based on the optical measurement for a single wavelength.

Determine the absorbance for given intensity values: I=2mW/m², I₀=10mW/m²

.699

Determine the mass concentration of 1 nM of BSA (66 kDa) in ng/mL

66

Find all correct statements about hemoglobin (multiple answers):

 

Hemoglobin has a molecular weight of 64.5 kDa.

 

Their primary function is the carriage of oxygen from the lungs to the tissues.

 

Normal hemoglobin consists of globin and two heme groups.

 

The benzene ring strongly absorbs light at 405 nm.

Hemoglobin has a molecular weight of 64.5 kDa.

 

Their primary function is the carriage of oxygen from the lungs to the tissues.

Find all correct statements about the central dogma (multiple answers):

 

During translation, the cell creates a messenger RNA molecule at the site of a specific gene.

 

Transfer RNA carries the protein blueprint from a cell's DNA to its ribosomes.

 

Transcription happens in the nucleus.

 

DNA is a double-stranded molecule containing a set of instructions for creating proteins.

Transcription happens in the nucleus.

 

DNA is a double-stranded molecule containing a set of instructions for creating proteins.

Find components of a spectrophotometer (multiple answers):

 

Focusing mirror

 

Grating

 

Photodiode

 

Collimating mirror

Focusing mirror

 

Grating

 

Collimating mirror

Find all correct statements about an optical fiber (multiple answers):

 

The refractive index of the core of the optical fiber is higher than that of the cladding.

 

The optical signal is confined within the core through total internal reflection.

 

The multimode optical fiber supports only the fundamental mode.

 

The optical signal is propagating along the cladding.

The refractive index of the core of the optical fiber is higher than that of the cladding.

 

The optical signal is confined within the core through total internal reflection.

What is the difference between plasma and serum?

 

Serum contains clotting factors.

 

Plasma contains clotting factors.

 

Plasma contains white blood cells.

 

Serum contains red blood cells.

Plasma contains clotting factors.

Find all correct statements about Enzyme (multiple answers):

 

It binds to different proteins non-specifically.

 

The enzyme-substrate binding is highly specific.

 

It is a protein molecule that acts as a biological catalyst.

 

It absorbs light.

The enzyme-substrate binding is highly specific.

 

It is a protein molecule that acts as a biological catalyst

Find all correct statements about nucleic acid assay (multiple answers):

 

It is based on specific affinities of nucleobases of DNA and RNA.

 

It is based on the interaction between DNA and an antibody.

 

The nucleic acid bioreceptor is especially powerful in identifying different species of viruses and bacteria.

 

The specificity of the nucleic acid bioreceptor is enhanced by increasing the length of the DNA/RNA sequence.

It is based on specific affinities of nucleobases of DNA and RNA.

 

The nucleic acid bioreceptor is especially powerful in identifying different species of viruses and bacteria.

 

The specificity of the nucleic acid bioreceptor is enhanced by increasing the length of the DNA/RNA sequence.

Find a correct statement about B cells:

 

It is a type of lymphocyte that can contain viral infections.

 

It generates cytotoxic T cells.

 

It is a Y-shaped molecule.

 

It produces antibodies to fight against foreign molecules

It produces antibodies to fight against foreign molecules

Choose all optical transducers:

 

Surface Plasmon Resonator

 

Optical Ring Resonator

 

Quartz Crystal Microbalance

 

Microcantilever

Surface Plasmon Resonator

 

Optical Ring Resonator

Find the correct statements about a fluorescent dye (multiple answers):

 

 

It is not toxic and is safe to use.

 

It absorbs certain wavelengths of light.

 

It is relatively easy to conjugate to other molecules.

 

Its use is strictly regulated.

It is not toxic and is safe to use.

It is relatively easy to conjugate to other molecules.

What is the Stokes shift?

 

A shift due to the spontaneous emission of light.

 

A shift due to absorption of photon energy.

 

A shift due to a small amount of energy lost in molecular rotation and/or vibration and heat production.

 

A shift due to a small amount of energy gained through heat at the molecular level.

A shift due to a small amount of energy lost in molecular rotation and/or vibration and heat production.

What is FITC?

 

Rhodamine conjugated with isothiocyanate to facilitate chemical conjugation to proteins.

 

Quantum dot conjugated with isothiocyanate to facilitate chemical conjugation to proteins.

 

Cyanine conjugated with isothiocyanate to facilitate chemical conjugation to proteins.

 

Fluorescein conjugated with isothiocyanate to facilitate chemical conjugation to proteins.

Fluorescein conjugated with isothiocyanate to facilitate chemical conjugation to proteins.

What is a dichroic filter?

 

It is a single-layer filter to remove the signal's high-frequency components.

 

It is a multi-layer filter designed to transmit only a specific wavelength while reflecting others.

 

It is a single-layer filter to change the polarization state of a light wave.

 

It is a multi-layer filter designed to achieve a wide wavelength range of high reflectance.

 

It is a multi-layer filter designed to transmit only a specific wavelength while reflecting others.

Find all correct statements about the PCR (multiple answers):

 

It is also known as molecular photocopying.

 

The step involves denaturation at 50-65 degree C.

 

It is a process to make numerous copies of a segment of DNA.

 

It is used for DNA sequencing, DNA fingerprinting, and detecting microorganisms.

It is also known as molecular photocopying.

 

It is a process to make numerous copies of a segment of DNA.

 

It is used for DNA sequencing, DNA fingerprinting, and detecting microorganisms.

What is the photo-bleaching of fluorescent dyes?

 

Continuous exposure of fluorescent dyes to light results in a change in excitation wavelength.

 

Continuous exposure of fluorescent dyes to light results in a decrease in their fluorescent emission.

 

Continuous exposure of fluorescent dyes to light results in a decrease in their absorption property.

 

Focusing Continuous exposure of fluorescent dyes to light results in a change in emission wavelength.

Continuous exposure of fluorescent dyes to light results in a decrease in their fluorescent emission.

Find all correct statements about quantum dots (multiple answers):

 

They are colloidal semiconductor nanocrystals.

 

They are bandgap tunable by size.

 

Quantum dots absorb over a narrow spectrum.

 

Larger quantum dots have larger bandgaps.

 

Quantum dots are much brighter than fluorescent dyes.

They are colloidal semiconductor nanocrystals.

 

They are bandgap tunable by size.

Quantum dots are much brighter than fluorescent dyes.

Determine the cell potential at room temperature for the reaction equation shown below:

Fe(s)+Cu²⁺(aq, 0.2M)     →      Fe²⁺(aq, 0.1M)+Cu(s) 

.789

What are the correct statements about ISEs (multiple answers)?

 

It is based on an ion-selective membrane that allows only a specific ion to pass.

 

Both solid-state membranes and liquid membranes are used for ISEs.

 

The saturated calomel electrode is the standard electrode for ISEs.

 

They are only used for ion concentration detection.

It is based on an ion-selective membrane that allows only a specific ion to pass.

 

Both solid-state membranes and liquid membranes are used for ISEs.

What are the correct statements about Enzymes (multiple answers)?

 

Enzymes are globular proteins.

 

They slow down chemical reactions.

 

The substrate and the enzyme's active site match structurally and chemically.

 

The enzyme acts on the analyte (A) to yield a substrate (S).

Enzymes are globular proteins.

The substrate and the enzyme's active site match structurally and chemically.

Find the correct statements (multiple answers)?

 

Phosphate-buffered saline (PBS) is commonly used in biological research.

 

A buffer is a solution that resists change in pH.

 

Denaturation is a structural change in a protein that results in the loss of its biological properties.

 

Enzymes can be denatured only by temperature.

Phosphate-buffered saline (PBS) is commonly used in biological research.

 

A buffer is a solution that resists change in pH.

 

Denaturation is a structural change in a protein that results in the loss of its biological properties.

Find the correct statements about the cyclic voltammetry (multiple answers):

 

The Randles-Sevcik Equation can be used to determine the number of electrons transferred in the cell reaction.

 

It measures the current from a linear scanning of potential with a triangular (or square) waveform.

 

It is the most widely used technique for quantitative analysis of redox reactions.

 

From the cyclic voltammogram, the peak currents and peak potentials can be determined.

It measures the current from a linear scanning of potential with a triangular (or square) waveform.

 

It is the most widely used technique for quantitative analysis of redox reactions.

 

From the cyclic voltammogram, the peak currents and peak potentials can be determined.

Find all correct statements about impedimetric biosensors (multiple answers):

 

The response curves of impedimetric biosensors are called Nyquist plots.

 

It is based on the impedance, measured as the ratio of the voltage phasor to the current phasor.

 

It is based on the 1 kHz voltage source.

 

The Warburg impedance in the equivalent circuit for impedance spectroscopy corresponds to the electron transfer resistance.

The response curves of impedimetric biosensors are called Nyquist plots.

 

It is based on the impedance, measured as the ratio of the voltage phasor to the current phasor.

Find the correct statements about glucose biosensors (multiple answers):

 

It is a type of amperometric biosensor.

 

Continuous glucose monitoring requires inserting an electrode needle into a blood vessel.

 

Glucose detection with glucose oxidase, with a co-factor FAD+, doesn't require oxygen.

 

Glucose dehydrogenases with cofactors such as NAD+ or PQQ can be used for glucose detection

It is a type of amperometric biosensor.

Glucose dehydrogenases with cofactors such as NAD+ or PQQ can be used for glucose detectio

Find the correct statements about immunosensors (multiple answers):

 

They are biosensors that use antibodies or antigens as bioreceptors.

 

They are based on the ion-selective membrane.

 

The sensitivity and specificity of immunosensors are much superior to other types of biosensors.

 

Redox reagents are necessary for the operation of immunosensors.

They are biosensors that use antibodies or antigens as bioreceptors.

The sensitivity and specificity of immunosensors are much superior to other types of biosensors.

Find all antigens (multiple answers):

 

Viruses

 

Plasma

 

Red blood cells

 

Cancerous cells

 

Foreign proteins

Viruses

Cancerous cells

 

Foreign proteins

Find the correct statements about antibodies (multiple answers):

 

IgG molecules are shaped like a Y.

 

They are protein molecules created by the immune system.

 

Over 50% of human antibodies are in the immunoglobulin class IgG.

 

IgG molecules have a molecular weight of 15,000 Daltons

IgG molecules are shaped like a Y.

 

They are protein molecules created by the immune system.

ind the correct statements about the epitopes (multiple answers):

 

They are specific regions on an antigen where antibodies bind.

 

The shape of an epitope matches that of the matching antibody's variable region.

 

A single antigen can have multiple epitopes.

 

For a specific epitope, multiple antibodies can bind

They are specific regions on an antigen where antibodies bind.

 

The shape of an epitope matches that of the matching antibody's variable region.

 

A single antigen can have multiple epitopes.

Find all correct statements about antibody production (multiple answers):

 

Polyclonal antibodies are obtained in vivo by injecting lab animals.

 

Monoclonal antibodies are large quantities of nonspecific antibodies.

 

Monoclonal antibodies are produced in vitro using tissue-culture techniques.

 

Polyclonal antibody production is more expensive.

Polyclonal antibodies are obtained in vivo by injecting lab animals.

Monoclonal antibodies are produced in vitro using tissue-culture techniques.

Find all correct statements about antibody fragments (multiple answers):

 

The constant regions of antibodies are all different.

 

The top portions of hypervariable regions are where the antigen-binding sites are.

 

The whole antibody is more preferable than small antibody fragments for biosensing applications.

 

An antibody has heavy and light chains

The top portions of hypervariable regions are where the antigen-binding sites are.

An antibody has heavy and light chains

Find all correct statements about ELISA (multiple answers):

 

There are four types of ELISA methods: direct, indirect, sandwich, and competitive ELISA.

 

The sandwich ELISA is less sensitive and specific than other methods.

 

The direct ELISA doesn't require labeling of primary antibodies.

 

The indirect and sandwich ELISA methods are the two most common types used.

 

It requires expensive reagents and must be operated by trained personnel

There are four types of ELISA methods: direct, indirect, sandwich, and competitive ELISA

The indirect and sandwich ELISA methods are the two most common types used.

 

It requires expensive reagents and must be operated by trained personnel

Find all correct statements about antibody structure (multiple answers):

 

Antibodies' reactive functional groups are located at specific sites, allowing them to be easily oriented in a particular direction.

 

Hydrophilic residues on the antibody surface have chemically reactive functional groups.

 

Antibody's reactive functional groups are amine, carboxyl, and hydroxyl groups.

 

Hydrophobic amino acids are internalized.

Hydrophilic residues on the antibody surface have chemically reactive functional groups.

 

Antibody's reactive functional groups are amine, carboxyl, and hydroxyl groups.

 

Hydrophobic amino acids are internalized.

Find all correct statements about physical adsorption (multiple answers):

 

Van der Waals interactions are the attractive or repulsive interactions between molecules with electric charges.

 

Physical adsorption is fascinating because it allows antibodies to be oriented in a particular direction.

 

Hydrophobic interactions are attractions between polar and nonpolar parts of the molecules.

 

Physical adsorption is uncontrollable.

Van der Waals interactions are the attractive or repulsive interactions between molecules with electric charges

Physical adsorption is uncontrollable

The covalent coupling of capture antibodies ensures robust immobilization and can improve the density and orientation of the capture antibodies on the substrate.

 

True

 

False

true

Find all correct statements about the covalent bond between a carboxyl group and an amine group (multiple answers):

 

This method allows antibodies to be oriented in a particular direction.

 

EDC/NHS chemistry has been widely used for covalently attaching them.

 

Amine and carboxyl groups are ubiquitous throughout an antibody's structure.

 

This covalent bond is based on physical adsorption.

EDC/NHS chemistry has been widely used for covalently attaching them.

 

Amine and carboxyl groups are ubiquitous throughout an antibody's structure

Find all correct statements about silanization (multiple answers):

 

Epoxysilane covalently bonds to amine groups.

 

TESPSA produces carboxyl groups on the surface.

 

GOPS is a type of APTES.

 

APTES produces amine groups on the surface.

 

Plasma treatment helps increase surface hydrophobicit

Epoxysilane covalently bonds to amine groups.

 

TESPSA produces carboxyl groups on the surface.

APTES produces amine groups on the surface.

Find the correct statements about antibody immobilization using carbohydrate groups (multiple answers):

 

Periodate oxidation can be used to oxidize diols in carbohydrates into aldehyde groups that can react with amines.

 

Carbohydrate groups bind to the gold surface.

 

To form carbohydrate groups, the antibody needs to be treated with TCEP.

 

These carbohydrate groups are found in a very specific location in IgG antibodies.

Periodate oxidation can be used to oxidize diols in carbohydrates into aldehyde groups that can react with amines.

These carbohydrate groups are found in a very specific location in IgG antibodies.

Find the correct statements about SPR (multiple answers):

 

It allows real-time biomolecular binding measurements to determine the binding kinetics and affinity.

 

It has been successfully commercialized and is extensively used for various applications.

 

It is an electrochemical biosensor.

 

It requires a fluorescent label and spectrophotometric detection.

It allows real-time biomolecular binding measurements to determine the binding kinetics and affinity.

 

It has been successfully commercialized and is extensively used for various applications.

Find the correct statements about the principle of the SPR (multiple answers):

 

The traditional SPR configuration is called the Kretschmann configuration.

 

At the SPR angle, the reflected light intensity is maximized.

 

A SPR system consists of a TM-polarized light source, a prism, a thin metal film, and a light sensor.

 

At the SPR angle, the incident light excites a surface plasmon, a longitudinal charge density wave at the interface between a metal and a dielectric.

he traditional SPR configuration is called the Kretschmann configuration.

 

A SPR system consists of a TM-polarized light source, a prism, a thin metal film, and a light sensor.

 

At the SPR angle, the incident light excites a surface plasmon, a longitudinal charge density wave at the interface between a metal and a dielectric.

Find the correct statements about the wavelength modulation of SPR (multiple answers):

 

The wavelength of the light source is varied during the measurements.

 

The phase changes are measured.

 

The light source is fixed at a fixed angle of incidence.

 

The light source scans over a range of angles to find the SPR angle.

The wavelength of the light source is varied during the measurements.

 

The light source is fixed at a fixed angle of incidence.

Find all correct statements about the SPRi (multiple answers):

 

 

It is based on amplitude modulation, which offers superior sensitivity.

 

Most SPRi devices adopt the Kretschmann configuration, using a plane-polarized light with a fixed angle as incident light, and a charge-coupled device (CCD) camera for the detection of the reflected light.

 

It is an imaging technique for multiplexed detection and high throughput.

 

It is based on metal nanoparticles and the normal incidence of light

Most SPRi devices adopt the Kretschmann configuration, using a plane-polarized light with a fixed angle as incident light, and a charge-coupled device (CCD) camera for the detection of the reflected light.

 

It is an imaging technique for multiplexed detection and high throughput.