BIO CHEM 5 Flashcards
Which of the following is not one of the states of lipids?
Para crystalline state
Liquid ordered state
Liquid disordered state
Crystalline state
Crystalline state
Which of the following arrangement based on the increasing order of motion is correct?
Uncatalysed transverse motion, transverse diffusion catalyzed by flippase, uncatalysed lateral diffusion
Uncatalysed lateral diffusion, uncatalysed transverse motion, transverse diffusion catalyzed by flippase,
Uncatalysed transverse motion, uncatalysed lateral diffusion, transverse diffusion catalyzed by flippase
Transverse diffusion catalyzed by flippase, uncatalysed lateral diffusion, uncatalysed transverse motion,
Uncatalysed transverse motion, transverse diffusion catalyzed by flippase, uncatalysed lateral diffusion
Movement of phospholipids from side to side is called
Facilitated diffusion
Lateral diffusion
Transverse diffusion
Simple diffusion
Lateral diffusion
Movement of phospholipids to opposite sides is called
Facilitated diffusion
Lateral diffusion
Transverse diffusion
Simple diffusion
Transverse diffusion
Trans bilayer diffusion is also called
Facilitated diffusion
Lateral diffusion
Flip flop
Simple diffusion
Flip flop
Which of the following is an example of heterodimeric protein?
Integrin
Antibodies
Receptor tyrosine kinase
G-protein coupled receptor
Integrin
Which of the following is an example of peripheral membrane protein?
Insulin receptor
Glycophorin
Integrin
Glycolipid transfer proteins
Glycolipid transfer proteins
Which of the following proteins does not function in cell- cell interaction?
Integrin
Cadherin
N-CAM
Cytochrome c
Cytochrome c
Which of the following integral membrane protein is a special class of membrane rafts?
Caveolin
Integrin
Cadherin
Selectin
Caveolin
Which of the following is one of the family of immunoglobin like proteins that mediate Ca2+?
N-CAM
Integrin
Cadherin
Selectin
N-CAM
Erythrocyte glucose transporter is an example of
Ion driven active transport
Facilitated diffusion
Active transport
Simple diffusion
Facilitated diffusion
Which out of the following is not a mediated transport?
Facilitated diffusion
Primary active transport
Secondary active transport
Simple diffusion
Simple diffusion
Na+ glucose transporter is an example of
Symport
Antiport
Facilitated diffusion
ATP driven active transport
Symport
Which of the following is energy independent?
Active transport
Primary active transport
Secondary active transport
Passive transport
Passive transport
Semipermeable membrane allows
Solute to pass
Solution to pass
Solvent to pass
Proteins to pass
Solvent to pass
When does saturation occur?
`
When molecules are moved by the use of vesicles
When the energy from a high-energy bond is required to move molecules
When a group of carrier proteins is operating at its maximum rate
When a carrier molecule has the ability to transport only one molecule or a group of closely related molecules
When a group of carrier proteins is operating at its maximum rate
In which of the following means of transport a cell expels large molecules out of it?
Phagocytosis
Exocytosis
Endocytosis
Diffusion
Exocytosis
HCO3– – Cl– transporter is an example of
a. Uniport
b. Antiport
c. Symport
d. Facilitated diffusion
Antiport
Which of the following transports only one kind of substrate?
Uniport carriers
Symport carriers
Antiport carriers
Membrane proteins
Uniport carriers
Which of the following induces conformational change in protein?
Uniport
Symport
Antiport
Facilitated diffusion
Antiport
The information which is represented by a signal is detected by specific receptors and converted to a cellular response; this conversion is called
Signal amplification
Signal transversion
Signal transduction
Signal integration
Signal integration
Signal molecule fits the binding site on its complementary receptor called as
Specificity
Amplification
Integration
Cooperativity
Specificity
Number of affected molecules increases geometrically in an enzyme cascade in
Specificity
Amplification
Adaptation
Integration
Amplification
Receptor is removed from cell surface in
Specificity
Amplification
Adaptation
Integration
Adaptation
Regulatory outcome results from integrated input from both receptors is in
Specificity
Amplification
Adaptation
Integration
Integration
Acetylcholine receptor ion channel is an example of
Gated ion channel
Receptor enzymes
Membrane protein
Nuclear protein
Gated ion channel
How many types of signal transducers are there?
3
4
5
6
6
Which of the following is a nuclear receptor protein?
Steroid receptor
Adhesion receptor
Serpentine receptor
Receptor with no intrinsic enzyme activity
Steroid receptor
Receptor proteins that indirectly activate enzymes that generate intracellular second messengers are
Steroid receptors
Serpentine receptors
Adhesion receptors
Receptor enzymes
Serpentine receptors
Insulin receptor is an example of
Steroid receptors
Serpentine receptors
Adhesion receptors
Receptor enzymes
Receptor enzymes
Which of the following statements is true about transmembrane electrical potential?
The chemical gradient drives Cl– and K+ inwards
The electrical gradient drives Na+ and Ca2+ inwards
The chemical gradient drives Na+ and Ca2+ inwards
The chemical gradient drives Cl– and K+ outwards
The chemical gradient drives Na+ and Ca2+ inwards and K+ outward
Nicotinic acetylcholine receptor is an example of
Ligated gated receptor channel
Serpentine receptors
Adhesion receptors
Receptor enzymes
Ligated gated receptor channel
Which of the following are intracellular second messengers?
Acetylcholine
Glycine
IP3
Glutamate
IP3
The receptor channels for which of the following are gated by extracellular ligands?
Glycine
IP3
cAMP
cGMP
Glycine
Which of the following statements is false about a ligand-gated ion channel receptor?
They are present in the cell membrane
They consist of five glycoproteins
Differences in membrane potential affect whether the channel receptors are open or close
Neurotransmitters can act as the chemical messengers for these channels
Differences in membrane potential affect whether the channel receptors are open or close
Voltage regulation means
Na+/K+ pumps controls potential
Unless the voltage is regular gates will not respond
Oscilloscope only can control potential
With changes in the membrane potential voltage gated ion channels open and close
With changes in the membrane potential voltage gated ion channels open and close
Depolarization and repolarization changes that occur during the action potential are produced by
Negative feedback loops
Carrier mediated transport
Simple diffusion of ions down their concentration gradient
Active transport pumps along the neuron membrane
Active transport pumps along the neuron membrane
Diffusion of K+ out of the cell makes the inside of it less positive, or more negative and acts to restore the original resting membrane potential. This process is called
Repolarization
Depolarization
Hyperpolarization
Overshoot
Repolarization
Which of the following statements about action potential is false?
Na+/K+ pumps are directly involved in creating the action potential
Na+ and K+ concentrations are not significantly changed during an action potential
This includes both positive and negative feedback loops
Only a relatively small number of Na+ and K+ actually diffuse across the membrane
Na+ and K+ concentrations are not significantly changed during an action potential
Which out of the following is not a neurotransmitter?
Noadrenaline
Cyclic AMP
Dopamine
Acetyl choline
Cyclic AMP
SH2 domain specifically binds to
GDP
Ca2+
Phosphorylated tyrosine residues
Phosphorylated serine residues
Phosphorylated tyrosine residues
cAMP and cGMP are derived from
ATP and GTP by the actions of guanylate cyclase and adenylate cyclase respectively
ATP and GTP by the actions of adenylate cyclase and gualnlate cyclase respectively
GTP and ATP by the actions of adenylate cyclase and guanylate cyclase respectively
None
ATP and GTP by the actions of adenylate cyclase and gualnlate cyclase respectively
Which of the following is false about phosphorylation by IRS on serine residue?
It is an inhibitory phosphorylation
It is molecular mechanism for insulin resistance
It increases insulin levels
Target tissues fail to respond to circulating insulin
It increases insulin levels
The enzyme activated by cyclic AMP, passing on the hormonal signal is
Protein kinase B
Protein kinase A
Protein kinase C
G protein receptor kinase
Protein kinase A
Protein kinase ERK is activated by phosphorylation of
Only Thr
Only Tyr
Both Thr and Tyr
Only Ser
Both Thr and Tyr
Activation of guanylyl cyclase produces
Guanosine 3’, 5’-cyclic monophosphate
Guanosine 2’, 5’-cyclic monophosphate
Guanosine 4’, 5’-cyclic monophosphate
Guanosine 1’, 5’-cyclic monophosphate
Guanosine 3’, 5’-cyclic monophosphate
cGMP-dependent protein kinase is also called
Protein kinase B
Protein kinase A
Protein kinase G
Protein kinase C
Protein kinase G
Which of the following is not responsible of producing diarrhea?
Elevation in [cGMP]
Increase in Cl– secretion
Decrease in reabsorption of water by the intestinal epithelium
Decrease in Cl– secretion
Decrease in Cl– secretion
Which of the following is a short-lived messenger that acts by stimulating a soluble guanylyl cyclase, raising [cGMP] and stimulating PKG?
NO
NO2
NO3–
N2O
NO
- Ras protein is a
G-protein switch
Small monomeric GTPase switch protein
Serine-threonine kinase
Tyrosine kinase
Small monomeric GTPase switch protein
Which out of the following statements is true about G-protein couple receptors?
The N-terminal chain is extracellular and C-terminal chain is intracellular
It contains 5 trans-membrane hydrophobic sections
There are more extracellular loops than intracellular loops
The binding region for G-protein involves 2 extracellular loops
The N-terminal chain is extracellular and C-terminal chain is intracellular
Which of the following is not a G-protein coupled receptor?
Glycine receptor
Adrenergic receptor
Glutamate receptor
Muscarinic receptor
Glycine receptor
Protein kinase A is
Completely inhibited by cyclic AMP
Allosterically activated by cyclic AMP
Affected by cyclic AMP only under unusual circumstances
Activated by covalent binding of cyclic AMP
Allosterically activated by cyclic AMP
Which out of the following is not involved in signal transduction by β-adrenergic receptor pathway?
GTP
ATP
cAMP
cGMP
cAMP
Which of the following catalyzes the cutting of PIP2 into 2 moles of IP3 and diacylglycerol in cell signaling?
Phosphokinase C
Phospholipase C
Lipokinase
Phosphodiesterase C
Phospholipase C
The binding of ligands to many GPCRs leads to
Decrease in concentration of certain intracellular signal molecules called second messengers
Increase in concentration of certain intracellular signal molecules called second messengers
Decrease in concentration of certain extracellular signal molecules called first messengers
Increase in concentration of certain extracellular signal molecules called first messengers
Decrease in concentration of certain intracellular signal molecules called second messengers
A hormone or ligand can be considered as
First messenger
Second messenger
Third messenger
Fourth messenger
First messenger
Which of the following serves as a neurotransmitter in adrenergic neurons?
Serotonin
Epinephrine
Dopamine
Histamine
Epinephrine
Which second messenger signals the release of Ca+2 from endoplasmic reticulum?
IP3
1,2 diacyl glycerol
cAMP
cGMP
IP3
GPCR is comprised of
7 transmembrane helices
8 transmembrane helices
9 transmembrane helices
10 transmembrane helices
7 transmembrane helices
The specificity of signaling pathways does not include
Migration of signal proteins into membrane rafts
Assembly of large multiprotein complexes
Phosphorylation of target proteins at Ser, Thr/Tyr residues
Flippase-catalyzed movement of phospholipids from the inner to the outer leaflet
Flippase-catalyzed movement of phospholipids from the inner to the outer leaflet
Which of the following directly phosphorylate tyrosines to start a kinase protein enzymatic cascade?
Receptor tyrosine kinase
Receptor guanylyl cyclases
Receptor serine kinase
Receptor threonine kinase
Receptor tyrosine kinase
PTB domains bind to
Phosphorylated tyrosine
Phosphoryated threonine
Phosphorylated serine
Phosphorylated cysteine
Phosphorylated tyrosine
Scaffold protein in insulin signal transduction
KSR
IRS-1
MEKK1
AKAP
IRS-1
Which of the following is involved in extrinsic cell death pathway?
Heterotrimeric G protein complex
TRADD
IRS-1
Protein-kinase A
TRADD
Which of the following converts GTP to cGMP to start its enzymatic cascade?
Receptor guanylyl cyclase
Receptor adenylyl cyclase
Calmodulin
Protein kinase-A
Receptor guanylyl cyclase
Which of the following are stimulated to become membrane associated upon binding of insulin to the insulin receptor?
PH-domain
PTB
SH3
SH2
PH-domain
Which of the following is involved in phospho-tyrosine binding?
SH2
SH3
PTB
PH
SH2
Which of the following is involved in proline rich motif binding?
SH2
SH3
PTB
PH
SH3
Which of the following is not a downstream component?
Ras
MEK
ERK
PIP3
PIP3
Which of the following statements about Arabidopsis is not true?
In Arabidopsis, CTR-1 Ser/Thr protein kinase is activated by ethylene
Activation of MAPK cascade
EINI activation
Synthesis of ERF1 transcription factor
In Arabidopsis, CTR-1 Ser/Thr protein kinase is activated by ethylene
The 2-component system drives bacterial chemotaxis by coupling autophosphoryaltion of which receptor to phosphorylation of respective regulatory protein?
His kinase
Adenylyl cyclase
Guanylyl cyclase
None
His kinase
Bacteria do not have which of the following receptors
Adhesion receptors
Nuclear steroid receptors
Membrane proteins
GPCR
Nuclear steroid receptors
A factor involved in regulating the fate of stem cells in plant development
Adrenaline
Epinephrine
Thyroid stimulating hormone
CLV1
CLV1
The peptide trigger for the self-incompatibility response that prevents self-pollination
Salicylic acid
Jasmonates
Brassinosteroids
Plant peptide hormones
Brassinosteroids
Autophosphorylation is done on
His residues
Ser/Thr residues
Cys residues
Lys residues
Ser/Thr residues
In Arabidopsis flg22 binds to
FLS2
LPS
BAK1
MAPK
FLS2
Transcription factor in plants is
Serine
Threonine
WRKY22/29
Leucine
WRKY22/29
Negative regulator of ethylene response
LPS
CTR1
BAK1
MAPK
CTR1
ERF1is a
Translation terminating factor
Positive regulator
Translation promoting factor
Enzyme inhibitor
Translation terminating facto
The G protein involved in visual signal transduction is
Rhodopsin
GTP receptor
Arrestin
Transducin
Arrestin
Cholera toxin is not a/an
Enzyme inhibitor
Enzyme activator
Enzyme modifier
Toxin released from bacteria in the infected intestine
Enzyme activator
In cholera there is uncontrolled secretion of
Na+ and H2O
K+ and H2O
Ca2+ and H2O
Mg2+ and H2O
Na+ and H2O
Vision, olfaction and gustation employ
Serpentine receptors
Enzyme coupled receptors
Ligand gated receptors
Adhesion receptors
Serpentine receptors
Which out of the following statements about sense of smell is not true?
Olfactory receptor cells are bipolar neurons, not replaced when damaged
The chemicals are received by specific plasma membrane receptors in olfactory receptor cells
Olfactory receptors do not adapt quickly
The main areas of brain that interpret sense of smell be in the temporal and frontal lobes
Olfactory receptors do not adapt quickly
Most olfactory receptors are located on the
Superior surface of nasal cavity
Interior surface of nasal cavity
Lateral surface of nasal cavity
Medial surface of nasal cavity
Superior surface of nasal cavity
Objects are perceived by photo receptors because rods or cones
Depolarize
Hyperpolarize
Repolarize
Polarize
Hyperpolarize
Which of the following statements is not true about olfactory neurons?
Axons of olfactory neurons combine to form olfactory nerves
They synapse with cells in olfactory bulb
They have receptors that react with odorants dissolved in fluid
They are uni-polar neurons
They are uni-polar neurons
What is the relationship between olfactory sensors and gustatory sensors?
Gustatory hair can also detect odorants
Olfactory hair can also detect tastants
Olfactory sensors provides information about
substance that we are about to taste
No relation
Olfactory sensors provides information about substance that we are about to taste
When visual stimulus reaches receptors in retina of eye, first process involving absorption of physical energy by receptors is
Reception
Transduction
Coding
Adaptation
Reception
When visual stimulus reaches receptors in retina of eye, second process involving absorption of physical energy by receptors is
Reception
Transduction
Coding
Adaptation
Transduction
How do steroid hormones produce their effects in cells?
By activating key enzymes in metabolic pathway
By binding to intracellular receptors and promoting transcription of specific genes
By promoting degradation of specific m-RNAs
By activating translation of certain m-RNAs
By binding to intracellular receptors and promoting transcription of specific genes
An example of positive regulator
CAP
Lac 1 gene
Trp operon
Met operon
CAP
An example of negative regulator
CAP
Lac 1 gene
Nuclear receptors
Phosphorylated STAT proteins
Lac 1 gene
Steroid regulatory proteins mediate the act by binding at
Zinc finger motif
Leucine zipper motif
Helix turn helix motif
Histone helix motif
Zinc finger motif
Which out of the following statements is true about gene regulation in bacteria?
Repressor protein blocks transcription by binding to operator sequence
Activator proteins bind near promoters and increase the efficiency of transcription
Enhancers commonly regulate transcription
Genes with related functions are often grouped together and have a single start codon
Repressor protein blocks transcription by binding to operator sequence
Steroid hormones receptor binds to
Hormone response elements in m-RNA Hormone response elements in DNA Hormone response elements in proteins Ribosomes to stimulate translation Cell membrane thereby increases permeability
Hormone response elements in DNA
Mode of action of steroid hormones involve
Stimulation of DNA replication
Stimulation of m-RNA transcription
Inhibition of protein synthesis
Secondary messenger
Stimulation of m-RNA transcription
The drug antagonist of estrogen is
Tanoxifen
Metformin
Glucophage
Victoza
Tanoxifen
The drug used to terminate early pregnancies is
RU486
Metformin
Glucophage
Victoza
RU486
Plasma membrane protein predicted to have seen 7 transmembrane helices segment binds
Progesterone
Thyroid stimulating hormone
Insulin
Follicle stimulating hormone
Progesterone
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