Which of the following reactions is commonly used to replenish intermediates of the citric acid cycle?
glutamate --> ketoglutarate
Which of the following statements is true regarding the activity of the ribonuceltide reductase?
The enzyme is required to convert nucleotides from the ribose form to the deoxyribose form required for DNA synthesis
A Southern blot with a probe (denoted as XXXX in the figure) to DNA isolated from an individual who has both a mutant and a recessive allele would produce which of the following results?
DNA fragments of a molecular weight of 1.2kb and 0.9 kb
Under anaerobic conditions, the glucose is primarily oxidized to which of the following compounds?
Lactate
A mutation occurs deleting 9 base pairs in a coding region of the genome. It is downstream of both a transcriptional and translational start site. Assuming protein translation was not impacted by this insertion, comparison of a western blot of samples col
The Western Blot of samples from the individuals with the deletion would show proteins with a decrease in molecular weight
The order of prosthetic groups as they act in the three proteins of the PDC(pyruvate dehydrogenase complex)is:
thiamine pyrophosphate ? dihydrolipoamide ? FAD
Hemoglobin has the ability to display cooperative binding. The property of cooperative binding is only displayed by proteins that have __________________ structure.
quaternary
See page 97. Quaternary structure increases protein stability, enables a protein to exhibit cooperative binding or to form binding sites with a high affinity for large molecules.
The fully reduced quinol form of CoQ contains which of the following combinations of electrons and protons?
two electrons and two protons
A mutation occurs inserting a single base pair into a coding region of the genome. It is upstream of the translational start site but downstream of the transcriptional promoter. What impact will this have on the mRNA transcript when compared to the normal
the transcript will be longer
If the insertion is DOWNSTREAM of the transcriptional start it would be incorporated into the transcript and the transcript would be LONGER.
Damage of a single base (such as deamination) leading to small distortions in the DNA helix are repaired by which of the following mechanisms?
base excision repair
DNA is a double helix and the nucleotides form complementary hydrogen bonds to stablize this structure. If a stretch of DNA has the following sequence 5' AAC TTC GGC 3' what is the nucleotide sequence of the complementary strand?
3' TTG AAG CCG 5'
A deficiency in B6 (pyridoxal phosphate) would negatively impact which of the following pathways:
1. transsulfuration of homocysteine
2. remethylation of homocysteine
3. the folate cycle
1 only - 1. transsulfuration of homocysteine
The Epo receptor is an example of a classical Jak - STAT type of receptor. All of the following are true statements with regards to this receptor family except:
Signaling can be terminated through activation of phosphodiesterase
(true statement: Signaling can NOT BE terminated through activation of phosphodiesterase)
Glucokinase has a higher Km than hexokinase. Which of the following accurately describes the activity of glucokinase with respect to the enzymes Km?
Glucokinase will be less active then hexokinase at low concentrations of glucose.
Aldolase B facilitaes a reaction that cleaves fructose 1-phosphate into dihydroxyacetone-phosphate and what other glycolytic intermediate?
Glyceraldehyde 3-phosphate
Hereditary nonpolyposis colorectal cancer is caused by mutation in genes involved in mismatch repair. In these individuals you would except to see an increase in which of the following types of DNA mutations:
inappropriate pairing of a nucleotide base such that the base does not form normal Watson and Crick base pairs
Normal base pairs that are mismatched are fixed through mismatch repair.
Which oxidation reaction requires the coenzyme FAD because it involves oxidation of a carbon-carbon single bond to a double bond?
oxidation of succinate to fumarate
Steroid hormone receptors bind glucocorticoid response elements (GRE) on DNA. This type of regulation is referred to as:
transcriptional regulation
An individual is deficient in Vitamin B 12. In this individual, which of the following reactions would be compromised?
Conversion of methylmalonyl co A to succinyl coA
Individuals with deficiency in glucose 6 phosphate dehydrogenase often present with hemolytic anemia. This is primarily due to a deficiency in which of the following metabolic products?
NADPH
The non-oxidative stage of the pentose phosphate pathway produces substances that are intermediates of ________.
glycolysis
Transamination is the first step in amino acid metabolism and it involves which of the following processes?
the transfer of an amine group from an amino acid to a keto acid
Following protein translation, proteins can be targeted to various sub-cellular locations. The stretch of amino acids in the protein sequence that directs the protein to the appropriate location is refered to as which of the following?
Peptide signal sequence
All of the following stimulate the release of insulin except:
epinephrine
Explanation: Epinephrine is a counter regulatory hormone that facilitates catabolic reactions.
Two individuals are heterozygous for a deficiency in phenylalaine hydroxylase. The likelihood of these two individuals having a child who is a heterozygous carrier (genotype Rr) for this disorder is:
50%
Enzymes facilitate chemical reactions through which of the following mechanisms?
Decreasing the activation energy
Which of the following describes a correct and complete electron transfer pathway necessary for oxidative phosphorylation?
NADH ? complex I ? CoQ ? complex III ? cyt c ? complex IV
The second messenger in the signaling cascade initiated by glucagon is:
cAMP
After the initiation of protein translation, where the initial Met-tRNA is added to the P-site on the small ribosomal subunit. All other tRNAs enter into which location on the ribosome?
A site
All amino acids are added to the A site except for the Met-tRNA which is added to the P-site
A nucleotide is comprised of which of the following units?
a nucleoside and a phosphate group
Explanation: A nucleoside contains a base and a sugar group. A nucleotide contains all three portions: a base, sugar and phosphate group.
One of the differences in pro vs. eukaryotic protein translation is in the process of initiation. In eukaryotes, translational initiation starts with the small ribosomal subunit associating with the 5' cap on the mRNA. In prokaryotes, translational initia
The Shine-Dalgarno sequence
A series of reactions have the following ?G.
A + B --> C ?G = -1
C + D --> E ?G = +3
E + F --> G ?G = -5
-3
The ?G's for a series of reactions is additive.
A deficiency in thiamine can reduce the activity of the pyruvate dehydrogenase complex. Under these conditions, might you expect to have a higher than normal blood concentration of which of the following metabolites?
Pyruvate.
Platelet-derived growth factor is secreted from platelets aggregated at the site of an injury. This growth factor stimulates nearby smooth muscle cells to proliferate. This type of signaling is best described as which of the following?
paracrine
See figure 11.4
Cortisol is a steroid hormone that increases protein catabolism from skeletal muscle. It does this through which of the following mechanisms?
Transcriptional regulation
The steroid hormone receptor regulates expression of genes at the level of:
transcription
Explanation: The steroid hormone receptor is an example of a trans acting transcription factor that regulates gene expression at the level of transcription.
Purine biosynthesis starts with the activation of a 5 carbon sugar. In this initial reaction, ribose 5-phosphate is converted into which of the following compounds?
PRPP (5- phosphoribosylpyrophosphate)
Explanation: PRPP and glutamine are the first required substrates for the synthesis of purines.
To evaluate whether a protein is being translation the best method to use would be:
Western blot
Explanation: To evaluate if a protein product is being made you will need to look at protein levels. The only technique that looks at the level of protein is a Western blot. Northern blot evaluates mRNA levels; Southern blot allows you to ass
In a repressible operon, when the co-repressor is absent which of the following statements is true?
The repressor is inactive and the operon is transcribed
A repressible operon is shown in figure 16.6. In this case, both the repressor and co-repressor must be present and associated with each other before binding the operator. If one is absent, the opero
The folate cycle is directly involved in which of the following amino acid metabolic pathways?
Remethylation of homocysteine to methionine
In the case of an individual who is autosomal recessive for a deficiency in cystathione - beta- synthase. Which amino acid becomes essential?
cysteine
Under low energy conditions, AMP will bind to phosphofructokinase I and glycogen phosphorylase. This is an example of which of the follow types of enzyme regulation?
allosteric activation
Cortisol is a steroid hormone and it signals via which of the following mechanisms?
nuclear receptors
Hemoglobin is a large goblin protein that consists of 4 subunits. Each subunit is composed of 7 -alpha helicies. The interactions of those helical domains with each other within a single subunit is best described as:
tertiary structure of the protein
Tertairy structure refers to interactions between secondary structural components of a single subunit of a protein.
In the absence of iron, the iron response element binding protein is bound to the iron response element on mRNA. Under these conditions:
translation of ferritin is decreased
Glucogenic amino acids can enter the TCA cycle as all of the following intermediates except:
acetyl CoA
If the amino acid is fully metabolized to acetylCoA it does not provide excess carbons to generate glucose thru gluconeogenesis.
Pyruvate dehydrogenase kinase catalyzes a reaction that results in which of the following results?
The phosphorylation and inactivation of E1 subunit of PDC(pyruvate dehydrogenase complex)
Succinate is a substrate for which complex in the electron transport chain?
Complex II (Succinate dehydrogenase)
Complex II or Succinate dehydrogenase is coupled to the TCA cycle and accepts succinate rather than malate as a substrate.
What is the [OH] concentration in a 0.01 M = 10-2 M solution of HCl.
(10-14 = [H+] [OH-])
10 -12 M
Page 44. Section II
Movement of ammonia from an amino acid to an alpha-keto acid involves a family of enzymes best categorized as:
Transferases
The reduction of NAD+ is often coupled to the oxidation of an alcohol. In this reaction, NAD+ obtains which of the following from the oxidized compound?
two electrons as a hydride ion
In pyrimidine synthesis, uracil can feedback and inhibit which of the following enzymes?
Carbamoyl phosphate synthase II
Insulin stimulates fatty acid synthesis in the liver. These fatty acids are transported to the adipose tissue as:
VLDL particles
Explanation: Glucose can be used to synthesize fatty acids in the liver. These molecules are packaged into VLDL particles at triacylglycerols where they are delivered to the adipose.
A patient recently diagnosed with colon cancer is being treated with 5-fluorouracil. Which of the following enzymes will this drug directly inhibit?
thymidylate synthase
Separation of DNA by electrophoresis allows DNA to segregate based on molecular weight and charge. Based on this, how would a fragment of DNA that is 500 base pairs in length migrate on a gel when compared to a fragement that is 1000 base pairs in lenght?
The 500 base pair fragment would be located closest to the positive pole on the gel when compared to the 1000 base pair fragment.
DNA is negatively charged therefore all fragments run towards the positive electrode. The smaller fragments migrate the furth
Active transport by a Na-K ATPase requires ATP to move Na+ and K+ across the membrane. The primary role of this transporter is to:
Maintain a lower intracellular concentration of Na+ compared to the extracellular space
The Cori cycle describes the movement of lactate from the red blood cell to the liver. Within the liver, the lactate is primarily used as a substrate for which of the following metabolic processes?
Gluconeogenesis
The steroid hormone receptor contains several domains required for transcriptional regulation. It contains all of the following domains except:
repressor-domain
A DNA sample is determined to contain 20% guanine bases (G), what is the relative amount of thymine (T) in the sample:
30%
The DNA double helix is comprised of C and G base pairs and A and T base pairs. If 20% of the DNA is G bases; 20% will also be C bases = 40% of the total DNA. The remaining 60% of the DNA will be evenly split between A and T base pairs.
The enzyme responsible for freeing ammonia from glutamine to generate glutamate is:
glutaminase
Glutaminase frees ammonia from glutamine to generate glutamate
Buffers are essential components to biological systems. They consistent of a weak acid (HA) and conjugate base (A-). Which of the following represents the correct pairing of a weak acid and conjugate base?
CH3COOH (HA) ; CH3COO- (A-)
In eukaryotes, pre-mRNA must undergo a series of modifications leading to a mature mRNA. These include all of the following processes except:
The addition of a 3' CCA
Which of the following is an inhibitor of malate dehydrogenase, isocitrate dehydrogenase, and ?-ketoglutarate dehydrogenase?
NADH
Dinitrophenol is an uncoupler of the electron transport chain. The addition of dinitrophenol will have which of the following impacts?
Increase oxygen consumption
DNP is an uncoupler of the electron transport chain dissipating the proton gradient across the inner mitochondrial membrane and increasing oxygen consumption
At the base of a tRNA there is a trinucleotide sequence that is complementary to a trinucleotide sequence on mRNA and will determine what amino acids are added during the process of protein translation. Which of the following terms is used to describe thi
anticodon
the anticodon is the triplicate sequence at the base of a tRNA
A deficiency in thiamine (TPP) will directly decrease the activity of which of the following enzymes?
Transketolase
Which of the following is not a primary function of the products of the pentose pathway?
To directly generate ATP .
Regulation of the Lac operon is critical to bacteria. If glucose is absent, which of the following statements is true with regards to the lac operon?
RNA polymerase is bound to the promoter and the operon is transcribed
Water is a key component of biological systems. Which of the following statements is false with regards to the chemical properties of water?
Water has a very large dissociation constant
Complex II (Succinate dehydrogenase) is not considered to be part of the process of oxidative phosphorylation because it is unable to do which of the following activities?
Pump protons from the mitochondrial matrix to the intermembrane space
Complex II does not span the mitochondrial membrane and can not pump protons into the intermembrane spac
In the absence of iron, the iron response element binding protein is bound to the iron response element on mRNA. Which molecular techinque would best evaluate the amount of protein being translated under these condtions?
Western blot
Western blot is used to determine the quantity and size of a protein product
Heme synthesis requires succinyl CoA as a substrate. The end product of this pathway is heme which can regulate its own synthesis by functioning as which of the following?
allosteric inhibitor
Glucagon binds a G-Protein coupled receptor. Which of the following second messengers is generated by this cascade of events ?
cAMP
Immediately after a meal (insulin is high), in glucose 6-phosphate (or its oxidation products) will be utilized by all of the following pathways except:
Glycogen degradation
In the salvage of purines, hypoxanthine-guanine phosphoribosyl transferase (HGPRT) is responsible for which of the following processes?
guanine to guanosine monophosphate (GMP)
All of the following can be found within the transcribed region of a eukaryotic gene except:
TATA box
The TATA box is upstream of the transcriptional start site.
When glucagon binds to its receptor on a liver cell, which of the following sequence of events occurs to activate protein kinase A?
activation of G protein, activation of adenylate cyclase, production of cAMP
A deficiency in cobalamin would negatively impact which of the following pathways:
1. transsulfuration of homocysteine
2. remethylation of homocysteine
3. synthesis of succinyl CoA
2 and 3
2. remethylation of homocysteine
3. synthesis of succinyl CoA
Which of the following is an example of enzyme regulation through covalent modification?
Phosphorylation of muscle glycogen phosphorylase
Phosphorylation is an example of covlent mofication
A deficiency in glucose 6-phosphatase reduces the levels of NADPH in the red blood cell. This leads to an increase in which of the following compounds with the cell?
Oxidized glutathione
The transport of glucose from the intestinal lumen to the enterocytes is dependent on which of the following processes?
The maintenance of a sodium gradient across the intestinal lumen and the enterocyte.
The regulation of PRPP synthetase is critical in the production of both purines and pyrimidines. This enzyme is inhibited under which of the following conditions?
When both GTP and ATP are elevated
In the malate/aspartate shuttle, glutamate is converted to _________ in the mitochondria while aspartate is converted to ___________ in the cytosol.
?-ketoglutarate; oxaloacetate
Hereditary fructose intolerace is caused by a deficiency in Aldolase B. These individuals may present with hypoglycemia due to an accumulation of fructose 1 -phosphate in the cell and inhibition of which of the following pathways?
Gluconeogeneiss and glycogenolysis
What sequence of enzymes allows for the synthesis of glycogen from glucose-6-phosphate?
phosphoglucomutase, UDP-glucose pyrophosphorylase, glycogen synthase, amylo-(1,4?1,6)-transglycosylase
Alternative splicing and mRNA editing are two forms of post transcriptional regulation. Which of the following is an example of mRNA editting?
The modification of a base to introduce a stop codon into a transcript
Ca2+ influx thru a channel that is activated by a change in the membrane potential across the plasma membrane is an example of a(n):
Voltage-gated channel
In prokaryotic organisms, many genes are regulated by the same upstream promoter. This allows for all the genes to be transcripted and translated together. This organizational structure of prokarytoic genes is refered to as which of the following?
Operon
Under conditions when glucose is high, hexokinase will be more active then glucokinase kinase. This is due to which of the following rationales?
Glucokinase has a higher Km than hexokinase.
Which of the following is the primary role of the oxidiative portion of the Pentose Pathway?
To generate NADPH
Which of the following enzymes is involved in the non-oxidative portion of the Pentose Pathway?
Transketolase
PI 4, 5, bisphosphate can be cleaved by phospholipase C to initially generate which of the following second messengers?
Diacylglycerol (DAG) and Inositol 1,4,5 phosphate (IP3)
In the non-oxidative portion of the pathway 2-carbon fragements of keto sugars can be transfered to other sugars to generate a larger sugar molecule. This reaction is catalysized by which of the following enzymes?
transketolase
Folate is an essential compound in the synthesis of nucleotides. All of the following nucleotides require folate for sythesis except:
CTP
An individual is autosomal recessive for a branched chain keto acid dehydrogenase deficiency. This deficiency may result in the elevation of all of the following the following amino acids except:
homocysteine
Maple syrup urine disease (branched chain amino acids; tie in with pyruvate dehydrogenase complex and alpha-ketoglutarate dehydrogenase complex, and the requirement for thiamine, lipoic acid, niacin, riboflavin and pantothenate).
Glycogen degradatio in the liver can be enhanced by the activition of alpha -adrenergic receptors by epinepherine. The initial step in this cascades involves which of the following second messangers?
Phospholipase C
Which of the following would occur in the liver under levels of high glucose (think insulin is elevated)?
Generation of glucose 1-phosphate to be used for glycogen synthesis
ATP is a high energy molecule that is often hydrolyzed during reactions. The energy within ATP is stored primarily in which of the following components of the molecule?
In the high energy phosphate bonds
Heme can inhibit its own synthesis by inhibiting the activity of which of the following enzymes?
aminolevulinic acid synthase
In an inducible operon, in the absence of the inducer:
the repressor is bound
In the absence of the inducer the repressor binds the operators and transcription does not occur. When the inducer is present, it binds the repressor and the operator is accessible to RNA polymerase.
Which of the following allosterically activates mammalian isocitrate dehydrogenase?
A and C only
ADP and Calcium
As electrons flow through complexes in the inner mitochondrial membrane, protons are pumped from the matrix to the intermembrane space. Which of the following statements is most reflective of the pH in the intermembrane space?
The pH is higher in the matrix when compared to the intermembrane space.
The increase in protons in the intermembrane space makes the pH more acidic
A 40-year-old male comes in to the doctors office with severe pain in his big toe. He is diagnosed with gout. Allopurinol is administered and this drug will inhibit which of the following enzymes?
Xanthine Oxidase
Amino acids are said to be glucogenic if they are metabolized to all of the following except:
acetyl CoA
In this illustration, which strand is functioning as the template strand for transcription?
bottom
the 3' to 5' direction
All of the following compounds can move across a membrane by simple diffusion except:
peptide hormones
TCA cycle intermediates are always being removed for various metabolic processes. One example of this is the removal of succinyl CoA which is used for the synthesis of which of the following compounds?
Heme
Protein Kinase B has a pleckstrin homology domain that allows it to dock on the cell membrane by binding to which of the following substrates?
Phosphatidylinositol 3,4,5 tris phosphate
Which of the following is the primary GLUT transporter on skeletal muscle and adipose tissue?
GLUT4
GLUT4 is insulin sensitive on and skeletal muscle and adipose
You have identified a signaling molecule that is secreted from cells in the pancreas. It binds receptors on the cell it is secreted from and it also travels through the blood stream to additional target cells. Based on these observations you would best ca
Autocrine and endocrine hormone
Sucrase is the digestive enzyme for metabolizing sucrose. It does this by cleaving the bonds between dimers of which monosaccharides?
glucose and fructose
Alpha ketogluterate dehydrogenase is the enzyme responsible for one of the irreversible reactions in the TCA cycle. The enzyme catalyizes which of the following conversions?
alpha ketogluterate to succinyl CoA
In eukarytoic orgnaisms, which of the following enzymes is responsible for DNA synthesis on the lagging strand?
DNA polymerase ? (delta)
An example of enzyme activation by cleavage is best illustrated by which of the following?
activation of chymotrypsinogen to chymotrypsin
A nucleotide is comprised of which of the following functional groups?
a base, a sugar and a phosphate group
The last cytochrome in the ETC, cytochrome oxidase, passes electrons to O2. Cytochrome oxidase is able to do this because it has:
lower Km for oxygen then hemoglobin
Segements of DNA can move from one location to another in the genome to allow for the generation of different protein products. The synthesis of antibodies takes place. This type of gene regulation is best described as which of the following?
Gene rearrangement
Which amino acid has a side chain that has a pKa that can act as a buffer in a physiological pH range (~pH = 7.4)? The pH range over which a buffer is effective is called the buffering range, usually defined as pKa + 1 to pKa - 1.
Histidine
Which figure depicts translational initiation?
B -
where the Met in the center is the only figure in the set
After the initial priming, the enzyme responsible for leading strand synthesis is _______________ while, _________________________ synthesizes DNA on the lagging strand.
Polymerase ? (eplison); Polymerase ? (delta)
The glycerol 3-phosphate shuttle is the major shuttle of most tissues. Which of the following best describes the utility of this shuttle?
This shuttle transfers electrons from Glycerol 3-P to an FAD containing glycerol phosphate dehydrogenase
Coenzymes are complex nonprotein molecules that participate in catalysis by providing functional groups that form a covlanet intermediate between the enzyme and the substrate. Which of the following is an example of a coenzyme that participates in an acti
Thiamaine pyrophosphate (TPP)
Thiamine pyrophosphate is and example of a cofactor that is involved in an activation transfer reaction. All others are invovled in oxidation-reduction reactions.
At the base of a tRNA there is a trinucleotide sequence that is complementary to a trinucleotide sequence on mRNA and will determine what amino acids are added during the process of protein translation. Which of the following terms is used to describe thi
anticodon
Motifs are common structural elements that retain a particular function within the protien. Which of the following is an example of a protein motif?
An arrangment of ?-strands connected by ? - helicies (?????)
Heat can be generated in the brown adipose tissue of hibernating mammals due to which of the following processes?
Uncoupling of the electron transport chain by thermogenin
Thermogenin is an uncoupler of the electron transport chain
Chymotrypsin is a protease that cleaves peptide bonds. It is characterized as which of the following classes of enzymes?
Hydrolases
Which of the following enzymes is responsible for filling of the 3' overhang at the end of a newly synthesized strand of DNA?
Telomerase
Telomeres are repetitive sequences at the end of chromosomes that are used to fill in the shorter 5' end of a newly synthesized DNA strand. Because DNA polymerases can only function in the 5' to 3' direction the telomere functions as an RNA pri
Which step in the citric acid cycle is a rearrangement reaction?
Citrate to isocitrate.
Monosaccharides are transported from the intestine to the gut epithelium by which of the following processes?
secondary active transport
The association of DNA and histones can be modified by histone acetylation. A decrease in histone acetylation will have which of the following impacts on the assocation of DNA and histones?
Increase DNA: histone association
Histone acetylation decreases the positive charge on the lysine residues of histones. This will decrease the interaction of DNA (negatively charged) with histones (postively charged).
If histone acetylation decreases this
An allosteric activator will increase enzyme activity through which of the following mechanisms?
Binding the enzyme, and keeping it in the "R" conformation
Each strand has three potential reading frames. From the TSS, which of the reading frames should be used to generate an inframe ATG?
Frame 3: 2 base pairs after the TSS starting with GCC
Frame 3 will generate an inframe ATG which can be transcribed into AUG to be used as a translational start.
Which figure depicts immediately after the peptidyl transferase reaction?
D. Two cylinders in last two spaces with met-val created and HO is the second space
Under anaerobic conditions, the glucose is primarily oxidized to which of the following compounds?
Lactate
Muscular dystrophy is an X linked recessive trait. If a female carrier mates with a male individual (non-phenotypic), what are the potential genotype (s) of their female offspring?
XX or XX'
A decrease in histone acetylation _______________the affinity of DNA to histones.
increases
Activation of glycogen phosphorylase is regulated in several manners. In skeletal muscle, which of the following compounds can allosterically activate the enzyme?
AMP
Within the red blood cell glucose can be oxidized to which of the following products?
lactate and acetyl CoA
Which of the following terms is used to describe a mutation changes a codon to introduce a stop codon with in an exon?
nonsense mutation
Phenylkentonuria can be caused by a deficiency in the enyzyme phenylalanine hydroxylase or it can present due to a deficiency in which of the following required metabolic cofactors?
tetrahydrobiopterin
The synthesis of large molecules from smaller compounds is an example of what type of work?
biochemical
SMAD proteins are downstream targets of serine threonine receptors. Phosphorylation of the SMAD proteins by the receptor is required for translocation to the nucleus. This type of covalent modification is referred to as:
post translation regulation
A competitive inhibitor competes with a substrate for binding at the enzymes active site. This interaction causes which of the following changes in the enzymes activity?
The addition of a competitive inhibitor will have no impact on the Vmax of the enzyme
To evaluate whether a protein is being translation the best method to use would be:
Western Blot
What is the [OH] concentration in a 0.001 M = 10-3 M solution of HCl.
(10-14 = [H+] [OH-])
10 -11M
Starting at the level of the receptor, order the list of activities (given below) to illustrate the sequence of events that occurs following ligand binding of a tyrosine kinase receptor.
1. Activation of Ras-GTP
2. Recruitment of SOS (GEF)
3. Autophosphor
3, 4, 2, 1, 5
3. Autophosphorylation of the intracellular domain of the receptor
4. Association of Grb2 to the receptor through SH2 domains
2. Recruitment of SOS (GEF)
1. Activation of Ras-GTP
5. Association of Ras-GTP with Raf
A mutation occurs deleting 9 base pairs in a coding region of the genome. It is downstream of both a transcriptional and translational start site. Assuming protein translation was not impacted by this insertion, comparison of a western blot of samples col
The Western Blot of samples from the individuals with the deletion would show proteins with a decrease in molecular weight
Under low energy conditions, AMP will bind to phosphofructokinase I and glycogen phosphorylase. This is an example of which of the follow types of enzyme regulation?
allosteric activation
An alpha-helical arrangement of amino acids is considered to be part of what level of protein structure?
secondary structure of the protein
Following insulin binding its receptor and autophosphorylation of the beta chain, what is the initial step in this cascade of events?
Recruitment of the insulin receptor substrate
Explanation: The insulin receptor is an example of at tyrosine kinase. Upon insulin binding, there is an autophosphorylation event allowing for binding of the insulin receptor substrate (IRS). The IRS is phosp
rRNA is synthesized by RNA polymerase I. The primary utility of rRNA within the cell is best described as which of the following?
It is an integral part of a functional ribsome
Order the following statements to illustrate the correct cascade of events that occurs after ligand binding of G-protein coupled receptor (heptahelical receptor)
1. Degradation of cAMP by phosphodiesterase
2. Dissociation of Gbeta and Ggamma subunits
3. E
3, 2, 4, 1
3. Exchange of GDP for GTP in the G-alpha subunit
2. Dissociation of Gbeta and Ggamma subunits
4. Activation of adenyly cyclase to generate cAMP
1. Degradation of cAMP by phosphodiesterase
The malate aspartate shuttle is used to move NADH from the cytosol into the mitochondria where it can be oxidized. Which of the following compounds is used to move cytosolic NADH into the mitochondria?
Malate
Which of the following intermediates is an allosteric activator of pyruvate kinase?
fructose-1,6-bisphosphate