Previous Exam Questions Flashcards
The only coded aa that is chiral is
Gly
Pyruvic acid, or pyruvate, chemically is a
alpha-ketoacid
This non polar aa also works as a neurotransmitter
Gly
The number of oxygens in glycerin acid is
4
The only aa with a secondary alpha amino group is
Pro
When pyruvate serves as the substrate for an aminotransferase the product is
Ala
The aa is used as the source of CH3 groups is
Met
This aa is abundant in muscle tissues
Leu
These two aa are part of a motif in collagen
Gly and Pro
When I say AUG, most likely I am referring to
Met
A vitamin that is essential for strong triple helix collagen is
vit C
The first aa introduced in the synthesis of a new polypeptide is
Met
The most abundant free aa in blood is
Gln
This aa takes its name from a common vegetable where it is abundant
Asn
Two aa used as NH3 transporters to the liver are
Gln & Ala
The only essential aa from the polar, uncharged group is
Thr
The active form a protein is also called
Native
The most important structure of protein is the
primary
At enzymatic strait state, the factor that remains almost constant is
[ES]
The parameters involved in the Michaelis-Menten equation are
Vo, Vmax, Km, S
In a Lineweaver-Burk you plot
1/Vo and 1/[S]
The substrate concentration at which the reason rate is 1/2 Vmax is
Km
The number of substrate molecules converted to product in a given time is
kcat
Enzyme efficiency and substate specificity is best described by
kcat/Km
The rate limiting in an enzymatic reaction is
k2
A residue that can’t function in acid-base catalysis is
Phe
The reason the enzyme rate can’t go faster than 10^9 M-1 s-1 is
The limit in diffusion is reached
A competitive inhibitor
is reversible
An irreversible inhibitor
causes covalent modification
The only group that is not an electrophile is
An uncharged amine group
An allosteric site in an exam is
located away from the active site
Covalent modification in an enzyme is done to
Regulate the enzyme
A target residue for phosphorylation is
Thr
Adenylylation only occurs at
Tyr
Methylation only occurs at
Glu
The number of carbons introduced in myristoylation is
14
The target residue for acetylation is
Lys
A common residue for acetylation and ubiquitination is
Lys
A process that uses as target residues two polar and one positively charged aa is
ADP-ribosylation
Ser proteases perform their action by using
Covalent and acid/base catalysis
The recognition pocket in elastase contains as significant residue
Val
The final hydrolysis in Ser protease occurs when water attacks an
ester
The only aa absent in Cis proteases but present in Ser proteases is
Asp
HIV protease belong to the general type of proteases known as
Asp proteases
Enolase can be classified in general as a
isomerase
The vitamin used as part of a cofactor in oxidoreductases is most likely
B2
Activation and transfer of aldehydes involves as part of a cofactor
Thiamine
CO2 activation and transfer involved as coenzyme or part of coenzyme
Biotin
A schiff base is produced by the reaction of an
aldehyde with amine
The most common metal in metalloproteases is
Zn
The best type of aa present in membrane alpha helices in type III proteins should be
nonpolar
For glucose to move from the intestinal lumen into the blood capillaries requires the involvement of
one symporter, one anti porter, and one uniporter
If glucose is actively moving from the epithelial cell into the blood capillaries it means that
Concentrations of glucose and sodium are highest in the epithelial cell
In Na+K+ATPase, as in Ca2+ ATPase, the ions leave the transporter to the lumen when
Asp gets phosphorylated
Basal glucose uptake is provided by GLUT
1
A glucose transporter in the intestine is GLUT
2
A Kt of 5mM corresponds to a transporter located in the
Muscle
The GLUT transporters most likely stored in the endosome under normal blood glucose levels are GLUT
2
In the red cell,
Cl- and bicarbonate move through an antiporter
Analyzing cotransport systems that you know, it is logical that
An ion and an uncharged molecule move through a symporter
An agent of signal transduction that acts on a different organism is called?
Pheromone
A hormone that promotes gluconeogenesis is
Glucagon
Epinephrine can be chemically classified as a
aa derivative
Epinephrine is directly released by stimulation of the
adrenal medulla
If equimolar amounts epinephrine (Kd=5), isoproterenol (0.4) and propranolol (0.0046) are injected simultaneously, the action observed will be the one corresponding to
Propranolol only
A receptor that has the ability to alter interactions with the cytoskeleton is called
Adhesion receptor
The hormone response element is a
regulatory region in DNA
The enzyme cyclic nucleotide phosphodiesterase is associated with the processing of
cAMP
cGMP is the second messenger for the receptor
Guanylyl cyclase
PIP2 is hydrolysis by the enzyme
Phospholipase C
The enzyme adenylate kinase
Makes ATP from ADP
Inositol is chemically a
Cyclic alcohol
The ion that causes the release of neurotransmitter at the synapse is
Ca2+
The receptor for the neurotransmitter acetylcholine is a
Gated ion channel
The receptor for the hormone epinephrine is E
GPCR
The receptor for the hormone acetylcholine is
GPCR
TPP contains as an essential component vitamin
B1
CoA contains as an essential component vitamin
Pantothenic acid
Lipoic acid contains as critical groups
Two thiols
The actual cofactor for dihydrolipoyl dehydrogenase is
FAD
The active site of transaldolase contains a
Lys
An organ involved in gluconeogenesis is the
Kidney
An enzyme involved in gluconeogenesis but not in glycolysis is
PEP carboxykinase
The most important controlling enzyme in glycolysis is
PFK1
An enzyme that uses ATP as an allosteric modulator is
PFK-1
An enzyme that uses GTP as a cofactor is
PEP Carboxykinase
Phosphoglucomutase uses at the active site the amino acid
Ser
Phosphoglycerate mutase uses at the active site the amino acid
His
Glyceraldehyde-3-phosphate dehydrogenase uses of the active site the amino acid
Cys
A difference between glycolysis and gluconeogenesis is that
Gluconeogenesis uses GTP
In the muscle, hexokinase will be inhibited by
High levels of glucose-6-phosphate
The critical group in transketolase is
TPP
Formation of fructose-6-phosphate requires the amino acid
Glu
The number of asymmetric centers in D-glucose compared to D fructose is
One higher in D-glucose
Sucrose
Has one acetal group
The amino acid of hemoglobin involved in glycation are
Val and Lys
Gamma gluconolactone has a ring formed by
4 carbons and 1 oxygen
D glucose and D galactose are different on C4. Conversion of one to the other could be properly done using a
Epimerase
D glucose and D galactose are different on C4, and D-glucose and D-mannose are different on C2. Thus, D galactose and F-mannose are
Isomers
Mutarrotation of glucose
Produces more beta anomers than alpha
Glucuronic acid has a carboxylic group on
C6 of alpha D-glucose
The most oxidize carbon of D delta gluconolactone is carbon
One
Polysaccharide synthesis most commonly uses a sugar activated as
UDP
The most branch polysaccharide is
Glycogen
Of dietary glycogen and endogenous glycogen, one can say that
Only endogenous glycogen is converted to glucose-1-hosphate
Alcohol dehydrogenase uses as a cofactor
Zn2+
Pyruvate decarboxylase use as a cofactor
Mg2+
The number of hydrolases involved in the pentose phosphate pathway is
One
Substrate-based phosphorylation is involved with the enzyme
Citrate synthase
The number of carbons in glutaric acid is
Five
The only compound that can’t be produced reversibly and Krebs cycle is
Alpha ketoglutarate
Conversion of succinyl-CoA to oxaloacetate in the Krebs cycle involves the following sequences of enzymes
Synthetase to dehydrogenase to fumarase to dehydrogenase
Citrate synthase uses in its active site the amino acid
Asp and His
An example of an iron sulfur protein is
Aconitase
The number of reversible steps in the glyoxylate cycle is
0
The number of enzymes common to both the Krebs and glyoxylate cycles are
Three
The number of CoA – SH required to beta oxidize Palmitic acid to acetyl CoA is
Eight
A cofactor required to process a 15 carbon fatty acid by beta oxidation is vitamin B
12
If there is no oxaloacetate in the mitochondria, excess acetyl CoA will be converted to
Acetoacetate
A fatty acid did not require carnitine for transport, required biotin in one step of its beta oxidation, and produced 4 NADH. The fatty acid is
Nonanoic Acid
The nucleoli
have rRNA and proteins
The ribosomal subunits are made in the
nucleoli
Chromatin is a complex structure that contains chromosomes and
polypeptides
The part of the cell that contains a double membrane is the
nucleus
Phospholipids are assembled in the
SER
The number of fatty acids in a storage lipid is
3
The number of fatty acids in a sphingolipid is
1
The largest internal membrane is in the
ER
Hydrolytic enzymes that require low pH for activation are present in the
lysosome
Within the cell, Ca2+ is maintained in the
SER
The oxidation of fatty acids is performed mostly by the
peroxysomes
Catalase is commonly present in the
peroxysome
Catalase converts H2O2 into
H2O and O2
In the reaction of catalase with H2O2 the atoms that get oxidized and reduces are
O and O
The reaction of an acid with an amine normally occurs when one makes
proteins
Amides are present naturally in
proteins
Cis and trans faces are present in the
golgi
Hydrolysis of an ester produces
an acid and an alcohol
Oxidation number of the carbon attached to a primary alcohol?
-1
Oxidation number of the carbon of an aldehyde
+1
Oxidation number of the carboxylic carbon of a carboxylic acid
+3
Oxidation of the carbon of a secondary amine
-1
Oxidation number of the S in H2SO4
+6
Majority of carbons in 18:1(Δ9) have the oxidation number
-2
The compound all cis 18:3(Δ9,12,15) has the common name
alpha linolenic acid
The compound all cis 18:3(Δ9,12,15) is an omega
3
The fatty acid most commonly made by animal cells is
Palmitic
18:0 corresponds to the fatty acid
Stearic
Waxes are
esters
True or false: an omega 3 fatty acid must have 3 double bonds
False
True or false: all unsaturated natural fatty acids, including those from milk are cis
False
Chemically sphingosine is a(n)
aminoalcohol
The sum of the oxidation numbers of the 3 carbons of glycerol is
-2
A TAG that contains 18:0 as the only FA should be liquid compared to one that contains all cis 18:3 (Δ9,12,15) as the only FA
False
Plasmologens are commonly present in the
Heart
The antigens involved in blood type are normally
glycosphingolipids
The number of positively charged amino acids is
3
The number of polar uncharged amino acids is
5
The total number of aromatic amino acids is
4
The number of pKas for Arg is
3
The number of pKas for Gln is
2
Asm is polar because it contains a functional group called
amide
When [A-]=[HA] in the equilibrium then
pKa = pH
The major protein of humans is present as
collagen
The number of pKas in Trp is
2
The number of non polar essential amino acids is
4
The aromatic amino acids have an absorption in the
UV
In the conversion of 2 Cis to the disulfide Cystine the total electrons changed is
-2
The net charge in the zwitterion form of Ice is
0
If a protein has a lot of type 1 beta turns, most likely has the aa
Pro
Beta conformations are present in
silk
A motif frequently seen in collagen is
Gly-Pro-X
The aa that can adopt a cis beta turn configuration in peptides is
Pro
The only aa with a non-aromatic ring is
Pro
If the Kd of a protein with ligand X is 1x10^-18 M, it means the binding is
Very strong
The amino acid involved in holding thereon in myoglobin is a
positively charged
An amino acid used to transport ammonia from the muscles is
Ala
A branched amino acid is
Ile
An amino acid present in SAMe useful in methylations is
Met
An amino acid that acts also as a neurotransmitter is
Gly
