exam 3 (A) Flashcards
Select everything that correctly describes the molecule A:
i) D-ribose;
ii) L-ribose;
iii) It is an epimer of molecule B;
iv) Aldopentose;
v) Ketopentose.
a) i, iii
b) ii, iii
c) i, iii, iv
d) iv
e) v
c) i, iii, iv
What is the class of lipids the molecule shown above corresponds to?
a) Phosphatidylcholine
b) Phosphatidylserine
c) Galactocerebroside
d) Glucocerebroside
e) Phosphatidic acid
b) Phosphatidylserine
- Whas is a name of the disease that is determined by the defect in hexosaminidase A?
a) Generalized gangliosidosis
b) Fabry’s disease
c) Tay-Sachs disease
d) Gaucher’s disease
e) Niemann-Pick disease
c) Tay-Sachs disease
i) myristic acid
ii) palmitic acid
iii) octadecanoic acid
iv) oleic acid
v) linolenic acid
vi) 9-hexadecanoic acid
Select all saturated fatty acids from all molecules given above:
a) iii, iv, v
b) i, ii, iii
c) i, iv
d) i
e) ii, vi
b) i, ii, iii
- Arrange molecules iv, v and vi in the order of increase in their melting points
a) iv -> v -> vi
b) v -> iv -> vi
c) vi -> v -> iv
d) vi ->iv -> v
e) none of the above
e) none of the above
- Select all that apply to the molecule C:
i) In its cycled form, this molecule will form primarily pyranose ring;
ii) In its cycled form, this molecule will form primarily furanose ring;
iii) It can form glucaric acid;
iv) It can be oxidized only at C1 carbon producing D-iduronic acid;
v) It is D-mannose.
vi) C and D are epimers
a) i, iii, vi
b) ii, iii
c) i, iv
d) i, iii, v
e) ii, iv, vi
a) i, iii, vi
- Select a statement that most accurately describes the difference between cerebrosides and gangliosides?
a) Cerebrosides have 3 or more sugars at their head group; gangliosides act as receptors for pituitary glycoprotein hormones that regulate physiological functions;
b) Cerebrosides’ head group is a simple sugar; gangliosides are complex molecules that function as receptors of pituitary glycoprotein hormones.
c) Cerebrosides’ head group is phosphocholine or phospho-ethanolamine; gangliosides are ceramides with 3-or more sugars attached one of which is sialic acid
d) All of the above
e) None of the above
b) Cerebrosides’ head group is a simple sugar; gangliosides are complex molecules that function as receptors of pituitary glycoprotein hormones.
- What are the consequences of overproduction of vitamin D?
a) Kidney stones, kidney failure
b) Rickets
c) Blindness
d) Poor blood clotting
e) Extreme blood clotting
a) Kidney stones, kidney failure
- Select all molecules that can be obtained by reducing sugars:
i) Ribitol
ii) Xylitol
iii) Glycerol
iv) Myo-inositol
a) i, ii
b) i, iii
c) i, ii, iii
d) i, ii, iii, iv
e) ii, iv
d) i, ii, iii, iv
- What is the correct chemical name of maltose?
a) α-glucopyranosyl-(1-4)-glucopyranose
b) β-glucopyranosyl-(1-4)-glucopyranose
c) α-glucofuranosyl-(1-4)-glucopyranose
d) α-glucopyranosyl-(1-4)-glucofuranose
e) α-glucopyranosyl-(1-2)-glucopyranose
a) α-glucopyranosyl-(1-4)-glucopyranose
- Select a statement that correctly describes lactose:
a) Lactose is a disaccharide that is present in milk, the molecules as β(1-4) linkage and it is a reducing sugar
b) Lactose is a disaccharide that is present in sugar cane; the molecules as β(1-2) linkage and it is a reducing sugar
c) Lactose is a disaccharide that builds insects’ exoskeleton; the molecules as β(1-4) linkage
d) Lactose is a homopolymer of N-acetylglucosamine; it is not a reducing sugar
e) Lactose is a disaccharide that is present in milk, the molecules as β(1-4) linkage and it is a non-reducing sugar
a) Lactose is a disaccharide that is present in milk, the molecules as β(1-4) linkage and it is a reducing sugar
- Select the statement (s) that correctly describe blood composition of individuals with group A:
i. These individuals have B antibodies
ii. These individuals have A and B antibodies
iii. Their red blood cells have the following sugar sequences (bottom to top): glucose-galactose-N-acetylglucosamine-mannose-[attached to both fucose and A-acetylgalactosamine]
iv. Their red blood cells have the following sugar sequences (bottom to top): glucose-galactose-N-acetylglucosamine-galactose-[attached to both fucose and galactose]
v. Their red blood cells have the following sugar sequences (bottom to top): glucose-galactose-N-acetylglucosamine-galactose-[attached to both fucose and A-acetylgalactosamine]
a) i, iii
b) i, iv
c) i, v
d) ii, iii
e) ii, v
c) i, v
What class of vitamins that molecule shown above can be assigned to?
a) Vitamin A
b) Vitamin B
c) Vitamin K
d) Vitamin D
e) Vitamin E.
c) Vitamin K
- What statement incorrectly describes starch?
a) Starch is composed of amylose and amylopectin; a-amylose is a linear polymer of a(1 → 4) linkages; amylopectin has a(1 → 6) linkages
b) Starch is composed of amylose and amylopectin; a-amylose is a linear polymer of a(1 → 6) linkages; amylopectin has a(1 → 4) linkages
c) Starch is a storage polysaccharide in plants
d) Starch is hydrolyzed by Amylase which breaks down a(1 → 4) glycosidic bonds of starch
e) All of the above
b) Starch is composed of amylose and amylopectin; a-amylose is a linear polymer of a(1 → 6) linkages; amylopectin has a(1 → 4) linkages
- What are lectins?
a) monosaccharides that determine viral penetration in the cell
b) molecules that mediate the attachment between leukocytes and epithelial cells
c) phospholipids that build plasma membranes
d) antigens that are present on red blood cells
e) none of the above
b) molecules that mediate the attachment between leukocytes and epithelial cells
- Select everything that correctly describes glycosaminoglycan shown above:
i) Molecular name is hyaluronate;
ii) It is an important component of connective tissue and synovial fluid;
iii) It is keratan sulfate
iv) This molecule is a component of cell surface and extracellular substance in blood vessel walls and brain
v) It’s heparin
vi) This glycosaminoglycan is involved in wound healing
a) i, ii
b) iii, v
c) v, vi
d) i
e) iii, iv
a) i, ii
- What is the major difference between sphingosine and ceramide?
a) Ceramides are sphingosines with an esterified fatty acid
b) Ceramides are sphingosines that have one fatty acid connected to them through a peptide bond
c) The building block of sphingosines is glycerol, whereas ceramides’ building block is sphingosine
d) Sphingosines are present in neuronal membranes, while ceramides are used as energy sources
e) None of the above
b) Ceramides are sphingosines that have one fatty acid connected to them through a peptide bond
- Why the esterification of cholesterol at C3 position by fatty acids is disadvantageous or even dangerous for humans?
a) The resulted sterol esters cannot be transformed into vitamin D
b) These molecules cannot be transformed into mineralocorticoids
c) These molecules cannot be transformed into Glucocorticoids, which affects sexual development
d) Such sterol esters have low solubility and form deposits in blood vessels
e) The resulted sterol esters cause cancer
d) Such sterol esters have low solubility and form deposits in blood vessels
- What is the effect of cholesterol on membrane fluidity?
a) Cholesterol decreases membrane fluidity because of its rigid steroid ring system and serves to limit the movement of FA side chains
b) Cholesterol increases membrane fluidity
c) Cholesterol has no change on membrane fluidity
d) All of the above
e) None of the above
a) Cholesterol decreases membrane fluidity because of its rigid steroid ring system and serves to limit the movement of FA side chains
What statement(s) about SNAREs are false?
i. SNAREs: membrane associated protein that participates in vesicle fusion
ii. R-SNAREs contain Gln residues and located in the vesicle membrane
iii. R and Q SNAREs interact forming a 4 sandwich-like bundles
iv. Q-SNAREs contain Gln residues and located in the target membrane
v. The R from R-SNARE and three Qs from the Q-SNAREs hydrogen bond serving to bring the helices into proper position
a. i and iv
b. ii and iii
c. ii, iv
d. ii
e. iii
b. ii and iii
- What is the correct scientific name of a flip-flop diffusion of lipids in the membranes?
a) Transverse diffusion
b) Lateral diffusion
a) Transverse diffusion
What statement is incorrect about Lipid-Linked Proteins?
a. GPI-linked proteins are found on the surface of the plasma membrane
b. GPI anchors have more complex anchoring structure than prenylated proteins
c. Anchor always attached to the C-terminal residue of the protein
d. They contain a choline linker between C terminus of the protein and a sugar unit
e. Lipid-like proteins contain phosphatidylinositol
d. They contain a choline linker between C terminus of the protein and a sugar unit
Transporting Na+ in or out of a cell with when ∆Ψ = -80 mV; Cytosolic [K+] = 140 mM; Extracellular [K+] = 4 mM. What is the change in free energy associated with transporting Na into the cell at the body temperature of 37°C?
a. 1.44 kJ/mol
b. 16.88 kJ/mol
c. -1.44 J/mol
d. 1.44 J/mol
e. 5.12 kJ/mol
a. 1.44 kJ/mol
Select the statement best describes ionophores:
i. Organic molecules that carry ions across membranes; they can be divided into two group (carrier-ionophores and channel-forming ionophores); typically present in bacteria.
ii. Ionophores sustain high rates of water transport; their transport can be inhibited by addition of mercury; Always “open” solute can travel in either direction.
iii. Organic molecules that possess ion selectivity upon transportation.
iv. Require ATP hydrolysis.
v. Their opening and closing is known as gating.
a. i and iv
b. ii and iii
c. i and iii
d. i, iii, v
e. iii and v
c. i and iii
Locate events that are taking place upon antiport of Na from cytosol to the extracellular fluid and K from extracellular to the cytosol.
a. E1 binds 3Na+; ATP is hydrolyzed producing E1~P ∙3Na+; E1∙3Na+ binds ATP; 3Na+ are released outside the cell; E2-P binds 2K+; E2-P ∙2K+ has its phosphate group hydrolyzed and 2K+ are transported inside the cell.
b. E2-P binds 2K+; E2-P ∙2K+ has its phosphate group hydrolyzed and 2K+ are transported inside the cell; E1 binds 3Na+; ATP is hydrolyzed producing E1~P ∙3Na+; E1∙3Na+ binds ATP; 3Na+ are released outside the cell.
c. ATP is hydrolyzed producing E1~P ∙3Na+; 3 Na+ are released outside the cell; E2-P binds 2K+; E2-P ∙2K+ has its phosphate group hydrolyzed and 2K+ are transported inside the cell; E1 binds 3Na+; E1∙3Na+ binds ATP.
d. E1∙3Na+ binds ATP; ATP is hydrolyzed producing E1~P ∙3Na+; 3 Na+ are released outside the cell; E2-P binds 2K+; E2-P ∙2K+ has its phosphate group hydrolyzed and 2K+ are transported inside the cell; E1 binds 3Na+.
e. E1 binds 3Na+; E1∙3Na+ binds ATP; ATP is hydrolyzed producing E1~P ∙3Na+; 3 Na+ are released outside the cell; E2-P binds 2K+; E2-P ∙2K+ has its phosphate group hydrolyzed and 2K+ are transported inside the cell.
e. E1 binds 3Na+; E1∙3Na+ binds ATP; ATP is hydrolyzed producing E1~P ∙3Na+; 3 Na+ are released outside the cell; E2-P binds 2K+; E2-P ∙2K+ has its phosphate group hydrolyzed and 2K+ are transported inside the cell.
Arrange the following DNA sequences in the increasing order of thermal stability:
a. i, ii, iii, iv
b. iv, i, iii, ii
c. ii, iii, i, iv
d. iii, ii, i, iv
e. iv, ii, iii, i
b. iv, i, iii, ii
Is DNA exclusively right-handed?
a. true
b. false
b. false
Which statements are correct about chromosomes?
a. Composed of condensed chromatin
b. Contain miniband units
c. Contain DNA
d. Can be asymmetric or symmetric
e. All of above
e. All of above
The double helix model of DNA was proposed by
a. Watson and Crick
b. Chargaff
c. Fleming
d. Mendeleev
e. Arrhenius
a. Watson and Crick
Why people add antibiotics in media that is used to grow bacteria during DNA recombination?
a. To select for cells that have the plasmid present. These cells can grow in presence of antibiotic because of plasmid resistance
b. to keep Petri dishes bacteria-free
c. to make bacterial visible on electrophoresis
d. to keep media virus-free
e. to visualize plasmids.
a. To select for cells that have the plasmid present. These cells can grow in presence of antibiotic because of plasmid resistance
PCR-based forensic analysis of a blood stain found at the crime scene has shown the following electropherogram (shown below). The expert also analyzed DNA material of three suspects extracted from their saliva samples (suspect number 1-3). Based on the results of this PCR analysis what conclusions could be made?
a. Only suspect 2 may have a connection to the crime scene
b. Both suspect 2 may 3 can have a connection to the crime scene
c. Only suspect 1 may have a connection to the crime scene
d. Both suspect 1 may 2 may have a connection to the crime scene
e. All suspects may have a connection to the crime scene
b. Both suspect 2 may 3 can have a connection to the crime scene
What is the physiological importance of nucleotides
a. Form polymers (DNA and RNA)
b. Participate in metabolic reactions
c. Transport ions across lipid bilayer
d. All of above
e. a and b
e. a and b
Plasmids useful as cloning vectors must have:
a. replicator, selectable marker and cloning site
b. intron, exon and cloning site
c. selectable marker, virus and cloning site
d. ATP and primers
e. only cloning site
a. replicator, selectable marker and cloning site
According to this scheme, EcoRI and EcoRV can make this cleavage with no use of ATP. What statement is true about them?
a. Both are Type II Restriction Endonucleases
b. Only EcoRI is Type II Restriction Endonuclease
c. Both are Type I Restriction Endonucleases
d. Only EcoRV is Type II Restriction Endonuclease
e. EcoRI is Type II Restriction Endonuclease, whereas EcoRV is Type I Restriction Endonuclease
a. Both are Type II Restriction Endonucleases
Sequencing of a single-stranded DNA fragment resulted in the following set of the single-stranded DNAs. What is the sequence of the actual single-stranded DNA fragment (excluding the primer) in 3’ to 5’ order?
