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185 Cards in this Set

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Which level of amino acid structure has the MOST influence on the unique, overall 3D appearance of a polypeptide (the peptide's native conformation)?

A) primary
B) secondary
C) tertiary
D) quaternary
A) primary
True/False: The individual amino acids on a polypeptide chain are numbered beginning from the carboxyl terminus to the amino terminus.

A) true
B) false
false
A polypeptide's secondary structure is established primarily due to the presence of:

A) peptide bonds.
B) hydrogen bonds.
C) phosphodiester bonds.
D) hydrophobic interactions.
E) hydrophilic interactions
B) hydrogen bonds
An intra-chain hydrogen bond can form between a carbonyl oxygen atom of one amino acid and the amide hydrogen of an amino acid located 4 residues further down the polypeptide chain. Repetitions of these bonds result most significantly in the formation of:

A) primary structure of a polypeptide.
B) alpha helices.
C) beta sheets.
D) tertiary structure of a polypeptide.
E) quaternary structure of a polypeptide.
B) alpha helices.
_______ residues are often found at the beginning of alpha helices whereas _____ are often found at the ends, respectively.

A) alanine, lysine
B) glutamine, proline
C) glycine, proline
D) proline, glycine
E) lysine, alanine
D) proline, glycine
True/False: Glycine and proline are often found at the areas where an alpha helix "bends."

A) true
B) false
A) true
Hydrogen bonding that occurs between carbonyl oxygens and amide hydrogens on two separate polypeptide strands typically take place in:

A) primary structure.
B) alpha helices.
C) beta sheets.
D) tertiary structure.
E) quaternary structure.
C) beta sheets
True/False: Beta-barrels are often formed between polypeptide chains of beta helices that are running parallel.

A) true
B) false
B) false

Beta-barrels typically contain anti-parallel beta sheets.
True/False: Anti-parallel beta sheets are typically more stable than parallel beta sheets.

A) true
B) false
A) true
Bends, turns, loops, coils, and coiled coils are structures that are characteristic of polypeptide _____.

A) primary structure
B) secondary structure
C) tertiary structure
D) quaternary structure
E) linear sequence
B) secondary structure
The embedding of hydrophobic residues within regions of a polypeptide refers most specifically to a peptide's ____ structure.

A) primary
B) secondary
C) tertiary
D) quaternary
E) linear
C) tertiary
The overall fold of a protein is attributed to:

A) the number of proline & glycine residues present within the polypeptide.
B) the number of hydrogen bonds present.
C) the presence of alpha helices and beta sheets.
D) its tertiary structure.
E) its quaternary structure.
D) its tertiary structure.
Noncovalent interactions such as hydrogen bonding, ionic interactions, and disulfide bonds can attribute to the stabliization of a protein's:

A) primary structure.
B) alpha helices.
C) beta sheets.
D) tertiary structure.
E) quaternary structure.
D) tertiary structure.
True/False: Hydrophilic side-chains on a protein often cause folding pack tightly into a core of protein to minimize exposure to water.

A) true
B) false
B) false
Chaperonins (also called heat shock proteins) can aid in the folding of proteins as the proteins are synthesized. To accomplish this, they require:

A) ATP.
B) coenzymes.
C) Bip's.
D) GroEL or GroES.
E) transferases.
A) ATP
Cis-trans isomerases and protein disulfide isomerases (PDI's) assist heat shock proteins such as Hsp60 & Hsp70 with:

A) the proper folding of proteins.
B) the transfer of ATP to chaperonins.
C) post-transcriptional protein modification.
D) alternative splicing.
E) cytosolic protein transport.
A) the proper folding of proteins.
True/False: Hsp60 and Hsp70 proteins are also referred to as Bip and GroEL/GroES, respectively.

A) true
B) false
B) false

Hsp60 = GroEL/GroES
Hsp70 = Bip
Risk factors for proteopathies, such as Alzheimer's disease, prion disease, and cataracts include:

I. an increase in the number of beta-sheets.
II. a decrease in protein production.
III. advancing age.

A) I
B) II
C) III
D) Two of the above.
E) All of the above.
D) Two of the above - I and III
True/False: Risk factors for proteopathies almost always involve a decrease in beta-sheet secondary structures.

A) true
B) false
B) false

They almost always involve an INCREASE in beta-sheets.
A hemoglobin molecule consists of:

A) 4 heavy chains and 4 light chains.
B) 4 alpha chains and 4 beta chains.
C) 2 alpha chains and 2 beta chains.
D) 2 heavy chains and 2 light chains.
E) 2 heme groups and 4 polypeptide subunits.
C) 2 alpha chains and 2 beta chains.
In sickle-cell anemia there is a single change in the amino acid sequence of a ____ chain of hemoglobin where a normal ____ residue is wrongly substituted for a _____ residue.

A) alpha, lysine, valine
B) alpha, valine, glutamic acid
C) alpha, glutamic acid, valine
D) beta, glutamic acid, valine
E) beta, valine, glutamic acid
E) beta, valine, glutamic acid
Hair keratin consists of many:

A) glycine & valine residues.
B) alpha helices.
C) alpha chains & beta chains.
D) heavy chains & light chains.
E) beta sheets.
B) alpha helices.
Which of the following correctly lists the structures that make up a hair, from smallest to largest?

A) alpha helix, protofibril, microfibril, macrofibril
B) alpha helix, microfibril, macrofibril, protofibril
C) alpha helix, macrofibril, microfibril, protofibril
D) microfibril, alpha helix, protofibril, macrofibril
E) microfibril, alpha helix, macrofibril, protofibril
A) alpha helix, protofibril, microfibril, macrofibril
Hair contains a lot of sulfur, due to the fact that hair contains many ____ residues.

A) glycine
B) glutamic acid
C) arginine
D) aspartic acid
E) cysteine
E) cysteine
Which of the following is a cause of protein denaturation?

I. glycosylation
II. low concentrations of urea
III. solvents that disrupt hydrophobic bonds

A) I
B) II
C) III
D) Two of the above
E) All of the above
D) Two of the above
A molecule that has been implicated in nephropathy and retinopathy in diabetes mellitus is:

A) Hsp60
B) Hsp70
C) hemoglobin A1c
D) alpha-synuclein
E) prions
C) hemoglobin A1c
True/False: When hemoglobin becomes glycosylated, it loses its function, which is why it is often implicated in various proteopathies.

A) true
B) false
B) false
True/False: Hemoglobin A1c level is proportional to the average blood glucose concentration in a patient over the three to four weeks.

A) true
B) false
B) false

It is usually indicative over a period of one to three months.
What is the approximate percentage of cysteine residues in human hair?

A) 0.1%
B) 4%
C) 8%
D) 14%
E) 24%
D) 14%
There are ___ possible codons that code for ____ possible amino acids.

A) 20, 16
B) 64, 64
C) 32, 16
D) 64, 20
E) 64, 16
D) 64, 20
The 2 amino acids that each have only 1 codon are:

A) cysteine & methionine
B) methionine & histidine
C) tryptophan & methionine
D) cysteine & glycine
E) glycine & valine
C) tryptophan & methionine
AUG is the sequence that codes for the only START codon that initiates translation. What amino acid does "AUG" also code for?

A) cysteine
B) tryptophan
C) glycine
D) serine
E) methionine
E) methionine
The "wobble" phenomenon related to amino acids refers to a codon's:

A) 1st position.
B) 2nd position.
C) 3rd position
D) none of the above
E) all of the above
C) 3rd position
True/False: The genetic code is almost universal among all living organisms, with an exception being the genetic code used to translate mitochondrial RNA and proteins.

A) true
B) false
A) true
During translation, the genetic code of mRNA is read from:

A) 3' to 5'
B) 5' to 3'
B) 5' to 3'
Prokaryotic ribosomes are composed of _____ subunits, whereas eukaryotic ribosomes are composed of ____ subunits.

A) 30S, 50S
B) 40S, 60S
C) 50S, 70S
D) 30S, 40S
E) 70S, 80S
E) 70S, 80S
The G-protein dependent transporter that transports ribosomal subunits from the nucleolus to the cytoplasm is called:

A) Nmd30.
B) Hsp70
C) GTP
D) GroEL
E) cis/trans isomerase
A) Nmd30.
Which of the following is a true statement about tRNA molecules?

I. The 5’ end of the tRNA nucleotide strand usually ends with a G (guanosine)
II. The 3’ end usually consists of the nucleotide sequence CCA
III. Amino acids are attached to tRNA at the 3’ end

A) I
B) II
C) III
D) Two of these is true
E) All of these are true
E) All of these are true
True/False: The 5' end of tRNA usually ends with a C.
false

5' end of tRNA usually ends with a G (guanosine)
True/False: The 3’ end of a tRNA molecule usually consists of the nucleotide sequence CCA.
true
True/False: Amino acids are attached to a tRNA molecule at the 3’ end.
true
In the 3D structure of tRNA, you will find a D loop near the 5’ end, a T loop near the 3’ end, and an anticodon loop in the middle. (These loops provide the “clover leaf” shape.)
true
In the 3D structure of tRNA, the 3' end is associated with the ___, and the 5' end is associated with the ____.

A)
3' = T loop

5' = D loop
What is the name of the enzyme that charges tRNA?
amino-acyl tRNA synthetase
What does amino-acyl tRNA synthetase require in order to charge a tRNA molecule?
ATP !
At what end of a tRNA molecule does amino-acyl tRNA synthetase attach an amino acid?
3' end
What are the 3 main steps of translation?
Initiation, Elongation, & Termination

(the same as transcription !)
What 3 things constitute the "Pre-Initiation Sequence" in translation?
1. methionyl-tRNA molecule (tRNA bound to a START codon)
2. initiation factor 2 (elF2)
3. strand of mRNA
a) A tRNA molecule that is bound to a START codon is known as ____.

b) What is the START codon?
a) methionyl-tRNA

b) AUG (methionine)
What is the functions of elf4E, elF3, elF4A, & elF4G ?
They are initiation factors that bind to the 5' end of an mRNA strand.
What is the function of a poly-A binding protein (PABP) in translation?
It binds a the 3'-poly-A tail on an mRNA strand to a tRNA molecule.
What do methionyl-tRNA & elF2 bind to in order to complete a translational "Pre-initiation complex?"
a small (40S) ribosomal subunit
What occurs after charged-tRNA binds to the AUG start codon?
elF2 hydrolyzes a GTP molecule & removes initiation factors bound the the small ribosomal subunit
What are the specific ways that translation can be regulated with respect to elF2 and elF4?
1. elF2 can be PHOSPHORYLATED thus inactivating it

2. elF4 can be inactivated by DE-PHOSPHORYLATION
What pathologic condition can occur due to an inherited mutation on elF2B protein subunits?
Leukoencephalopathy wtih Vanishing White Matter (VWM)

This can occur secondary to head trauma.
What is the difference between the methionyl-tRNA in prokaryotes & eukaryotes?
prokaryotes have a FORMYLATED form of Met-tRNA
What are the initiation factors required by prokaryotes for translation (comparable to elF's) and how many are there?
There are 3 prokaryotic initiation factors:

IF-1, IF-2, and IF-3
a) Does the Shine-Dalgarno sequence refer to an aspect of prokaryotic or eukaryotic translation?

b) Does it refer to the SMALL or LARGE ribosomal subunit?
a) prokaryotic

b) small ribosomal subunit
What does streptomycin inhibit in bacterial translation? tetracyclines?
Streptomycin inhibits initiation via binding the 30S subunit

Tetracycline inhibits the binding of aminoacyl-tRNA to the A site
What is the difference between amino-acyl tRNA and methionyl-tRNA ?
amino-acyl tRNA = charged tRNA (tRNA bound to an mRNA strand at the 3' end)

methionyl-tRNA = initiator tRNA that has elF2 bound to it
During what stage of translation does aminoacyl-tRNA bind to EF1-alpha and a GTP molecule?
elongation
What enzyme forms the peptide bonds on a polypeptide in the P site of a ribosome?
peptidyltransferase
What molecule moves an uncharged tRNA from the P-site to the E-site on a ribosome, which requires GTP?
elongation factor-2 (EF2)
What enzyme ends the process of translation at the ribosome after the A-site reads a STOP codon?
peptidyltransferase
What molecule serves as the primary source of carbon in a fatty acid chain?
glucose
What enzyme converts pyruvate into acetyl-CoA?
pyruvate dehydrogenase
Once a molecule of citrate leaves a mitochondrion, what enzyme converts citrate into acetyl-CoA?
citrate lyase
What is the pathway in which citrate can be "recycled" into pyruvate?
citrate -> oxaloacetate -> malate -> pyruvate
What molecule serves as a "reducing agent" for fatty acid synthesis?
NADPH
Is insulin an ACTIVATOR or INHIBITOR of fatty acid synthesis?
ACTIVATOR

Insulin uses a PHOSPHATASE to stimulate fatty acid synthesis via de-phosphorylation of acetyl-CoA carboxylase.
Is glucagon an ACTIVATOR or INHIBITOR of fatty acid synthesis?
INHIBITOR

Glucagon uses a KINASE to inhibit fatty acid synthesis via phosphorylation of acetyl-CoA carboxylase.
What molecule is an end-product inhibitor of fatty acid synthesis via downregulation of citrate formation?
palmitoyl CoA
What is the 16-carbon end product of fatty acid synthesis?
palmitate
Where does elongation occur in a cell with respect to fatty acid synthesis?
smooth ER
What are the 4 major steps of elongation in fatty acid synthesis?
1. condensation
2. reduction
3. dehydration
4. reduction (again)
What are the 3 major classes of omega fatty acids?
1) omega-3
2) omega-6
3) omega-9
What are the 2 ESSENTIAL fatty acids?
linoleic acid (omega-6)
&
alpha-linolenic acid (omega-3)
To increase the intake of linoleic acid (an eicosanoid precursor to arachidonic acid), one could start eating more _____.

A) plant oils
B) cold-water fish
C) walnuts
D) eggs
A) plant oils

Plant oils, such as canola, corn, sunflower, & olive are good sources of linoleic acid, an ESSENTIAL omega-6 fatty acids.
Which of the following are precursors to ANTI-inflammatory molecules?

A) triglycerides
B) sphingolipids
C) omega-3 fatty acids
D) omega-6 fatty acids
C) omega-3 fatty acids
Which of the following are precursors to PRO-inflammatory molecules (vs. anti-inflammatory)?

A) triglycerides
B) sphingolipids
C) omega-3 fatty acids
D) omega-6 fatty acids
D) omega-6 fatty acids
What fatty acid molecule is produced by adipocytes via use of the enzyme DHAP (dihydroxyacetone phosphate)?
glycerol-3-phosphate
What 2 molecules are required for the synthesis of triglycerides, prior to the formatio of DAG (diacylglycerol)?
glycerol-3-phosphate
&
fatty-acyl CoA
What molecule adds carbon atoms, two at a time, to elongate fatty acid chains?
fatty acid synthase complex

(which is composed of phosphopantetheine & ACP - acyl carrier protein)
In the process of fatty acid synthesis, what molecule must be converted to citrate because it can NOT exit mitochondria?
acetyl CoA
What are the 3 major components of a triglyceride (triacylglycerol)?
1. glycerol
2. fatty acid chain
3. fatty acid chain
What are the 4 major components of a glycerophospholipid, such as phosphatidylserine?
1. glycerol
2. fatty acid chain
3. phosphate functional group
4. polar head group
What are the 4 major components of sphingomyelin?
1. sphingosine "backbone"
2. fatty acid chain
3. phosphate functional group
4. polar head group
What are the 3 major components of a glycolipid?
1. sphingosine "backbone"
2. fatty acid chain
3. carbohydrate
What are the 5 major components of an ether glycerolipid?
1. glycerol
2. ether functional group
3. fatty acid chain
4. phosphate functional group
5. polar head group
Which of the following is NOT an amphipathic molecule?

A) triacylglycerol
B) phosphatidylethanolamine
C) platelet activating factor
D) sphingomyelin
E) phosphatidylserine
A) triacylglycerol

Amphipathic molecules typically have a non-polar fatty acid chain bound to a polar head group.
Which of the following is a component of myelin sheaths that surround neurons?

A) triacylglycerol
B) phosphatidylethanolamine
C) platelet activating factor
D) sphingomyelin
E) phosphatidylserine
D) sphingomyelin
Which of the following can function as an antioxidant?

A) triacylglycerol
B) phosphatidylethanolamine
C) platelet activating factor
D) sphingomyelin
E) phosphatidylserine
C) platelet activating factor (PAF)

PAF is a type of Plasmalogen (ether glycerolipid) which plays a role in inflammatory reactions.
Which of the following contains an ether functional group?

A) triacylglycerol
B) phosphatidylethanolamine
C) platelet activating factor
D) sphingomyelin
E) phosphatidylserine
C) platelet activating factor (PAF)
Eicosanoids are fatty acids that form inflammatory precursor molecules. What 2 major enzymes are required for synthesis of eicosanoids?
cyclooxygenase (COX) & lipoxygenase
What are the 5 major classes of lipids?
1. triglycerides (triacylglycerols)
2. phospholipids
3. sphingolipids
4. eicosanoids
5. cholesterols
Which of the following would be considered the most "healthy" fatty acid?

A) saturated fat
B) hydrogenated fat
C) trans unsaturated fat
D) cis unsaturated fat
E) LDL
D) cis unsaturated fat
Which of the following is composed of a four-ring aliphatic structure?

A) triacylglycerol
B) plasmalogen
C) ether glycerolipid
D) eicosanoid
E) cholesterol
E) cholesterol
Which of the following refers to a site where the cell membrane invaginates & also plays an important role in endocytosis?

A) caveolae
B) phosphatidylcholine
C) mannose-6-phosphate
D) eicosanoid
E) phosphatidylinositol
A) caveolae
Which of the following is typically NOT found on the inner leaflet of the cell membrane?

A) phosphatidylserine
B) phosphatidylcholine
C) phosphatidylinositol
D) phosphatidylethanolamine
E) glycolipid
B) phosphatidylcholine
Which molecule is found in greatest concentration in the membrane of endoplasmic reticulum?

A) phosphatidylserine
B) phosphatidylcholine
C) phosphatidylinositol
D) phosphatidylethanolamine
E) glycolipid
B) phosphatidylcholine
What 2 molecules make up the greatest proportion of the cell plasma membrane?

A) phosphatidylserine
B) phosphatidylcholine
C) phosphatidylinositol
D) sphingomyelin
E) glycolipid
B) phosphatidylcholine and D) sphingomyelin
Which of the following is typically NOT found in a cell plasma membrane?

A) glycolipid
B) sphingomyelin
C) phosphatidylinnositol
D) alpha-helices
E) beta-barrels
E) beta-barrels

Beta-barrels are only found in outer membranes of Gram-negative bacteria and outer membranes of mitochondria and chloroplasts.
When a group of alpha-helices together form a transmembrane channel, what groups line the lumen of the channel?

A) polar amino acid R-groups
B) nonpolar amino acid R-groups
A) polar amino acid R-groups
Which of the following is also known as "lecithin"?

A) phosphatidylserine
B) phosphatidylcholine
C) phosphatidylinositol
D) phosphatidylethanolamine
E) sphingomyelin
B) phosphatidylcholine
What is produced during the reaction where malate is converted to pyruvate? (hint: it is also produced during glycolysis)
NADPH
In the mitochondrion, what enzyme catalyzes the conversion reaction of pyruvate to acetyl CoA?
pyruvate dehydrogenase
What is the 16-carbon molecule that serves as the backbone for adding additional 2-carbon molecules?
palmitate
What enzyme catalyzes the reaction that converts malonyl CoA to palmitate?
fatty acid synthase
True/False: After consumption of carbohydrates, the ratio of insulin/glucagon decreases.
false

The ratio INCREASES after a meal.
What are the 2 essential fatty acids?
linoleic acid &
alpha-linolenic acid
When forming a triglyceride, what 2 components form phosphatidic acid, the precursor of diacylglycerol?
glycerol-3-phosphate & fatty acyl CoA
What is the carrier molecule that transports triglycerides to cells, especially those of muscle & adipose?
VLDL
Which of these is typically NOT found on the outside of the cell membrane?

a) sphingomyelin
b) phosphatidylcholine
c) phosphatidylinositol
d) glycolipids
e) the hydroxide group of a cholesterol molecule
c) phosphatidylinositol
Which of the following is the source of PUFAs, the precursors to eicosanoids?

a) phospholipids
b) sphingolipids
c) cholesterols
d) glycolipids
e) omega-6 fatty acids
a) phospholipids
The molecule formed by the addition of palmitoyl CoA to the amino acid serine?

a) diacylglycerol
b) sphingosine
c) phosphatidylcholine
d) acetyl CoA
e) sphingomyelin
b) sphingosine
The baby that is born with respiratory distress syndrome (RSD) would likely have shown a ratio of ______ to sphingomyelin less than 2:1, which indicates insufficient lung surfactant.

a) cholesterol
b) phosphatidylserine
c) phosphatidylethanolamine
d) phosphatidylcholine
e) PAF
d) phosphatidylcholine
Which of the following plays a significant role in ABO blood typing?

a) cholesterols
b) phosphatidylserines
c) phosphatidylcholines
d) sphingolipids
e) PAFs
d) sphingolipids
Lovastatin and pravastatin are drugs that lower cholesterol by inhibiting:

a) pyruvate dehydrogenase
b) HMG-CoA synthase
c) fatty acid complex synthase
d) glucose-3-phosphatase
e) NADPH
b) HMG-CoA synthase
Which of the following reactions is the rate-limiting step of cholesterol synthesis?

a) acetyl CoA to mevalonate
b) mevalonate to isoprenes
c) isoprenes to squalene
d) squalene to 4-ring structure
a) acetyl CoA to mevalonate

This step is catalyzed by the enzyme HMG-CoA synthase.
Where are lipids primarily synthesized within a cell?

a) Golgi
b) smooth ER
c) rough ER
d) mitochondria
e) polyribosomes
b) smooth ER

Most lipid is produced in smooth ER while a minor amount is also produced in the mitochondria.
True/False: The smooth ER tends to be more tubular than rough ER.
true

smooth ER = more tubular
rough ER = more "plate-like"
True/False: Chronic use of some drugs, such as barbituates, will induce a decrease in the amount of smooth ER, resulting in drug tolerance.
false

Chronic drug use would cause an INCREASE in smooth ER.
What are the 3 types of cytoskeletal filaments? (Also, name them in order from smallest to largest)
1. microfilaments (actin, myosin)
2. intermediate filaments
3. microtubules
True/False: Charged Phospholipid-Transporting Proteins carry phospholipids from the smooth ER membrane to the plasma membrane.
true

Charged PTP's carry phospholids from SER to cell membrane; they then return to the SER uncharged.
In erythrocytes, a defect in ____ can lead to a condition known as heriditary spherocytosis.

a) collagen
b) desmin
c) keratin
d) spectrin
e) dynein
d) spectrin
Which of the following is NOT a characteristic of microvilli?

a) can increase the surface area of a polarized cell
b) are stabilized by actin filaments
c) are composed of tubulin
d) are anchored at the terminal web
e) is sometimes interwoven with a glycocalyx
c) are composed of tubulin

Tubulin is a protein component of MICROTUBULES.
Microtubules are stablized by proteins known as:

a) actins
b) MAPs
c) vimentins
d) keratins
e) lamins
b) MAPs

(Microtubule-Associated Proteins)
Movement of organelles within a cell is associated with what type of cytoskeletal elements?

a) microfilaments
b) intermediate filaments
c) microtubules
d) keratins
e) desmins
c) microtubules

Organelle movement is due to Microtubule-Organizing Centers, which are composed of microtubules.
Vinblastin, taxol, and vincristine are examples of anti-cancer chemotherapeutics that effectively destabilize:

a) microfilaments.
b) intermediate filaments.
c) microtubules.
d) keratins.
e) desmins.
c) microtubules.
Which of the following is true?

a) microvilli attach to a cell's surface at basal bodies
b) centrioles are made up of microtubules & play a role during mitosis
c) cilia function to increase the surface area of a cell
d) flagella are composed of microfilaments
e) centrioles are composed of 9 sets of microtubule doublets, arranged in a "pinwheel" fashion
b) centrioles are made up of microtubules & function during mitosis
What cytoskeletal elements allow pathologists to identify cancer cells that are otherwise too de-differentiated to classify by light microscopy?

a) microfilaments
b) intermediate filaments
c) microtubules
d) dyneins
e) desmosomes
b) intermediate filaments
Cancer cells that are of epithelial origin can be specifically identified by special microscopic techniques that detect:

a) keratin proteins.
b) vimentin proteins.
c) desmin proteins.
d) lamin proteins.
e) actin proteins.
a) keratin proteins.
The cytoskeletal elements that are prominent in the nuclear lamina & the nuclear envelope surrounding the rough ER are:

a) microfilaments
b) intermediate filaments
c) microtubules
d) dyneins
e) desmosomes
b) intermediate filaments
What are the 3 types of motor proteins and in what direction does each typically direct movement?
1. myosins: plus-end directed
2. kinesins: plus-end directed
3: dyneins: minus-end directed
a) What 2 motor proteins direct intracellular MICROTUBULE-based motility?

b) In which directions?
a,b) kinesins: plus-end

dyneins: minus-end
The movement of intracellular organelles towards the periphery of the cell (towards the + end) is known as:

a) kinesin walking
b) antegrade transport
c) retrograde transport
d) diapedesis
e) sliding
b) antegrade transport

The motor protein typically responsible for antegrade transport is KINESIN.
The movement of intracellular organelles towards the center of the cell (towards the - end) is known as:

a) kinesin walking
b) antegrade transport
c) retrograde transport
d) diapedesis
e) sliding
c) retrograde transport

The motor protein typically responsible for antegrade transport is DYNEIN.
Which of the following is true regarding axonemes?

a) possess dynein arms that allow for movement
b) are composed of microtubules arranged in 9 sets of triplets that are arranged in a "pinwheel" pattern
c) possess dynein arms that convert bending motion into sliding motion
a) possess dynein arms that allow for movement

Note: Axonemes are composed of microtubules arranged in 9 sets of doublets that surround 2 central microtubules
The cross-linking protein responsible for converting the sliding-to-bending movement of microtubule dynein arms is:

a) keratin
b) kinesin
c) laminin
d) nexin
e) vimentin
d) nexin
Which of the following protein filaments does NOT have polarity (+ and - ends)?

a) microfilaments
b) intermediate filaments
c) microtubules
b) intermediate filaments
Proteins that are destined to become integral membrane proteins, lysosomal proteins, or secretory proteins are produced where within the cell?
ribosomes bound to rough ER

Note: different from polyribosomes that produce cytoplasmic proteins
Flattened sacs of smooth and rough ER are refered to as:

a) caveolae
b) cisternae
c) cristae
d) lamina
b) cisternae
A cell from an exocrine gland that functions solely to produce and secrete protein hormones would likely have all of the following except:

a) prominent smooth ER
b) prominent rough ER
c) prominent nucleolus
d) many ribosomes
e) many mitochondria
a) prominent smooth ER

This is an important feature of a cell that produces, stores, and secretes lipid (steroid) products.
True/False: Polyribosomes produce proteins that are usually either secreted or integrated into the plasma membrane.
false

Polyribosomes typically produce proteins that eventually remain within the cytosol or mitochondrial proteins.
The Golgi apparatus is composed of several membranous structures known as:

a) cisternae
b) cristae
c) caveolae
d) lamina
e) nexins
a) cisternae
True/False: Vesicles that leave the ER carrying proteins for modification and packaging enter the Golgi apparatus at its trans (maturing) face.
false

Vesicles enter the Golgi at the cis (forming) face.
True/False: The face of the Golgi that faces the ER & cell nucleus is the trans (maturing) face.
false

The cis (maturing) face is the portion of the Golgi that directly faces the ER and nucleus.
Which of the following post-translational modifications does NOT usually occur in the Golgi apparatus?

a) glycosylation of proteins
b) addition of Signal Recognition Sequences (SRPs)
c) phosphorylation of lysosomal enzymes
d) sulfation
e) removal of mannose sugars
b) addition of Signal Recognition Sequences (SRPs)

SRP's are added to proteins for modification, prior to entering the rough ER
a) What are the 3 possible outcomes of a modified protein after it leaves the Golgi?

b) 3 outcomes of a protein leaving a polyribosome?
a) 1. secretion 2. to lysosomes 3. integrated in cell membrane

b) 1. stored in cytosol 2. to mitochondria 3. to nucleus
Which of the following is a linker protein located within microvilli?

a) dynein
b) kinesin
c) myosin
d) keratin
e) fimbrin
e) fimbrin
Which of the following is a protein that can coat vesicles leaving the rough ER?

a) mannose-6-phosphate
b) COPI
c) COPII
d) SRP
e) clathrin
c) COPII
Which of the following structures could be labeled by a cytochemical marker that can specifically bind to acid phosphatases?

a) smooth ER
b) rough ER
c) cis-face of Golgi
d) trans-face of Golgi
e) nuclear lamina
d) trans-face of Golgi
Which of the following is a protein that can coat vesicles that are transported from the Golgi to the rough ER?

a) mannose-6-phosphate
b) COPI
c) COPII
d) SRP
e) clathrin
b) COPI
What are 2 methods of secretion that can occur as a vesicle leaves the Golgi?
1. constitutive: vesicles & their contents travel to the plasma membrane for exocytosis

2. regulated: vesicles are coated with clathrin and leave the Golgi where they condense with other vesicles & then secreted
Which of the following conditions occurs as a result of defects in mannose phosphotransferases in the Golgi?

a) I-cell disease
b) hereditary spherocytosis
c) Marfan's syndrome
d) amyloidosis
e) Gauchier's disease
a) I-cell disease
Active transport involves movement across a gradient from an area of (high, low) concentration to an area of (high, low) concentration.
low to high concentration (against a gradient)
Which of the following ions is typically found in highest concentration relative to the inside a cell?

a) Na
b) K
c) Cl
d) Ca
e) H
b) K
What disease occurs as a result of defective chloride membrane channels?
Cystic Fibrosis
Which of the following can NOT diffuse across a plasma membrane?

a) ethanol
b) molecular oxygen
c) molecular carbon dioxide
d) steroid molecules
e) glucose
e) glucose
Which of the following is NOT an example of a channel that operates via facilitated diffusion?

a) ion-gated channel
b) ligand-gated channel
c) voltage-gated channel
d) Na/K pump
e) mechanically-gated channel
d) Na/K pump
The channel that permits the entry of acetylcholine into a cell is a/an:

a) ion-gated channel.
b) ligand-gated channel.
c) voltage-gated channel.
d) Na/K pump.
e) mechanically-gated channel.
b) ligand-gated channel
The specialized channel that is opened via stimulation of stereocilia on hair cells in the ear is an example of a/an:

a) ion-gated channel.
b) ligand-gated channel.
c) voltage-gated channel.
d) Na/K pump.
e) mechanically-gated channel.
e) mechanically-gated channel.
The specialized channel that allows the entry of sodium into a neuronal axon during the propagation of an action potential is an example of a/an:

a) ion-gated channel.
b) ligand-gated channel.
c) voltage-gated channel.
d) Na/K pump.
e) mechanically-gated channel.
a) ion-gated channel.
Clathrin, adaptin (AP2), and dynamin are elements that play a significant role in:

a) active transport.
b) cell "crawling."
c) cell "walking."
d) receptor-mediated endocytosis.
e) transport of vesicles from rough ER to the Golgi.
d) receptor-mediated endocytosis.
The formation of endosomes that eventually fuse with lysosomes within a cell requires:

a) clathrin.
b) caveolae.
c) dynein.
d) keratin.
e) mannose-6-phosphate.
a) clathrin.

This is the process of clathrin-dependent receptor-mediated endocytosis.
Familial hypercholesterolemia is a condition resulting in increased serum cholesterol that can be due to a defect in:

a) lysosomal storage.
b) lipid rafts.
c) LDL receptors.
d) ion-gated channels.
e) mechanically-gated channels.
c) LDL receptors.
A molecule that is typically required for the transcytosis of particles across intercellular space is:

a) COPI
b) COPII
c) clathrin
d) caveolae
e) dynein
d) caveolae
Porins are specialized transport proteins that are found on the outer membrane of:

a) rough ER
b) smooth ER
c) Golgi
d) mitochondria
e) lysosomes
d) mitochondria
The phospholipid that plays a significant role in the inner membranes of mitochondria by aiding in formation of an electrochemical gradient is:

a) cardiolipin.
b) phosphatidylcholine.
c) phosphatidylinositol.
d) sphingomyelin.
e) plasmalogen.
a) cardiolipin.
The molecule that interacts with proteins at the surface of the outer mitochondrial membrane is:

a) COPI
b) COPII
c) TIM
d) TOM
e) SRP
d) TOM
The protein that forms a transmembrane channel across mitochondrial membranes, allowing for the entry of small particles is:

a) COPI
b) COPII
c) TIM
d) TOM
e) SRP
c) TIM
Which of the following is NOT located in the mitochondrial matrix?

a) calcium stores
b) TCA cycle enzymes
c) mitochondrial DNA
d) mitochondrial RNA
e) ATP synthetase
e) ATP synthetase
Mitochondria contain their own source of DNA, which are capable of coding for ____ mitochondrial proteins.

a) 4
b) 13
c) 25
d) approximately 300
e) approximately 800
b) 13
Which of the following products is MOST likely to originate from a cell that contains mitochondria possessing tubular cristae, rather than cristae that are plate-like?

a) antibodies
b) cortisone
c) acetylcholine
d) chymotrypsin
e) hemoglobin
b) cortisone

Tubular cristae are located most prominently in mitochondria of cells that function in producing steroid-hormones & lipids.
What does the "H" refer to in the Gibbs free energy equation?

a) free energy
b) entropy
c) enthalpy
d) temperature
e) activation energy
c) enthalpy
Regarding the Gibbs free energy equation, what values for "H" and "S" will ALWAYS result in a spontaneous reaction?
a negative "H" (enthalpy) and a positive "S" (entropy) value
What does the "S" refer to in the Gibbs free energy equation?

a) free energy
b) entropy
c) enthalpy
d) temperature
e) activation energy
b) entropy
Regarding the Gibbs free energy equation, what values for "H" and "S" will ALWAYS result in a non-spontaneous reaction?
a positive "H" (enthalpy) and a negative "S" (entropy) value
What are 2 equations that can be used to compute the enthalpy in a system?
1. H = (Temp)x Change in Entropy)

2. H = G / [Temp x Change in Entropy]
What are the 2 equations for calculating Gibbs free energy with respect to the Thermodynamic Triquetri?
1. G = Go + RT (ln Keq)

2. G = Go + RT (ln MAR)

MAR = Mass Action Ratio
A Reduction Potential refers to the ability to (accept/donate) electrons.
accept

DONATE = oxidation
MFM/OPP: A Mediterranean Diet may include high or moderate portions of all of the following except:

a) olive oil
b) poultry
c) beans
d) red meat
e) nuts
d) fish

Mediterranean diets tend to be low to moderate in dairy, fish, & poultry and also consists of very little red meat.
MFM/OPP: True/False - A high ratio of omega-6 to omega-3 fatty acids in the diet makes an inflammatory reaction more likely to occur in the body (i.e. hypersensitivity)
true
MFM/OPP: True/False - A high ratio of HDL to LDL correlates to an increased risk of heart disease.
false

high LDL = increase risk
low LDL = lower risk
MFM/OPP: Metabolic Syndrome may consist of all of the following except:

a) abdominal obesity
b) low LDL:HDL ratio
c) hypertension
d) elevated C-reactive proteins
e) high amount of serum PAF or PAF-1
b) low LDL:HDL ratio