Protein Structure and Function — Flashcards

Flashcard 1: Curve A indicates which compound? _____

Answer: Myoglobin

Flashcard 2: The given image represents a _____ which is a secondary structure of proteins.

Answer: beta-sheet

Flashcard 3: egg white forms _____% weight of egg

Answer: 60

Extra: 

Flashcard 4: serum _____ is most sensitive indicator for protein estimation

Answer: albumin

Extra: 

Flashcard 5: Collagen Synthesis: After the collagen pro-alpha chains are synthesized, specific residues of the amino acids _____ and lysine are hydroxylated

Answer: proline

Flashcard 6: The N-terminal signal sequence of a newly synthesized protein is bound by a _____, which attaches the complex to the ER membrane

Answer: signal recognition particle (SRP)

Flashcard 7: Collagen Synthesis: Once in the extracellular space, cleavage of disulfide-rich terminal regions of procollagen by _____ forms the insoluble tropocollagen

Answer: procollagen peptidase

Flashcard 8: _____ increase binding of thyroxine to thyroxine binding globulin

Answer: Estrogens

Flashcard 9: _____ are a cylindrical outer structure composed of a helical array of polymerized heterodimersof - and -tubulin

Answer: Microtubules

Flashcard 10: Collagen Synthesis: Staggered tropocollagen molecules are reinforced by covalent _____ cross-linkages to make collagen fibrils

Answer: lysine-hydroxylysine

Flashcard 11: In the _____, post-translational O-glycosylation adds sugars onto the amino acids serine and threonine

Answer: Golgi apparatus

Flashcard 12: Insulin is a peptide hormone consisting of two straight chains, an _____ chain (21 AA) and a B chain (30 AA), connected by two disulfide bridges

Answer: A

Flashcard 13: Microtubules grow _____ and collapse quickly (speed)

Answer: slowly

Flashcard 14: Prion protein is normally expressed in CNS neurons in an _____ conformation, known as PrPc

Answer: -helical

Flashcard 15: Dystrophin normally anchors the muscle _____ to the extracellular matrix; primarily in skeletal and cardiac muscle

Answer: cytoskeleton

Flashcard 16: Formation of lysine-hydroxylysine cross-linkages (collagen synthesis) requires both _____ and the enzyme lysyl oxidase

Answer: copper

Flashcard 17: The _____ of preproinsulin is cleaved while the peptide chains are being assembled, yielding proinsulin

Answer: signal peptide

Flashcard 18: In the golgi apparatus, peptide sequences are cleaved from the prohormone to form the _____, which is stored in secretory vesicles for later release

Answer: hormone

Flashcard 19: The _____ family of hormones is derived from a single precursor, pro-opiomelanocortin (POMC)

Answer: ACTH

Flashcard 20: Each B cell produces light chains that are either _____ or lambda

Answer: kappa

Flashcard 21: Opsin combines with _____ to produce rhodopsin.

Answer: 11 cis retinal

Flashcard 22: Histones are rich in the amino acids _____ and arginine

Answer: lysine

Flashcard 23: A _____ protein, is an intracellular protein involved in facilitating and/or maintaining protein folding

Answer: chaperone

Flashcard 24: Thyroglobulin synthesis (as part of thyroid hormone synthesis) occurs in the _____ and Golgi apparatus of the thyroid follicular cells

Answer: RER

Flashcard 25: The shiga toxin of Shigella binds the _____ subunit of ribosomes, inhibiting protein synthesis

Answer: 60S

Flashcard 26: The direction of protein synthesis is _____-terminus to C-terminus

Answer: N

Flashcard 27: _____ is packaged with neurophysin II and glycoprotein

Answer: Antidiuretic hormone (ADH)

Flashcard 28: After fibrin is formed from fibrinogen, it is _____ by factor XIII yielding a stable platelet-fibrin thrombus

Answer: cross-linked

Flashcard 29: _____ and oxytocin are homologous nonapeptides (9 AA)

Answer: Antidiuretic hormone (ADH)

Flashcard 30: _____ -ation of proteins recruits the proteasome to degrade them

Answer: Ubiquitin

Flashcard 31: _____ and osteocalcin are the predominant glycoproteins present in bone

Answer: Osteonectin

Flashcard 32: Stokes radius of a protein is a function of its _____ and shape

Answer: molecular mass

Flashcard 33: Elastin is rich in non-hydroxylated _____, glycine, and lysine residues (amino acids)

Answer: proline

Flashcard 34: In the _____, co-translational N-glycosylation adds sugars onto the amino acid asparagine

Answer: ER

Flashcard 35: Free radicals may be eliminated via metal carrier proteins, such as _____ and ceruloplasmin (Cu2+)

Answer: transferrin (Fe2+)

Flashcard 36: _____ test is used for detecting the presence of histidine in proteins.

Answer: Pauly's

Flashcard 37: _____ makes the major contribution to the ability of most proteins to absorb light in the region of 280 nm.

Answer: Tryptophan

Flashcard 38: Collagen Synthesis: Following hydroxylation of proline and lysine, there is _____ of pro--chain hydroxylysine residues

Answer: glycosylation

Flashcard 39: In the Golgi apparatus, _____ is added to proteins for trafficking to lysosomes

Answer: mannose-6-phosphate

Flashcard 40: The amino acids _____ and glutamate are negatively charged at body pH (acidic)

Answer: aspartate

Flashcard 41: All tissues coming into contact with _____ acid turn yellow in color

Answer: nitric

Flashcard 42: The typical ratio of kappa to lambda immunoglobulin light chain phenotypes is _____:2

Answer: 3

Flashcard 43: Prion proteins have two isoforms: _____ that causes disease and PrPc, the normal prion protein, found in human cells

Answer: PrPSc

Flashcard 44: Prion disease arises with conversion to a _____ conformation, known as PrPsc

Answer: -pleated

Flashcard 45: One normal type of hemoglobin is _____ which is composed of two alpha and two beta chains

Answer: HbA

Flashcard 46: There are four superfamilies of proteins namely _____, dynein, myosin, dynamins referred to as molecular motors.

Answer: kinesin

Flashcard 47: Sickle cell anemia occurs due to a point mutation that substitutes _____ (hydrophilic) with valine (hydrophobic)

Answer: glutamic acid

Flashcard 48: While being packed into secretory granules, proteases cleave the _____ of proinsulin, yielding insulin

Answer: connecting peptide

Flashcard 49: Compounds that have the same chemical formula but different structures are called _____ of each other

Answer: isomers

Flashcard 50: Curve A indicates which compound? _____

Answer: Myoglobin

Flashcard 51: Which amino acid does not participate in the formation of alpha helix?_____

Answer: Proline

Flashcard 52: _____ is an amino acid with an imino ring.

Answer: Proline

Flashcard 53: Which amino acid has an thioether group?_____

Answer: Methionine

Flashcard 54: Proteoglycans have a _____ appearance.

Answer: bottle brush

Flashcard 55: Collagen comes under glycoprotein sub-classes of _____-glycosidic linkages.

Answer: O (O/N)

Flashcard 56: Which amino-acid is most sterically flexible?_____

Answer: Glycine

Flashcard 57: Which amino acid has an phenol group?_____

Answer: Tyrosine

Flashcard 58: A complete turn of the alpha helix contains an average of _____ aminoacyl residues.

Answer: 3.6

Flashcard 59: What is the stabilizing bond in quarternary protein structure?_____

Answer: Hydrophobic bond>Hydrogen bond>Ionic bond

Flashcard 60: Biuret reaction is used to check for _____ linkages

Answer: dipeptide

Flashcard 61: Apo-a is a structural analogue of _____

Answer: plasminogen

Flashcard 62: _____ is the most reliable marker for cellular autophagy

Answer: Microtubule-associated protein light chain 3 (LC3)

Flashcard 63: Aromatic amino acids such as tyrosine, tryptophan, and phenylalanine absorb _____ nm UV light.

Answer: 250 to 290

Flashcard 64: What is the stabilizing bond in secondary protein structure?_____

Answer: Hydrogen bond and Van der Waals forces

Flashcard 65: Free - and -chains are _____ soluble than free -chains.

Answer: more

Flashcard 66: 11-cis-retinal (a chromophore) is covalently bound to opsins via a _____ residue on one of the transmembrane domains.

Answer: lysine

Flashcard 67: Which 2 protiens play a role in corneal transparency?_____

Answer: Keratan sulfate and dermatan sulfate

Flashcard 68: What is the predominant whey protein in cow milk?_____

Answer: -globulin

Flashcard 69: What is the stabilizing bond in tertiary protein structure?_____

Answer: Hydrophobic bond>Hydrogen bond>Ionic bond

Flashcard 70: _____ induces bends within alpha helix, because of its small size.

Answer: Glycine (Amino acid)

Flashcard 71: GAGs maybe attached to a protein molecule to form a _____

Answer: proteoglycan

Flashcard 72: _____ is seen in the family of oxidoreductases that share a common N-terminal NAD(P)+ -binding domain.

Answer: Rossmann fold

Flashcard 73: Marker of Apoptosis is the protein _____

Answer: Annexin V

Flashcard 74: What is the stabilizing bond in primary protein structure?_____

Answer: peptide bond

Flashcard 75: Which structure of protein is the most common and most stable?_____

Answer: alpha helix

Flashcard 76: Cytoplasmic proteins such as transferrin receptor CD_____ and EGFR can be used as limbal stem cell markers

Answer: 71

Flashcard 77: Amino acids have _____imum buffering action at isoelectic pH

Answer: min

Flashcard 78: Higher the _____ of the protein lesser the salt required for precipitation

Answer: molecular weight

Flashcard 79: C1-inhibitor (C1 INH) is the largest member of the _____ superfamily of proteins.

Answer: serpin

Flashcard 80: What is the predominant whey protein in breast milk?_____

Answer: -lactalbumin

Flashcard 81: Charcot Leyden crystals are made of an eosinophilic membrane protein called _____

Answer: galectin 10

Flashcard 82: At pH above the isoelectric point, the ampholyte will be _____

Answer: anion

Flashcard 83: _____ is largest protein expressed in humans

Answer: Titin

Flashcard 84: Which amino acid has an imidazole group?_____

Answer: Histidine

Flashcard 85: _____ is a measure of the effective volume occupied by a protein as it rapidly tumbles in free solution

Answer: Stokes radius

Flashcard 86: When _____ acts on a molecule of immunoglobulin, the end products are _____ fragment and many smaller fragments

Answer: pepsin; 1 F(ab )2

Flashcard 87: _____, the 21st amino acid, is coded by the _____ codon by co-translational modification.

Answer: Selenocysteine; UGA