ABI 103 Notes + clickers + discussions

study the diff nucleotide structures

... will make another set

______of the world's human population carries an inherited variant hemoglobin gene. A) 5% B) 25% C) 50% D) 75% E) 90%

A) 5%

Myoglobin increases the effective solubility of oxygen in muscle cells. A) True B) False

A) True

Which of the following proteins are synthesized on free ribosomes? A) mitochondrial proteins B) secretory proteins C) signal peptides D) lysosomal proteins E) transmembrane proteins

A) mitochondrial proteins

Which of the following is the source of the two carbon fragments in fatty acids biosynthesis? A) acetyl CoA B) malonyl CoA C) palmitic acid D) propionyl CoA E) ceramides

B) malonyl CoA

energy of ATP is transferred via

its phosphate groups

How many antigen-binding sites are present on an IgM molecule? A) 2 B) 4 C) 10 D) 16 E) 25

C) 10

The energy needed to drive muscle contraction comes from ATP hydrolysis that is carried out by: A) G-actin. B) F-actin. C) myosin heads. D) myosin tails. E) tropomyosin.

C) myosin heads.

Hemoglobin's p50 value is about ______ as great as myoglobin's p50 value. A) one-tenth B) half C) twice D) ten times E) twenty times

D) ten times

The activity of protein kinase A is affected by which of the following? I. caffeine II. levels of cAMP III. phosphodiesterases IV. cholera toxin A) I only B) II only C) I, IV D) I, II, III E) I, II, III, IV

E) I, II, III, IV

Under what metabolic conditions does gluconeogenesis typically occur? A. Starvation B. Fasting C. Intense Exercise D. A & B E. All of the above

E. All of the above

a nucleotide consists of

a five-carbon sugar, a nitrogenous base, and one or more phosphate groups

DNA base composition differs between organisms with a range from ~__ to ___ mol% G + C in bacteria and ~__mol% G + C in mammals

25 to 75; 40

Where is phosphate on dna

3' oh

Where is phosphate on rna

5' oh

What is the fractional saturation of myoglobin at pO2 =2.8 torr, ifp50 = 2.8 torr? A) 2.8 B) 0.28 C) 50 D) 0.5 E) 1

D) 0.5

Affinity of O2 for hemoglobin is about ___________ than affinity of CO for hemoglobin. A) 200 times greater B) 20 times greater C) 20 times smaller D) 200 times smaller E) None of the above

D) 200 times smaller

The secondary structure of myoglobin consists of _______ helices and the connecting loops. A) 6 B) 12 C) 4 D) 8 E) 7

D) 8

Free fatty acids bind to ________ for circulation in the bloodstream. A) HDL B) malonyl-CoA C) ACP D) albumin E) cholesterol

D) Albumin

Which of the following describes the similarity between the following words? DAG, cAMP, IP3 A) All of them induce conformational changes in PKA. B) All of them activate adenylate cyclase. C) All of them require phosphorylation in order to function. D) All of them function as second messengers. E) All them result from the activity of phosphoprotein lipase.

D) All of them function as second messengers.

Which of the following vitamins is part of the prosthetic group 5ʹ deoxyadenosylcobalamin? A) B1 B) B2 C) B6 D) B12 E) none of the above

D) B12

Polypeptides smaller than 40 residues are called: A) Proteins B) Polymerases C) Polyphenoles D) Peptides

D) Peptides

The synthesis of N-linked oligosaccharides occur in the _____ while O-linked oligosaccharides are synthesized in the ______. A) Golgi apparatus; endoplasmic reticulum B) cytosol; Golgi apparatus C) mitochondrial matrix; endoplasmic reticulum D) endoplasmic reticulum; Golgi apparatus E) Golgi apparatus; mitochondrial matrix

D) endoplasmic reticulum; Golgi apparatus

The protein that forms a transmembrane pore that allows growing polypeptides to pass through the RER membrane is called the ______. A) signal recognition particle B) signal peptide C) docking protein D) translocon E) none of the above

D) translocon

Which of the following statements are true regarding fatty acids? I. Fatty acids with fewer than 14 carbons are the most common. II. Synthesis of fatty acids occurs in 2 carbon units. III. Fatty acids with conjugated double bonds are the most common type of fatty acid. IV. In higher plants and animals, C16and C18 species predominate. A) I, II, III, IV B) I, II, III C) I, III D) II, III, IV E) II, IV

E) II, IV

Which of the following correctly describes the usefulness of SNAREs? I. They are essential for proper post-translation processing. II. They are a critical element in the function of the secretory pathway. III. They are effective at overcoming electrostatic repulsion between vesicle membranes. IV. They facilitate anchoring between vesicle membranes. A) I, II, III, IV B) II, III C) III D) IV E) III, IV

E) III, IV

The ____ signaling pathway undergoes autophosphorylation resulting in kinase activation. A) Receptors B) Insulin C) Hypothalamus D) Islets of Langerhans E) Receptor tyrosine kinase

E) Receptor tyrosine kinase

Myoglobin's primary physiological role is to facilitate oxygen ________. A) storage B) metabolism C) binding D) reduction E) diffusion

E) diffusion

Phosphoprotein phosphatase -1 (PP1) ___________. A. catalyzes the phosphorylation of phosphorylase kinase. B. increases glycogen breakdown when active. C. catalyzes the dephosphorylation of phosphorylase kinase. D. catalyzes the dephosphorylation of glycogen phosphorylase. E. Both C and D are correct.

E. Both C and D are correct. C. catalyzes the dephosphorylation of phosphorylase kinase. D. catalyzes the dephosphorylation of glycogen phosphorylase.

Select the statement the best matches that following: ATP is.... A. Functional unit of the myofibril. B. Major component of the thin filament of the myofibril. C. Major component of the thick filament of the myofibril. D. Calcium binding protein. E. Chemical energy source for muscle contraction.

E. Chemical energy source for muscle contraction.

The bases on opposite strands of DNA are held together by what kind of bond?

hydrogen (complementary base pairing)

_______ rule: DNA has equal #s of ______ and ________ as well as _____and ___________

chargaff's; adenine and thymine; guanine and cytosine

Pyrimidines

cytosine, thymine, uracil

dna sugar

deoxyribose

If you have a polypeptide with 67 amino acid residues, how often do you have to perform the Edman Degradation reaction in order to determine the amino acid composition of the peptide? A) 67-times B) 66-times C) 68-times D) 132-times E) 134-times

A) 67-times

Why do DNA fragments move towards anode? A) Charge of phosphate group B) Length of nucleotide chain C) Charge of deoxyribose group D) All of the above E) None of the above

A) Charge of phosphate group

Digestion of triacylglycerols is aided by the cholesterol derivatives synthesized by the liver known as ____________. A) bile acids. B) lipoproteins. C) lanosterols. D) chylomicrons. E) colipases

A) bile acids.

Amino acids are degraded to one of ___________ glucogenic intermediates: A) five B) six C) seven D) eight E) twelve

A) five

The majority of amino acids are deaminated by a ______ reaction. A) transaminmation B) reduction C) condensation D) transacetylation E) oxidation

A) transaminmation

Carbon monoxide binds to heme: A) with a higher affinity than oxygen. B) resulting in the oxidation of the Fe(II) to Fe(III) C) in a manner that displaces carbon dioxide, causing CO2 poisoning. D) from the side opposite oxygen, resulting in a brown colored heme. E) with a lower affinity than oxygen.

A) with a higher affinity than oxygen.

Muscle glycogen phosphorylase is activated by: A. AMP B. ATP C. G6P D. ATP & G6P E. All of the above

A. AMP

An increase in pCO2 causes hemoglobin's affinity for oxygen to ______. A. Decrease B. Increase C. Stay the same

A. Decrease

The primary structure of mammalian hemoglobin, an a2b2 tetramer, is approximately _____ identical to myoglobin. A) 2% B) 18% C) 50% D) 78% E) 98%

B) 18%

Triacylglycerols are synthesized by ____ during times of starvation via a process known as ____. A) Dihydroxyacetone phosphate; ketosis B) Dihydroxyacetone phosphate; glyceroneogenesis C) acetyl CoA; ketosis D) acetyl CoA; glyceroneogenesis E) ketone bodies; ketosis

B) Dihydroxyacetone phosphate; glyceroneogenesis

p50, or oxygen tension, is the oxygen pressure (pO2) at which hemoglobin or myoglobin is 25% saturated with oxygen. A) True B) False

B) False

The conversion of glycogen phosphorylase b to glycogen phosphorylase a is triggered by an increase in [Ca2+] and through phosphorylase kinase ac`vity (Fig 16-10). Ca2+ release occurs in response to nerve impulses. Response of muscle to increased [Ca2+] ???? Increased [Ca2+] results in increased: A) Glycogen synthesis B) Glycogen breakdown

B) Glycogen breakdown

In myoglobin, the amino acid _____ is the only ligand for the heme that is supplied by the protein. A) Asp B) His C) Leu D) Cys

B) His

The Lambert-Ber law determines: A) Protein structure B) Protein concentration C) Protein calorimetry D) None of the above E) All of the above

B) Protein concentration

Which of the following is TRUE regarding catabolism of leucine? A) The pathway begins with aspartate. B) The pathway requires α-ketoglutarate. C) The pathway requires TPP. D) The pathway generates HMG-CoA E) none of the above.

B) The pathway requires α-ketoglutarate.

Which of the following proteins has a structural motif called an "EF hand"? A) insulin B) calmodulin (CaM) C) receptor tyrosine kinases (RTK) D) cAMP-dependent protein kinase E) scaffold proteins

B) calmodulin (CaM)

The β cells of the islets of Langerhans secrete ______ in response to ______ glucose levels in the muscle and/or adipose tissue. A) insulin; low B) insulin; elevated C) glucagon; low D) glucagon; elevated E) somatostatin; elevated

B) insulin; elevated

Heme biosynthesis A) requires that synthesis of the protoporphryin ring occur in the mitochondria due to difficulties in transporting large molecule. B) is inhibited in lead poisoning. C) can be completed using enzymes from the cytosol. D) A and B E) A, B, and C

B) is inhibited in lead poisoning.

In which cellular location listed below does the following reaction take place? ornithine + carbamoyl-phosphate → citrulline A) cytosol B) mitochondrial matrix C) lysosome D) A or B E) none of the above

B) mitochondrial matrix

Which of the following functions as a regulatory protein by dephosphorylating activated enzymes? A) receptor tyrosine kinase B) phosphoprotein phosphatase C) guanine nucleotide exchange factor D) Sos protein

B) phosphoprotein phosphatase

Which enzyme catalyses the key regulatory step of cholesterol synthesis? A) β-ketothiolase B) HMG-CoA synthase C) HMG-CoA reductase D) mevalonate-5-phosphotransferase E) phenyltransferase

C) HMG-CoA reductase

Which of the following lipids would NOT likely be found in a lipid raft? I. glycosphingolipids II. glycerophospholipids III. cholesterol IV. palmitoleic acid A) I, IV B) I, II, IV C) II, IV D) III, IV

C) II, IV

A suspension of which of the following is most likely to form a liposome? I. fatty acids II. triacylglycerols III. glycerophospholipids IV. sphingomyelins A) I, II B) II, III C) III, IV D) II, IV E) I, IV

C) III, IV

Which are components of DNA? A) Ribose B) Dexoxyribose C) Nitrogenous bases & Dexoxyribose D) Phosphate groups & Ribose

C) Nitrogenous bases & Dexoxyribose

Mass spectrometry (MS) allows to determine the amino acid sequence of polypeptides without performing the Edman Degradation reaction. What is determined during MS analysis? A) The charge-to-mass ratio of ions B) The mass-to-charge ratio of ions in aqueous phase C) The mass-to-charge ratio of ions in gas-phase

C) The mass-to-charge ratio of ions in gas-phase

Myoglobin's secondary structure is primarily composed of______________: A) parallel b-sheets B) antiparallel b-sheets C) a-helices D) Ω-loops E) polyproline helices

C) a-helices

BPG stands for: A) biphenylglycine. B) boronylphenylglutamate. C) bisphosphoglycerate. D) bisphenylglycerol. E) betapropylglutamine.

C) bisphosphoglycerate.

Scaffold proteins limit: A) oncogene transfer. B) MAPK activity. C) cross-talk D) cell differentiation. E) signal amplification

C) cross-talk

The α cells of the islets of Langerhans secrete _____ in response to ____ glucose levels in the liver. A) insulin; low B) insulin; elevated C) glucagon; low D) glucagon; elevated E) somatostatin; elevated

C) glucagon; low

Individuals with McArdle's disease lack the ____ in the ____, A) debranching enzyme; liver B) phosphoglucomutase; liver C) glycogen phosphorylase; muscle D) phosphoglucomutase; muscle E) glycogen phosphorylase; liver

C) glycogen phosphorylase; muscle

Muscle contraction is directly caused by: A) structural changes in actin. B) structural changes in myosin. C) thick and thin filaments sliding past each other. D) structural changes in the Z disk. E) None of the above is correct.

C) thick and thin filaments sliding past each other.

Which of the following describes a sequence which will ultimately activate glycogen breakdown in a muscle? A. epinephrine binds β receptors. => cAMP => PKA => phosphorylase kinase => glycogen phosphorylase B. epinephrine bind α receptors => Ca2+ increase => phosphorylase kinase => glycogen phosphorylase C. glucagon => glucagon receptors => cAMP => PKA => phosphorylase kinase => glycogen phosphorylase D. PP1 binding to unphosphorylated Gm => dephosphorylates glycogen phosphorylase and phosphorylase kinase E. All of these will activate glycogen breakdown in a muscle.

A. epinephrine binds β receptors. => cAMP => PKA => phosphorylase kinase => glycogen phosphorylase

Cholesterol: A. incorporation into the membrane results in increased rigidity. B. functions as a precursor to cerebrosides. C. is synthesized in two-carbon units. D. is synthesized from steroid hormones. E. all of the above

A. incorporation into the membrane results in increased rigidity.

Cross bridge formation between myosin heads and actin molecules is caused by the elevation of calcium ion concentration in the cytosol. During rigor mortis, this elevation of calcium ion concentration in the cytosol is permanent because ________. A. mitochondria stop producing ATP molecules required by the sarcoplasmic reticulum's calcium ion pumps B. tropomyosin molecules bind irreversibly to calcium ions to prevent them from being removed from the cytosol C. troponin molecules bind irreversibly to calcium ions to prevent them from being removed from the cytosol

A. mitochondria stop producing ATP molecules required by the sarcoplasmic reticulum's calcium ion pumps

Muscle contraction is ________ by increase in the level of cytosolic Ca2+. A. triggered B. inhibited C. not dependent on [Ca2+]

A. triggered

purines

Adenine and Guanine

After glycogen reserves are depleted during starvation what is/are the major gluconeogenic precursors? A. Lactate B. Palmitate C. Alanine D. A and B E. All of the above

Alanine

Why is BPG essential for the delivery of O2 to the tissues? A. BPG enables hemoglobin to adopt the R state conformation. B. BPG enables stabilization of the T state conformation. C. A and B

B. BPG enables stabilization of the T state conformation. This shifts the T:R equilibrium towards the T state, which lowers Hb's O2 affinity -> release of O2 into tissue

Appropriate approaches for end group analysis of a peptide are: A. Mercaptan Treatment B. Edman Degradation C. Ion exchange chromatography. D. A and C E. None of the above.

B. Edman Degradation

The four nucleotides that make up DNA are adenine, guanine, thymine, and cytosine. A. True B. False

B. False

Which of the following is true regarding the reaction shown below? Pyruvate + HCO3- + ATP ----> oxaloacetate + Pi I. It requires the direct transport of oxaloacetate across the membrane. II. It utilizes the malate-aspartate shuttle in some species. III. It is essential for gluconeogensis. IV. Its reactants require the function of enzymes which are only found in the cytosol. A. I only B. II, III C. II, III, IV D. III only E. II, IV

B. II, III

Is it correct that during the dansyl chloride reaction only the N-terminal amino group is removed from a polypeptide chain? A. Yes B. No

B. No

The breakdown of glycogen is referred to as ______. A. gluconeogenesis B. glycogenolysis C. glycolysis D. glycogenesis

B. glycogenolysis

Which of the following enzymes directly converts phosphorylase b into the more active form, phosphorylase a? A. cAMP-dependent protein kinase B. phosphorylase kinase C. protein kinase A D. adenylate cyclase E. phosphoprotein phosphatase-1

B. phosphorylase kinase

p50 of Hemoglobin is approx. __ times greater than p50 of myoglobin. A. 2 times B. 5 times C. 10 times D. 100 times E. 1000 times

C. 10 times

The following molecule is: A. A tetrapeptide with 4 peptide bonds. B. A tripeptide with 4 peptide bonds. C. A tetrapeptide with 3 peptide bonds. D. A tripeptide with 3 peptide bonds.

C. A tetrapeptide with 3 peptide bonds.

Lipid transport in the blood is more complicated than the transport of sugar such as glucose. Why? A. Because lipids are much larger than sugars B. Because lipids have a wider variety of chemical structures than sugars C. Because lipids are hydrophobic and sugars are hydrophilic D. Because lipids must be supplied to a greater variety of cells and tissues than sugars

C. Because lipids are hydrophobic and sugars are hydrophilic

Hemoglobin's subunits bind oxygen in a ______ manner. A. Negatively cooperative B. Non-cooperative C. Positively cooperative

C. Positively cooperative

In the ______ state of hemoglobin, the iron ion is out of the plane of the porphyrin ring. A. R B. S C. T D. A E. TSA

C. T

Which of the following statements about the oxygen binding site in myoglobin is FALSE? A. Oxygen binds to myoglobin by forming an H bond with the distal histidine. B. The heme prosthetic group is held in the heme binding pocket via hydrophobic interactions. C. The proximal histidine partially blocks the oxygen binding site, forcing oxygen to bind at an angle. D. The distal histidine helps to define the geometry of the oxygen binding site

C. The proximal histidine partially blocks the oxygen binding site, forcing oxygen to bind at an angle.

How would you predict that acetyl- CoAs get into the mitochondrial matrix? A. They enter via porins B.. They are hydrophobic, so they cross bilayers without requiring a carrier protein C. They require a specific carrier protein

C. They require a specific carrier protein

Which of the following aides in formation of a primer for glycogen synthesis? A. glycogen synthase B. UDP-glucose pyrophosphatate C. glycogenin D. UDP-glycogen E. amylo-(1,4→1,6)-transglycosylase

C. glycogenin

Members of the ______ family have four fused, nonplanar rings and a C3-OH group. A. vitamin D B. arachidonic acid C. sterol D. glycerophospholipids E. triacylglycerols

C. sterol

Which of the following fractionating procedures separates proteins according to their molecular weight? A. Gel filtration chromatography. B. SDS-PAGE. C. Ion exchange chromatography. D. A and B E. All of the above

D. A and B

Muscle glycogen synthase is activated by: A. AMP B. ATP C. G6P D. ATP & G6P E. All of the above

D. ATP & G6P

The Bohr effect: A. O2 affinity of Hb decreases with increasing pH B. O2 affinity of Hb decreases with increasing pO2 C. O2 affinity of Hb increases with decreasing pH D. O2 affinity of Hb increases with increasing pH

D. O2 affinity of Hb increases with increasing pH

A steroid-derived hormone that must be activated by hydroxylation, ______ regulates Ca2+ metabolism. A. Vitamin A B. Vitamin K C. Vitamin C D. Vitamin D E. Vitamin E

D. Vitamin D

Which of the following best describes the function of the glycogen debranching enzyme in glycogenolysis? A. It cleaves α(1→6) branch points releasing glucose-6- phosphate. B. It cleaves α(1→6) branch points releasing glucose-1- phosphate. C. It cleaves α(1→6) branch points releasing glucose. D. It transfers an α(1→4) linked trisaccharide unit to the nonreducing end of an alternate branch, then cleaves the α(1→6) branch point releasing glucose-1-phosphate. E. It transfers an α(1→4) linked trisaccharide to the nonreducing end of an alternate branch, then cleaves the α(1→6) branch point releasing glucose

E. It transfers an α(1→4) linked trisaccharide to the nonreducing end of an alternate branch, then cleaves the α(1→6) branch point releasing glucose

What molecules correspond to X and Y in the following gluconeogenic reaction? Fructose-1,6-bisphosphate + X ------> Fructose-6phosphate + Y A. X = NADH + H+ Y = NAD+ B. X = ATP Y= ADP + Pi C. X = NAD+ Y = NADH + H+ D. X = GTP Y = GTP + Pi E. X = H2O Y = Pi

E. X = H2O Y = Pi

A molecule that open functions as a second messenger is ______. A. phosphoinositide B. insulin C. ATP D. cortisol E. cyclic AMP

E. cyclic AMP

Ribose order

Up down down up (ch2) then oh on that

Deoxyribose order

Up down(h) down up (ch2) then oh on that

starch synthesis in plants via repeated _____ of glucose units from ____-_______

addition; ADP-glucose

humans recycle approx ___ _____ of atp each ____

own weight of atp each day

rna sugar

ribose

difference between ribose and deoxyribose

ribose has a 2'-OH group and deoxyribose has a 2'-H