BIOC384: Exam 1

Which of the following cellular structures does not have an associated membrane? a) chromosome b) endoplasmic reticulum c) mitochondria d) golgi apparatus

a) chromosome

The fluidity of a membrane depends on a) osmotic pressure b) the size of the polar head group c) the number of phospholipids in the membrane d) the degree of saturation of the phospholipid e) the protein composition

d) the degree of saturation of the phospholipid

In the following set of reactions, which reactant is the shared intermediate? A+B--> C+D C+E--> F a) D b) C c) E d) B e) A f) F

b) C

Trace directly the covalently bonded backbone atoms from the N to C terminus of a dipeptide. Which atoms are found in this trace? a) NCONCONC b) CCNCCNCC c) NCCONCCO d) NCOCNCOC

b) CCNCCNCC

Which best describes the pKa of a weak acid? a) the pKa value depends on the pH b) the pKa value depends on the concentration of the molecule present c) pkA values change over the course of a titration d) the pKa is an intrinsic property of a molecule in question and depends on how tightly bound the acidic H+ is

d) the pKa is an intrinsic property of a molecule in question and depends on how tightly bound the acidic H+ is

From the list below, which amino acid has an uncharged side chain at pH 7? a) lysine b) arginine c) aspartate d) tyrosine e) glutamate

d) tyrosine

When DNA is sequenced, which analytical technique is used to separate the chain-terminated DNA fragments? a) blue-white screening b) fluorescent labeling c) polymerase chain reaction d) antibiotic resistance e) gel electrophoresis

e) gel electrophoresis

Polycistronic genes that contain a coding sequence for proteins that are only involved in one biochemical process are called ______________. a) introns b) enhancers c) promoters d) exons e) operons

e) operons

During 2020, the COVID-19 virus led to a global pandemic. This virus mutated like all other viruses, although all viruses mutate at different rates. In terms of producing an effective vaccine for a virus, it is better to have a ___________ for a virus.

low mutation rate

There are approximately ______________ complete wraps of DNA around the histone octamer.

two

Given that the standard free energy change of ATP hydrolysis is -30.5 kJ/mol, what is the change in free energy in a cell at 37°C where the ATP and Pi are both 10 mM and ADP is 10 uM?

-60.181 kJ/mol

__________ hydrogen bonds would connect these two complementary strands together. This nucleic acid is most likely __________.

a) eight b) DNA

During eukaryotic DNA condensation, nucleosomes are packed together to form ______________. a) chromosomes b) genes c) chromatin d) histones e) genomes

c) chromatin

Why can humans digest starch but not cellulose or chitin? a) humans can't chew cellulose or chitin b) cellulose and chitin contain sulfur c) humans lack the necessary enzymes d) starch contains glucose and cellulose and chitin does not

c) humans lack the necessary enzymes

As DNA unwinds and denatures, absorbance is predicted to ______________. a) vary unpredictably b) decrease c) increase d) remain the same

c) incrase

The polarity of the solvent and other environmental factors can affect the pKa of a weak acid. Suppose the alpha-amino group of a protein has a pKa of about 8.0 when it is exposed to H2O on the outside of a protein. Would you expect the pKa to be higher or lower than 8.0 if the alpha-amino group were buried in the hydrophobic interior of the protein and why? a) the hydrophobic environment would have no effect on the pKa and therefore it would be the same b) the hydrophobic environment would provide stability to the proton and therefore it would be higher c) alpha-amino group would be unchanged at neutral pH, which is favorable and therefore it would be higher d) the alpha-amino group would be uncharged at neutral pH, which is favorable and therefore it would be lower

d) the alpha-amino group would be uncharged at neutral pH, which is favorable and therefore it would be lower

Which one of the following amino acid residues would most likely be buried in the interior of a water-soluble protein? a) asp b) arg c) ser d) trp e) lys

d) trp

Within the middle base pair, measure the distance between guanine amide oxygen to the cytosine amine nitrogen. This distance between atomic nuclei is approximately __________ .

2.6 angstroms

A patient presents in your clinic with what appears to be be spontaneous TSE. a) What type of biochemical test would be the most definitive to distinguish between a case of spontaneous TSE in a patient that resulted from sporadic PrP protein mis-folding in brain cells or the result of a somatic DNA mutation in the PrP gene? b) Regardless of the molecular basis of spontaneous TSE in this patient, is the probability of their children getting spontaneous TSE later in life high or low? A- Obtain DNA from cells in the region of several brain plaques in the patient and sequence the PrP gene B-Probability is low A- Obtain DNA from cells in the region of several brain plaques in the patient and sequence the PrP gene B- Probability is high A- Obtain protein from cells in the region of several brain plaques in the patient and determine the structure of PrP molecules B-Probability is low A- Obtain protein from cells in the region of several brain plaques in the patient and determine the structure of PrP protein molecules. B-Probability is high

A- Obtain DNA from cells in the region of several brain plaques in the patient and sequence the PrP gene B-Probability is low

True or False: the single-stranded DNA binding protein binds DNA non-specifically through hydrogen bonding interactions.

False

True or False: the structure of the single-stranded DNA binding protein is homotrimeric

False

Sort the following diseases into the appropriate categories of protein malfunction. Type of malfunction: Protein is degraded: Protein aggregates:

Protein is degraded: -Cystic Fibrosis -Phenylketonuria -Tay-Sachs -Hypercholesterolemia Protein aggregates: -Alzheimer's -Sickle cell anemia -Creutzfeldt-Jakob and kuru -Huntington's

GFP fluorescence depends entirely on the final folded structure of the protein itself. The folding process requires dynamic chemistry across amino acid R-groups; in this case, Ser65, Tyr66, and Gly67 are the primary participants in formation of the GFP chromophore. Add the correct names of the chemical reactions to the figure that will successfully complete the folding chemistry for GFP.

Reaction 1= cyclization Reaction 2= dehydration Reaction 3= oxidation

What characterizes (a) secondary and (b) tertiary protein structure? a) (a) alpha helices/beta sheets; (b) zinc fingers b) (a) amino R groups; (b) hydroxyproline helices c) (a) disulfide bonds; (b) hydrophobic effect d) (a) amino acid sequence; (b) multisubunit complexes e) (a) salt bridges; (b) hydrogen bonds

a) (a) alpha helices/beta sheets; (b) zinc fingers

Put the following steps in the GroEL/ES cycle into the correct order. a) Following ADP dissociation, GroES dissociates and folded proteins is released from the lower chamber b) ATP hydrolysis in the upper chamber facilitates protein refolding and resets the lower chamber c) A new unfolded protein enters the lower chamber and the cycle continues d) GroES and ATP bind to the GroEL ring and trap unfolded protein in the upper chamber

a) 2 b) 3 c) 4 d) 1

The discovery of green fluorescent protein in jellyfish and its use as a tag for proteins in cells allowed for major scientific advances in the fields of biochemistry and cellular biology. Which of the following statements best explains why? a) GFP allowed researchers to track fusion proteins in live cells, tissues, and animals using advanced fluorescence microscopy techniques in real time rather than needing to preserve, fix, and stain dead specimens b) GFP allowed researchers to finally study jellyfish proteins in cells, which up until then needed radioactive tracing methods for identification c) the use of GFP in experiments marked the first time optical properties of proteins were used for biochemical study d) this was the first example of a protein from one organism being successfully cloned and expressed with proper function in a different organism

a) GFP allowed researchers to track fusion proteins in live cells, tissues, and animals using advanced fluorescence microscopy techniques in real time rather than needing to preserve, fix, and stain dead specimens

Take a moment to examine the junctions between hemoglobin subunits in the above model. Which of the following might you say is a reasonable assumption? a) altered structure of one subunit may cause a structural shift in a neighborhood subunit b) each subunit functions independently of all the others c) hemoglobin should be able to function with all α or all β subunits since each has a heme group d) a small molecule inhibitor that prevents association of oxygen with the heme should disrupt quaternary assembly of hemoglobin.

a) altered structure of one subunit may cause a structural shift in a neighborhood subunit

Upon reading a primary article, you discover that negative, long-term prognosis for Huntington's patients is directly related to the size of the polyglutamine track expansion in the patient's DNA. Which of the following must be true? a) as the number of glutamines present in the patient's huntingtin protein increases, the higher the probability of protein aggregation b) as the number of glutamines present in the patient's huntingtin protein increases, the lower the probability of protein aggregation c) as the number of glutamines present in the patient's DNA increases, the greater the probability of protein aggregation d) as the number of glutamines present in the patient's DNA increases, the lower the probability of protein aggregation

a) as the number of glutamines present in the patient's huntingtin protein increases, the higher the probability of protein aggregation

Cystic fibrosis is caused by a point mutation in CFTR, a chloride channel responsible for regulating fluid accumulation in the lungs. This mutation tricks the cell into thinking it is mis-folded and it is subsequently degraded by the ubiquitin-proteasome pathway. Which of the following strategies do you think has the highest probability of curing the patient? a) delivering the correct CFTR gene to lung cells by gene therapy b) treating the patient with ubiquitin-proteasome inhibitors c) initiating aggregation of cellular CFTR d) increasing the patient's chloride intake

a) delivering the correct CFTR gene to lung cells by gene therapy

Based on the prion hypothesis, proposed by Dr. Prusiner at UCSF Medical School, which do you think is the best approach to developing a treatment for Creutzfeldt-Jakob disease? a) develop a biochemical that prevents aggregation of the prion protein b) use gene therapy to prevent the mutation from occurring c) initiate prion protein mis-folding d) provide the cell with more ATP to better handle the mis-folded protein load

a) develop a biochemical that prevents aggregation of the prion protein

Match the description of PrP protein diseases on the left with the clinical term on the right. a) presence of an inherited PrP genetic mutation that causes PrP mis-folding b) sporadic PrP mis-folding with or without a PrP DNA mutation c) consuming meat with mis-folded PrP protein without the transfer of pathogenic DNA

a) familial TSE b) spontaneous TSE c) transmissible TSE

Cellular chaperones are incredibly important for human health. Which of the following do you think would be most detrimental to protein folding in the cell and necessitate upregulation of chaperone activity to maintain homeostasis? a) high fever b) low blood oxygen levels c) accelerated cell division d) migration to high altitude

a) high fever

Match the description of a disease caused by misfolded protein on the left with the correct phenotype on the right. a) DNA mutation encodes a protein that is misfolded when synthesized and is quickly degraded by the proteasome b) protein misfolding occurs spontaneously and the protein is rapidly degraded by the proteasome c) protein aggregates form spontaneously from misfolded protein in cells with no DNA mutations in the corresponding gene - gain-of-function d) protein aggregates from in cells as a result of consuming meat from an animal with Mad Cow Disease e) DNA mutation encodes a protein that is misfolded when synthesized and it forms large aggregates - gain-of-function

a) loss-of-function b) loss-of-function c) gain-of-function d) gain-of-function e) gain-of-function

A homopolymer or lysine residues (polylysine) can adopt an alpha-helical conformation or a random coil conformation depending on the pH of the solution. Predict whether the conformation of polylysine would be alpha-helical or random could at a pH of 1, 7, and 11. (Choose a total of three answers. Choose either helix or random coil for pH 1, pH 7, and pH 11) a) pH11 b) pH7 c) pH1

a) pH11- helix b) pH7- random coil c) pH1- random coil

Which of the following is correct about protein folding? a) the amino acid sequence of a protein leads to a limited number of possible folding pathways b) the decrease in possible conformations for a polypeptide is a larger contribution to the entropy of folding than the increased disorder of surrounding water molecules c) protein folding in vivo takes place under more dilute conditions than those used in vitro d) folding does not begin in vivo until the entire polypeptide chain is synthesized

a) the amino acid sequence of a protein leads to a limited number of possible folding pathways

The quaternary structure of hemoglobin includes the assembly of two α and two β subunits, each containing a heme group that is essential for oxygen binding. Double-click on one of the gray heme group atoms in the model above and zoom in to examine it. Which of the following statements best describes the shape and location of the heme groups? a) the heme groups are flat like a pancake embedded within each individual subunit and are not located at the subunit-subunit interaction sites b) oxygen is more accessible to the heme group for the α subunits than for the β subunits because these heme groups are flat and facing outward from the molecule c) the heme groups are flat like a pancake and placed on the surface of hemoglobin to maximize exposure to oxygen in tissues d) the heme group is spherical and is located at the sites of subunit-subunit interaction

a) the heme groups are flat like a pancake embedded within each individual subunit and are not located at the subunit-subunit interaction sites

What level of protein structure describes the spatial location of every atom in a protein? a) 2° b) 3° c) 1° d) 4°

b) 3°

What is the dominant secondary structure found in hair keratin? a) beta-sheets b) alpha helices c) loop structures d) disulfide bonds

b) alpha helices

Which FOUR statements are true regarding the b sheets? a) found in same percentage in all proteins b) an extended conformation of the polypeptide chain c) stabilized by H-bonds between -NH and -CO groups d) hydrophobic interactions are responsible for the primary structure e) includes all 20 standard amino acids in equal frequencies f) the stability is affected by amino acid sequence g) found in globular proteins

b) an extended conformation of the polypeptide chain c) stabilized by H-bonds between -NH and -CO groups f) the stability is affected by amino acid sequence g) found in globular proteins

An antigen binds to an antibody at which of the following locations? a) at the constant domain b) at the variable domain c) only at the heavy chain d) only at the light chain

b) at the variable domain

This mouse is expressing green fluorescent protein (GFP) in its cells. What color light is being shone on the animal to induce fluorescence? a) green b) blue c) red d) yellow

b) blue

Which of the following fibrous proteins contains 4-hydroxyproline as part of its repeating pattern? a) keratin b) collagen c) fibroin light chain d) fibroin heavy chain

b) collagen

What might be a best CRISPR-Cas9 treatment for heterozygous familial TSE based on the success of recent human gene therapies using gene editing? a) could target the known mutated PrP gene in muscle cells using a CRISPR-Cas9 gene knock-out approach because targeting brain cells is dangerous b) could target the known mutated PrP gene in brain cells using a CRISPR-Cas9 gene knock-out approach; normal PrP is still expressed in brain cells c) could target the known mutated PrP gene in brain cells using a CRISPR-Cas9 gene knock-in approach; no PrP protein is expressed in brain cells. d) could pass multiple copies of normal PrP genes to brain cells so that the amount of PrP protein is 100x higher than the mutant PrP protein

b) could target the known mutated PrP gene in brain cells using a CRISPR-Cas9 gene knock-out approach; normal PrP is still expressed in brain cells

Sickle cell anemia patients suffer from distorted red blood cell shape and an anemic condition as a result of a genetic mutation in the HBB gene, which codes for the hemoglobin β subunits. This mutation changes a Glu to a Val at position 6 in the protein, and these patients express two alleles (one from each parent) with this mutation. When individuals inherit just one copy of this mutated gene, they are considered carriers, and have very few symptoms. Based on the quaternary structure of hemoglobin, what can you predict about the assembly of hemoglobin in sickle cell anemia patients versus carriers of the sickle cell trait? a) in sickle cell anemia patients, 100% of the hemoglobin is fully functional, whereas in those that carry the trait, there is no functional hemoglobin assembled b) in sickle cell anemia patients, 100% of the hemoglobin assembled contains the mutant β globin, while in carriers, 50% of the hemoglobin assembled contains the mutated version c) in individuals with the sickle cell mutation, hemoglobin α subunits cannot bind to β globin at all, and the quaternary structure cannot assemble d) in sickle cell anemia patients, the α globin subunits have complementary mutations to ensure the quaternary structure of hemoglobin is attained

b) in sickle cell anemia patients, 100% of the hemoglobin assembled contains the mutant β globin, while in carriers, 50% of the hemoglobin assembled contains the mutated version

In the opening sequence of the video, a protein is "unraveled' down to an extended linear conformation. Which of the following statements accurately captures what is happening in this process? a) the protein's primary structure is destroyed frist, followed by the secondary, then tertiary, and finally quaternary structure. b) linearizing the polypeptide destroys the spatial relationships that define secondary and tertiary structure c) because this process does not interconvert alpha helices and beta sheets, the secondary structure is unchanged d) because no amino acids are added or removed in this process, the tertiary structure is unchanged.

b) linearizing the polypeptide destroys the spatial relationships that define secondary and tertiary structure

The point in the Ramachandran plot are derived by _____. a) experimentally measuring the optical rotation of polarized light b) measuring the phi and psi angles in an experimentally determined protein crystal structure c) placing each amino acid in regions commonly occupied by that amino acid d) counting the number of amino acids and placing points in allowed regions

b) measuring the phi and psi angles in an experimentally determined protein crystal structure

What is a difference between parallel and antiparallel b-sheet secondary structures? a) parallel b-sheets have amino acid side chains alternating up and down, whereas antiparallel side chains alternate down and up b) parallel b-sheets require a larger loop connecting together the individual peptide strands in the sheet c) parallel b-sheets are longer than antiparallel sheets d) antiparallel b-sheets have a larger number of stabilizing H bonds between backbone amides than parallel b-sheets

b) parallel b-sheets require a larger loop connecting together the individual peptide strands in the sheet

hat would be the expected orientation of an amphipathic alpha helix occurring in a globular protein in aqueous solution? a) asoluble protein will have a hydrophobic core and a hydrophilic surface, so hydrophilic and hydrophobic amino acids will alternate every other position in the polypeptide chain b) hydrophilic amino acids are complementary to hydrophobic amino acids so the hydrophilic side of the alpha helix should be facing toward the hydrophobic core of the protein c) a soluble protein will have many hydrophilic amino acids on its surface, so the helix will be arranged to have the hydrophilic side facing toward the outside of the protein d) a soluble protein will have mostly hydrophilic amino acids in its core, so the helix will be arranged to have the hydrophobic side facing toward the core of the protein

c) a soluble protein will have many hydrophilic amino acids on its surface, so the helix will be arranged to have the hydrophilic side facing toward the outside of the protein

Rotate the molecular structure. This can be done by clicking and dragging with your mouse, track pad, or touchscreen, depending on your device. Locate the adenine nitrogenous base and determine its location within the molecular structure. Which best describes its location? a) not as part of a base pair; at the 5' end in one polynucleotide strand b) as part of a base pair; at the 5' end in one polynucleotide strand c) as part of a base pair; at the 3' end in one polynucleotide strand d) not as part of a base pair; at the 3' end within one polynucleotide strand

c) as part of a base pair; at the 3' end in one polynucleotide strand

When Hsp70 binds ATP, it undergoes a conformational change that exposes hydrophobic residues. The exposed hydrophobic residues on Hsp70 a) cause the clamp to close b) bind to the hydrophilic residues on the mis-folded protein c) bind to the hydrophobic residues on the mis-folded protein d) hydrolyze ATP to ADP

c) bind to the hydrophobic residues on the mis-folded protein

Two amphipathic alpha helices in a dilute aqueous solution are likely to ______________. a) rearranges into B sheets in order to stack against each other to bury hydrophobic side chains b) repel each other and remain as individual helical molecules c) form a coiled coil structure with the hydrophobic amino acid side chain interacting with each other down the middle d) form a coiled structure with the polar amino acid side chains interacting with each other down the middle

c) form a coiled coil structure with the hydrophobic amino acid side chain interacting with each other down the middle

A protein solution is more likely to maintain its native conformation when _____. a) the number of hydrogen bonds within a protein is minimized b) The protein is least stable c) its hydrophobic residues are largely buried in the protein interior d) the shell of water becomes more ordered

c) its hydrophobic residues are largely buried in the protein interior

Which of the following statements could be considered true for both the Hsp-70 mediate and GroEL-GroES-mediated protein-folding processes? a) both Hsp70 and GroEL-GroES are considered chamber-type chaperones b) ADP hydrolysis is critical to completion of the protein-folding cycle c) proteins are typically released from both complexes in a partially folded form and the folding cycle may need to be repeated multiple times d) exposed hydrophilic patches on the surface of unfolded proteins initiate recognition with chaperones.

c) proteins are typically released from both complexes in a partially folded form and the folding cycle may need to be repeated multiple times

For Anfinsen's studies of RNase A folding, which of the following is correct? a) trace amounts of urea could be added to inactive protein to rescue the experiment b) B-mercaptoethanol (BME) was used to disrupt disulfide bonds of the native protein so refolding could occur under favorable conditions c) removal of β -mercaptoethanol (BME) and urea at the same time allowed for the unfolded protein to refold d) removal of β-mercaptoethanol (BME), followed by raising the temperature to 90℃, resulted in active RNaseA e) urea is a highly polar solvent that can be used to fold proteins through formation of intramolecular hydrogen bonds f) addition of β-mercaptoethanol and urea at the same time resulted in active RNaseA g) removal of β-mercaptoethanol (BME) and urea at the same time allowed for the folded protein to unfold

c) removal of β -mercaptoethanol (BME) and urea at the same time allowed for the unfolded protein to refold

Disulfide bonds stabilize ____________ level of proteins structure and above. Choose one: a) secondary b) primary c) tertiary d) quaternary

c) tertiary

Which of the following protein-folding diseases is a loss-of-function disease? a) Creutzfeldt-Jakob disease b) Alzheimer's disease c) Huntington's disease d) Cystic fibrosis

d) Cystic fibrosis

Which of the of four amino acids residues listed in the choices below are all most likely to be buried in the interior of a water soluble protein? a) asp, cys, lys, val b) thr, glu, phe, arg c) trp, arg, his, tyr d) ala, val, leu, ile e) cys, ser, the, lys

d) ala, val, leu, ile

The Hsp70 and GroEL-GroES chaperones initiate protein folding in which cellular compartment? a) nucleus b) mitochondria c) plasma membrane d) cytosol

d) cytosol

Which stabilizing force in protein teriary structures is a covalent bonding force? a) hydrophobic effects b) van der waals interaction c) ionic bonding d) disulfide bonding

d) disulfide bonding

Currently, there is much interest in studying the different "omes". Which of the following "ome" is matched with its correct biomolecule? a) metabolome- mRNA b) genome- mRNA c) transcriptome- protein d) proteome- proteins

d) proteome- proteins

What is the energy change for the cell with concentrations of [ATP]= 1.000 mM, [ADP]= 10.00 uM, and [AMP]= 3.00 uM?

0.992 (unitless)

The partial sidechain of asparagine or glutamine is shown above. For the three atoms marked A, B, and C, indicate whether they serve as donors, acceptors, or neither for hydrogen bonds.

A- neither B- acceptor C- donor

A histidine residue is in a hydrophobic environment in the interior of a protein. If the pKa of the imidazole group of this histidine is 5.5, what would be the ratio of deprotonated imidazole sidechain to pronated imidazole sidechain at pH 7? a) 31.6/1 b) .0316/1 c) 4.5/1 d) .22/1

a) 31.6/1

Match each of the four building block biomolecules on the left with the one specific biomolecule on the right that best represents it. a) simple sugars b) fatty acids c) nucleotides d) amino acids 1-aspartate 2- adenine 3- polypropylene 4- ribose 5- palmitate 6- dinitrophenol 7- sulfur 8- methyl group 9- plasmid DNA 10- protein kinase A 11- ibuprofen 12- cytidine monophosphate

a) 4 b) 5 c) 12 d) 1

True or False: Positively-charged amino acids on the surface of SSB bind to the negatively charged phosphate group on DNA to facilitate nonspecific binding.

True

True or False: Rosalind Franklin died before the Nobel Prize was awarded for solving the structure of DNA and her seminal contributions to this discovery were not recognized because Novel Prizes are not awarded posthumously.

True

True or False: Two proteins have the same overall fold, but different amino acid sequences. These proteins likely derived from a common ancestor.

True

Pyruvate decarboxylase converts pyruvate into ______________. a) ethanol and carbon dioxide b) carbon dioxide and acetaldehyde c) water and glucose d) carbon monoxide and acetaldehyde

b) carbon dioxide and acetaldehyde

COVID-19 is an RNA virus. This means that RNA is packed inside the protein coating of the virus, along with some factors needed for infectivity. The RNA is injected into cells and then reverse transcribed into DNA in the cell. One of the methods of detecting COVID-19 in potentially infected people is using the polymerase chain reaction. Order the steps of PCR used to amplify the DNA from a COVID-19 infection.

[First step in PCR] a) Add heat resistant polymerase, dNTPs, cofactors, water, primer, and purified DNA from patient sample to PCR tube Increase temperature of PCR instruments to 95 °C to denature the DNA Reduce temperature of PCR instrument to approximately 55 °C to allow primer to anneal to DNA Increase temperature of DNA instrument to 72 °C to allow the polymerase to extend Repeat temperature cycling until enough DNA is produced [Last Step]

What is the approximate net charge of the molecule shown below at pH 7? a) -1 b) +1 c) 0 d) -2

a) -1

Identify the four building block biomolecules from the list, and then match them with the best description of each primary cellular function. a) cell membranes b) enzymes catalysis c) neurotransmission d) cell recognition 1- nucleotides 2- proteins 3- amino acids 4- glucose 5- pyruvate 6- simple sugars 7- lipids 8- ATP 9- carbohydrates 10- fatty acids 11- acetyl-CoA 12- carbon dioxide

a) 10 b) 1 c) 3 d) 6

The HindIII-DNA complex that is shown in this molecular structure contains __________ amino terminus/termini and __________ carboxy terminus/termini. An amino terminus sequence KSALEKLLSL is associated with a(n) _________. Use the sequence view from the dropdown menu and determine the location of KSALEKLLSL within the folded peptide.

a) 2 b) 2 c) Ɑ helix

Put the following hierarchical levels in the correct oder representing the structure organization of life on Earth. The number 1 is the lowest hierarchical level (base of the pyramid) and the number 7 is the highest hierarchical level (tip of the pyramid). a) adenine b) ketogenesis c) phosphoryl group d) cellulose e) manta ray f) great barrier reef g) mitochondria

a) 2 b) 4 c) 1 d) 3 e) 6 f) 7 g) 5

Sort the following as belonging to both DNA and RNA, DNA only, or RNA only. a) used in transcription b) guanine c) is base labile d) adenine e) uracil f) thymine g) ribose sugar h) used in translation i) cytosine j) usually forms single strands, multiple conformations k) nitrogenous bases l) phosphate group m) deoxyribose sugar n) usually forms double-stranded double helix

a) DNA and RNA b) DNA and RNA c) RNA d) DNA and RNA e) RNA f) DNA g) RNA h) RNA i) DNA and RNA j) RNA k) RNA and DNA l) RNA and DNA m) DNA n) DNA

Which three statements below accurately describe the structure and function of nucleic acids in living cells? a) DNA can be the template for RNA synthesis b) all RNA molecules in cells encode proteins c) DNA is the template for protein synthesis d) RNA can be the template for protein synthesis e) all DNA in a human cell is contained in the nucleus f) DNA can be the template for DNA synthesis g) viral DNA cannot be the template for DNA synthesis h) all protein in cells encodes enzymes

a) DNA can be the template for RNA synthesis d) RNA can be the template for protein synthesis f) DNA can be the template for DNA synthesis

DNA samples from four individuals are cleaved with the same endonuclease, and the fragments are separated by gel electrophoresis (as shown above). The DNA is incubated with a probe complementary to part of the DNA. Lanes I, II, III and IV are the samples from individuals I, II, III, and IV, respectively Individual I has five restriction sites - A, B, C, D and E (see diagram above) a) Which individual has a point mutation that eliminates restriction site C only? b) Which individual has a point mutation that eliminates restriction sites B and C? c) Which individual has a point mutation that eliminates restriction site A?

a) II b) IV c) cannot be determined

The secondary structure of DNA is often B-DNA, which is a double helix that contains a minor groove and a major groove. When dying DNA molecules for DNA laboratory techniques, there are two general types of dyes that specifically bind to DNA to make it fluorescent. One type of dye, such as ethidium bromide, intercalates in between bases inside the DNA, and is only fluorescent when it is intercalated into DNA. Another type of dye rests in the major or minor groove of DNA, such as SYBR Green, and is only fluorescent when it is bound in the groove of DNA. Intercalating dyes are considered to be more carcinogenic than groove-binding DNA dyes if they are absorbed through the skin of the researcher. Which of the following options is the most reasonable explanation for this? a) The intercalated dyes will lead to increased mutations upon DNA replication since they are inserted into the bases that are used as a template for DNA replication. b) The groove-binding dyes increase the chance of mutation when DNA is being replicated because the sugar phosphate backbone is used as a template during DNA replication. c) The intercalated dyes emit more UV light, causing more damage to the DNA than the groove-binding dyes. d) The intercalated dyes attract more carcinogens in the cell to the DNA than the groove-binding dyes.

a) The intercalated dyes will lead to increased mutations upon DNA replication since they are inserted into the bases that are used as a template for DNA replication.

Given a solution composed of equal volumes of .05 M acetic acid and 0.1 M sodium acetate, determine if the following statements are true or false. a) doubling the concentration of acetic acid and sodium acetate will double the pH capacity b) doubling the concentration of acetic acid will increase the pH c) doubling the concentration of sodium acetate will decrease the pH d) adding acetic acid will decrease pH of a solution

a) True b) False c) False d) True

A titratable group is in the active site of an enzyme and must be protonated for the enzyme to function. Assume that the group has a pKa of 6.5 and that the activity is proportional to the fraction of molecules in the protonated state. Which four of the following statements is true? a) at pH close to 100% of the enzyme molecules are inactive v) at pH 7.2 there are about 5 inactive enzymes for every active enzyme c) at pH 6.5 the enzyme is 50% active d) at pH 9.0 close to 100% of the enzyme molecules are active e) at pH 6.8 the enzyme is 66.6% inactive

a) at pH close to 100% of the enzyme molecules are inactive

Why is it energetically favorable to form one large oil droplet (protein complex) rather than many oil droplets (protein monomers) in an aqueous solution? a) because there is less ordered water with large oil droplets, so higher entropy overall b) because large oil droplets have a more positive standard change in free energy than do smaller water droplets, so more favorable c) because there is more ordered water with large oil droplets, so higher entropy overall d) because there is less ordered water with large oil droplets, so lower entropy overall

a) because there is less ordered water with large oil droplets, so higher entropy overall

When DNA is transcribed into RNA, the ______________ strand has the same base sequences as the RNA transcript. a) coding b) mirror c) antiparallel d) template e) parallel

a) coding

Which molecular event is most responsible for transducing the signal from outside of the cell to the inside of the cell? a) conformational change in the receptor b) hormone dissociation from the receptor c) interaction of the receptor with cytosolic proteins d) hormone association with the receptor

a) conformational change in the receptor

Match each description on the left with the most accurate thermodynamic term on the right on the right. a) the ratio of the concentration of products divided by the concentration of reactants when the rate of the product formation is equal to the rate of reactant formation. b) unplugging an ice maker results in a puddle of water on the floor because the energy required to form ice crystals in not available c) a value greater than 1 indicates that the reaction as written is spontaneous in the forward direction d) the amount of energy available form the oxidation of 1 gram of glucose is exactly the same regardless of the physical or biological process required for oxidation to occur e) thermogenesis in a hibernating bear results from oxidizing fat stores that are required to keep the bear alive during winter f) staying as far away from equilibrium with the environment as possible is the only way to stay alive, this requires a constant input of energy. g) the difference between the enthalpy (bond energy) and entropy (level or order) of a reactant and product at a given reaction temperature h) a positive value indicates that the reaction as written is spontaneous in the reverse direction

a) equilibrium constant b) second law of thermodynamics c) equilibrium constant d) first law of thermodynamics e) first law of thermodynamics f) second law of thermodynamics g) Gibbs' free energy h) Gibbs' free energy

Within the double helices that are shown above, which relationships between both strands of DNA double helix are present? a) non-complementary b) complementary c) identical d) antiparallel e) parallel

b) complementary d) antiparallel

Which THREE of the following statements about autotrophs and heterotrophs are true? a) heterotrophs are dependent on autotrophs to generate O2 from H2O in order to support aerobic respiration b) heterotrophs depend on autotrophs for conversion of light energy to chemical energy c) the majority of autotrophs on Earth require aerobic respiration in order to survive d) heterotrophs that do not eat autotrophs every day will die in a short time e) autotrophs depend on heterotrophs to oxidize sugar and release CO2 into the atmosphere f) there are no metabolic differences between autotrophs and heterotrophs g) the majority of heterotrophs on Earth do not use aerobic respiration as a form of energy conversion

a) heterotrophs are dependent on autotrophs to generate O2 from H2O in order to support aerobic respiration b) heterotrophs depend on autotrophs for conversion of light energy to chemical energy c) the majority of autotrophs on Earth require aerobic respiration in order to survive

In CRISPR-Cas9, ______________ is used to replace a mutated DNA sequence that leads to genetic disease with an alternative DNA sequence that does not contain the mutation. This method of DNA repair can be used to produce a ______________. There are many appplication of CRISPR-Cas9 and if a researcher needed to find the location of a particular gene on a chromosome using light microscopy a(n) ______________ would be useful.

a) homology directed repair b) gene knock-in c) auto-fluorescent protein domain

Match the four amino acid structures below with each of the four chemical groups. Each amino acid fits into only one chemical group: hydrophobic (HB), charged (C), hydrophilic (HL), aromatic (A). a) valine b) tryptophan c) arginine d) threonine

a) hydrophobic b) aromatic c) charged d) hydrophilic

Structure determines function, however structure alone is not always sufficient to predict function, especially for proteins. one way to understand the association between protein structure and protein function, even if it is not absolute, is to use analogies. Based on the following protein examples, match the analogy with the protein pair i. ribonucleotide reductase (bacteria) and ribonucleotide reductase (mouse) ii. porin channel protein and green fluorescent protein iii. GR transcription factor and GCN4 transcription factor a) apple tree and pear tree b) lemon and tennis ball c) boat and submarine

a) i b) ii c) iii

Select the four TRUE statements below describing the standard free energy change (delta G) and the equilibrium constant (Keq) a) if the value of the equilibrium constant is known, the value for the standard free energy change can be determined b) the value for the equilibrium constant can be experimentally determined for a given reaction c) the equilibrium constant is equal to the ratio of the concentration of reactants over products at equilibrium d) a reaction is spontaneous when the standard free energy change and the equilibrium constant are both negative values e) the standard free energy change is a function of enzyme concentration in the reaction f) the equilibrium constant is the ratio of product and reactant concentrations at equilibrium g) the value for the standard free energy change is constant for a given reaction

a) if the value of the equilibrium constant is known, the value for the standard free energy change can be determined b) the value for the equilibrium constant can be experimentally determined for a given reaction f) the equilibrium constant is the ratio of product and reactant concentrations at equilibrium g) the value for the standard free energy change is constant for a given reaction

When a gene sequence is cloned from mRNA is first isolated from the cell and then converted into a double-stranded sequence using the enzyme ______________. a) reverse transcriptase b) DNA methylase c) restriction endonucleases d) telomerase e) DNA ligase

a) reverse transcriptase

Which of the following statements about phospholipids is false? a) the polar head group of phosphatidylcholine cannot form hydrogen bonds b) the polar head group of phospholipids is hydrophilic c) the hydrocarbon tail of phospholipids is hydrophobic d) phospholipids orient in lipid bilayers with the hydrophobic tails pointing inward, interacting with each other

a) the polar head group of phosphatidylcholine cannot form hydrogen bonds

Which of the following best describes the relationship between D-amino acids and L-amino acids? a) they are mirror images of each other b) they are counterclockwise to each other c) they are oppositely charged to each other d) they are chemically equivalent

a) they are mirror images of each other

Which of the following statements are true regarding reaction A and reaction B at standard conditions? a) reaction B is favorable b) reaction A is spontaneous c) reaction A coupled to reaction B is spontaneous d) reaction B is spontaneous e) reaction A releases energy to the surroundings

a) true b) false c) true d) true e) false

If a cell is placed in a hypotonic solution, then ______________. a) water will flow into the cell b) solutes in the cell will be pumped out c) there will be no net change in flow of water into or out of the cell d) solutes in the solution will enter the cell e) water will flow out of the cell

a) water will flow into the cell

How much space along the logitudinal axis of DNA does the HindIII enzyme occupy when bound? a)approximately one major groove and one neighboring minor groove, which in total is approximately 40 angstroms b) approximately two major grooves and the two neighboring minor grooves, which in total is approximately 40 angstroms c) approximately three major grooves and the three neighboring minor grooves, which in total is approximately 20 angstroms d) approximately four major grooves and the four neighboring minor grooves, which in total is approximately 20 angstroms

a)approximately one major groove and one neighboring minor groove, which in total is approximately 40 angstroms

The partial sidechain of asparagine or glutamine is shown above. For the three atoms marked A, B, and C, indicate whether they serve as donors, acceptors, or neither for hydrogen bonds. (Choose THREE total answers (one each for A, B, and C) from the list of nine possibilities.

a- neither b- acceptor c- donor

What is the approximate ratio of the base to acid forms of the amino glutamate contained within a protein at pH 7.2 given that the pKa of the carboxyl R group os 4.0? a) 3.2 b) 1,580 c) 150 d) 6.3x10^4

b) 1,580

The DNA of bacteria was isolated and it was determined that 15% of the DNA is composed of cytosine, What percentage of the DNA is adenine? a) 15% b) 35% c) 70% d) 30%

b) 35%

The following figure maps the spread of an infectious disease by using DNA sequencing and bioinformatics to chart the changes in the viral DNA sequence across space. The magnitude of the outbreak in different geographical locations is indicated by the size of the circle, with the larger circles showing the extent of the outbreak in that area. According to the map, what was the sequence of the original virus? a) CAATGC b) CAGTGC c) TTGGGA d) TTGTGC

b) CAGTGC

Although Watson and Crick could construct a DNA double helix with A-A and C-C base pairs, there were two reasons why this arrangement was unlikely to be valid. Choose the two reasons from the list below. a) there are three times more adenine nucleotides in DNA compared to cytosine nucleotides, which is inconsistent with A-A and C-C base pairs. b) Erwin Chargaff showed that the abundance of A equaled T and G equaled C nucleotides, so A-A and C-C base pairs is inconsistent with this data c) Chargaff's rule says the abundance of adenine and cytosine nucleotides are equal in DNA from different species, which is inconsistent with A-A and C-C d) the A-A and C-C base pairing structures would not allow for RNA transcription because U-U base pairing would be required and Watson already knew this e) distance between the ribosome sugars in A-A and C-C base pairs are significantly different, whereas purine-pyrimidine base pairs are equally spaced f) it was known that purine and pyrimidine nucleotides have complementary sp2 orbitals and are more likely to form hydrogen bonds than A-A and C-C

b) Erwin Chargaff showed that the abundance of A equaled T and G equaled C nucleotides, so A-A and C-C base pairs is inconsistent with this data e) distance between the ribosome sugars in A-A and C-C base pairs are significantly different, whereas purine-pyrimidine base pairs are equally spaced

For the reaction: A + B <--> C + D, which of the following is correct? a) Keq = [A][B]/[C][D] b) Keq = [C][D]/[A][B] c) ΔG° = -RT log Keq d) ΔG° = RT ln Keq

b) Keq = [C][D]/[A][B]

Given the following reactions or reaction conditions, determine which are spontaneous. a) △G°'>0 b) Keq=10,000 c) △H<0 and △S>0 d) △G°'= +12.0 kJ/mol e) The hydrolysis of ATP under standard conditions: ATP↔ADP+Pi

b) Keq=10,000 c) △H<0 and △S>0 e) The hydrolysis of ATP under standard conditions: ATP↔ADP+Pi

What type of histone amino acid substitution would be least likely to impact the histone-DNA interaction? a) arginine to alanine b) arginine to lysine c) arginine to leucine d) arginine to glycine

b) arginine to lysine

Two amphipathic a-helicies in a dilute aqueous solution are likely to a) repel reach other and remain as individual helical molecules b) form a coiled coil structure with the hydrophobic amino acid side chains interacting with each other down the middle c) form a coiled coil structure with the polar amino acid side chains interacting with each other down the middle d) rearrange into B sheets in order to stack against each other to bury hydrophobic side chains

b) form a coiled coil structure with the hydrophobic amino acid side chains interacting with each other down the middle

Which three molecules listed below are examples of biological polymers? a) pyruvate b) glycogen c) glycolysis d) monosaccharide e) DNA f) fatty acid g) alcohol dehydrogenase h) cyanobacteria

b) glycogen e) DNA g) alcohol dehydrogenase

Red blood cells are placed into a solution of unknown solute concentration. After an hour they have all burst open. The best explanation is that the solution ______________. a) was at equilibrium b) had no solutes c) had a very high concentration of solutes d) had a very high concentration of solvent

b) had no solutes

Limonene is a non-polar molecule. The water molecules around it forms ______________. a) covalent bonds with limonene and entropy increases b) hydrogen bonds with itself and the entropy decreases c) ionic bonds with itself and the entropy decreases d) hydrogen bonds with limonene and the entropy increases

b) hydrogen bonds with itself and entropy decreases

DNA methylase enzymes transfer a methyl group to C-5 of a cytosine or to N-6 of an adenine within a DNA sequence recognized by the enzyme. What effect, if any, would this have on the establishment of the HindIII-DNA complex that is shown in this molecular structure? a) If the HindIII target DNA were methylated, then it would increase the probability of binding between HindIII and DNA and would increase the endonuclease activity at that methylated site. b) if the HindIII target DNA were methylated, then it would decrease the probability of binding between HindIII and DNA and would decrease the endonuclease activity at that methylated site. c) if the HindIII target DNA were methylated, then it would not alter the probability of binding between HindIII and DNA and would not alter the endonuclease activity at that methylated site. d) if the HindIII target DNA were methylated, then it would increase the probability of binding between HindIII and DNA and would decrease the endonuclease activity at that methylated site. e) if the HindIII target DNA were methylated, then it would decrease the probability of binding between HindIII and DNA and would increase the endonuclease activity at that methylated site.

b) if the HindIII target DNA were methylated, then it would decrease the probability of binding between HindIII and DNA and would decrease the endonuclease activity at that methylated site.

What happens to an organism if it is no longer able to convert energy from the environment (nutrients or sunlight) into chemical energy? a) it converts from being a heterotroph to an autotroph b) it reaches equilibrium with the environment and dies c) it reaches equilibrium with the environment and goes to sleep d) it uses 100 kj/mol of standard free energy to regenerate

b) it reached equilibrium with the environment and dies

Identify the THREE conditions in the list below that BEST describe low energy charge in a cell. a) AMP concentrations are very low b) low ATP concentrations c) high ATP concentrations d) high glucose concentrations e) the energy charge ratio is above 0.85 f) the amount of stored glycogen in the cell is high g) high AMP concentrations h) flux in anabolic pathways > catabolic pathways i) very low ADP concentrations j) the energy charge ratio is below 0.70

b) low ATP concentrations g) high AMP concentrations j) the energy charge ratio is below 0.70

Energy conversion in living system is required for what three types of work? a) osmotic work, chemical work, mechanical work b) osmotic work, chemical work, mechanical work c) osmotic work, photosynthetic work, mechanical work d) kinetic work, chemical work, mechanical work

b) osmotic work, chemical work, mechanical work

For the figure shown below, which of the following is correct? a) the minor groove is labeled B b) the blue and yellow strands have an antiparallel orientation c) the blue and yellow strands have a parallel orientation d) the major groove is labeled A

b) the blue and yellow strands have an antiparallel orientation

Given the energy charge equation below, if a biological system has an EC= .8, what is true about the concentration of ATP, ADP, and AMP in the system? a) there is more ADP in the system than ATP or AMP b) there is more ATP in the system than ADP or AMP c) the concentrations are all equal d) there is more AMP in the system than ATP or ADP

b) there is more ATP in the system than ADP or AMP

What is the isoelectric point (pI) of the free amino acid lysine, which has the following three pKa values: 2.1 for the a-carboxyl group 9.7 for the a-amino group 10.5 for the side chain amino group a) 6.3 b) 5.9 c) 10.1 d) 7.0

c) 10.1

A solution with a [H+] of 1x10^-9 M has a pH of ______________ and a [OH-] concentration of 1x10-______________ . This is considered a(n) ______________ solution, whereas a solution with a pH of 4 would be considered a(n) ______________ solution. a) 10; 9; basic; acidic b) -9; 9; acidic; basic c) 9; 5; basic; acidic d) 9; 5; acidic; basic

c) 9; 5; basic; acidic

Choose the ONE answer below that correctly identifies the nucleic acid bases in the chemical structures shown. The atoms colors are blue= nitrogen, red= oxygen, carbon= light green, phosphate= dark green a) uracil, thymine b) adenine, cytosine c) adenine, uracil d) adenine, thymine e) guanine, adenine

c) adenine, uracil

Fatty acids are important for cell membrane formation because they are ______________. a) only hydrophilic b) only hydrophobic c) amphipathic d) only polar

c) amphipathic

Watson and Crick had an alternative model for the DNA double helix that had A-A, T-T, C-C, and G-G base pairs. How is it possible to form hydrogen bonds between A-A and C-C base pairs? a) if the nucleotide base can be rotated 90 degrees relative to each other, then three hydrogen bonds can be formed between A-A and C-C base pairs b) if the DNA strands are oriented in a parallel direction and are 5' to 3', then the nucleotide bases will lines up correctly to base pair A-A and C-C c) if the nucleotide base can be rotated 180 degrees within the DNA helix, then two hydrogen bonds can be formed between A-A and C-C base pairs d) by inverting the ribose sugars relative to the phosphates nucleotide bases will also be inverted and hydrogen bonds will form between A-A and C-C

c) if the nucleotide base can be rotated 180 degrees within the DNA helix, then two hydrogen bonds can be formed between A-A and C-C base pairs

When K+ ion concentration in a DNA sample is increased from 50 mM to 100 mM, then the tm will ______________. a) decrease b) remain the same c) increase d) vary unpredictably

c) increase

To study red blood cells without damaging them through osmotic shock, they should be kept in a solution which is... a) hypotonic b) hypertonic c) isotonic d) at the pH e) allosteric

c) isotonic

The cell fusion experiment using heterokaryons provided evidence that a) that phospholipids are able to flip from the outside to the inside of the cell b) that phospholipids are held in place and unable to move laterally in the membrane c) membrane proteins are able to move laterally across the cell surface d) the viruses cause proteins to move from the inside of the cell to the outside of the cell e) that cell membranes are either red or green depending on the virus

c) membrane proteins are able to move laterally across the cell surface

The excess sodium ions are most likely interacting with which chemical component of the nucleotides? a) pentose sugar b) nitrogenous base c) phosphate group

c) phosphate group

The figure below shows two different transcription factors. Which one of the following statements describes these two proteins? a) proteins with a similar structure can have similar functions b) protein structure is not determined by its amino acid sequence c) proteins with different structures can have similar functions d) proteins with a similar structure can have different functions

c) proteins with different structures can have similar functions

Type II topoisomerase enzymes are important in replication and transcription because they ______________. a) stabilize the cleaved complex b) prevent DNA cleavage c) relieve the positive supercoiling d) prevent autocleavage

c) relieve the positive supercoiling

Choose the two correct answers below that most accurately describe the difference between the actual change in free energy and the standard change in free energy. a) the actual change in free energy is dependent on temperature whereas the standard change in free energy is dependent on pressure but not temperature b) the standard charge of free energy is a function of time whereas the actual change in free energy is a function of the rate constant c) the standard change in free energy reflects the potential energy in reactants and products independent of concentration whereas the actual change in free energy is dependent on the concentration of reactants and products under steady state conditions d) the actual change in free energy changes in response to the environment whereas the standard change in free energy is a constant for a given reaction e) there is no difference between the actual change in free energy and the standard change in free energy as long as the concentration of H2O is 55 M.

c) the standard change in free energy reflects the potential energy in reactants and products independent of concentration whereas the actual change in free energy is dependent on the concentration of reactants and products under steady state conditions d) the actual change in free energy changes in response to the environment whereas the standard change in free energy is a constant for a given reaction

Select the two TRUE statements from the choice below. a) in liquid water, the hydrogen bonds between water molecules are long-lived, thus accounting for the cohesiveness of liquid water b) water can readily form hydrogen bonds with N-H, C=O, and C-H groups of proteins c) water is less dense as a solid than a liquid, which is why ice floats d) each water molecule can form up to four hydrogen bonds simultaneously

c) water is less dense as a solid than a liquid, which is why ice floats d) each water molecule can form up to four hydrogen bonds simultaneously

Choose the two correct statements below regarding the effect of NaCl in solution on the integrity of the red blood cell membrane. (Check all that apply). a) when placed in an isotonic solution, the RBC will remain the same size because [solute] inside the cell is lower than the [solute] outside the cell b) when placed in a hypotonic solution, the RBC will burst because [H2O] inside the cell is higher than the [H2O] outside the cell c) when placed in a hypertonic solution, the RBC will shrink because [H2O] inside the cell is higher than the [H2O] outside the cell d) when placed in a hypotonic solution, the RBC will burst because [H2O] outside the cell is higher than the [H2O] inside teh cell e) When placed in a hypertonic solution, the RBC will shrink because [H2O] inside the cell is lower than the [H2O] outside the cell

c) when placed in a hypertonic solution, the RBC will shrink because [H2O] inside the cell is higher than the [H2O] outside the cell d) when placed in a hypotonic solution, the RBC will burst because [H2O] outside the cell is higher than the [H2O] inside teh cell

A 20 bp duplex with ______________ content at ______________ will have the highest absorbance at 280 nm. a) 40 percent G-C, 50 degrees C and 50 mM NaCl b) 60 percent G-C, 50 degrees C c) 60 percent G-C, 50 degrees and 50 mM NaCl d) 60 percent A-T, 50 degrees C

d) 60 percent A-T, 50 degrees C

DNA strands containing 20 base pairs, 40 base pairs, and 60 base pairs were denatured and the results were graphed below. Identify the curve from the 60 base pair DNA strand. a) B b) A c) not enough information is included to determine the curve d) C

d) C

The energy change in a system is related to the amount of heat transferred and work done. If there is no heat transferred, what is the magnitude of work in a system equal to? a) Initial energy of the system (E initial) b) Total energy of the system (E initial + E final) c) Final energy of the system (E final) d) Energy change in the system (△E= E final -E Initial)

d) Energy change in the system (△E= E final -E Initial)

A polypeptide has a high pI value. Which statement below best describes what might be contributing to the observed high pI value? a) a mixture of aspartate and arginine residues b) a large number of aspartate and glutamate residues c) a large number of non-polar amino acids d) a large number of arginine and lysine residues

d) a large number of arginine and lysine residues

Serine is an example of a(n) ______________, maltose is an example of a(n) ______________, guanine is an example of a(n) ______________, and sterate is an example of a(n) ______________. Choose the answer below that fills in all the blanks correctly. a) nucleotide; amino acid; simple sugar; fatty acid b) sugar; amino acid; nucleotide; fatty acid c) fatty acid; amino acid; simple sugar; nucleotide d) amino acid; simple sugar; nucleotide; fatty acid

d) amino acid; simple sugar; nucleotide; fatty acid

Organisms on Earth are considered ______________ life forms. a) nitrogen b) hydrogen c) oxygen d) carbon

d) carbon

The ______________ strand is the same sequence as the mRNA, whereas the ______________ strand is complementary to the mRNA. If the DNA sequence of the template strand is 5'-GGA-3', then the mRNA sequence is 5'-______________-3', which encodes the amino acid. a) coding; template; CCU; serine b) coding; template; TCC; glycine c) template; coding; uCC; serine d) coding; template; UCC; serine

d) coding; template; UCC; serine

The evolution of antifreeze proteins is an example of two proteins that are a) different structure, different function b) similar function, similar structure c) different function, similar structure d) different structure, similar function

d) different structure, similar function

Fill int he blanks with the two words that BEST complete the sentence: Eduard Buchner is considered the first modern biochemist because he proved that ______________ are sufficient for alcohol fermentation in the absence of live yeast- as long as a source of ______________ is provided. a) receptor proteins, nucleic acids b) nucleotides, amino acids c) nucleic acids, lipids d) enzymes, sugar e) lipids, sugar

d) enzymes, sugar

In aerobic respiration, the reductant (reducing agent) is ______________ and the oxidant (oxidizing agent) is ______________ with carbon dioxide being one of the products and ______________ being the other product. The conversion of ______________ energy to chemical energy generates ATP for use in metabolism. a) glucose; oxygen; water; metabolic b) carbon dioxide; oxygen; water; redox c) glucose; water; oxygen; redox d) glucose; oxygen; water; redox

d) glucose; oxygen; water; redox

Anabolic pathways are most active when the energy charge is ______________ whereas catabolic pathways are most active when the energy charge is ______________. The source of energy for ______________ pathways is stored fuels whereas the source of energy for ______________ pathways is abundant resources from the environment (nutrients or light). a) high; low; anabolic; catabolic b) low; high; anabolic; catabolic c) low; high; catabolic; anabolic d) high; low; catabolic; anabolic

d) high; low; catabolic; anabolic

What mediates the binding of histone proteins to DNA? a) london dispersion forces b) hydrophilic interactions c) hydrophobic interactions d) ionic interactions

d) ionic interactions

Which statement below most accurately describes the key result and primary conclusion drawn from the cell fusion experiment illustrated in Figure 2.46 in the textbook? a) green proteins and pink proteins are present on mouse and human cells respectively, but when the two cells are fused together, the resulting heterokayon is brown rather than either green or pink b) the experiment used viruses to form mouse-human hybrid cells demonstrating that Sendai virus can be used to create hybrid cells with equal number of green and pink proteins c) mouse cells and human cells were allowed to mate to form a zygote consisting of nuclei form two different species, this result indicated that fusion of cells fro two different mammals is possible in the lab d) it was observed that differentially-labelled fluorescent proteins are evenly distributed in fused heterokaryon cells, indicating that membrane proteins are able to diffuse laterally in cell membranes

d) it was observed that differentially-labelled fluorescent proteins are evenly distributed in fused heterokaryon cells, indicating that membrane proteins are able to diffuse laterally in cell membranes

Which THREE of the following biochemical relationships are correct statements illustrating the hierarchical organization of molecular life? a) the citrate cycle is a central process in select ecosystems that uses geothermal energy to recycle phosphate compounds b) amino acids are the building blocks of DNA c) monomers are linked together by noncovalent hydrogen bonds in reactions catalyzed by enzymes d) metabolic pathways are considered more complex than biomolecules but less complex than ecosystems e) carbon, hydrogen, and oxygen are the most abundant elements in biomolecules f) life would not exist on Planet Earth without pine trees g) insects degrade organic materials on the forest floor and generate nitrogen compounds that are used by tree seedlings as nutrients h) rice, cabbage, and lobsters are examples of life forms consisting of only glucose and water

d) metabolic pathways are considered more complex than biomolecules but less complex than ecosystems e) carbon, hydrogen, and oxygen are the most abundant elements in biomolecules g) insects degrade organic materials on the forest floor and generate nitrogen compounds that are used by tree seedlings as nutrients

The membrane separating the outside of the cell from the inside of the cell is called the ______________ membrane. The membrane separating the DNA in the nucleus from the cytoplasm is considered part of the ______________ system. The ______________ membrane is found only in plant cells and represents an organelle membrane. a) endomembrane; plasma; chloroplast b) cell wall; endomembrane; chloroplast c) nuclear; endomembrane; mitochondrial d) plasma; endomembrane; chloroplast

d) plasma; endomembrane; chloroplast

Linus Pauling proposed a triple helix structure for DNA that had the phosphate backbones of the three strands facing inward and the nucleotide bases facing outward. What are two reasons why this structure did not make any sense based on the chemical properties of DNA? a) the phosphate groups are non-polar and hydrophobic so would more likely form hydrogen bonds with water than with each other b) the symmetry of the x-ray diffraction data indicated that nucleotide bases face inward and phosphoryl groups face the aqueous environment c) the nucleotide bases would not be able to form hydrogen bonds with water in and be more stable facing outward toward the aqueous environment d) the charged phosphoryl groups will form hydrogen bonds with water in and be more stable facing outward toward the aqueous environment e) a triple helix would be more difficult to replicate during cell division f) the ring structure of nucleotide bases have hydrophobic properties and would more likely associate with each other in the interior of the helix

d) the charged phosphoryl groups will form hydrogen bonds with water in and be more stable facing outward toward the aqueous environment f) the ring structure of nucleotide bases have hydrophobic properties and would more likely associate with each other in the interior of the helix

How do plants, fungi, and bacteria avoid the damaging effects of a hypotonic environment? a) they lack cell walls b) they utilize photosynthesis c) they have semi-permeable cell walls d) they have rigid cell walls

d) they have rigid cell walls