Upgrade to remove ads
Only $35.99/year

BCHM 307 Final Exam

Terms in this set (64)

T/F: Enzymes catalyze reactions by lowering the free energy of the products.
False, they lower the activation energy
T/F: The template strand of the DNA has the same sequence as the RNA that it encodes.
False, it has the opposite base pairs
Which amino acid is likely to introduce a kink in the protein structure?
a. Met
b. Thr
c. Phe
d. Pln
e. Pro
e. Pro, proline's side chain loops back into its own backbone
A nucleoside
a. is charged
b. is phosphorylated
c. lacks a ribose or deoxyribose
d. contains a phosphodiester linkage
e. none of the above
d. none of the above, nucleoside= base and sugar, lacking phosphate group
Which of the following is the least likely to be on the surface of the protein?
a. Ser
b. Thr
c. Trp
d. Arg
e. Asn
c. Trp, it is nonpolar/hydrophobic
Genes are transcribed into ___, ___, has a three nucleotide anticodon that base pairs to codons, and ___ is a component of the ribosome.
a. mRNA, tRNA, rRNA
b. mRNA, rRNA, tRNA
c. rRNA, tRNA, mRNA
d. mRNA, tRNA, nRNA
e. none of the above
a. mRNA, tRNA, rRNA; messenger RNA, transcription RNA, ribosomal RNA
Which of the following are all charged at a neutral pH?
a. Asp, Gln, Lys, Arg
b. Glu, Arg, Asp, Lys
c. Lys, Arg, San, Glu
d. Gly, Lys, Arg, Asp
e. none of the above
b. Glu, Arg, Asp, Lys; 4 of the 5 charged amino acids
Given the following peptide, Gln-Gly-Ser-Lys-Phe-Glu, which amino acid is at the C terminal?
a. serine
b. glycine
c. glutamic acid
d. lysine
e. glutamine
c. glutamic acid; C terminal is the right, N terminal is the left
In competitive inhibition, the inhibitor binds ___, the apparent Vmax will ___, and the apparent Km will ___.
a. E only, not change, change
b. ES only, not change, change
c. E only, decrease, not change
d. ES only, decrease, not change
e. none of the above
a. E only, not change, change; inhibitor binds to enzyme instead of substrate binding to enzyme
Where would chymotrypsin cut the following peptide?
Val-a-Leu-b-Lys-c-Ser-d-Phe-e-Gly-f-Arg-g-Tyr-h-Ala-i-Gln
a. c and g
b. c
c. g
d. d
e. e
f. h
g. e and h
g. e and h; chymotrypsin hydrolyzes bonds after Phe, Tyr, and Trp
In non-competitive inhibition, the inhibitor binds ___, apparent Vmax will ___, and apparent Km will ___.
a. both E and ES complex, decrease, not change
b. ES only, decrease, not change
c. both E and ES complex, not change, change
d. E only, decrease, change
e. none of the above
a. both E and ES complex, decrease, not change; non competitive inhibitor can bind a long enzyme or an enzyme-substrate complex
Which polysaccharide hydrogen bonds extensively and provides strength to plants?
a. cellulose
b. amylose and amylopectin
c. amylose
d. glycogen
e. amylopectin
a. cellulose, makes up plant cell walls
Actin and tubulin polymerization involve ATP or GTP hydrolysis because
a. polymerization requires a drop in pH
b. the polymerization reaction is not spontaneous
c. The nucleotide binds in the protein-protein interface
d. nucleotide hydrolysis is not spontaneous
b. the polymerization reaction is not spontaneous, non-spontaneous reactions require ATP/GTP
Which amino acid stabilizes protein structures by forming crosslinks in most cellular proteins?
a. Cys
b. Met
c. Ser
d. Try
e. Csn
A. Cys; Cystine residues can form disulfide bonds, which facilitate cross linking
Which of the following statements about the fluid mosaic model are true? Select all that apply
a. lateral diffusion occurs readily
b. lateral diffusion is slow
c. transverse diffusion occurs readily
d. transverse diffusion is slow
a. lateral diffusion occurs readily
d. transverse diffusion is slow
*transverse= one bilayer leaflet (layer) to the other and very slow, lateral= diffusion within a bilayer leaflet (layer) and very fast
Read the following sentences and identify each statement as describing the primary, secondary, tertiary, or quaternary structure of the protein:
1. myosin tails wrap around each other to form the thick filament of muscle cells
2. chymotrypsin adopts a globular structure with an active site cleft
3. DNA binding proteins often contain many positively charged amino acids
4. integral membrane proteins span the membrane with a long alpha helix or beta barrel
1. quaternary
2. quaternary
3. primary
4. secondary;
primary= amino acid sequences
secondary= alpha helix and beta sheet
tertiary= 3d folding
quaternary= more than one amino acid chain
Match the lipids with their primary functioning the cell.
1. building blocks for other lipids
2. diverse functions including signaling, etc.
3. energy storage
4. neurons
5. lipid membranes

a. fatty acids
b. triacylglycerols
c. glycerophospholipids
d. sphingolipids
e. isoprenoids
1. building blocks for other lipids: fatty acids
2. diverse functions including signaling, etc.: isoprenoids
3. energy storage: triacylglycerols
4. neurons: sphingolipids
5. lipid membranes: glycerophospholipids
A reaction that is non-spontaneous (select all that apply)
a. has a positive delta G
b. has a negative delta G
c. can be driven forward by coupling to a spontaneous reaction
d. is very slow
a. has a positive delta G
c. can be driven forward by coupling to a spontaneous reaction
Non-polar molecules aggregate in aqueous solutions because (select all that apply)
a. delta H is more favorable when the non-polar material aggregates
b. delta S is more favorable when the non-polar material aggregates
c. delta G is more favorable when the non-polar material aggregates
d. there is less ordered water and delta S is decreased when the non-polar material aggregates
b. delta S is more favorable when the non-polar material aggregates
c. delta G is more favorable when the non-polar material aggregates
d. there is less ordered water and delta S is decreased when the non-polar material aggregates
Associate the processes of the Central Dogma with the appropriate starting materials, templates, and products.
1. transcription
2. translation
3. reverse transcription
4. replication

a. incoming nucleotide: deoxyribose containing NTP (dNTP)
template: DNA
product: DNA
b. incoming nucleotide: ribose containing NTP (NTP)
template: DNA
product: RNA
c. incoming nucleotide: deoxyribose containing NTP (dNTP)
template: RNA
product: DNA
d. incoming substrate: amino acids
template: DNA
product: protein
e. incoming substrate: amino acids
template: RNA
product: protein
f. incoming nucleotide: ribose containing NTP (NTP)
template: RNA
product: DNA
1. transcription: b
2. translation: e
3. reverse transcription: c
4. replication : a;
replication= DNA to DNA
transcription= DNA to RNA
reverse transcription= RNA to DNA
translation= RNA to protein
Incoming nucleotides are added to the ___ end of the growing nucleic acid chain.
3'
Which of the following are STOP codons?
a. UAG
b. UGC
c. UAA
d. UGG
e. UGA
f. UUA
a. UAG
c. UAA
e. UGA;
you go away, you are away, you are gone
Transpeptidation
a. involves transfer of the growing polypeptide chain to the A-site tRNA
b. involves initiation factor Tu
c. occurs in a C to N direction
d. involves transfer of the growing polypeptide chain to the P-site tRNA
a. involves transfer of the growing polypeptide chain to the A-site tRNA
Most of the ribosome is made up of
a. protein
b. lipids
c. amino acids
d. RNA
d. RNA
Which two functional groups make up the linkage between an amino acid and a charged tRNA?
a. the amino group/amino terminus of the amino acid
b. the 5'-hydroxyl at the 5' end of the tRNA
c. the 3'-hydroxyl at the 3' end tRNA
d. the carboxylate/carboxyl terminus of the amino acid
c. the 3'-hydroxyl at the 3' end tRNA
d. the carboxylate/carboxyl terminus of the amino acid
What property does the redundancy in the genetic code confer upon organism?
a. many mutations in the third or wobble nucleotide of the codon have no effect on the sequence of the encoded protein
b. one tRNA can be aminoacylated with multiple amino acids
c. tRNAs can be charged multiple times
d. none of the above
a. many mutations in the third or wobble nucleotide of the codon have no effect on the sequence of the encoded protein; due to the repetition and multiple amino acids coding for one protein
Which of the following statements about EF-Tu is not true?
a. EF-Tu can determine if the anticodon on the bound tRNA matches the codon on the message RNA
b. the reaction of EF-Tu is coupled to ATP hydrolysis
c. EF-Tu delivers a charged tRNA to the A-sire of the ribosome
d. EF-Tu possess equal affinity for all of the tRNAs
b. the reaction of EF-Tu is coupled to ATP hydrolysis
Which of the following is a start codon?
a. AUG
b. AAG
c. AUC
D. UUG
a. AUG
What features allow a single open reading frame at the 5' end of the virus to encode two different polypeptides? Select all that apply.
a. slippery sequence
b. (+) sense subgenomic RNAs
c. psuedoknot
d. nsp14
e. transcriptional regulatory sequences (TRS)
a. slippery sequence
c. psuedoknot
The SARA coronavirus 2 genome (select all that apply)
a. is double stranded
b. uses 3 different strategies to allow translation of the 14 open reading frames
c. encodes a single viral polyprotein
d. can be directly translated by a eukaryotic ribosome
e. is transcribed in replication and transcription complexes
b. uses 3 different strategies to allow translation of the 14 open reading frames
d. can be directly translated by a eukaryotic ribosome
e. is transcribed in replication and transcription complexes
Match the viral proteins with their function.
1. spike
2. RNA dependent RNA polymerase
3. ExoN/nsp14/exonuclease
4. nucleocapsid

a. viral fusion/ cell entry
b. genome packaging
c. genome replication
d. proofreading
e. none of the above
1. spike: a
2. RNA dependent RNA polymerase: c
3. ExoN/nsp14/exonuclease: d
4. nucleocapsid: b
Select all the true statements.
a. two protease cleavage events are required to activate the coronavirus fusion peptide of the spike protein
b. on the cell surface, the coronavirus binds to the ACE2 receptor and the cellular protease TMPRSS2 cleaves the spike protein
c. release of the coronavirus fusion peptide causes endocytosis of the virus due to activation of the ACE2 receptor
d. two protease cleavage events are required to activate the coronavirus fusion peptide of the matrix protein
a. two protease cleavage events are required to activate the coronavirus fusion peptide of the spike protein
b. on the cell surface, the coronavirus binds to the ACE2 receptor and the cellular protease TMPRSS2 cleaves the spike protein
What RNAs are translated to express the structural proteins of the SARS coronavirus 2?
a. (+) sense subgenomic RNAs
b. (+) sense full length genomic RNAs
c. (-) sense full length genomic RNAs
d. (-) sense subgenomic RNAs
a. (+) sense subgenomic RNAs
The name of the enzyme used to overcome the end-replication problem for linear chromosomes is
telomerase
T/F: During DNA synthesis, incoming nucleotides are added to the 5' end of the primer strand.
False
Nucleic acids are synthesized in the __A__ to __B__ direction and there are __C__ exceptions.
1. 5'
2. 3'
3. no
4. some
A: 5'
B: 3'
C: no
Match the proteins with their roles in DNA synthesis:
1. removing primers from Okazaki fragments
2. replication fork DNA synthesis
3. unpairing DNA
4. RNA primer formation
5. connecting 2 DNA strands

a. DNA polymerase 3
b. primase
c. DNA polymerase 1
d. ligase
e. helicase
1. removing primers from Okazaki fragments: DNA polymerase 1
2. replication fork DNA synthesis: DNA polymerase 3
3. unpairing DNA: helicase
4. RNA primer formation: primase
5. connecting 2 DNA strands: ligase
T/F: Semi-conservative DNA synthesis means that DNA is not 100% accurately copied because mutations are occasionally introduced.
False
The name of the enzyme that can change the number of supercoils in DNA is
topoisomerase
T/F: Eukaryotes can express multiple forms of a protein from a single gene/open reading frame.
True
What is required for transcriptional termination via a hairpin loop?
a. rho
b. a sequence rich in G-C base pairs
c. a consensus sequence
d. a palindromic sequence
d. a palindromic sequence
Match the following post translational modifications with their associated function in the cell.
1. Histone modification associated with transcriptionally active DNA
2. Transition of eukaryotic RNA polymerase from initiation to elongation
3. Histone modification associated with transcriptionally silent DNA

a. methylation of lysine
b. acetylation of lysine
c. phosphorylation
d. glycosylation
1. Histone modification associated with transcriptionally active DNA: acetylation of lysine
2. Transition of eukaryotic RNA polymerase from initiation to elongation: phosphorylation
3. Histone modification associated with transcriptionally silent DNA: methylation of lysine
Processivity is
a. the tendency of a protein to do multiple repetitions of a reaction before falling off its substrate
b. the ability of a polymerase to correct its mistakes
c. the tendency of a protein to spin around its substrate
d. none of the above
a. the tendency of a protein to do multiple repetitions of a reaction before falling off its substrate
What is the name of the sequence of DNA that the Mediator complex binds?
a. enhancer
b. promotor
c. TATA box
d. mediator doesn't bind DNA
d. mediator doesn't bind DNA
Which polymerase is responsible for synthesizing messenger RNAs in a eukaryotic cell?
a. RNA polymerase I
b. RNA dependent RNA polymerase
c. RNA polymerase III
d. RNA polymerase II
d. RNA polymerase II
T/F: The only base-pairs that RNA can make are the Watson-Crick base pairs like those found in DNA.
False
Indicate whether the following processes occur in eukaryotes, prokaryotes, or both.
a. promotor
b. rho-dependent transcription termination
c. ribosomal splicing
d. hairpin dependent transcription termination
e. transcription bubble
f. RNA polymerase
g. mRNA capping
a. promotor: both
b. rho-dependent transcription termination: prokaryotic
c. ribosomal splicing: eukaryotic
d. hairpin dependent transcription termination: prokaryotic
e. transcription bubble: both
f. RNA polymerase: both
g. mRNA capping: eukaryotic
The enzyme Rubisco
a. fixes carbon
b. lacks specificity for carbon dioxide
c. generates three carbon carbohydrates
d. all of the above
d. all of the above
Reaction A to B has a Gibbs free energy of +5 and reaction B to C has a Gibbs free energy of -10. What is the Gibbs free energy of the coupled reaction A to B to C?
a. 5
b. 0.5
c. -5
d. -50
c. -5
How does light activation impact the reduction potential of the chlorophyll P680 and P700?
a. it reduces their reduction potential and makes it easier for them to donate electrons
b. it increases their reduction potential and makes it easier for them to receive electrons
c. it reduces their reduction potential and makes it easier for them to receive electrons
d. it increases their reduction potential and makes it easier for them to donate electrons
a. it reduces their reduction potential and makes it easier for them to donate electrons
In the following electron transfer pathway, the reactants have the indicated redox potentials:
A(-0.6)->B(-0.2)->C(0.5)->D(-1)
Assuming there is no other influence on the reaction, where will the electrons end up?
a. a
b. b
c. c
d. d
c. c
T/F: The first phase of the glycolysis pathway generates ATP.
False: it uses it
What metal ions are present in the specialized metal cluster in the oxygen evolving complex?
a. manganese and calcium
b. iron, manganese, and calcium
c. manganese only
d. M
a. manganese and calcium
Chlorophylls are green because they absorb what color light?
a. yellow
b. green
c. red and purple
d. blue
c. red and purple
What are aspartate and malate shuttled across the inner mitochondrial membrane? Select all that apply.
a. to shuttle reducing equivalents into the matrix
b. to shuttle reducing equivalents into the cytosol
c. no NADH is synthesized in the mitochondria
d. the transporter proteins generate a proton gradient
a. to shuttle reducing equivalents into the matrix
Which of the following is a peripheral membrane protein that can deliver electrons from one integral membrane complex to another?
a. plastocyanin
b. cytochrom b6f
c. ubiquinol
d. plastoquinone
a. plastocyanin
How many protons are pumped across the membrane in one round of cyclic electron flow?
a. none, photosystem I doesn't pump protons across the membrane
b. 2
c. 4
d. 8
b. 2
Which of the following is not a common pigment in chloroplasts?
a. chlorophyll
b. phycocyanin
c. carotene
d. plastoquinone
d. plastoquinone
The process of breaking down macromolecules into building blocks is called ___ and the process of making macromolecules from building blocks is called ___.
catabolism, anabolism
In a redox reaction, electrons flow towards the ___ species.
reduced
T/F: The dark reactions only occur in the absence of light.
False
Are the following associated with light or dark reactions in photosynthesis?
a. Calvin cycle
b. plastocyanin reduction
c. splitting water
d. carbon fixation
e. cyclic electron flow
f. Z-scheme
g. photorespiration
a. Calvin cycle: dark
b. plastocyanin reduction: light
c. splitting water: light
d. carbon fixation: dark
e. cyclic electron flow: light
f. Z-scheme: light
g. photorespiration: dark
What are the sources of ubiquinol in the electron transport chain? Select all that apply.
a. complex 1
b. complex 2
c. complex 3
d. complex 4
e. F1 ATPase
a. complex 1
b. complex 2
Select all the products of the redox reaction performed by Complex I.
a. NAD+
b. transfer of 2H+
c. NADH
d. 2QH2
e. 2Q
f. transfer of 8H+
g. transfer of 4H+
h. Q
i. QH2
a. NAD+
g. transfer of 4H+
i. QH2
Recommended textbook explanations

Biocalculus: Calculus for the Life Sciences

1st EditionDay, Stewart
5,054 explanations

Lehninger Principles of Biochemistry

6th EditionDavid L Nelson, Michael M. Cox
616 explanations

Fundamentals of Biochemistry: Life at the Molecular Level

5th EditionCharlotte W. Pratt, Donald Voet, Judith G. Voet
980 explanations

Biocalculus: Calculus, Probability, and Statistics for the Life Sciences

1st EditionDay, Stewart
5,058 explanations