CHEM 3212 GRADED QUIZ 6

______enzymes bind with small regulatory molecules that ______the effect of the enzyme. allosteric, modulate 178 nucleotide B2 lncRNA represses RNAPII. A model that has been repeated and confirmed by many different observations is a theory Acetylcholine is a neurotransmitter. AGO2-RISC binds to ____ and is capable of forming a “closed-loop” even in the absence of poly(A) tail or associated proteins and, hence, could activate translation directly. eIF4E Amphipathic describes a molecule that has both hydrophobic and hydrophilic groups. True Binding sites of antibodies are selective to a complementary epitope (a small peptide sequence on the surface of an antigen) Carbonic anhydrase catalyzes the reaction H20 + CO2 ↔ HCO3- + H+ Cholesterol is the precursor to: All of the above Chromatin components change during cell cycling. DNA methylation is essential for embryogenesis. True Evolutionary theory is based on observations that different organisms have different genotypes, and different genotypes produce different phenotypes. True NC2 and Mot1 activate DPE-driven transcription. Nucleotides exist in various _________forms in the cell. Phosphorylated Phospholipids consist of 1glycerol, 2 fatty acids, 1 phosphate Ribonucleic acids contain ribose with C2 hydroxyl group. The denaturing (opening) of the DNA duplex for transcription requires energy to overcome base-pairing and stacking energies. False The Michaelis-Menten equation determines that a [substrate] that produces ½ Vmax is numerically equal to Km Which histone is lysine rich and neutralizes the negatively charged DNA backbone? H1 Which is true regarding telomeres? They protect DNA ends from damage UNIT 4, 5 and 6 A ribozyme is an RNA that demonstrates catalytic activity. True An example of a signal sequence that facilitates a protein translocation to the nucleus is ______. PPKKKRKV An isomerase serves what function? Rotates a bond such as changing a molecule from a cis to trans conformation. Benefits to a multidomain protein architecture include: All of the above Catalysis by bond strain infers that the transition state is achieved by structural rearrangements that alter bond stability.

Chemical reaction coupling involves work that drives thermodynamically favorable reactions? False During translation initiation, the ribosome migrates along the ____, removing inhibitory stem loops, until it finds a start codon (___). 5’ UTR, AUG Every reaction is characterized by its equilibrium constant, Keq, which is a function of the All of the above Following deadenylation of the poly A tail, mRNA degradation occurs in both a 5’ to 3’ and 3’ to 5’ direction. GABA receptors act as GABA-gated anion channels selective to Cl-ions and have an inhibitory effect on neurotransmitter response. Larger RNA molecules have separate domains created by the polyribonucleotide chain that folds back on itself to allow base pairing between nearby lengths of RNA with complementary base sequences to produce what type of structure? : Hairpin loop Micro RNAs (microRNAs or miRs) are processed by Dicer, which is a(an) ribonuclease. miRs bind to the 3’ UTR to inhibit translation. Nonsense-mediated decay minimizes synthesis of truncated proteins. Peptide bonds link ______ and consist of ______. amino acids, CO-NH Polarity is characterized as All of the above. Prenylation involves the attachment of a _____ to a ______ and are common in ________ proteins lipids, sulfur group on cysteine, membrane bound Proteins that facilitate the folding of other proteins are chaperones. RNA secondary structure is driven by hydrophobic base interactions. The binding of TBP to the minor groove of DNA appears to present a paradox because, as a sequence-specific binding protein, TBP needs to be able to detect the bases that are ‘shielded’ within the minor groove of B-DNA. True The bond between carbon atoms in CH4 is a covalent bond. The conformation adopted by the polypeptide backbone is referred to as secondary structure. The equilibrium constant is the quotient of forward reaction kf (reactants to products)/ by the rate of the reverse reaction kr (products to reactants). The folding of conformation of a 3-D conformation is determined by a protein’s amino acid sequence c. post translational modification The sharing of electrons in a peptide bond is referred to as resonance. Trans-acting factors are RNA-binding proteins that regulate transcription of many mRNAs. False Transfer RNA (tRNA) structure includes All of the above What is a zinc finger? A DNA-binding protein domain with either a pair of cysteines and histidines or two pairs of cysteines that act together to coordinate zinc ion. What type of bond aids to stabilize a folded protein? Disulfide Which model of protein transport developed form the observation that vesicles formed in the Golgi moved cargo proteins between cisternae from the cis face to the trans face? The Vesicular Transport Model