MCAT HIGH YIELD TEST-101 QUESTIONS AND ANSWERS 2024.

When does pKa=pH? when there are an equal amount of Hs and OHs How does volume in a thermometer expand? it must have a larger volume expansion coefficient to fluctuate with temperature Brainpower Read More 0:13 / 0:15 Two amino acids linking together make a ____ bond peptide Fischer esterification forms an ester (COOR) involves reacting an acid and alcohol with a COOH to form an ester a protecting group does what? reduces nucleophilicity of the group that it is protecting oxidizing agent it oxidizes another species but becomes reduced itself in the process In an electrochemical cell oxidation occurs at the _____ and reduction occurs at the _____. So electron flow is from ____ to_____. anode, cathode anode to cathode Eocell is calculated how? E reduction potential at cathode- E reduction potential at anode charge on an cathode? the charge is negative because it attracts cations charge on an anode? the charge is positive because it attracts anions What is the molecular weight of each peptide bond formed? 18 Amino acids form in which direction? amino (N terminus) to carboxyl (C terminus) Equation for torque? Fsin0d (from the center fulcrum) or F*d (if the torque is perpendicular) Why might an electron configuration not fill like you might think it should? it is more stable filling the top one fulling and half filling the lower subshell (s) Beta decay an electron is released and a neutron is converted into a proton...the mass number increases by one Henderson-Hasselbalch equation pH=pKa+log(conj base/acid) log (1/10) log(10/1) -1 1 Hydrofluoric acid+ calcium= calcium fluoride-- highly insoluble and therefore precipitates in the body and lower serum calcium in body in splicing what is removed introns are removed and exons are fused together to leave the nucleus after further modification Diffraction increases (resolution decreases) with... increased wavelength, increased size of objective lens Coordinate bond when an atom contributes both electrons for a bond Basic amino acids lysine, arginine, histidine Which of the following can form disulfide bonds? I2, O2, H2, H2O2 I2, O2, H2O2 Hydrophobic amino acids valine, alanine, phenylalanine How is direction of light that is rotated determined? Dextrorotary or levorotatory. Also (+) and (-) experimentally so if the direction of polarized light is in the answer ignore it unless it was determined experimentally Lactone formation alcohol group and a carboxylic acid What bonds are delocalized in conjugation? pi bonds Conjugation decreases/increases energy of the molecule usually decreases IR spectrometry- OH peak- broad at 3300 C=O is a peak at Calculating stereoisomers-- 2^n n=stereocenters volume of water affected by temperature freezing- increases volume heating- decreases volume Specific heat equation q=mc(delta)T Drying reagent drives a reaction forward, removes products as they are formed What is going on in the heart during diastole? heart exerts no force, the muscles are relaxing melting point lower- then it will be a liquid higher-then it will be a solid at RT Periodic table trends atomic radius-- increases to bottom left corner ionization (most protons=smallest atom) energy/electron affinity-- increases to top right corner Hypermethylation would do what to a gene inactivate it back mutation a second mutation occurring to restore function to the gene that was originally damaged by a mutation sense mutation DNA sequence still codes for the same amino acid missense mutation changes a codon for one amino acid into a codon for a different amino acid S phase where DNA is replicated to prepare for mitosis during centrifuging where is the cytoplasm most likely to be found? In the supernatant because it is a smaller, less dense object Under what conditions does pyruvate get converted into lactate? fermentation in eukaryotic cells during a particularly anaerobic condition Plasma membrane is made primarily of ______ (type of lipid) and what is their general structure? phospholipids-- glycerol backbone attached to two fatty acids and a phosphate group Are protein allowed to cross membranes no.. they require a channel or transport molecule How do polypeptides enter the mitochondria? through receptors on the outer surface of the mitochondria Structure of mitochondrial DNA double-stranded, unprotected by histone complexes, not contained within a nuclear membrane During exercise what happens with PO2 it generally remains the same because ventilation increases as metabolism increases Ectoderm neural tube, nervous system, integument(skin), lens of the eye, (EVERYTHING YOU CAN SEE) Endoderm lining of digestive and reporter tracts, parts of liver, pancreas, thyroid and bladder Mesoderm circulatory system, excretory system, muscles, connective tissue (bones included), organs Cholesterol in the plasma membrane generally makes membranes more fluid but at pH 7.4 more cholesterol actually decreases membrane fluidity