Download WGU C785 BIOCHEMISTRY FINAL SCRIPT 2026 QUESTIONS WITH ANSWERS GRADED A+ and more Exams Biochemistry in PDF only on Docsity!
WGU C785 BIOCHEMISTRY FINAL SCRIPT
2026 QUESTIONS WITH ANSWERS GRADED
A+
●● How do you identify the 3 different types of side chains: non- polar/hydrophobic, polar, and charged? Answer: Non-polar/hydrophobic - end with CH or "can't have" water. Polar - end with OH, SH, or NH. Charged - end with a charge ●● what kinds of bonds do each of the 3 different types of side chains make? Answer: ionic, hydrophobic/non-polar, charged ●● What are the 4 levels of protein structure? Answer: Primary - linear structure, Secondary - Folded into helix or pleated sheet caused by hydrogen bonding, tertiary - 3D structure caused by side chain interactions, quaternary - 1+ amino acid chains combine = multiple subunits MUST have 1+ subunit ●● What enviormental change breaks each type of bond? Answer: hydrophobic - temperature change, ionic - salt or decreased pH, hydrogen - temperature, change in pH, disulfide - reducing agents
●● what type of amino acid side chain leads to protein aggregration? Answer: hydrophobic bonds ●● how do environmental changes affect protein folding? Answer: Extreme temp can cause hydrogen bonds to break apart = malformation of protein folding ●● how do mutations affect protein structure? Answer: Can cause structure to change. Protein loses form = loses function. May form a different protein. ●● What is an electron? Answer: Negatively charged atom on outer ring for bonding ●● What is energy: Answer: Power derived fro chemical interaction ●● what are covalent bonds? Answer: chemical bond, atoms share 1+ valence electrons ●● what is an ionic bond? Answer: bond between positive and negative
●● what is a polypeptide Answer: polymer of amino acids ●● What is dehydration synthesis? Answer: Process of forming peptide bonds ●● what is hydrolysis? Answer: adding water to destroy bonds ●● what is an alpha helix? Answer: twisted secondary structure, formed by hydrogen bonds ●● what is a beta sheet? Answer: folded second structure shape, formed by hydrogen bonds ●● what is denaturation? Answer: loss of shape duet o interruption of chemical bonds; occurs via extreme salt, temp, pH ●● what is aggregation? Answer: clumping of inner or outer cellular proteins caused by misfolded proteins leading to diseases such as Alzheimers, ALS, Parkinson's
●● how do enzymes catalyze reactions? Answer: bind with substrates to decrease activation energy required and decrease reaction rate ●● how do enzymes affect reaction rate and activation energy? Answer: decrease activation energy and decrease reaction rate ●● what are the 4 steps of the enzymatic cycle? Answer: enzyme recognizes substrate, substrate attracts the enzyme; enzyme-substrate complex is formed; enzyme-product complex formed; product is released, enzyme recycled ●● how do environmental changes affect enzymes? Answer: High heat, pH change, high salt concentration, and reducing agents can cause an enzyme to lose its form/lose function ●● what is a competitive inhibitor? Answer: Mimics substrate and takes its place on the active binding site ●● what is a noncompetitive inhibitor? Answer: Binds to allosteric site causing active site to change shape = preventing substrate from binding with enzyme
●● what is induced fit? Answer: Enzyme changes shape in enzyme-substrate complex to facilitate formation of enzyme-product complex ●● what is kinase? Answer: Enzyme, adds phosphate group via phosphorlation ●● what is phosphatase? Answer: enzyme, removes phosphate group via dephosphorylation ●● with is an allosteric site? Answer: secondary site on an enzyme an inhibitor binds to via non- competitive inhibition ●● what is competitive inhibition? Answer: enzyme substrate and inhibitor complex compete to bind with enzyme's active site. no product formed when inhibitor binds with enzyme. ●● what is non-competitive inhibition? Answer: inhibitor binds to allosteric site, not active site. Changes shape of active site, preventing substrate from binding and making product
●● what is feedback inhibition? Answer: End product sends feedback to beginning of enzyme pathway inhibiting 1st enzyme via noncompetitive inhibition ●● what nucleotides/bases are used in DNA? what are their abbreviations/full names? Answer: C - cytosine, G - guanine, A - adenine, T - thyamine ●● what nucleotides/bases are used in RNA? Answer: C - cytosine, G - guanine, U - uracil, A - adenine ●● which nucleotides base-pair together in DNA? Answer: T-A, G-C ●● which nucleotides base-pair together in RNA? Answer: U-A, G-C ●● how to we make complementary DNA? (i.e. coding to temple et reverse) Answer: Taking coding DNA, write in reverse, then pair them up to make template. Template DNA, write in reverse, then pair up to make coding
Answer: Decreased methylation, increased acetylation, Widely spaced neucleosomes, exposed promoter, use of transcription factors, use RNA polymerase ●● what factors decrease gene expression? Answer: Increased methylation/decreased acetylation, tightly packed nucleosomes, hidden promoter, no transcription factors, no RNA polymerase ●● what steps do you take to determine what type of mutation occurred between a normal and mutated DNA/RNA sequence? Answer: look between the two strands, determine what changed, name the mutation ●● What are the types of mutations? Answer: silent, missense, nonsense, frameshift ●● what type of DNA damage does each repair pathway fix? Answer: base excision - single nucleotide, nucleotide excision repair - multiple nucleotides, missmatch - mistakes made in DNA replication, homologous recombination/nonhomologous end joining - double stranded breaks ●● what are the steps of excision repair?
Answer: Recognize damage, cut damage out, recreate DNA strand, glue DNA strand back together ●● what are the steps of mismatch repair? Answer: Remove mismatched base, try again ●● what are the steps of homologous recombination and nonhomologous end joining? Answer: HR uses DNA from unbroken strand to fix broken strand, NHEJ reconnects broken pieces, may have pieces missing ●● what are the steps of PCR? Answer: denature, anneal, elongation/extension ●● how do we denature DNA in PCR? Answer: heat to 95 degrees C to separate DNA strands ●● how do we anneal DNA? Answer: primers base pair with DNA strands ●● how do we elongation/extend DNA? Answer: DNA polymerase attach primers and synthesize new DNA strands
●● what is antiparallel? Answer: refers to arrangement of DNA double helix (run in opposite directions) ●● what is complementary? Answer: predictable counterparts ●● what is template DNA? Answer: DNA strand, provides pattern for ordering via complementary base pairing in RNA transcript ●● what is coding DNA? Answer: nontemplate strand of DNA, same sequence as mRNA except has T instead of U ●● what is replication? Answer: processing of copying DNA molecules via DNA synthesis ●● what is transcription? Answer: creation of RNA using info from DNA ●● What is RNA polymerase?
Answer: enzyme, links ribonucleotides to growing RNA chain during transcription ●● what is a promoter? Answer: sequence of DNA that binds with RNA, encourages RNA transcription ●● what is a transcription factor? Answer: proteins that bind to promoter regions, help initiate transcription ●● what is mRNA? Answer: type of RNA, created via DNA template, specifies primary structure of protein ●● what is translation? Answer: creation of polypeptide using info in the mRNA ●● what is tRNA? Answer: RNA that brings amino acids to ribosomes during creation of polypeptide ●● what are ribosomes?
Answer: Protein; high proportion and charged amino acid that binds with DNA. Plays key role in chromatin structure. ●● what is a nucleosome? Answer: basic bead like unit of DNA. ●● what is methylation? Answer: presence of methyl groups on DNA bases, adding of methyl groups to DNA bases ●● what is acetylation? Answer: attachment of acetyl groups to certain amino acids of proteins (mainly histones) ●● what is the structural difference between myoglobin and hemoglobin? Answer: myoglobin - primary, secondary, tertiary, single subunit protein (1 heme, 1 iron, 1 O2). hemoglobin - primary, secondary, teriary, quaternary, 4 subunit protein (4 heme, 4 iron, 4 O2) ●● what are the functional differences between myoglobin and hemoglobin?
Answer: myoglobin - found in muscle, stores O2 in muscle, higher affinity for O2. hemoglobin - found in blood, delivers O2 to tissues in need, decreased affinity for O ●● what are the structural properties of the tense state of hemoglobin? Answer: deoxygenated hemoglobin = deep purple color. heme is bent; subunits move farther apart. decreased affinity of O2 binding. ●● what is the structural properties of hemoglobin in the relaxed state? Answer: Bright red color. Heme is planar with subunits moved closer, increased affinity of O2 binding ●● what causes hemoglobin to change between relaxed and tense state? Answer: O2 binding with hemoglobin in tense state causing subunits to move in closer and change hemoglobin to relaxed state ●● how does carbon monoxide affect the structure of hemoglobin? Answer: locks HgB in R-state, and takes up space on HgB for binding to O ●● how does it cause carbon monoxide poisoning? Answer: keeps HgB in R-state, HgB does not release O2. HgB has higher affinity for O2, but CO has higher affinity than HgB for O2.
●● what factors change pH in blood? Answer: Increased or decreased CO2, increased or decreased H+ ●● how to do changes in pH affect hemoglobin's structure? Answer: Increased CO2/Increased pH = T-state, Decreased CO2/Decreased pH = R-state ●● what is a heme? Answer: subunit of hemoglobin/myoglobin ●● what is affinity Answer: stickiness of oxygen binding ●● what is cooperativity? Answer: binding of O2 to deoxygenated blood ●● what is bicarbonate? Answer: carbon dioxide in disguise, outcome of CO2/H2O + carbonic anhydrase ●● what is carbonic anhydrase? Answer: enzyme; converts CO2 into bicarb and proton
●● what do chaperones do? Answer: assist with protein folding ●● difference between fetal and adult hemoglobin? Answer: fetal hemoglobin has higher affinity for oxygen than maternal hemoglobin. fetal has alpha and gamma forms of hemoglobin while adults have alpha and beta ●● Right left shift curve for decreased pH? increased pH? Answer: Decreased pH = right shift curve. Increased pH = left shift curve. ●● what can show an MI? Answer: myoglobin - can show muscle damage ●● Examples of monosaccharides Answer: glucose, fructose, galactose ●● examples of disaccharides Answer: sucrose, lactose, maltose ●● examples of polysaccharides Answer: starch, glycogen, cellulose, chitin
