WGU C785 Final Exam Questions With Answers | Latest 2023/2024 (GRADED)

What are the 4 levels of protein structure? - correct 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? - correct 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? - correct answer hydrophobic bonds how do environmental changes affect protein folding? - correct answer Extreme temp can cause hydrogen bonds to break apart = malformation of protein folding how do mutations affect protein structure? - correct answer Can cause structure to change. Protein loses form = loses function. May form a different protein. What is an electron? - correct answer Negatively charged atom on outer ring for bonding What is energy: - correct answer Power derived fro chemical interaction what are covalent bonds? - correct answer chemical bond, atoms share 1+ valence electrons what is an ionic bond? - correct answer bond between positive and negative what is a hydrogen bond? - correct answer weak bond between positive and negative with an amino? - correct answer piece of amino acid, NH2 or NH3 what is a carboyxl? - correct answer piece of amino acid, COO or COOH What is hydrophobic? - correct answer Doesn't like water, end with CH what is hydrophilic? - correct answer Water loving, end with OH, NH, or SH what is disulfide bond? - correct answer strongest bond between reduction agents, formed between SH's. what are zwitterions? - correct answer amino with positive and negative charges = overall charge of zero what is a polypeptide - correct answer polymer of amino acids What is dehydration synthesis? - correct answer Process of forming peptide bonds what is hydrolysis? - correct answer adding water to destroy bonds what is an alpha helix? - correct answer twisted secondary structure, formed by hydrogen bonds what is a beta sheet? - correct answer folded second structure shape, formed by hydrogen bonds what is denaturation? - correct answer loss of shape duet o interruption of chemical bonds; occurs via extreme salt, temp, pH what is aggregation? - correct 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? - correct answer bind with substrates to decrease activation energy required and decrease reaction rate how do enzymes affect reaction rate and activation energy? - correct answer decrease activation energy and decrease reaction rate what are the 4 steps of the enzymatic cycle? - correct 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? - correct 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? - correct answer Mimics substrate and takes its place on the active binding site what is a noncompetitive inhibitor? - correct answer Binds to allosteric site causing active site to change shape = preventing substrate from binding with enzyme what molecules increase/build up or decrease given a specific inhibitor? A -> (enzyme 1) -> B -> (enzyme 2) -> C -> (enzyme 3) -> D. Pretend Enzyme 2 is inhibited. - correct answer Inhibitor would cause a build up for product B, decrease product C. Enzyme 3 and product D would not be created. what is substrate? - correct answer the substance on which an enzyme acts what is a product? - correct answer result of a reaction what is an intermediate? - correct answer products produced in an enzyme pathway before final product what is an active site? - correct answer location where substrate binds with enzyme what is enzyme specificity? - correct answer Enzymes bind with certain substrate or type of substrate to create a certain reaction what is induced fit? - correct answer Enzyme changes shape in enzyme-substrate complex to facilitate formation of enzyme-product complex what is kinase? - correct answer Enzyme, adds phosphate group via phosphorlation what is phosphatase? - correct answer enzyme, removes phosphate group via dephosphorylation with is an allosteric site? - correct answer secondary site on an enzyme an inhibitor binds to via non-competitive inhibition what is competitive inhibition? - correct 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? - correct 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? - correct 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? - correct answer C - cytosine, G - guanine, A - adenine, T - thyamine what nucleotides/bases are used in RNA? - correct answer C - cytosine, G - guanine, U - uracil, A - adenine which nucleotides base-pair together in DNA? - correct answer T-A, G-C which nucleotides base-pair together in RNA? - correct answer U-A, G-C how to we make complementary DNA? (i.e. coding to temple et reverse) - correct 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 how do we make mRNA? - correct answer template DNA to mRNA by switching back and forth OR coding DNA to mRNA by switching out T's for U's which strand of DNA is complementary to mRNA? - correct answer Template DNA how do we make protein? - correct answer DNA -> RNA -> Protein which type of nucleotide sequence is used and in which direction? - correct answer RNA is used 5' to 3' what is the relationship between mRNA and tRNA? - correct answer tRNA is complementary to mRNA how does mRNA splicing allow use to create multiple proteins from a single gene/mRNA? - correct answer Alternative splicing allows for all introns to be cut and some exons = multiple proteins form from same MRNA what factors increase gene expression? - correct answer Decreased methylation, increased acetylation, Widely spaced neucleosomes, exposed promoter, use of transcription factors, use RNA polymerase what factors decrease gene expression? - correct 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? - correct answer look between the two strands, determine what changed, name the mutation What are the types of mutations? - correct answer silent, missense, nonsense, frameshift what type of DNA damage does each repair pathway fix? - correct 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? - correct answer Recognize damage, cut damage out, recreate DNA strand, glue DNA strand back together what are the steps of mismatch repair? - correct answer Remove mismatched base, try again what are the steps of homologous recombination and nonhomologous end joining? - correct 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? - correct answer denature, anneal, elongation/extension how do we denature DNA in PCR? - correct answer heat to 95 degrees C to separate DNA strands how do we anneal DNA? - correct answer primers base pair with DNA strands how do we elongation/extend DNA? - correct answer DNA polymerase attach primers and synthesize new DNA strands what are the components of PCR? - correct answer target DNA, heat stable DNA polymerase, nucelotides (dNTP), primers how are primers used to assist in a PCR reaction? - correct answer Primers allow DNA polymerase to bind to target DNA how do you calculate the number of copies of DNA produced by specific number of PCR cycles? - correct answer Each cycle produces doubles the amount of DNA how does PCR compare to normal DNA replication in the cell? - correct answer RNA primers used instead of DNA in normal replication. Helicase enzymes separate DNA strands instead of heat in normal replication. DNA polymerase is not heat stable in normal replication. what is gene expression? - correct answer process by which info coded in DNA creates proteins and RNAs What are nucleotides? - correct answer building blocks of nucleic acids what is antiparallel? - correct answer refers to arrangement of DNA double helix (run in opposite directions) what is complementary? - correct answer predictable counterparts what is template DNA? - correct answer DNA strand, provides pattern for ordering via complementary base pairing in RNA transcript what is coding DNA? - correct answer nontemplate strand of DNA, same sequence as mRNA except has T instead of U what is replication? - correct answer processing of copying DNA molecules via DNA synthesis what is transcription? - correct answer creation of RNA using info from DNA What is RNA polymerase? - correct answer enzyme, links ribonucleotides to growing RNA chain during transcription what is a promoter? - correct answer sequence of DNA that binds with RNA, encourages RNA transcription what is a transcription factor? - correct answer proteins that bind to promoter regions, help initiate transcription what is mRNA? - correct answer type of RNA, created via DNA template, specifies primary structure of protein what is translation? - correct answer creation of polypeptide using info in the mRNA what is tRNA? - correct answer RNA that brings amino acids to ribosomes during creation of polypeptide what are ribosomes? - correct answer molecular complex, assist with orderly linking of amino acids/polypeptide chains what are codons? - correct answer nucleotide triplet of DNA or RNA. Basic genetic code. Specifies type of amino acid or termination signal what are anticodons? - correct answer nucleotide triplet at one end of tRNA. Base pairs with complementary codon on mRNA what is splicing? - correct answer parts of transcript are removed and others are reconncected what are introns? - correct answer pieces of noncoding that are removed during RNA processing what are exons? - correct answer pieces of coding that stay with RNA during processing - ARE NOT DISCARDED what are histones? - correct answer Protein; high proportion and charged amino acid that binds with DNA. Plays key role in chromatin structure. what is a nucleosome? - correct answer basic bead like unit of DNA. what is methylation? - correct answer presence of methyl groups on DNA bases, adding of methyl groups to DNA bases what is acetylation? - correct answer attachment of acetyl groups to certain amino acids of proteins (mainly histones) what is the structural difference between myoglobin and hemoglobin? - correct 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? - correct 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 O2 what are the structural properties of the tense state of hemoglobin? - correct 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? - correct 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? - correct 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? - correct answer locks HgB in R-state, and takes up space on HgB for binding to O2 how does it cause carbon monoxide poisoning? - correct answer keeps HgB in Rstate, HgB does not release O2. HgB has higher affinity for O2, but CO has higher affinity than HgB for O2. steps of DNA replication to protein? - correct answer DNA -> transcribed -> mRNA - > translation -> protein