front 1 top 3 leading cancer related deaths result from proto-oncogene activation and TSG inactivation | back 1 lung breast/prostate colorectal |
front 2 minimum amount of DNA alterations needed for a cell to become malignant | back 2 6 |
front 3 process of a normal cell evolving into a highly malignant cell | back 3 tumor progression |
front 4 transcription factor, most frequently mutated gene in cancer, guardian of the genome, regulates at G1- growth arrest and apoptosis, suffers from point mutation which inactivates it -resulting in no DNA repair | back 4 p53 inactivated in 50% of all cancers |
front 5 genes that are like the car brakes, help regulate cell growth, gives loss of function to mutant genes | back 5 TSG tumor suppressor genes |
front 6 cell dividing out of control, mutant form of normal has genes, dominant genes, code for RTK, G proteins, transcription factors, Ras gene, classified as | back 6 oncogene |
front 7 normal cell division like a gas pedal on a car, but has the potential for a gain-of-function in cancer, these genes are | back 7 proto-oncogene |
front 8 signaling that effects the same cell | back 8 autocrine |
front 9 signaling that effects neighboring cells, even of a different type | back 9 paracrine |
front 10 long distance signaling that is able to signal the whole body, usually through the circulatory | back 10 endocrine |
front 11 high-affinity cell surface receptors for many polypeptide growth factors, cytokines, and hormones, key regulators of normal cellular processes but also to have a critical role in the development and progression of many types of cancer | back 11 enzyme-coupled receptors Receptor tyrosine kinases (RTK) |
front 12 how does the G-protein coupled receptor work | back 12 Binding of an agonist results in a conformation change in the receptor that is transmitted to the bound α subunit, the α subunit exchanges GTP in place of GDP which in turn triggers the dissociation of it from the βγ dimer and from the receptor. The dissociated α subunit interacts with other intracellular proteins to continue the signal transduction cascade |
front 13 a large protein family of receptors that sense molecules outside the cell and activate inside signal transduction pathways and, ultimately, cellular responses. They are called seven-transmembrane receptors because they pass through the cell membrane seven times, ligands that bind and activate these receptors include light-sensitive compounds, odors, pheromones, hormones, and neurotransmitters, and vary in size from small molecules to peptides to large proteins. They are involved in many diseases, and are also the target of approximately 40% of all modern medicinal drugs | back 13 G-protein coupled receptor guanine nucleotide |
front 14 general name for a group of more that 100 diseases in which cells in a part of the body begin to grow out of control | back 14 cancer |
front 15 Conversion of an impulse or stimulus from one physical or chemical form to another. In cell biology, the process by which a cell responds to an extracellular signal. | back 15 signal transduction |
front 16 Protein that recognizes and responds to a specific signal molecule. | back 16 receptor |
front 17 A set of proteins and small-molecule second messengers that interact with each other to relay a signal from the cell membrane to its final destination in the cytoplasm or nucleus. | back 17 intracellular signaling pathway |
front 18 Extracellular signal molecule that is secreted and transported via the bloodstream (in animals) or the sap (in plants) to target tissues on which it exerts a specific effect. | back 18 hormone |
front 19 The molecular mechanisms by which cells detect and respond to external stimuli and send messages to other cells. | back 19 cell signalling |
front 20 what do vSNARES do | back 20 SNAREs on the vesicle compliment the target tSNAREs |
front 21 in order to use protein translocators, is the protein folded or unfolded? how about a nuclear pore? | back 21 unfolded to go through the membrane folded to go through the nucleus |
front 22 Which of the following is true of lysosomes?
A. The products of digestion in lysosomes leave the
lysosome by transport vesicles. | back 22 c |
front 23 Proteins destined for regulated secretion:
A. have special surface properties that cause them to
form aggregates that are packaged into secretory vesicles. | back 23 a |
front 24 Which type of protein binds to improperly folded or improperly assembled proteins in the ER, holding them there until proper folding occurs?
A. Tethering proteins | back 24 c |
front 25 Vesicle budding is driven by the assembly of a protein coat.
A. True | back 25 a |
front 26 The ER signal sequence on a growing polypeptide chain is recognized by a signal recognition particle (SRP) in the cytosol. This interaction:
A. causes the polypeptide chain to dissociate from
the ribosome. | back 26 c |
front 27 Which of the following is true?
A. A special class of ribosomes embedded in the ER
translates the proteins destined for that organelle. | back 27 b |
front 28 Which of the following statements is NOT true of mitochondrial proteins that are synthesized in the cytosol?
A. The proteins are unfolded as they are transported
into the mitochondria. | back 28 c |
front 29 Which proteins bind to nuclear localization signals on newly synthesized proteins?
A. Nuclear pore proteins | back 29 b |
front 30 The interiors of the ER, Golgi apparatus, endosomes, and lysosomes communicate with each other in which of the following ways?
A. By small vesicles that bud off of one organelle
and fuse with another | back 30 a |
front 31 Which organelle is essentially a small sac of digestive enzymes that functions in degrading worn-out organelles, as well as macromolecules and particles taken into the cell by endocytosis?
A. An endosome | back 31 c |
front 32 Which organelle sorts ingested molecules and recycles some of them back to the plasma membrane?
A. An endosome | back 32 a |
front 33 Which organelle receives proteins and lipids from the endoplasmic reticulum, modifies them, and then dispatches them to other destinations in the cell?
A. A mitochondrion | back 33 c |
front 34 what signals for proteins to have parts of them embedded in the membrane ER | back 34 stop transfer sequence start transfer sequence both hydrophobic |
front 35 two protein components help guide ER signal sequences to the ER membrane | back 35 signal recognition particle (SRP) in the cytosol binds with the ribosome and the signal sequence SRP receptor embedded in the ER membrane recognizes the SRP |
front 36 2 kinds of proteins transferred from the cytosol to the ER | back 36 water soluble completely translocated prospective transmembrane partly translocated ( embedded in membrane ) |
front 37 small membrane enclosed organelles that contain several enzymes that produce hydrogen peroxide and have a variety of other functions, derived from the endoplasmic reticulum or replicate by fission- it also transports proteins via translocation | back 37 peroxisome |
front 38 main site of lipid synthesis | back 38 ER |
front 39 how do proteins know to go to the mitochondria | back 39 signal sequence at their N-terminus recognized by a chaperone protein that grabs it, unfolds it, the folds back once entered, requires ATP use a translocator channel- similar to a nuclear pore, but instead of one big pore, it is one in each bi-layer |
front 40 how are mitochondria and chloroplasts similar to nucleus | back 40 double phospholipid bi-layer own DNA and therefore own proteins recognize signal sequence- positive charge hydrophobic AA |
front 41 what brings proteins to the nucleus | back 41 importin- nuclear import receptors take the protein in its 3 prime shape unlike other oraganelles |
front 42 how do proteins get to where they need to go | back 42 signal sequence- nuclear localization signal positive charged hydrophobic lysine and arginine binds to the nuclear import receptor to bring it in - requires GTP for energy |
front 43 nuclear pores are made of | back 43 30 proteins complex, act as a gate for proteins to enter and RNA to exit |
front 44 inner nuclear membrane conatins | back 44 membrane most similar to the cell membrane and is continuous with the membrane of the ER |
front 45 inner layer of nuclear membrane conatins | back 45 proteins and binding sites for chromosomes nuclear lamina for structural support |
front 46 how many membranes of the nuclear envelope, aka nuclear membrane | back 46 4 double phospholipid bi-layer inner and outer |
front 47 The lac operon: | back 47 d |
front 48 At the E site A)transfer RNA is released B)anticodons match with codons C)peptide bonds are formed between amino acids D)transcription occurs | back 48 a |
front 49 An activator must react with its substrate before it can bind to DNA. A)True B)False | back 49 a |
front 50 Negative control occurs when a repressor is inactivated by an inducer. A )True B)False | back 50 a |
front 51 In regulation by induction A)an inducer inactivates the repressor so transcription can proceed B)an inducer inactivates the repressor so transcription is stopped C)an inducer activates the repressor so transcription can proceed D)an inducer activates the repressor so transcription is stopped | back 51 a |
front 52 In regulation by repression A)a sugar, such as lactose, acts as an inducer and combines with the repressor to prevent transcription B)an inducer activates the activator so that it binds to DNA and prevents transcription C)an amino acid activates the repressor so that the repressor binds to the operator and prevents transcription D)an amino acid binds to the operator, blocking the repressor, allowing transcription to proceed | back 52 c |
front 53 Transcription is turned off by A)induction B)repression C)activation D)all of the above | back 53 d |
front 54 how does the cell know what proteins go where | back 54 1. signal patches made of amino acid residues that are distant to one another in primary form but are close together in tertiary structure 2. sorting signal made of amino acid sequences no signal= stays in cytosol and functions there |
front 55 proteins transported to the nucleus are completely synthesized in the cytosol and ______ before import, unlike other organelles | back 55 correctly folded |
front 56 three ways proteins are transported throughout the cell | back 56 1. through nuclear pores from cytosol into nucleus 2. across organelle membranes via protein translocators 3. by transport vesicles through plasma membrane to outside of cell |
front 57 two ways cells can isolate and organize their chemical reactions | back 57 aggregate different enzymes confine different metabolic processes within different membrane enclosed compartments (organelles) |
front 58 large protein complexes found in the cytosol and nucleus that have protease activity | back 58 proteosomes |
front 59 enzymes that degrade proteins by a process known as proteolysis (hydrolyzes peptide bonds) | back 59 proteases |
front 60 regulatory RNA's work by | back 60 base pairing with complementary sequences within target mRNA's, leading to mRNA degradation and inhibition of translation |
front 61 two key aspects of eukaryotic translation are regulated by phosphorylation- same as effects in DNA transcription | back 61 1. recognition of the mRNA by ribosome can be inhibited by PO4 2. 5' cap binding proteins can be bound by non-PO4 binding proteins |
front 62 proteins that block the translation of mRNA because they prevent the attachment of ribosomes by binding to specific nucleotide sequences in the 5' untranslated region (promoter) | back 62 translation repressor |
front 63 translation of mRNA is regulated by regulatory proteins that are needed so ribosomes can translate mRNA are called | back 63 translation factors |
front 64 three chemical modifications to histones to regulate transcription | back 64 1.activator- histone acetyltransferases (nucleosomes loosened) 2.repressor- histone deacetylases 3.repressor- histone methyltransferases |
front 65 two ways transcription regulators act | back 65 1.directly effect the assembly process that require RNA polymerase and transcription factors at the promoter- histone proteins 2.modify the chromatin structure of promoter regions- DNA itself |
front 66 cell defense mechanism that destroys foreign RNA, man made, double stranded | back 66 siRNA |
front 67 controls gene expression, single stranded, regulate our own genes, base pairs with specific mRNA | back 67 miRNA |
front 68 in the absence of lactose, the lac repressor A)binds to the operator and prevents transcription B)binds to the CAP site and prevents transcription C)binds to the CAP site and facilitates transcription D)binds to the operator and facilitates transcription | back 68 a |
front 69 The main regulatory gene that acts on the lac operon is a | back 69 lac repressor with no lactose and CAP activator with no glucose repressor binds to the lac operon operator, where it blocks RNA polymerase from transcribing the lac operon CAP binds to cyclic cAMP before it can bind to DNA, switches on genes to increase intracellular cAMP |
front 70 In a eukaryote, activating transcription factors may stimulate gene expression by binding to a DNA site called a(n) _____. | back 70 enhancers |
front 71 You have inserted the gene for human growth factor into the E. coli lactose operon, replacing the structural genes with the gene for human growth factor. What substance must you add to your culture of bacteria to cause them to produce human growth factor for you? | back 71 allolactose |
front 72 In an inducible operon, the inducer is often the _____ in the pathway being regulated; the inducer binds to the _____, thus rendering it _____. | back 72 substrate ... repressor ... inactive |
front 73 the genetic information contained within the order of nucleotides in mRNA is interpreted to generate the linear sequence of amino acids | back 73 translation |
front 74 which part of the mRNA is used | back 74 middle |
front 75 the protein coding region with nonoverlapping string of codons | back 75 ORF- open reading frame |
front 76 translation starts at what end | back 76 5' to the 3' |
front 77 how many possible codons | back 77 3 bases, 4 nucleotides = 43 = 64 61 are translated into AA, the rest are stop codons |
front 78 provides the genetic information template to be translated | back 78 mRNA |
front 79 provides the interface between the mRNA and their corresponding AA | back 79 tRNA |
front 80 enzyme links AA to their corresponding tRNA, one for each of the 20 AA | back 80 aminoacyl-tRNA synthetase |
front 81 coordinates recognition between the mRNA and corresponding tRNA and catalyzes the peptide bond formation between tRNA associated AA | back 81 ribosomes |
front 82 does transcription and translation occur at the same time in eukaryotes | back 82 no one is in the nucleus and the other in the cytoplasm |
front 83 three binding sites in the ribosome | back 83 A- enters P- attaches AA E- exit |
front 84 what determines the start of translation | back 84 5' end of ORF is methionine (AUG) |
front 85 base pairing results in structural conformational change which in turn causes some of the bound initiation factors to be | back 85 released and new ones bind |
front 86 in addition to codon-anticodon base pairing, the ribosome has additional proofreading mechanisms to ensure | back 86 the correct tRNA is brought into the A site |
front 87 stop codons are recognized by proteins called | back 87 release factors activates hydrolysis of the polypeptide from the tRNA |
front 88 an mRNA with multiple ribosomes attached is a | back 88 polyribosome |
front 89
Which type of RNA includes the anticodon and brings the
amino acids to the site of protein
synthesis? | back 89 c |
front 90 Where does translation occur? A.Cytoplasm B.Nucleus C.Mitochondria D. Ribosome | back 90 a |
front 91 Which molecule contains codons? A)DNA B)mRNA C)tRNA D)rRNA | back 91 b |
front 92 What form of RNA binds to both the codon and an amino acid? A)mRNA B)tRNA C)rRNA D)None of the above. | back 92 b |
front 93 What area of a gene does the RNA polymerase bind to? A)promoter B)exon C)intron D)codon | back 93 a |
front 94 RNA is transcribed using the ____ strand of DNA. A)coding B)alternate C)template D)non-template | back 94 a |
front 95 Which of the statements below is FALSE? A)The genetic code is overlapping. B)The genetic code is universal. C)Degenerate codons specify the same amino acids D)The genetic code is triplet in nature. | back 95 a |
front 96 The first mRNA codon to specify an amino acid in a protein sequence is always _____. A)TAC B)UAA C)UAG D)AUG | back 96 d |
front 97 Transfer RNAs bind to messenger RNAs during translation via their _____. A)codon B)anticodon C)template | back 97 b |
front 98 Of the ____ different possible codons, ____ specify amino acids and ____ signal stop. A)20; 17; 3 B)180; 20; 60 C)64; 61; 3 D)61; 60; 1 | back 98 c |
front 99 An antibiotic interferes with the ability of the ribosome to move. What effect would exposure to this chemical have on a bacterial cell? A)Protein synthesis will be enhanced. B)The protein synthesized will be shorter than normal. C)The protein synthesized will be longer than normal. D)No proteins will be produced. | back 99 d |
front 100 What sequence on the template strand of DNA corresponds to the first amino acid inserted into a protein? A)TAC B)UAA C)UAG D)AUG | back 100 a |
front 101 Which of the following is an example of the degeneracy of the genetic code? A)A given amino acid has more than one codon. B)Each codon specifies more than one amino acid. C)The first base specifies the amino acid. D)The genetic code is not degenerate | back 101 a |
front 102 During translation, the _____ site within the ribosome holds the growing amino acid chain while the ____ site holds the next amino acid to be added to the chain. A)A; P B)P; A C)A; B D)B; A | back 102 b |
front 103 Translation terminates when _____. A)the A site is empty B)a stop codon is present in the A site C)a release factor is present in the P site D)translation reaches the end of the mRNA | back 103 b |
front 104 what dictates which genes are expressed, where, and when | back 104 regulatory mechanisms |
front 105 we rarely use any more of _____ % of our genes at any given time | back 105 5-10% |
front 106 all cells have the same DNA and therefore the same | back 106 genes but they are not all expressed- gives specificity to muscle, nerve, skeletal cells |
front 107 all cells require | back 107 ATP |
front 108 what events does gene expression control | back 108 when and how often a gene is transcribed how mRNA is spliced which mRNA is transported how quickly mRNA is degraded which mRNA is translated how quickly protein is degraded |
front 109 what stage is the most regulated | back 109 initiation of transcription |
front 110 slight continuous level of expression of a gene | back 110 basal level |
front 111 transcription activator proteins bind to the DNA and RNA polymerase near the promoter which brings in the RNA polymerase to the promoter | back 111 cooperative binding resulting from recruitment an indirect mechanism because of the domino effect |
front 112 two proteins acting in one complex, need both of them to be active, one end binds to the DNA binding site, the other end binds to the RNA polymerase | back 112 dimer |
front 113 set of three genes plus other things in E. coli involved in the transport and breakdown of lactose into glucose | back 113 lac operon |
front 114 what is the lac operon composed of | back 114 3 genes- lacZ, lacY, lacA promoter terminator operator |
front 115 what is the lac operon regulated by | back 115 availability of lactose and glucose |
front 116 how does a cell use lactose as energy | back 116 produces beta-galactosidase to break down lactose into glucose |
front 117 lac promoter directs transcription of all 3 genes as a single mRNA molecule called | back 117 polycistronic message |
front 118 what does lacZ do | back 118 produces enzyme beta-galactosidase to break down lactose into galactose and glucose |
front 119 what does lacY do | back 119 produces the protein lactose permease that transports lactose into the cell |
front 120 what does lacA do | back 120 produces the enzyme thiogalactosidase transacetylase to break down the toxic thiogalactosidase that was brought into the cell with lactose |
front 121 when lactose is present and glucose is not then the genes are | back 121 expressed |
front 122 regulation in the expression of the lac operon is upstream and controlled by | back 122 if or not there is an activator CAP lac repressor which is encoded by a gene |
front 123 gene that encodes the lac repressor that binds to the lac promoter region and prevents transcription when there is no lactose | back 123 lacI gene and allolactose |
front 124 when glucose is present but there is no lactose, then A)cyclic AMP is high, the catabolite activator protein (CAP) binds to the activator binding site, and transcription of lactose is turned on B)cyclic AMP is low, CAP binds to the site activator binding site, and transcription of lactose is turned on C)cyclic AMP is high, CAP does not bind to the activator binding site, and transcription of lactose is turned on D)cyclic AMP is low, CAP does not bind to the activator binding site, and transcription is turned off | back 124 d inhibitor activated lac repressor binds to operator region and prevents RNA polymerase from binding |
front 125 when glucose is absent but lactose is present, then | back 125 promoter activated an allosteric effect on CAP binding site cyclic cAMP binds to CAP which then binds to the CAP site on mRNA and RNA polymerase then attaches to the promoter site so transcription can occur |
front 126 when both glucose and lactose are present A)cyclic AMP is high so transcription occurs B)the lac repressor binds with the lactose and transcription occurs C)RNA polymerase is able to bind to the operator so transcription occurs D)transcription is at a minimal level | back 126 d a basal level of transcription occurs |
front 127 protein exerts its effects from a distance away from the promoter region works by changing the structure of the mRNA so it bends around in a loop, can activate or repress | back 127 enhancer site for binding of an activator protein |