Term
| A covalent bond is likely to be polar when... |
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Definition
| One of the atoms sharing electrons is much more electronegative than the other atom. |
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Term
| A group of molecular biologists is trying to synthesize a new artificial compound to mimic the effects of a known hornmone that influences sexual behavior. They have turned to you for advice. Which of the following compounds is most likely to mimic the effects of the hormone? |
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Definition
| A compound with the same number of carbon atoms as the hormone. |
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Term
| Which functional groups are always found in amino acids? |
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Definition
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Term
| What best summarizes the relationship between dehydration reactions and hydrolysis? |
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Definition
| dehydration reactions assemle polymers and hydrolysis reactions break down polymers. |
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Term
| The label on a container of margarine lists "hydrogenated vegetable oil" as the major ingredient. What is the result of adding hydrogens to a vegetable oil? |
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Definition
| The hydrogenated vegetable oil stays solid at room temperature. |
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Term
| There are 20 different amino acids. What makes one amino acid different from another? |
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Definition
| Different side chains (R groups) attached to the amino groups. |
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Term
| What aspects of protein structure are stabilized or assisted by hydrogen bonds? |
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Definition
| Secondary, tertiary, quaternary, but not primary structures. |
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Term
| Which level of protein structure do the alpha helic and beta pleated sheet represent? |
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Definition
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Term
| Which bonds are created during the formation of the primary structure of a protein? |
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Definition
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Term
| Misfolding of polypeptides is a serious problem in cells. Which of the following diseases are associated with an accumulation of misfolded peptides? |
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Definition
| Alzheimers and Parkinsons |
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Term
| Normal hemoglobin is a tetramer, consisting of two molecules of beta hemoglobin and two molecules of alpha hemoglobin. In sickle-cell disease, as a result of a single amino acid change, the mutant hemoglobin tetramers associate with each other and assemle into large fibers. Based on this information alone, we can conclude that sickle-cell hemoglobin exhibits.. |
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Definition
| Altered primary structure and altered quaternary structure; the secondary and tertiary structures may or may not be altered. |
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Term
| What is the term used for a protein molecule that assists in the proper folding of other proteins? |
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Definition
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Term
How do you describe the class of molecules known as nucleotides?
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Definition
| a nitrogenous base, a phosphate group, and a pentose sugar |
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Term
| Large numbers of ribosomes are present in cells that specialize in producing which of the following molecules? |
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Definition
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Term
| Which structure is the site of synthesis of proteins that may be exported from the cell? |
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Definition
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Term
| The liver is involved in detoxification of many poisons and drugs. Which of the following structures is primarily involved in this process and therefore abundant in liver cells? |
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Definition
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Term
| One of the key innovations in the evolution of eukaryotes from a prokaryotic ancestor is the endomembrane system. What eukaryotic organelles or features might have evolved as a part of or as an elaboration of the endomembrane system? |
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Definition
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Term
| Cyanide binds with at least one molecule involved in producting ATP. If a cell is exposed to cyanide, most of the cyanide will be found within... |
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Definition
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Term
| Which cell would be best for studying lysosomes? |
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Definition
| phagocytic white blood cell |
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Term
| Some regions of the plasma membrane, called lipid rafts, have a higher concentration of cholesterol molecules. As a result, these lipid rafts.. |
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Definition
| Are more rigid than the surrounding membrane |
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Term
| Singer and nicolsons fluid mosaic model of the membrane proposed that |
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Definition
| membranes consist of protein molecules embedded in a fluid bilayer of phospholipids |
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Term
| which of the following is true of integral membrane proteins? |
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Definition
| They are usually transmembrane proteins |
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Term
| Cell membranes are asymmetrical. Which of the following is the most likely explanation? |
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Definition
| The two sides of a cell membrane face different environments and carry out different functions. |
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Term
| Water passes quickly through cell membranes because... |
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Definition
| It moves through aquaporins in the membrane |
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Term
| Which of the following membrane activities require energy from ATP hydrolysis? |
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Definition
| NA+ ions moving out of a mammalian cell bathed in physiological saline |
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Term
| You are working on a team that is designing a new drug. In order for this drug to work, it must enter the cytoplasm of specific target cells. Which of the following would be a factor that determines whether the molecule selectively enters the target cells? |
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Definition
| Lipid composition of the target cells' plasma membrane |
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Term
| Increasing the substrate concentration in an enzyme reaction could overcome which of the following? |
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Definition
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Term
| Some of the drugs used to treat HIV patients are competitive inhibitors of the HIV reverse transcriptase enzyme. Unfortunately, the high mutation rate of HIV means that the virus rapidly acquires mutations with amino acid changes that make them resistant to these competitive inhibitors. Where in the reverse transcriptase enzyme would such amino acid changes most likely occur in drug-resistant viruses? |
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Definition
| in or near the active site |
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Term
| Which of the following statements describes ezymes cooperativity? |
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Definition
| A substrate molecule bound to an active site of one subunit promotes substrate binding to the active site of other subunits |
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Term
| Besides turning enzymes on or off, what other means does a cell use to control enzymatic activity? |
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Definition
| localization of enzymes into specific organelles or membranes |
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Term
Where does glycolysis take place in eukaryotic cells?
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Definition
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Term
| Starting with one molecule of glucose, the energy-containing products of glycolysis are |
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Definition
| 2 NADH, 2 pyruvate and 2 ATP |
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Term
One function of both alchol fermentation and lactic acid fermentation is to...
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Definition
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Term
| When skeletal muscle cells are oxygen deprived, the heart still pumps. What must the heart muscle cells be able to do? |
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Definition
| continue aerobic metabolism when skeletal muscles cannot |
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Term
| Phosphofructokinase is an imoprtant control enzyme in the regulation of cellular respiration. Which of the following statements correctly describes phosphofructokinase activity? |
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Definition
| It is an allosteric enzyme |
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Term
| If pyruvate ozidation is blocked, what will happen to the levels of oxaloacetate and citric acid in the citric acid cycle? |
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Definition
| Oxaloacetate will accumulate and citric acid will decrease |
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Term
| Starting with citrate, which of the following combinations of products would resul from three acetyl CoA molecules entering the citric acid cycle? |
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Definition
| 3 ATP, 6 CO2, 9 NADH, and 3 FADH2 |
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Term
| In the presence of oxygen, the three carbon compound pyruvate can be catabolized in the citric acid cucle. In the transition step between glycolysis and Krebs cycle, a two carbon molecule is bonded to a coenzyme A which is then fed into the Krebs cycle. What is the correct sequence of carbon reduction in the kreb cycle? |
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Definition
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Term
| The transitions phase which a combination of three steps results in the formation of |
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Definition
| Acetyl CoA, NADH, H+, CO2 |
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Term
| Which steps of glycolysis require the input of ATP and thus are collectively called pump priming? |
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Definition
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Term
| What of the following plays a role in the degredation of proteins? |
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Definition
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Term
Which of the following modification marks a protein for degredation in proteosomes?
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Definition
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Term
| Peripheral membrane proteins... |
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Definition
| May noncovalently interact with phospholipid heads |
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Term
| Cholesterol mixes with phospholipids in a biomembrane because cholesterol molecules are.. |
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Definition
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Term
| Which of the following conditions forms a proton gradient in the ETC? |
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Definition
| Higher H+ concentration in the intermembrane space than matrix |
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Term
| A protein being transported to the trans-golgi network from the ER will be taken there by _____ coated vesicles. |
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Definition
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Term
| A specific gene is known to code for three different but related proteins. This could be due to which of the following? |
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Definition
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Term
| Which is not a constituent of deoxyribonucleotides? |
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Definition
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Term
WHat is removed from mRNA's during processing?
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Definition
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Term
| In eukaryotic cells protein synthesis in the cytoplasm utilizes three types of RNA molecules. Which contains a three nucleotide sequence called the anticodon? |
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Definition
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Term
| All the following steps are performed by the enzyme transposase during nonreplicative transposition of bacterial insertion sequences except.. |
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Definition
| Synthesis of DNA to fill in the single-stranded gaps |
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Term
What is not true about the nucleosome?
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Definition
| Is is the "String" of the "beads-on-a-string" appearance |
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Term
| DNA that is transcriptionally active.. |
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Definition
| Is more susceptible to DNase I digestion (DNA is degradede or cut up by this enzyme) |
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Term
| All of the following can be found in chromatin except |
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Definition
|
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Term
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Definition
| Consist of repetitive sequences with high G content and have a specific protein bound at the DNA ends |
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Term
| All the following statements about heterochromatin are true except.. |
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Definition
| It is usually transcriptionally active. |
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Term
What is the order in which mature mRNA is produced?
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Definition
| Inititiation of transcription, addition of 5' cap, addition of poly A tail, splicing, transport to cytoplasm |
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Term
| The plasma membane of eukaryotic cells is supported by.. |
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Definition
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Term
| Vesicle transport along actin filaments is driven by.. |
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Definition
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Term
| During treadmilling, actin subunits add.. |
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Definition
predominantly to filament + ends
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Term
| Membrane extension during cell locomotion is driven by |
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Definition
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Term
| The region of a motor protein that interacts with the motors cellular cargo |
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Definition
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Term
| Cytosolic dynein is linked to vesicles and chromosomes via |
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Definition
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Term
| Which of the following is typical feature of prokaryotic genes? |
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Definition
| Polycistronic messenger RNA's |
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Term
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Definition
| acts to position RNA polymerase II for transcription initiaion |
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Term
| All the following statements about heterochromatin are true except |
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Definition
| Heterochromatin is more susceptible to DNase than euchromatin |
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Term
| Transcriptionally inactive genes |
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Definition
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Term
| Which of the following variations on translation would be most disadvantageous for a cell? |
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Definition
| Translating polypeptides directly from DNA |
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Term
| The nitrogenous base adenine is found in all members of which groups? |
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Definition
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Term
| Which of the following statements best describes the termination of transcription in prokaryotes? |
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Definition
| RNA polymerase transcribes through the terminator sequence, causing the polymerase to separate from the DNA and release the transcript. |
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Term
| Which of the following does not occur in prokaryotic gene expression, but does in eukaryotic gene expression? |
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Definition
| A poly-A tail is added to the 3' end of an mRNA and a cap is added to the 5' end. |
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Term
| Transcription is eukaryotes requires which of the following in addition to RNA polymerase? |
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Definition
| Several general transcription factors |
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Term
| During splicing, which molecular component of the sliceosome catalyzes the excision reaction? |
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Definition
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Term
| When spliceosome binds to elements of this structure, where can it attach? |
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Definition
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Term
| Accuracy in the translation of mRNA into the primary structure of a polypeptide depends on specificity in the.. |
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Definition
| bonding of the anticodon to the codon and the attachment of amino acids to tRNAs |
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Term
| Which is the first event to take place in translation in eukaryotes? |
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Definition
| The small subunit of the ribosome recognizes and attaches to the 5' cap of mRNA |
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Term
| Which of the following is a function of a signal peptide? |
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Definition
| to translocate polypeptides across the ER membrane. |
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Term
| When the function of the newly made polypeptide is to be secreted from the cell where it has been made, what must occur? |
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Definition
| Its signal sequence must target it to the ET, from which it goes to the Golgi |
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Term
| What is the most current description of a gene? |
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Definition
| A DNA sequence that is expressed to form a functional product: either RNA or polypeptide |
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Term
| tRNA its 3' end projecting beyond its 5' end. What will occur at this 3' end? |
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Definition
| the amino acid binds covalently |
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Term
| COP I coat proteins mediate transport between the golgi apparatus and other organelles |
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Definition
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Term
| Protein sorting of anterograde cargo to different destinations within the Golgi complez occurs in the |
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Definition
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Term
| Within the centrosome what actually nucleates the microtubules? |
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Definition
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Term
| Rapid depolymerization tubulin is called |
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Definition
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Term
| Catastrophe is caused by.. |
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Definition
| hydrolysis of GTP to GDP in + end |
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Term
| Which motor protein is plus end directed? |
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Definition
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Term
One symptom kartanener syndrome is immotile sperm. The mutation likely results in defective..
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Definition
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Term
| The length of a particular gene in human DNA, measured from the start site for transcription to the end of the protein-coding region, is 10,000 nucleotides, whereas the length of mRNA produced from this gene is 4,000 nucleotides. What is most likely the reason for this discrpency? |
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Definition
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Term
| You take the normal NLS and fuse it a non nuclear protein like serum albumin and inject it into the cytoplasm of the cell. You then monitor what happens to the protein. What happens? |
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Definition
| Serum albumin moves to the nucleus |
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Term
| Chromosomes compact using proteins called |
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Definition
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Term
| Tay-Sachs disease is a human genetic abnormality that results in cells accumulating and becoming clogged with very large and complex lipids. Which cellular organelle must be involved in this condition? |
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Definition
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Term
| Which structure is the site of the synthesis of proteins that may be exported from the cell? |
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Definition
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Term
| Which of the following contain 9+2 arrangement of microtubules, consisting of nine doublets of microtubules surrounding a pair of single microtubules? |
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Definition
| both flagella and motile cilia |
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Term
| Vinblastine, a drug that inhibits microtubule polymerization, is used to treat some forms of cancer. Cancer cells given vinblastine wouldn't be able to.. |
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Definition
| separate chromsomes during cell division |
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Term
| If an individual has abnormal microtubules, due to a hereditary condition, in which organs or tissues would you expect dysfunction? |
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Definition
| Sperm, larynx, and trachea: Cells and tissues that contain flagella or cilia |
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Term
Cytochalasin B is a drug that prevents actin polymerization. A cell treated with cytochalsin B will still be able to
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Definition
| move vesicles around the cell. |
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