Karp g cell and molecular biology pdf
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- Basic Cell and Molecular Biology: What We Know & How We Found Out - 4e
- Karp G. Cell and Molecular Biology: Concepts and Experiments (6th Edition)
- Cell and Molecular Biology Concepts and Experiments
Basic Cell and Molecular Biology: What We Know & How We Found Out - 4e
Question Type: Multiple Choice 1 The energy stored in ATP is converted to mechanical energy that moves organelles around within the cell. Section Reference: Section 3. Willard Gibbs d the energy available to do work and the total energy content of a system e All of these are correct. After its initial interaction with the substrate, the enzyme alters its shape and thus improves the fit of the substrate in the active site What is the name of this model?
Learning Objective: LO 3. The existence of this type of motion has suggested that enzymes are capable - even in the absence of substrate - of many of the same movements that can be detected during their catalytic cycle.
The reaction also results in an increase in entropy. Is the reaction spontaneous? How do you know? Explain your answer. Solution: The reaction is nonspontaneous. If not, why not? If the reaction is slightly positive, it may be coupled as well, although it may also be driven forward by. The Law of Mass Action would be likely to allow the reaction to run under these conditions. To the reaction mixture you add a chemical X which inhibits the reaction.
If you add more substrate, the reaction rate approaches the Vmax of the uninhibited reaction. Furthermore, the structure of X is similar to the natural substrate. What kind of inhibitor is X? First, competitive inhibitors resemble the substrates of the reactions they inhibit. Second, their effects can be reversed by increasing substrate concentration, since both the substrate and the competitive inhibitor are capable of binding to the enzyme active site.
As the amount of substrate increases relative to the competitive inhibitor, the active site is more likely to pick up substrate and thus reaction rate increases and the inhibition is reversed. ATP will act like a noncompetitive inhibitor and will inhibit one of the early reactions in the glycolytic pathway. What kind of inhibitor was used in the experiment?
M is a product of one series of these reactions. It is also a regulatory molecule. Look at the pathway below and indicate the position s at which M is most likely to act as a feedback inhibitor when its concentration gets too high. Usually, a feedback inhibitor will work on an enzyme near the beginning of the pathway that.
Therefore, positions 1 and 2 are the most likely with 1 being slightly favored. When presented with substrate K in amounts significantly larger than M, basinase converts K to L which leads eventually to the production of the end product R. The activity of the second pathway is depressed simultaneously. In the presence of large amounts of substrate M and lower amounts of substrate K, the second pathway is activated and culminates in the production of that pathway's end product Y. The activity of the first pathway is depressed simultaneously.
What are the alternative substrates K and M acting like? If one is present in excess, the pathway involving the other is inhibited.
Why then is there a net production of only 2 ATPs for each glucose molecule in the pathway? Consequently, there is a net gain of only 2 ATPs per glucose. Solution: The decrease in the pharmaceutical industry's resources devoted to the development of new antibiotics is generally attributed to three factors. First, there is a lack of financial incentives since antibiotics are taken for only a short period of time, as opposed to drugs prescribed for chronic conditions diabetes, depression.
Second, new antibiotics run the risk of having a relatively short lifetime in the marketplace as bacteria become resistant to each successive product. Last, the most effective antibiotics are being held back from widespread use and being kept instead as weapons of last resort when other drugs have failed.
Name two common antibiotics that work this way. What is their site of action and why don't they affect eukaryotic protein synthesis? They act by binding to prokaryotic ribosomes. Eukaryotic ribosomes are sufficiently different from those in prokaryotes to prevent binding of these substances. Thus, eukaryotic protein synthesis is unaffected. The cell wall is thus fragile and the bacteria die. Penicillin and its derivatives are structural analogs of the natural substrates of these enzymes.
Why doesn't penicillin normally kill humans, unless a severe allergic reaction anaphylaxis develops? How does penicillin inhibit transpeptidase? Thus, penicillin cannot inhibit an enzyme that humans do not possess and it will not normally harm humans. Since penicillin occupies the transpeptidase active site, it acts somewhat like a competitive inhibitor, but since it binds irreversibly, it is not truly competitive.
You find, not surprisingly, that sulfa drugs inhibit the enzyme's activity. What happens to the Vmax and KM of this enzyme when it is treated with sulfa drugs? Why do sulfa drugs have no effect on human metabolism? Sulfa drugs work by acting as a competitive inhibitor of an enzyme that converts p-aminobenzoic acid PABA to the essential coenzyme folic acid. Since humans lack a folic-acid synthesizing enzyme, they must obtain this essential coenzyme in their diet and, consequently, sulfa drugs have no effect on human metabolism.
Why is it more difficult for bacteria to develop resistance to vancomycin than to other antibiotics? To become resistant to vancomycin, a bacterial cell must synthesize an alternate terminus that does not bind the drug. This is a roundabout process that requires the acquisition of several new enzymatic activities. Consequently, vancomycin is the antibiotic to which bacteria have been least able to develop resistance and thus is usually given as a last resort when other antibiotics have failed.
What kind of hospitalized patients develop life-threatening S. Distressingly, instead of just showing up in hospitals, methicillin-resistant S. What are some examples?
Those patients who have open wounds or invasive tubes. It has appeared in community settings, like high school gyms and children's daycare centers. How is the effect of such an inhibitor usually able to be reversed? Why would this approach not work with penicillin? Such inhibition is usually reversible by increasing substrate concentration, which would tend to displace the inhibitor from the active site.
An increase in substrate concentration does not reverse penicillin's effect because penicillin forges a covalent bond between itself and the enzyme active site, thus occupying the active site permanently and irreversibly inactivating the enzyme. Bacteria may also exchange genes by the process of transduction in which a virus carries bacterial DNA from one bacterium to another. DNA may also be passed by transformation in which a bacterium can pick up naked DNA from its surrounding medium.
However, some have developed resistance without acquiring this gene. How do these bacteria escape the fatal effects of penicillin? Others are resistant because they are able to selectively export the antibiotic once it has entered the cell.
Still others are resistant because they possess modified transpeptidases that fail to bind the antibiotic as a result of mutations in the gene that encodes the enzyme. This strategy greatly reduces the likelihood that a variant will emerge that is resistant to all of the drugs.
Second, drugs have been designed that interact with the most highly conserved portions of each targeted enzyme, those portions within which mutations are most likely to produce a defective enzyme. One of these antibiotics acts specifically on bacterial ribosomes. What is it? Another new group of antibiotics is the cyclic lipopeptides. What is a representative of this group and how does this group of antibiotics work? A representative cyclic lipopeptide is daptomycin brand name Cubicin.
They disrupt bacterial membrane function. How does it render them immune to the effects of penicillin? Thus, penicillinase breaks the ring and renders penicillin harmless to the bacterium. Alternatively, it is tested for its ability to bind and inhibit a particular target protein that has been purified from bacterial cells. Completed download at: cell and molecular biology karp test bank cell and molecular biology karp 7th edition test bank cell and molecular biology concepts and experiments 7th edition pdf cell and molecular biology karp 7th edition test bank free karp cell and molecular biology pdf cell and molecular biology karp 8th edition pdf cell and molecular biology by gerald karp 7th edition pdf free download karp cell and molecular biology 8th edition.
See More. Usually, a feedback inhibitor will work on an enzyme near the beginning of the pathway that leads to its production. Published on Jul 2, Go explore.
Karp G. Cell and Molecular Biology: Concepts and Experiments (6th Edition)
British Wildlife is the leading natural history magazine in the UK, providing essential reading for both enthusiast and professional naturalists and wildlife conservationists. Published eight times a year, British Wildlife bridges the gap between popular writing and scientific literature through a combination of long-form articles, regular columns and reports, book reviews and letters. Conservation Land Management CLM is a quarterly magazine that is widely regarded as essential reading for all who are involved in land management for nature conservation, across the British Isles. CLM includes long-form articles, events listings, publication reviews, new product information and updates, reports of conferences and letters. Karp's Cell Biology , 8th edition continues to build on its strength at connecting key concepts to the experiments that reveal how we know what we know in the world of cell biology.
The Dictionary of Cell and Molecular Biology, Fifth Edition , provides definitions for thousands of terms used in the study of cell and molecular biology. The headword count has been expanded to 12, from 10, in the Fourth Edition. Over 4, headwords have been rewritten. Some headwords have second, third, and even sixth definitions, while fewer than half are unchanged. Many of the additions were made to extend the scope in plant cell biology, microbiology, and bioinformatics. The Appendix includes prefixes for SI units, the Greek alphabet, useful constants, and single-letter codes for amino acids.
Cell and Molecular Biology Concepts and Experiments
Karp continues to help biologists make important connections between key concepts and experimentation. The sixth edition explores core concepts in considerable depth and presents experimental detail when it helps to explain and reinforce the concepts. The majority of discussions have been modified to reflect the latest changes in the field. Over 60 new micrographs and computer-derived images have been added to enhance the material. Biologists benefit from these changes as they build their skills in making the connection.
Karp G. Wiley, The majority of discussions have been modified to reflect the latest changes in the field.
Question Type: Multiple Choice 1 The energy stored in ATP is converted to mechanical energy that moves organelles around within the cell. Section Reference: Section 3. Willard Gibbs d the energy available to do work and the total energy content of a system e All of these are correct. After its initial interaction with the substrate, the enzyme alters its shape and thus improves the fit of the substrate in the active site What is the name of this model? Learning Objective: LO 3.