Gwendolyn Quintana @011872351. Choose the answer that best fits the statement. Cholesterol is an essential component of biological membranes. Although it is much smalle isolate DNA from several different tissues of an animal and find the following molar ratios of moles of each base to moles of phosphate in the samples. … than the typical phospholipids and glycoplipids in the membrane, it is a(n) _________________ molecule, having both hydrophilic and hydrophobic regions.(d) amphipathic 2. DNA and RNA are different types of nucleic acid polymer. Which of the following is true of DNA but not true of RNA? (b) It contains thymine. 3. Match each term related to the structure of nucleic acids (A–I) with one of the descriptions provided.A. baseB. glycosidic bondC. nucleosideD. nucleotideE. phosphoanyhydride bondF. phosphoester bondG. riboseH. phosphodiester bondI. deoxyribose4. F the linkage between two nucleotides5. H the linkage between the 5′ sugar hydroxyl and a phosphate group6. A the nitrogen-containing aromatic ring7. I five-carbon sugar found in DNA8. C sugar unit linked to a base9. B linkage between the sugar and the base10. E linkages between phosphate groups11. D sugar linked to a base and a phosphate12. G five-carbon sugar found in RNA13, 14, 15.Your lab director requests that you add new growth medium to the mammalian cell cultures before heading home from the lab on a Friday night. Unfortunately, you need to make fresh medium because all the pre-mixed bottles of medium have been used. One of the ingredients you know you need to add is a mix of the essential amino acids (those that cannot be made by the cells, but are needed in proteins). On the shelf of dry chemicals you find the amino acids you need, and you mix them intoyour medium, along with all the other necessary nutrients and replace the old medium with your new medium. On Sunday, you come in to the lab just to check on your cells and find that the cells have not grown. You are sure you made the medium correctly, but on checking you see that somebody wrote a note on the dry mixture of amino acids you used: “Note: this mixture contains only D-amino acids.”A. What is the meaning of the note and how does it explain the lack of cell growth in your culture?There are two isoforms of amino acids: right-handed amino acids (D-AA) and left-handed amino acids (L-AA). L-amino acids constitute all AA found in proteins during translation in the ribosome, therefore essential for general growth and proliferation (mitosis, etc.). D-amino acids are found in some proteins produced by enzyme posttranslational modifications after translation and translocation to the endoplasmic reticulum they are also important in peptidoglycan cell wall synthesis of bacteria. Nonetheless, if the mixture did not contain L-amino acids proliferation could not occur and thus D-AA yield unnecessary. 16, 17. You are trying to make a synthetic copy of a particular protein but accidentally join the amino acids together in exactly the reverse order. One of your classmates says the two proteins must be identical, and bets you $20 that your synthetic protein will have exactly the same biological activity as the original. You have no hesitation in staking your $20 that it won’t. What particular feature of a polypeptide chain makes you sure your $20 is safe and that your project will have to be redone.As a peptide bond has a distinct chemical polarity, a polypeptide chain also has a distinct polarity. The reversed protein chains cannot make the same noncovalent interactions during folding and thus will not adopt the same 3-D structure as the original protein. The activities of these two proteins will definitely be different, since the activity of a protein depends on its 3-D structure. It is unlikely that the reverse chain will fold into any well-defined, and hence, functionally-useful structure at all, because it has not passed the stringent selective pressures imposed during evolution.18 - 26 Fill in the blanks in the following brief description of the experiment with Streptococcus pneumoniae that identified which biological molecule carries heritable genetic information. Some terms may be used more than once.Cell-free extracts from S-strain cells of S. pneumoniae were fractionated to purify DNA, RNA, protein, and other cell components. Each fraction was then mixed with R strain cells of S. pneumoniae. Its ability to change these into cells with pathogenic properties resembling the S strain cells was tested by injecting the mixture into mice. Only the fraction containing DNA was able to transform the R strain cells to pathogenic (or S strain ) cells that could kill mice.27. The complete set of information found in a given organism’s DNA is called its ____________. (d) genome 28-31. The number of cells in an average-sized adult human is on the order of 1014. Use this information, and the estimate that the length of DNA contained in each cell is 2m, to do the following calculations (look up the necessary distances and show your working): A. Over how many miles would the total DNA from the average human stretch?(10 14 cells)(2miles)=2x10 14 miles 2m=2 meters of 2 miles? If, meters reference below. If miles, reference above. 1 mile = 1609.34m :. (2x1014m)÷ 1609.34 m = 3.22 x 1017 milesB. How many times would the total DNA from the average human wrap around the planet Earth at the Equator?Earth’s Circumference = 24,901.55 miles24,901.55 miles ÷ 2x10 14 miles = 8.03x10 9 times 32-36The human genome comprises 23 pairs of chromosomes found in nearly every cell in the body. Answer the quantitative questions elow by choosing one of the numbers in the following list:23 69 >20046 92 >109A. How many centromeres are in each cell? 23 What is the main function of the centromere?The centromere is a specialized region od the chromosome that plays a critical role in ensuring the correct distribution of duplicated chromosomes to daughter cells during mitosis.B. How many telomeres are in each cell? 92 What is their main function? Telomere DNA loops back on itself to forma circular structure and associates with a protein complex that protects the ends of chromosomes and plays a role in chromosome replication and maintenance. C. How many replication origins are in each cell? Various (up to 100,000 present in a single human cell).Is their