Loading....
Coupon Accepted Successfully!

Biological Sciences

Open Flashcards

Biological Molecules

Question
8 out of 10
 

Which of the following statements is true regarding proteins?

A All proteins exhibit quaternary folding.
B The primary structure of a protein refers simply to the linear order of amino acids it contains.
C Not all proteins contain amino acids, only the ones that have extensive three-dimensional folding.
D All proteins are composed of one polypeptide chain.
Ans. B

Protein primary structure refers only to the linear order of amino acids. Secondary and tertiary folding are characteristics of all proteins, and involve interactions between various amino acids and ultimately cause specific three-dimensional folding. Both A and D are incorrect for related reasons; some proteins consist of more than one polypeptide chain, and it is only these proteins that exhibit quaternary folding (the association of multiple polypeptides). All proteins contain amino acids, by definition, so C cannot be correct.

Biological Molecules Flashcard List

10 flashcards
1)
Often, bacteria are grown on a medium that contains all of the components they need to survive. This includes an energy source, a carbon source, and sources of all the mineral salts the bacteria require to carry out their metabolic reactions. Sometimes, a mutant bacterium is isolated that needs more than the usual minimum requirements, because it cannot carry out the reactions necessary to produce a needed substance. These mutants are referred to as auxotrophs; if they are to grow, they must be supplemented with the substance they need but cannot manufacture. Experiment 1 Bacteria were grown on media containing different radioactively labeled atoms to determine which types of biological molecules would be radioactively labeled. Molecules become labeled as they are synthesized by the bacteria using the raw materials provided by the medium. The bacteria were grown for a period of time that was sufficient to label all molecules that could be labeled, and the major types of biomolecules were isolated and tested for the presence of radioactivity. The following table shows the various strains of bacteria and the radioactive element present in the media in which they were grown. Bacterial strain Radioactive element strain 1 carbon strain 2 phosphorous strain 3 nitrogen strain 4 oxygen Experiment 2 Auxotrophic bacteria were grown on media supplemented with the substance that they need but cannot manufacture. If they were not supplemented in this way, no growth would be observed. The following table shows two auxotrophic strains and the substance with which they were supplemented. Auxotrophic strain Supplement strain A arginine, an amino acid strain B decanoic acid, a fatty acid Experiment 3 Auxotrophic strain A (from Experiment 2) was grown on a medium that contained supplemental arginine and radioactive phosphorus, and the major types of biomolecules were again isolated and tested for radioactivity. Which of the following biomolecules isolated from Strain 2 would we expect to be radioactively labeled according to the table from experiment 1?A RNAB ProteinsC GlucoseD Amino acids
2)
Often, bacteria are grown on a medium that contains all of the components they need to survive. This includes an energy source, a carbon source, and sources of all the mineral salts the bacteria require to carry out their metabolic reactions. Sometimes, a mutant bacterium is isolated that needs more than the usual minimum requirements, because it cannot carry out the reactions necessary to produce a needed substance. These mutants are referred to as auxotrophs; if they are to grow, they must be supplemented with the substance they need but cannot manufacture. Experiment 1 Bacteria were grown on media containing different radioactively labeled atoms to determine which types of biological molecules would be radioactively labeled. Molecules become labeled as they are synthesized by the bacteria using the raw materials provided by the medium. The bacteria were grown for a period of time that was sufficient to label all molecules that could be labeled, and the major types of biomolecules were isolated and tested for the presence of radioactivity. The following table shows the various strains of bacteria and the radioactive element present in the media in which they were grown. Bacterial strain Radioactive element strain 1 carbon strain 2 phosphorous strain 3 nitrogen strain 4 oxygen Experiment 2 Auxotrophic bacteria were grown on media supplemented with the substance that they need but cannot manufacture. If they were not supplemented in this way, no growth would be observed. The following table shows two auxotrophic strains and the substance with which they were supplemented. Auxotrophic strain Supplement strain A arginine, an amino acid strain B decanoic acid, a fatty acid Experiment 3 Auxotrophic strain A (from Experiment 2) was grown on a medium that contained supplemental arginine and radioactive phosphorus, and the major types of biomolecules were again isolated and tested for radioactivity. Which of the following biomolecules isolated from Strain 3 would we expect to be radioactively labeled according to the table from experiment 1?A DNA, but not RNAB DNA and RNA, but not proteinsC RNA and proteinsD DNA and fatty acids
3)
Often, bacteria are grown on a medium that contains all of the components they need to survive. This includes an energy source, a carbon source, and sources of all the mineral salts the bacteria require to carry out their metabolic reactions. Sometimes, a mutant bacterium is isolated that needs more than the usual minimum requirements, because it cannot carry out the reactions necessary to produce a needed substance. These mutants are referred to as auxotrophs; if they are to grow, they must be supplemented with the substance they need but cannot manufacture. Experiment 1 Bacteria were grown on media containing different radioactively labeled atoms to determine which types of biological molecules would be radioactively labeled. Molecules become labeled as they are synthesized by the bacteria using the raw materials provided by the medium. The bacteria were grown for a period of time that was sufficient to label all molecules that could be labeled, and the major types of biomolecules were isolated and tested for the presence of radioactivity. The following table shows the various strains of bacteria and the radioactive element present in the media in which they were grown. Bacterial strain Radioactive element strain 1 carbon strain 2 phosphorous strain 3 nitrogen strain 4 oxygen Experiment 2 Auxotrophic bacteria were grown on media supplemented with the substance that they need but cannot manufacture. If they were not supplemented in this way, no growth would be observed. The following table shows two auxotrophic strains and the substance with which they were supplemented. Auxotrophic strain Supplement strain A arginine, an amino acid strain B decanoic acid, a fatty acid Experiment 3 Auxotrophic strain A (from Experiment 2) was grown on a medium that contained supplemental arginine and radioactive phosphorus, and the major types of biomolecules were again isolated and tested for radioactivity. Which of the following biomolecules isolated from Strain 1 would we expect to be radioactively labeled according to the table from experiment 1?A CholesterolB PhospholipidsC Both A and BD Neither A nor B
4)
Often, bacteria are grown on a medium that contains all of the components they need to survive. This includes an energy source, a carbon source, and sources of all the mineral salts the bacteria require to carry out their metabolic reactions. Sometimes, a mutant bacterium is isolated that needs more than the usual minimum requirements, because it cannot carry out the reactions necessary to produce a needed substance. These mutants are referred to as auxotrophs; if they are to grow, they must be supplemented with the substance they need but cannot manufacture. Experiment 1 Bacteria were grown on media containing different radioactively labeled atoms to determine which types of biological molecules would be radioactively labeled. Molecules become labeled as they are synthesized by the bacteria using the raw materials provided by the medium. The bacteria were grown for a period of time that was sufficient to label all molecules that could be labeled, and the major types of biomolecules were isolated and tested for the presence of radioactivity. The following table shows the various strains of bacteria and the radioactive element present in the media in which they were grown. Bacterial strain Radioactive element strain 1 carbon strain 2 phosphorous strain 3 nitrogen strain 4 oxygen Experiment 2 Auxotrophic bacteria were grown on media supplemented with the substance that they need but cannot manufacture. If they were not supplemented in this way, no growth would be observed. The following table shows two auxotrophic strains and the substance with which they were supplemented. Auxotrophic strain Supplement strain A arginine, an amino acid strain B decanoic acid, a fatty acid Experiment 3 Auxotrophic strain A (from Experiment 2) was grown on a medium that contained supplemental arginine and radioactive phosphorus, and the major types of biomolecules were again isolated and tested for radioactivity. In experiment 2, the arginine requiring auxotrophic strain A was supplemented with arginine to allow growth. If the cells were not supplemented with arginine, the cells could not grow because arginine is directly required for the synthesis of:A DNAB ProteinsC Fatty acidsD RNA
5)
Often, bacteria are grown on a medium that contains all of the components they need to survive. This includes an energy source, a carbon source, and sources of all the mineral salts the bacteria require to carry out their metabolic reactions. Sometimes, a mutant bacterium is isolated that needs more than the usual minimum requirements, because it cannot carry out the reactions necessary to produce a needed substance. These mutants are referred to as auxotrophs; if they are to grow, they must be supplemented with the substance they need but cannot manufacture. Experiment 1 Bacteria were grown on media containing different radioactively labeled atoms to determine which types of biological molecules would be radioactively labeled. Molecules become labeled as they are synthesized by the bacteria using the raw materials provided by the medium. The bacteria were grown for a period of time that was sufficient to label all molecules that could be labeled, and the major types of biomolecules were isolated and tested for the presence of radioactivity. The following table shows the various strains of bacteria and the radioactive element present in the media in which they were grown. Bacterial strain Radioactive element strain 1 carbon strain 2 phosphorous strain 3 nitrogen strain 4 oxygen Experiment 2 Auxotrophic bacteria were grown on media supplemented with the substance that they need but cannot manufacture. If they were not supplemented in this way, no growth would be observed. The following table shows two auxotrophic strains and the substance with which they were supplemented. Auxotrophic strain Supplement strain A arginine, an amino acid strain B decanoic acid, a fatty acid Experiment 3 Auxotrophic strain A (from Experiment 2) was grown on a medium that contained supplemental arginine and radioactive phosphorus, and the major types of biomolecules were again isolated and tested for radioactivity. In experiment 3, which of the following biomolecules would we expect to become labeled?A All proteins, DNA, and RNAB Only proteins containing arginine, but not DNA or RNAC DNA, RNA, and only those proteins that contain arginineD RNA and phospholipids
6)
7)
8)
9)
10)