Past Biology Final Questions Flashcards
The CFTR protein is made up of 1,480 amino acids linked together in a chain. Some humans produce a version of the CFTR protein in which phenylalanine (an amino acid) has been deleted from position 508 of the amino acid chain. What best predicts how the amino acid deletion will affect the structure of the CFTR protein?
It will affect the primary, secondary, and tertiary structures of the CFTR protein.
Scientists examined the folded structure of a purified protein resuspended in water and found that amino acids with non-polar R groups were primarily buried in the middle of the protein, whereas amino acids with polar R groups were primarily on the surface of the protein. What best explains the location of the amino acids in the folded protein?
Non-polar R groups that cannot form hydrogen bonds with water are pushed into the middle of the protein.
A mutation in the genes coding for a single-polypeptide enzyme results in the substitution of the amino acid serine, which has a polar R group, by the amino acid phenylalanine, which has a non-polar R group. When researchers test the catalysis of the normal enzyme and the mutated enzyme, they find that the mutated enzyme has much lower activity than the normal enzyme does. What most likely explains how the amino acid substitution has resulted in decreased catalytic activity by the mutated enzyme?
The substitution altered the secondary and tertiary structure of the enzyme so that the mutated enzyme folds into a different shape than the normal enzyme does.
Bacteriophages are viruses that infect bacteria. In an experiment, bacteriophages were labeled with either radioactive phosphorus or radioactive sulfur. The labeled bacteriophages were incubated with bacteria for a brief amount of time and then removed. The infected bacteria cells were found to contain significant amounts of radioactivity phosphorus but not radioactive sulfur. Based on the results of the experiment, which of the following types of molecules did the bacteriophages most likely inject into the bacteria cells?
DNA
The carbohydrates glucose, galactose, and fructose have the same chemical formula (C6H12O6) but different structural formulas. Based on the figure, what statement about glucose, galactose and fructose is most likely true?
The carbohydrates have different properties because they have different arrangements of carbon, hydrogen, and oxygen atoms.
What size cell is likely to be the most efficient at eliminating waste by diffusion?
1 micrometer x 1 micrometer
(The smaller possible choice)
In an experiment, the efficiency of oxygen exchange across the plasma membrane is being assessed on four artificial blood cells. The table above lists some properties of those artificial cells. Other conditions being equal, which artificial cell is predicted to be the efficient in exchanging oxygen with the environment by diffusion?
The cubodial cell
(The one with the highest ratio of surface area to volume)
What is responsible for the cohesive property of water?
Hydrogen bonds between the oxygen atom of one water molecule and a hydrogen atom of another water molecule
A typical bag a fertilizer contains high levels of nitrogen, phosphorus, and potassium but trace amounts of magnesium and calcium. What best matches the fertilizer component with the molecules in which will be incorporated by organisms in the area?
nitrogen will be incorporated into nucleic acid.
What is the site of modification and packaging of proteins and lipids prior to export from the cell?
Golgi apparatus
What is the site of conversion of chemical energy of glucose to ATP?
Mitochondria
(Specifically the inner membrane)
Amylase is an enzyme that converts carbohydrate polymers into monomers. Glycogen synthase is one of the enzymes involved in converting carbohydrate monomers into polymers. What best explains the reactions of these enzymes?
Analyses aids in the addition of a water molecule to break covalent bonds whereas glycogen synthase aids in the removal of a water molecule to form covalent bonds
What correctly illustrates a dipeptide and an amino acid in the optional position to form a tripeptide?
Dipeptide: C==O and C—OH
Amino acid: H—N and H—N
DNA and RNA are nucleic acids that can store biological information based on the sequence of their nucleotide monomers. What describes a structural difference between DNA and RNA?
The backbone of DNA contains deoxyribose, whereas the backbone of RNA contains ribose.
Organelles such as mitochondria and the endoplasmic reticulum have membranes that compartmentalize reactions and other metabolic processes. To function properly, the organelles must move substances across their membranes. What describes a feature shared by mitochondria and the endoplasmic reticulum that increases the efficiency of their basic functions?
They have highly folded membranes.
