Practise AP Biology's Chemistry of Life questions on water, macromolecules, proteins, carbohydrates and nucleic acids, using molecular structure to explain biological function.
Humans produce sweat as a cooling mechanism to maintain a stable internal temperature. Which of the following best explains how the properties of water contribute to this physiological process?
The high specific heat capacity of water allows the body to absorb a large amount of excess heat energy.
The high heat of vaporization of water allows the body to remove excess heat through a phase change of water from liquid to gas.
The high surface tension of water contributes to the physical process by which water leaves the body.
The high melting temperature of water allows the body to remove excess heat through a phase change of water from solid to liquid.
A typical bag of fertilizer contains high levels of nitrogen, phosphorus, and potassium but trace amounts of magnesium and calcium. Which of the following best matches the fertilizer component with the molecule in which it will be incorporated by organisms in the area?
Figure 1. Change in energy over the course of four chemical reactions
Nitrogen will be incorporated into nucleic acids.
Phosphorus will be incorporated into amino acids.
Potassium will be incorporated into lipids.
Magnesium will be incorporated into carbohydrates.
To investigate how increases in environmental temperatures affect the metabolism of certain organisms, researchers incubated liver cells from toads at different temperatures and measured two markers of metabolic activity (Table 1): the rate of oxygen consumption and the rate of ATP synthesis.
Describe the role of water in the hydrolysis of ATP.
TABLE 1. RATE OF OXYGEN CONSUMPTION AND ATP SYNTHESIS AT DIFFERENT TEMPERATURES
Geneticists investigated the mode of inheritance of a rare disorder that alters glucose metabolism and first shows symptoms in adulthood. The geneticists studied a family in which some individuals of generations II and III are known to have the disorder. Based on the pedigree (Figure 1), the geneticists concluded that the disorder arose in individual II-2 and was caused by a mutation in mitochondrial DNA.
Figure 1. Pedigree of a family showing individuals with the glucose metabolism disorder. A question mark indicates that the phenotype is unknown.
TABLE 1. AVERAGE BLOOD GLUCOSE LEVELS OF INDIVIDUALS IN GENERATION IV
TABLE 2. PHENOTYPIC CLASSIFICATIONS BASED ON BLOOD GLUCOSE LEVELS
The disorder alters glucose metabolism. Describe the atoms AND types of bonds in a glucose molecule.