Answer the following question given this paragraph: 3.4 Proteins Proteins are a class of macromolecules that perform a diverse range of functions for the cell. They help in metabolism by providing structural support and by acting as enzymes, carriers, or hormones. The building blocks of proteins (monomers) are amino acids. Each amino acid has a central carbon that is linked to an amino group, a carboxyl group, a hydrogen atom, and an R group or side chain. There are 20 commonly occurring amino acids, each of which differs in the R group. Each amino acid is linked to its neighbors by a peptide bond. A long chain of amino acids is known as a polypeptide. Proteins are organized at four levels: primary, secondary, tertiary, and (optional) quaternary. The primary structure is the unique sequence of amino acids. The local folding of the polypeptide to form structures such as the helix and -pleated sheet constitutes the secondary structure. The overall three-dimensional structure is the tertiary structure. When two or more polypeptides combine to form the complete protein structure, the configuration is known as the quaternary structure of a protein. Protein shape and function are intricately linked; any change in shape caused by changes in temperature or pH may lead to protein denaturation and a loss in function. Q: Amino acids are the building blocks of what macromolecules? Choices: - lipids - sugars - carbohydrates - proteins A:
proteins
Answer the following question given this paragraph: The interior space that surrounds the thylakoids is filled with a fluid called stroma . This is where carbon dioxide is used to produce glucose, the second part of photosynthesis. Q: Fluid-filled thylakoids are the site of glucose production in the second stage of what process? Choices: - measurements - glycolysis - birth - photosynthesis A:
photosynthesis
Q: Answer the following question given this paragraph: Hydrocarbons are compounds that contain only carbon and hydrogen. Hydrocarbons are the simplest type of carbon-based compounds. Nonetheless, they can vary greatly in size. The smallest hydrocarbons have just one or two carbon atoms, but large hydrocarbons may have hundreds. The size of hydrocarbon molecules influences their properties. For example, it influences their boiling and melting points. As a result, some hydrocarbons are gases at room temperature, while others are liquids or solids. Hydrocarbons are generally nonpolar and do not dissolve in water. In fact, they tend to repel water. That's why they are used in floor wax and similar products. Q: What is the simplest type of carbon-based compounds? Choices: - Buckminsterfullerine - graphite - particles - hydrocarbons A:
A: hydrocarbons
Question: Answer the following question given this paragraph: Summary Changes of state are examples of phase changes, or phase transitions. All phase changes are accompanied by changes in the energy of a system. Changes from a more-ordered state to a less-ordered state (such as a liquid to a gas) areendothermic. Changes from a less-ordered state to a more-ordered state (such as a liquid to a solid) are always exothermic. The conversion of a solid to a liquid is called fusion (or melting). The energy required to melt 1 mol of a substance is its enthalpy of fusion (Hfus). The energy change required to vaporize 1 mol of a substance is the enthalpy of vaporization (Hvap). The direct conversion of a solid to a gas is sublimation. The amount of energy needed to sublime 1 mol of a substance is its enthalpy of sublimation (Hsub) and is the sum of the enthalpies of fusion and vaporization. Plots of the temperature of a substance versus heat added or versus heating time at a constant rate of heating are calledheating curves. Heating curves relate temperature changes to phase transitions. A superheated liquid, a liquid at a temperature and pressure at which it should be a gas, is not stable. A cooling curve is not exactly the reverse of the heating curve because many liquids do not freeze at the expected temperature. Instead, they form a supercooled liquid, a metastable liquid phase that exists below the normal melting point. Supercooled liquids usually crystallize on standing, or adding a seed crystal of the same or another substance can induce crystallization. Q: Changes from a less-ordered state to a more-ordered state (such as a liquid to a solid) are always what? Choices: - unbalanced - reactive - endothermic - exothermic A:
Answer: exothermic
*Question*
Answer the following question given this paragraph: Adulthood is divided into the stages of early, middle, and late adulthood. Q: Adulthood is divided into how many stages? Choices: - two - four - five - three A:
**Answer**
three
Q: Answer the following question given this paragraph: Q: What is the term for many different types of animals within the same species? Choices: - pollution - habitat - differentiation - diversity A:
A: diversity