Q: The general term peptide refers to an amino acid chain of what? Read this paragraph and choose the correct option from the provided answers: The general term peptide refers to an amino acid chain of unspecified length. However, chains of about 50 amino acids or more are usually called proteins or polypeptides. In its physiologically active form, a protein may be composed of one or more polypeptide chains. For peptides and proteins to be physiologically active, it is not enough that they incorporate certain amounts of specific amino acids. The order, or sequence, in which the amino acids are connected is also of critical importance. Bradykinin is a nine-amino acid peptide produced in the blood that has the following amino acid sequence: arg-pro-pro-gly-phe-ser-pro-phe-arg This peptide lowers blood pressure, stimulates smooth muscle tissue, increases capillary permeability, and causes pain. When the order of amino acids in bradykinin is reversed, arg-phe-pro-ser-phe-gly-pro-pro-arg the peptide resulting from this synthesis shows none of the activity of bradykinin. Saylor URL: http://www. saylor. org/books. Choices: - large length - incomplete length - small length - unspecified length A:
unspecified length

Q: A hot-water heating system uses what type of energy to heat water? Read this paragraph and choose the correct option from the provided answers: A hot-water heating system uses thermal energy to heat water and then pumps the hot water throughout the building in a system of pipes and radiators. You can see a diagram of this type of heating system in Figure below . Typically, the water is heated in a boiler that burns natural gas or heating oil. There is usually a radiator in each room that gets warm when the hot water flows through it. The radiator transfers thermal energy to the air around it by conduction and radiation. The warm air then circulates throughout the room in convection currents. The hot water cools as it flows through the system and transfers its thermal energy. When it finally returns to the boiler, it is heated again and the cycle repeats. Choices: - negative energy - potential energy - atmospheric energy - thermal energy A:
thermal energy

Q: Nuclear power plants produce electricity through what? Read this paragraph and choose the correct option from the provided answers: Nuclear power plants produce electricity through induced fission. Choices: - High Fission - intense fission - severe fission - induced fission A:
induced fission

Q: Small crustaceans exchange gases across thin areas of the cuticle; larger species have what to accomplish this? Read this paragraph and choose the correct option from the provided answers: Choices: - noses - pores - lungs - gills A:
gills