发布日期：12-22 16:56 分类：ACT科学 阅读次数：50
摘要ellipse— A geometric shape that is formed when a plane Is Intersected with a cone. In this case ...
ellipse— A geometric shape that is formed when a plane Is Intersected with a cone. In this case the plane intersects the cone at an angle so that a shape similar to a circle but stretched in one direction is formed. The orbits of the planets around the Sun represent ellipses.
endoplasmic reticulum— An organelle that is used to transport proteins throughout the cell.
energy— The ability to do work or undergo change. Kinetic energy is the energy of motion, while potential energy is stored energy.
enzyme — any one of the complex proteins that are produced by cells and ACT as catalysts in specific biochemical reactions
epicycle—Smaller circles on which the planets traveled around the Earth in the geocentric model of the solar system. Epicycles were used to explain the retrograde motion of planets and help make the predicted positions of the planets match the observed positions.
equilibrium—A state at which the forward and reverse reaction proceed at the same rate.
focal length— The distance from a focal point to a mirror or lens.
force— That which acts on an object to change its motion; a push or pull exerted on one object by another. Common units are Newtons (N).
freefall— An object in one-dimensional motion that is only acted on by the force of the Earth's gravity. In this case its acceleration will be -g or g downward.
frequency— The number of cycles or repetitions per second. Frequency is also often measured as the number of revolutions per second. The common units of frequency are Hertz (Hz) where one Hertz equals 1/second.
frictional force— The force that acts parallel to surfaces in contact opposite the direction of motion or tendency of motion.
functional group— A group of atoms that give a molecule a certain characteristic or property.
gel electrophoresis—A process used in laboratories to determine the genetic makeup of DNA strands. This process involves the movement of chromosomes through a gel from one pole to the other. Magnetism is used to pull the chromosomes through the gel.
geology— The study of rocks and minerals.
glacier— A large mass of snow-covered ice.
golgi apparatus—An organelle that packages proteins so that they can be sent out of the cell.
gravitational force— The attractive force that exists between all particles with mass.
heliocentric model— The model of the solar system that places the Sun at the center with the planets orbiting around it.
heterogeneous— A mixture that is not uniform in composition.
homogeneous— A mixture in which the components are uniformly distributed.