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Define an element
Elements are the substances that make up all things
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Describe the Structure of an Atom
An atom is the basic building block for all things. At the center of an atom is the nucleus, which is composed of positively charge particles called protons and non-charged particles, called neutrons. Orbiting the nucleus are negatively charged particles called electrons. Protons and neutrons are always equal in number and contribute to nearly all of the atom’s weight
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when two or more atoms unite on the basis of their electron structures and can be made of like atoms
Molecule
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The smallest sub-unit of a compound is a molecule; however a compound must be made up of two or more different elements
A Compound
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why is water is so important to the body
Water is critical in all of the physiological processes in body tissues. It carries substances to and from the cells and makes possible the essential processes of absorption, exchange, secretion, and excretion
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Define: mixture
A mixture is a substance where the elements in it do not combine chemically, but rather maintain their own identity within the substance
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List the three types of mixtures and give examples of each
- Solutions
- 1. Salt water
- 2. Sugar Water
- Suspensions
- 1. Blood cells in blood plasma
- 2. Milk of Magnesia
- Colloids
- 1. Blood Plasma
- 2. cytosol
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shares the electrons in the valence layer of each atom in the molecule
covalent bonds
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When electrons are transferred from one atom to another
ionic bond
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produced from compounds formed by ionic bonds, but release ions when they are dropped into a solution and separate into charged particles
electrolyte
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Define: electrolyte
Electrolytes are produced from compounds formed by ionic bonds, but release ions when they are dropped into a solution and separate into charged particles
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Define: acid
a chemical substance capable of donating a hydrogen atom to another substance. 0-6.9 on the pH scale
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Define: Base
a chemical substance that can accept a hydrogen ion, and usually contains hydroxide. 7.1-14 on the pH scale
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Define: Salt
Produced as the outcome of a reaction between and acid and a base
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Explain how the numbers of the pH scale are related to acidity and basicity (Alkalinity.)
The greater the concentration of hydrogen ions in a solution, the greater the acidity. The greater the concentration of hydroxide ions in a solution, the greater the base, or alkalinity. This concentration is measured in pH units and each number represents a ten-fold change in the level of hydrogen and hydroxide ions present. The ph scale is listed in units from 0-14 with 7 being neutral. Zero is the highest acidity level and fourteen is the highest basic level.
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Define: enzyme
any of several complex proteins that are produced by cells and act as catalysts in specific biochemical reactions.
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Explain how an Enzyme works:
Each particular enzyme works only on a specific substrate and does only one specific job. They only take place in reactions temporarily and they are not used up or changed in the reaction. An enzyme is like a key that starts the ignition of a car. It is responsible for starting the reaction and has one specific purpose, but is not used up while performing its task.
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