Chemistry of Life
Energy
Ability to do work
Covalent bond
Forms when two or more atoms share one or more pairs of electrons
Nucleus
Makes up the bulk (main part) of the mass of the atom and consists of two kinds of subatomic particles
Classify each of the following as an element or compound: HCI, CO2, Cl, Li, and H20
HCl: Compound CO2: Compound Cl: Element Li: Element H2O: Compound
Orbital
3-D region around the nucleus that indicates the probable location of an electron
Redox reaction
A chemical reaction involving both reduction and oxidation, which results in changes in oxidation numbers of atoms included in the reaction
Hydroxide ion
A hydroxide ion is a negatively charged ion con- sisting of one oxygen atom and one hydrogen atom, OH-
Reduction reaction
A reactant gains one or more electrons and becomes a negative charge
Oxidation reaction
A reactant loses one or more electrons and becomes positive charged
pH scale
A scale that scientists have developed for comparing the relative concentrations of hydronium ions and hydroxide ions in a solution. It ranges from 0 to 14
Metabolism
All of the chemical reactions that occur in an organism
Ion
An atom or molecule with an electrical charge
Cohesion
An attractive force that holds molecules of a single substance together
What is matter
Anything that has mass and takes up space
Matter
Anything that occupies space and has mass
What is the relationship between elements and atoms
Atoms make up elements
Isotope
Atoms of the same element that have different number of neutrons
Capillarity
Attraction between molecules that results in the rise of the surface of a liquid when in contact with a solid
Adhesion
Attractive force between two particles of different substances
Chemical bond
Attractive forces that hold atoms together
What is the relationship among hydrogen bonds and the forces of cohesions, adhesions, and capillarity
Cohesion: water clings to polar molecules through hydrogen bonding. Water is adhesive to any substance with which it can form hydrogen bonds. Together help water rise through narrow tubes against the force of gravity
Distinguish between covalent and ionic bonds
Covalent bonds: atoms share one or more pairs of electrons. Ionic bonds: when electrons are transferred from one atom to another
Product
Ending substance in a chemical reaction
Mass number
Equal to the total number of protons and neutrons of the atom
Hydrogen bond
Force of attraction between a hydrogen molecule with a partial positive charge and another atom or molecule with a partial or full negative charge
Why does a reduction reaction always accompany an oxidation reaction
Forces in the universe don't act alone. If one atom or molecule is giving electrons, another must be taking (or sharing). They are apart of a redox reaction
Identify the properties of water that are important for life to be able to exist
High specific heat, adhesion, cohesion, surface tension, density, universal solvent, and polarity
Why is water called a polar molecule
Hydrogen and oxygen atoms share electrons to form covalent bonds. They don't share the electrons equally. The oxygen atom has a greater ability to attract electrons to it because it pulls hydrogen's electrons towards it nucleus. Oxygen then has a negative charge while hydrogen has a positive charge. Because of the uneven distribution of charge, water is called a polar molecule
Acid
If the number of hydronium ions in a solution is greater than the number of hydroxide atoms
Explain the roles of reactants and products in a chemical reaction
In a chemical reaction, bonds present in the reactants are broken, and the elements are rearranged and new compounds are formed as the products
Describe the effect of an enzyme on the activation energy in a chemical reaction
In living organisms, enzymes act as catalysts. It decreases the activation energy in chemical reactions without being permanently changed or destroyed
Neutron
Inside the nucleus and has no charge
Proton
Inside the nucleus and is positively charged
Enzymes are biological catalysts. Explain what they do in living systems
It is a protein or RNA molecule that speeds up metabolic reactions without being permanently changed or destroyed
What effect might a molecule that interferes with the action of carbonic anhydrase have on your body
It is made of carbon dioxide and water into carbonic acid and bicarbonate ions. It help transport oxygen molecules from lung to red blood cells. If the molecule interferes with carbonic anhydrase, the level of oxygen in the blood will drop. If you don't get enough oxgen supply to the brain, you may faint, your heart may stop beating, have a seizure, many things
Solution
MIxture in which one or more substances are uniformly distributed in another substance
Compound
Made up of atoms of two or more elements that are chemically bonded in a fixed proportions. Cake would be a compound because all of the ingredients are together to make batter you cannot see the individual components
Electron
Negative charged particles in an atom that has the same number of protons
Given that elements are pure substances, how many types of atoms make up the structure of a single element?
One because if it had more than one then it would be a compound
Chemical reaction
One or more substances changed to produce one or more different substances
Outline a reason why the control of pH is important in living systems
Our bodies can function when our pH is good. If we have high ph levels then we are most likely to get sick. This is because diseases like cancer like to live in high acidic levels
Mixture
Physical blend of substances that are not chemically bonded
Enzyme
Protein or RNA molecule that speeds up metabolic reactions without being permanently changed or destroyed. Type of catalyst
Catalyst
Reduces the amount of activation energy that is needed for a reaction to take place because it allows the reaction to proceed faster
Molecule
Simplest part of a substance that retain all of the properties of that substance and can exist in a free state
Name and describe the physical properties of the three states of matter
Solid: atoms or molecules are more closely linked together than in liquid or gas. Move less rapidly than the particles that make up a liquid or gas. Maintains a fixed volume and shape. Liquid: fixed volume but no shape. Particles move more freely than in a solid. Gas: particles move the most rapidly. Have little to no attraction to each and they fill the volume of the container they occupy. Thermal energy must be added to the substance to cause a substance to change states
Base
Solution in which there are more hydroxide ions than hydronium ions
Saturated solution
Solution where no more solute can dissolve
Aqueous solution
Solutions in which water is the solvent
Reactant
Starting substance in a chemical reaction
Solute
Substance dissolved in the solvent
Solvent
Substance in which the solute is dissolved
Element
Substances that cannot be broken down chemically into simpler kinds of matter
Electrons
Surrounds the nucleus and is negatively charged
Activation energy
The amount of energy needed to start the reaction
Concentration
The amount of solute dissolved in a fixed amount of the solution. The more solute dissolved, the greater is the concentration of that solution
Ionic bond
The attraction between negative and positive electrical charges
Identify the solute and solvent in a hot chocolate solution that is made of chocolate syrup and warm milk
The chocolate syrup would be the solute (because it is dissolved) and the warm milk would be the solvent since it dissolves the syrup
Why does pure water have a neutral pH
The concentrations of ions are balanced and it is neither acidic or basic
Buffer
The control of pH in organisms is often accomplished with buffers. They neutralize small amounts of either an acid or a base added to a solution.
Hydronium ion
The ion H3O+, consisting of a protonated water molecule and present in all aqueous acids.
Atomic number
The number of protons in an atom. Appears directly above the chemical symbol of the element. It determines the chemical properties of an element and where it goes in the periodic table.
Atom
The simplest particle of an element that retains all of the properties of that element
Describe the arrangement within energy levels of the six electrons of an atom of carbon
There are two electrons in its first orbital. The second orbital can hold 8 but carbon only has 4 more electrons
How are isotopes of the same element alike
They have the same chemical properties but slightly different masses
Polar
Uneven distribution of charge
Explain why the terms mass and weight should not be used interchangeably
Weight is dependent on gravity and mass is not. Weight is the amount of gravitational pull on an object. That is why your weight changes is different gravity environments. Mass is the amount of matter IN the object
How can we predict which element are reactive under normal conditions and which are unreactive
What group they are in.If they are closer to the Alkaline metals then they are reactive but if they are closer to the noble gases then they are unreactive
In a reduction reaction, the reduced atom gains one or more electrons. Why is this reaction called a reduction
When you add electrons to an atom, the atom's charge is being reduced and it becomes negatively charged
Why do living things need a constant supply of energy
Without energy, living things shut down, the organs cannot produce the various enzymes and other fluids the body requires to function
Mass
the quantity of matter an object has