Chapter 2: Intro to Chemistry Flashcards
What is the difference between matter and mass?
Matter is anything that occupies space and has mass, whereas mass is the amount of matter in any living organism or nonliving thing
What are chemical elements?
These are substances that cannot be broken down into simpler forms by ordinary chemical means
How many different elements are normally present in the body?
26
What are the major elements of the body?
Oxygen
Carbon
Hydrogen
Nitrogen
What percentage of the body’s mass is comprised of the major elements?
96%
What are the lesser elements of the body?
Calcium
Phosphorus
Potassium
Sulfur
Sodium
Chlorine
Magnesium
Iron
How many trace elements are there in the body?
There are 14 elements in this category
Why is iodine important for the body despite it being a trace element?
This element is important for making thyroid gland hormones
What is the significance of oxygen in the body?
It is part of water and many organic molecules
It is used to generate ATP
It is a molecule used by cells to temporarily store chemical energy
What is the importance of carbon in the body?
This forms the backbone chains and rings of all organic molecules: carbohydrates, lipids, proteins, and nucleic acids
What is the importance of hydrogen in the body?
It is part of water and most organic molecules
In its ionized form, it makes body fluids more acidic
What is the importance of nitrogen in the body?
It is a component of all proteins and nucleic acids
What is the importance of calcium in the body?
Contributes to hardness of bones and teeth
In its ionized form, it is vital for blood clotting, releasing hormones, contracting muscles, and other processes
What is the importance of phosphorus in the body?
It is a component of nucleic acids and ATP
It is also required for normal bone and tooth structure
What is the importance of potassium in the body?
In its ionized form, it is the most plentiful cation in intracellular fluid, which is key for the generation of action potentials
What is the importance of sulfur in the body?
This is a component of some vitamins and many proteins
What is the importance of sodium in the body?
In its ionized form, it is the most plentiful cation in the extracellular fluid, which is vital in the generation of action potentials
What is the importance of chlorine in the body?
In its ionized form, it is the most plentiful anion in extracellular fluid, which is key for maintaining water balance
What is the importance of magnesium in the body?
In its ionized form, it is needed for the action of many enzymes
What is the importance of iron in the body?
In its ionized forms, it is part of hemoglobin and some enzymes
What is an atom
This is the smallest unit of matter that retains the properties and characteristics of the element
What are the two basic parts of an atom?
The nucleus and one or more electrons
What is a nucleus of an atom comprised of?
This is made up of positively charged proteins and neutral neutrons
Is the nucleus of an atom neutral, positively, or negatively charged?
This is positively charged
How is the atomic number of an atom determined?
This is determined by the number of protons in the nucleus
How is the mass number of an atom determined?
This is determined by the number of protons plus the neutrons
What are electron shells?
These are the regions around the nucleus in which electrons are more likely to move about within
How many electrons can be held in the first, second, and third electron shells?
In order: 2, 8, 18
What is an ion?
This is a particle that has a positive or negative charge due to unequal numbers of protons and electrons
What is a molecule?
This is a combination of atoms that share electrons
How many hydrogen and oxygen molecules are required to create 2 water molecules?
2 hydrogen molecules 2x(H2) and 1 oxygen molecule (O2) = 2x(H2O)
What is a compound?
This is a substance that contains atoms of two or more different elements.
Is oxygen (O2) a molecule, compound, or both?
It is only a molecule. Because it only has one type of atom, it cannot be a compound
Is water (H2O) a molecule, compound, or both?
It is both. Because it has atoms that share electrons, it is a molecule. Because it is a substance containing two types of atoms, it is also a compound.
What is a free radical?
This is an ion or molecule that has an extra unpaired electron in its outermost shell
Superoxide is an example of what, and how is it formed?
This is an example of a free radical, and it is formed by the addition of an electron to an oxygen molecule)
Why are free radicals destructive to other molecules?
Because there is an unpaired electron on the radical, it is unstable and will break apart important body molecules by giving up their unpaired electron, or by taking an electron from another molecule
What are disorders and diseases that are linked to oxygen-derived free radicals?
Cancer
Atherosclerosis
Alzheimer’s
Emphysema
Diabetes mellitus
Cataracts
Macular degeneration
Rheumatoid arthritis
Deterioration associated with aging
What are antioxidants?
These are substances that inactivate oxygen-derived free radicals
What are chemical bonds?
These are the forces that bind atoms of molecules and compounds together, resisting their separation
What makes an atom or molecule chemically stable?
This occurs when the atom or molecule has 8 electrons in its outer shell
What are the three general types of chemical bonds?
Ionic bonds
Covalent bonds
Hydrogen bonds
What are ionic bonds?
This is a force of attraction between ions of opposite charges
Describe the ionic bond process between two ions
When one ion donates its electron to have a more stable outer shell, it becomes positively charged. For example, when Na donates its one outer shell electron, it becomes positively charged.
When another ion accepts an electron to have a more outer shell, it becomes negatively charged. For example, when chloride accepts an electron to obtain 8 electrons in its outer shell, it becomes negatively charged.
The positive and the negative charge attract each other, creating an ionic bond.
Where are ionic bonds most commonly found? Why?
These are most commonly found in teeth and bones. They give strength to tissue.
What is an electrolyte? Why is it called this?
This is an ionic compound that breaks apart into cations and anions when dissolved. It is called this because it can conduct an electric current.
What is a covalent bond?
This is when atoms form a molecule by sharing one, two, or three pairs of their outer shell electrons.
What is the most common chemical bond in the body?
The covalent bond
What is a single, double, and triple covalent bond?
These describe the number of electron pairs that are being shared between two atoms. A single covalent bond has 2 electrons that are shared between two atoms, a double has 4 electrons shared, and a triple has 6 electrons shared.
What is a nonpolar covalent bond?
This is when two atoms attract electrons equally. No one atom attracts the shared electrons more strongly than the other.
What is a polar covalent bond?
This is when the sharing of electrons between atoms is unequal
What is a hydrogen bond?
This is a bond that forms when a hydrogen atom with a partial positive charge attracts the partial negative charge of neighboring electronegative atoms, usually oxygen or nitrogen.
A hydrogen bond does not involve the sharing of electrons
Which of ionic, covalent, or hydrogen bonds cannot bind atoms into molecules?
Hydrogen bonds are not strong enough for this
Where are hydrogen bonds important in the body?
Water molecules,
Different parts of large molecules like proteins and DNA to provide strength and stability
What determines the 3D shape of DNA and proteins?
Hydrogen bonds
What is a chemical reaction?
This is when new bonds form or old bonds break between atoms.
What are the two main forms of energy?
Potential energy
Kinetic energy
What is potential energy?
This is stored energy
What is kinetic energy?
This is the energy in motion
What is chemical energy?
This is a form of potential energy that is stored in the bonds of molecules
In chemical reactions, does breaking old bonds require an input of energy, or release energy?
This will require an input of energy
In chemical reactions, does forming new bonds require an input of energy, or release energy?
This will release energy.
What is a synthesis reaction?
This is when two or more atoms, ions, or molecules combine to form new and larger molecules
What is anabolism
This is the collective term for all of the synthesis reactions that occur in the body
Combining amino acids into proteins is an example of what?
Anabolism (synthesis reaction)
What is a decomposition reaction?
This is when a molecule is split apart