TRU BIOL 1593 Module 2 - Introduction to Chemistry

What is an atom?

the single, smallest unit of a (chemical) element; units of matter; have a nucleus of protons and neutrons and are surrounded by electrons

What are the 3 subatomic particles and what are their charge and location?

protons (positive), neutrons (neutral/uncharged) - in nucleus; electrons (negative); around nucleus

What are isotopes?

different atoms of the same chemical element that have the same number of protons but different numbers of neutrons and thus a slightly different mass

What are radioactive isotopes?

isotopes with a nucleus that easily decays; unstable and emits radiation (energy) as it breaks down

What subatomic particle provides the atomic number?

the number of protons in its nucleus (this is also the number of electrons in an unionized atom)

What subatomic particle(s) determine the mass number?

the sum of the number of protons and neutrons in its nucleus

What is an ion?

an atom that has a positive or negative charge due to its unequal number of protons and electrons

What is a cation?

positively charged ion

What is an anion?

negatively charged ion

What is a molecule?

two or more atoms that share electrons (i.e. are covalently bonded)

What is a compound?

the combination of two or more different atoms; all compounds are molecules, but not all molecules are compounds

What is a free radical?

electrically-charged atom or group of atoms with an unpaired electron in its outermost shell

What are antioxidants?

substances that inactivate oxygen-derived free radicals (by giving up some of their own electons)

What is a chemical bond?

atoms of a molecule are held together by forces of attraction

What is an ionic bond?

attraction between negatively and positively charges ions

What is the strength of an ionic bond relative to covalent and hydrogen bonds?

weaker than covalent bonds, stronger than hydrogen bonds; the bond breaks when molecule is placed in water

What are electrolytes?

ions in solution

What is a covalent bond? How common are they in the human body?

when the atoms of molecules share electrons; most common bond in the body

What is the strength of a covalent bond relative to ionic and hydrogen bonds?

it's the strongest

What are 2 types of covalent bonds?

polar or nonpolar

What are polar covalent bonds?

when atoms share electrons unequally, resulting in weak positive and negative regions that can attract other atoms or molecules (e.g. create hydrogen bonds)

What is a hydrogen bond?

extremely weak bonds between a bonded hydrogen atom that maintains a weak positive charge and another negatively charged atom

What is the strength of a hydrogen bond relative to ionic and covalent bonds?

it's the weakest

Do hydrogen bonds form molecules? What do hydrogen bonds do?

they do not form molecules, but link molecules to provide strength, stability and shape; bond molecules such as hormones to receptors and enzymes to substrates

What is a chemical reaction?

when new bonds are formed or old bonds broken between atoms

What are reactant(s)?

starting substance(s) of a chemical reaction

What are product(s)?

ending substance(s) of a chemical reaction

What is the law of conversation of mass?

components of reactants are present in product(s); overall mass unchanged; matter cannot be created or destroyed

What is metabolism?

all the chemical reactions occurring in an organism

What is energy?

capacity to do work

What is kinetic energy?

energy associated with matter in motion

What is potential energy?

energy stored by matter due to its position or structure

What is chemical energy?

a form of potential energy stored in the bonds of compounds or molecules; not created or destroyed, but transformed; energy is invested to create bonds and released when bonds are broken

What is a synthesis reaction? Is is anabolic or catabolic?

when two or more atoms, ions, or molecules combine to form new and larger molecules; anabolic

What is a decomposition reaction? Is is anabolic or catabolic?

a molecule is broken down into smaller parts; catabolic

What is oxidation?

loss of electrons from a molecule, which results in a decrease in the potential energy of the molecule

What is reduction?

gain of electrons by a molecule, which results in an increase in the potential energy of the molecule

What is an oxidation-reduction reaction?

electrons are taken from the atom being oxidized by the atom being reduced

What is an inorganic compound?

a compound that doesn't contain both carbon and hydrogen; may contain one or the other, but rarely is that carbon; is a simple molecule

What is an organic compound?

a compound that always contains carbon and hydrogen, always have covalent bonds, and usually contains oxygen

What is the most important and abundant inorganic compound in all living systems?

water

Does water have polarity? If so, why?

Yes, due to unequal sharing of electron - partial negative charge on oxygen and partial positive charges on each hydrogen

Name 4 reasons that water is the most important and abundant inorganic compound in all living systems.

enables reactants to collide to form products; dissolves wastes; idea medium for chemical reactions; participates as a reactant or product in certain reactions

What is hydrolysis?

when water is added to break bonds of larger molecules; water splits and binds to portions of severed compound

What is dehydration synthesis?

when two simple molecules join together, eliminating a molecule of water in the process; the reactants release H and OH which bond to form water as a byproduct

What are 4 functions of water in the body?

a good solvent, participates in vital chemical reactions, acts as a heat sink (absorbs heat), acts as a lubricant

What is dissociation/ionization?

when the molecules of inorganic acids, bases, or salts dissolve in water (i.e. separate into ions)

What is pH?

a measure of hydrogen ion concentration in solution

What is an acid?

a substance that when put in water dissociates into one or more hydrogen ions (H+) and one or more anions (negative ions)

What is a base?

a substance that when put in water dissociates into one or more hydroxyl ions (OH-) and one or more cations (positive ions); has the capacity to bond H+ ions

What is a salt?

a substance when dissolved in water, dissociates into cations and anions, neither of which is H+ or OH-

What is an electrolyte?

a substance such as a salt, an acid, or a base, that, when put in water dissociates or ionizes into ions; in solution, electrolytes conduct an electric current.

What is an acidic solution? What pH does it have?

a solution with more H+ than OH-; below 7.0 pH

What is an alkaline solution? What pH does it have?

a solution with more OH- than H+; above 7.0 pH

What is a buffer?

a weak acid or base that can react with strong acids or bases to weaken them; chemicals that minimize changes in pH when acids or bases are added

What are the 3 elements of carbohydrates?

carbon, hydrogen, oxygen; typically a 2:1 ratio of hydrogen to oxygen (like water)

What are the 3 major groups of carbohydrates (from a molecular level)?

monosaccharides, disaccharides, polysaccharides

What are monosaccharides? What are some examples?

simple sugars made of carbon, hydrogen, and oxygen; examples glucose, fructose, galactose, ribose, deoxyribose

What are disaccharides? What are some examples?

two monosaccharides joined together (by dehydration synthesis - can be split by hydrolysis) (lactose, sucrose)

What are polysaccharides? What are some examples?

complex carbs; hundreds of monosaccharides (starch, glycogen)

What is glycogen and where is it stored?

principal polysaccharide in the human body; stored in the liver and skeletal muscles

What is a lipid? Is it hydrophilic or hydrophobic?

a class of nonpolar organic compounds build primarily from hydrocarbons (and some oxygen); hydrophobic (b/c nonpolar nature) and thus not soluble in water

What are triglycerides and what 3 functions do they provide?

the most plentiful lipids in the body and provide protection, insulation, and energy (both immediate and stored); aka fat

What are phospholipids and why are they important?

similar to triglycerides but has a hydrophilic head that contains a phosphate group and nitrogen atom; are important membrane components

What are steroids composed of? What are some examples?

composed of four rings of carbon atoms; e.g. dietary cholesterol, estrogen, testosterone

What are 6 functions of proteins?

give structure to the body, regulate processes, provide protection, help muscles to contract, transport substances, and serve as enzymes

What are the 4 elements in amino acids?

carbon, hydrogen, oxygen, and nitrogen

What are the 4 chemical groups of an amino acid?

hydrogen, amine, carboxyl, side chain (R group)

What is a peptide bond?

a covalent bond between two amino acids (formed by dehydration synthesis)

What is denaturation?

change in normal structure due to chemical or physical means; results in loss of function

What are enzymes? What suffix do they usually carry?

catalysts; usually have suffix -ase; highly specific and efficient in what they react with

Enzmyes are highly _________ and ________ in what they react with.

specific; efficient

What do enzymes do? And by which 3 means do they accomplish this?

speed up chemical reactions by increasing the frequency of molecule collisions, lowering the activation energy, and properly orienting colliding molecules

What are the 2 nucleic acids?

DNA and RNA

What are the 5 elements of nucleic acids?

carbon, hydrogen, oxygen, nitrogen, and phosphorus

What does deoxyribonucleic acid (DNA) do?

forms the genetic code inside each cell and thus regulates most of the activities that occur in our cells throughout our lifetime

DNA is a ________________ composed of 2 nucleotide chains containing ____________, one _________ group, and a nitrogen containing base of adenine, cytosine, guanine, or _____________; chains are held together by ___________ bonds between nitrogenous base pairs

double-helix; deoxyribose; phosphate; thymine; hydrogen

What does ribonucleic acid (RNA) do?

carries instructions from the genes in the nucleus of the cell to guide how the ribosomes assemble amino acids into proteins

RNA is a ________________ strand containing ____________, one _________ group, and a nitrogen containing base of adenine, cytosine, guanine, or _____________

single, ribose, phosphate, uracil

What 3 nitrogen containing bases do DNA and RNA have in common?

adenine, cytosine, guanine

What are nucleotides? What 3 things are they composed of?

basic units of nucleic acids; composed of a nitrogenous base, a pentose sugar, and one of more phosphate groups

What is adenosine triphosphate (ATP) used for?

the principal energy-storing molecule in the body

What is the structure of adenosine triphosphate (ATP)?

a nucleotide (or nucleic acid) compound; three phosphate groups attached to an adenosine unit, which is composed of adenine and the five-carbon sugar ribose

How is energy liberated from adenosine triphosphate (ATP)?

it's decomposed to adenosine diphosphate (ADP) and phosphorus (P); the breaking of two high energy phosphate bonds

How is adenosine triphosphate (ATP) created?

manufactured from ADP and P using the energy supplied by various decomposition reactions, particularly that of glucose