Describe two ways that atoms may combine with other atoms.
Two atoms of hydrogen can combine with one atom of oxygen to produce a molecule of the compound water.
Atoms of the same element combine, they produce molecules of that element.
What is a molecular formula? A structural formula?
Molecular: consists of the symbols of the elements in the molecule with numerical subscripts that indicate how many atoms of each element are present.
Structural: representation of the way atoms bond in a molecule.
Distinguish between an ion and a polar molecule.
Ions: atom or molecule with an electrical charge.
Polar: molecule in which the electrons and protons are not distributed symmetrically.
How does the number of protons in a water molecule compare with the number of electrons?
The number of protons equals the number of electrons.
Why is a knowledge of chemistry essential to understanding physiology?
Because body functions result from cellular functions that in turn, result form chemical change
What is the relationship between matter and elements?
All matter is composed of fundamental substances.
Which elements are most common in the human body?
Carbon, hydrogen, oxygen, nitrogen, sulfur, phosphorus.
Distinguish between a molecule and a compound.
Molecule: two or more atoms may combine to form a distinctive type of particle.
Compound: substance composed of two or more chemically bonded elements.
How does the hydrogen ion concentration compare between a solution of pH 6.4 and a solution of pH 8.42.
The solution at pH 6.4 has 100 times the hydrogen ion concentration of a solution at pH 8.42.
Describe 4 types of chemical reactions.
Synthesis: when 2 or more atoms, ions, or molecules bond to form a more complex structure A+B->AB
Decomposition: bonds of a reactant molecule break to form simpler molecules, atoms, or ions AB->A+B
Exchange: parts of 2 different types of molecular trade positions as bonds are broken and new are formed AB + CD-> AD+ BC
Reversible: product or products can change back to reactant or reactants A+B<-> AB
Compare the characteristics of an acid, a base & a salt.
Acid: substance that releases hydrogen ion
Base: substance that release ions that can combine with hydrogen ions
Salt: substance formed by the reaction between and acid and a base.
What are the general difference between an organic molecule and an inorganic molecule?
Organic: compounds have carbon and hydrogen.
Inorganic: all other chemicals, chemicals that does not include both carbon and hydrogen atoms.
What is the difference between an electrolyte and a nonelectrolyte?
Electrolyte: substance that ionizes in a water solution
Nonelectrolyte: organic compounds that dissolve in water, usually do not release ions.
Compare the chemical composition of carbohydrates, lipids, proteins, and nucleic acid.
Carbohydrates: C, H, O
Lipids: C, H, O (often P)
Protein: C, H, O, N, ( often S)
Nucleic acids: C, H, O , N , P
Define electrolyte balance.
The body regularly gains and loses these electrolytes, but they must be present in certain concentrations, both inside and outside cells, to maintain homeostasis.
How does an enzymes affect a chemical reactions?
They bring the reactants close together, chemical bonds may be weakened and reactions will proceed faster and without catalyst. They speed specific chemical reactions without being consumed.
What is likely to happen to a protein molecule exposed to intense heat or radiation?
All proteins have a special shape and their shape determines what function they will perform. Proteins can become denatured or their shape can change and it'll cause the loss of function. Proteins exposed to heat will most likely become denatured and lose the ability to perform their task.
What are the functions of DNA and RNA?
DNA: molecules store the information for protein synthesis.
RNA: molecules use this information to construct specific protein molecules.
What does the pH scale measure?
tracks the number of decimal places in a hydrogen ion concentration without writing them out.
What is a buffer?
they are chemicals that resist pH change. They combine with hydrogen ions when these ions are in excess or they donate hydrogen ions when these ions are depleted.
Identify 2 types of macromolecules in which hydrogen bonds are important parts of the structure.
Hydrogen bonding is important to Tertiary & Secondary protein structures.
Explain the difference between saturated & unsaturated fats.
Saturated: single carbon-carbon bond link all the carbon atoms; each carbon atom binds as many hydrogen atoms as possible & is thus saturated with hydrogen atoms.
Unsaturated: have one or more double bond between carbon atoms. Fatty acids with one double bond.
Distinguish between simple and complex carbohydrates.
Simple: sugars include monosaccharaides, disaccharides; straight chains or rings.
Complex: polysaccharides are built of simple carbohydrates made of many bonded glucose molecules chains of sugars, cant digest.
An ionic bond forms when? A covalent bond forms when?
Ionic: ions with opposite electrical charges attract
Covalent: a chemical bond between atoms that share electrons.
Explain why some atoms are chemically inert.
Atoms whose outermost electron shells are filled already have stable structures and are chemically inactive.
Explain how electrons are distributed within the electron shell of atoms.
Each electron shell can hold a limited # of electrons. The maximum number of electrons that each of the 1st three shells can hold for elements of atomic number 18 and under is ...1st shell ( close to the nucleus) 2 e-, second shell 8 e-, third shell 8 e-. More complex atoms may have as many as 18 e- in the 3rd shell.