Chapter 2 The Chemical Level of Organization Flashcards
What is chemistry?
the science that investigates matter and its interact
What is matter?
Anything that takes up space and has mass
What is atomic number?
the number of protons in an atom
Mass number
total number of protons and neutrons in the nucleus
Atoms are electrically neutral, meaning:
every positively charged proton is balanced by a negatively charged electron
What determines the chemical properties of an element?
The number of electron’s in the atom’s outer shell
Chemical bonding produces ____ and ____.
molecules and compounds
Molecules are:
chemical structures that contain more than one atom bonded together by shared electrons
A compound is:
any chemical substance made up of atoms of two or more elements
What are surfactants?
Chemicals that act as wetting agents
Why do premature babies often suffer from pulmonary disease?
Because surfactant is not produced by the fetus until approximately 28-32 weeks of gestation
What is energy?
the capacity to perform work
What is work?
the movement or change in the physical structure of matter
What is kinetic energy?
the energy of motion
What is potential energy?
stored energy
What is a decomposition reaction?
breaks a molecule into smaller fragments
Hydrolysis
one of the bonds in a complex molecule is broken, and the components of a water molecule are added to the resulting fragments
What is dehydration synthesis?
condensation; the formation of a complex molecule by the removal of water
What is anabolism?
the synthesis of new compounds in the body
What is an exergonic reaction?
a reaction that releases energy
What is an endergonic reaction?
A reaction that absorbs energy
What are nutrients?
The essential elements and molecules that are obtained from the diet
What is an acid?
any substance that breaks apart in solution to release hydrogen ions
What is a base?
a substance that removes hydrogen ions from a solution
How is the concentration of hydrogen ions reported?
as the pH
Pure water has a pH of ___
7
A solution with a pH of 7 is called ____ because:
neutral; it contains equal numbers of hydrogen ions and hydroxide ions
A solution with a pH below 7 is:
acidic
A solution with a pH above 7 is:
basic or alkaline
The pH of blood and most body fluids normally ranges from ____ to ____
7.35 to 7.45
A blood pH below 7 can produce:
coma
A blood pH above 7.8 usually causes:
uncontrollable, sustained muscular contractions
What are buffers?
compounds that stabilize pH by either removing or replacing hydrogen ions
pH is an abbreviation of:
potential of hydrogen
How is the value of 7.0 derived as the pH of a precisely neutral solution?
it is the absolute value of the hydrogen ion concentration at 25°C
A pH of 14 indicates that:
only hydroxide ions are present
A pH of 0 indicates that:
only hydrogen ions are present
What is pOH?
denotes the alkalinity of a solution; represents the number of hydroxide ions present
pH + pOH = ____
14
Organic compounds always contain:
carbon and hydrogen and generally water as well
What is a carbohydrate?
an organic molecule that contains carbon, hydrogen, and oxygen in a ratio near 1:2:1
What is a monosaccharide?
a simple sugar; a carbohydrate that contains from 3 to 7 carbon atoms
What is the most important metabolic “fuel” in the body?
glucose
Two monosaccharides joined together form a ______
disaccharide
What is a disaccharide?
two monosaccharides joined together; i.e. sucrose (table sugar)
What is a salt?
an ionic compound that consists of any cation except a hydrogen ion and any anion except a hydroxide ion
What is an ion?
an atom or molecule with an electric charge
What are cations?
Ions with a positive charge
What are anions?
Ions with a negative charge
What is an ionic bond?
a chemical bond created by the electrical attraction between anions and cations
What is covalent bonding?
a bond in which atoms share electrons with other atoms
Activation energy
the amount of energy required to start a reaction
Enzymes
belong to a class of substances called catalysts, which are compounds that accelerate chemical reactions without themselves being permanently changed
Inorganic compounds are small molecules that do not contain ____ and ____ atoms.
carbon and hydrogen
What are electrolytes?
Inorganic compounds whose ions can conduct an electrical current in solution
What are steroids?
Large lipid molecules composed of four connected rings of carbon atoms
Phospholipids
consist of a glycerol and two fatty acids linked to a nonlipid group by a phosphate group
What are the 7 functions of protein?
- support
- movement
- transport
- buffering
- metabolic regulation
- coordination, communication, and control
- defense
What are proteins?
long chains of organic molecules called amino acids
What determines the functional properties of a protein?
it’s shape
What are the reactants in an enzymatic reaction?
substrates
What are nucleic acids?
Large organic molecules composed of carbon, hydrogen, oxygen, nitrogen, and phosphorus. They store and process information at the molecular level inside cells
What are the five nitrogenous bases in a nucleotide?
adenine, guanine, cytosine, thymine, and uracil
The energy that powers a cell is obtained by:
the breakdown (catabolism) of organic molecules such as glucose
ATP is composed of:
adenosine monophosphate and two phosphate groups