The Chemical Level Of Organization Flashcards
____________is the force of gravity acting on matter, that does not change.
Weight
Is the force of gravity acting on matter, that does not change
Name the four major elements in your body that compromise 96% of body mass.
carbon, hydrogen, oxygen, nitrogen
How many lesser elements are found in the body’s mass? 3.6%
8 lesser elements
Na
P
k
s
cl
mg
Fe
How many trace elements are found in the body? 0.4%
14 trace elements
Oxygen is about _____ % of total body mass.
65 % oxygen
-oxygen is a part of water and many organic (carbon containing) molecules
-used to generate ATP
What forms the backbone chains and rings of all organic molecules?
carbon
-forms backbone chains and rings of all organic molecules: carbohydrates, lipids, proteins, and nucleic acid (DNA and RNA)
Carbon is about _____% of total body mass.
18.5 % carbon
Hydrogen is about ____% of total body mass.
9.5 % hydrogen
Nitrogen is about _____% of total body mass.
3.2 % nitrogen
What chemical element in it’s ionized form (h+) makes body fluids more acidic?
Hydrogen
(9.5% in body mass)
What chemical element is part of water and most organic molecules?
Hydrogen
(9.5% in body mass)
__________ is a component of all proteins and nucleic acids.
Nitrogen
Calcium is about ____% of total body mass.
Calcium 1.5 % of body mass
What element in it’s iodized form is needed for blood clotting?
Ca2+
Calcium
______________is a component of nucleic acids and ATP; also it is required for normal bone and tooth structure.
phosphorus
(1.0% in body mass)
__________ is the most plentiful cation in intracellular fluid; is needed to generate action potentials.
ionized form of potassium
(k+)
What type of charge does a cation have?
positive
Cation is a positively charged particle
The number of proton’s in the nucleus is an atom’s __________ ____________.
Atomic number
Oxygen has 8 protons, so it’s atomic number is 8
The _________number of an atom is the sum of its protons and _____________.
proton + neutron = __________ _________.
The mass number of an atom is the sum of it’s protons and neutrons.
proton + neutron= mass number
Sodium has 11 protons and 12 neutrons. 11 + 12 = 23
Mass number is 23
________________ are atoms of the same element that have the same number of protons, but different number of neutrons.
Isotopes
So they also have same atomic number, same position on periodic table but a different number of neutrons, meaning that their mass number varies.
Explain the difference between stable and unstable isotopes.
Unstable -change over time, harmful or helpful
Stable-does not change over time
Most isotopes are STABLE, which means there nuclear structure does not change over time.
UNSTABLE isotope, called radioactive isotopes; their nuclei decay (spontaneously change) into a stable structure. They can be helpful or harmful
In what ways are radioactive isotopes helpful or harmful?
HELPFUL- when used as tracers in medical imaging, tests for diagnosis, and procedures
HARMFUL-radiation can break apart molecules causing tissue damage or cancer
___________ is the time required for half of the radioactive atom of isotope to decay into more stable time.
The half-life of an isotope is the time required for a half of the radioactive atoms in a sample of that isotope to decay into a more stable form.
What is the standard unit for measuring the mass of atoms and their sub atomic particles called?
dalton
atomic mass unit (amu)
A ________ has a mass of 1.008 daltons, and a________ has a mass of 1.007, and a _________ has a mass of 0.0005 dalton.
neutron 1.008 daltons
protron 1.007 daltons
electron 0.0005 dalton
The average mass of all naturally occurring isotopes in an element is called the _________ _______ or the ________ ________.
The atomic mass or the atomic weight.
‘
Usually the atomic mass of an element is close to the mass number of its most abundant isotope
What is a compound?
2 or more different atoms
A substance that contains atoms of two or more elements.
Most of the atoms of the body are joined into compounds- H20 and NaCl (table salt, sodium chloride)
**a molecule of oxygen (02) is NOT a compound it only has atoms of one element
What is a molecule?
2 more atoms - share electrons 02
What is a free radical?
atom (s) with unpaired electron in outermost shell (usually unstable and reactive)
Having an unpaired electron makes a free radial highly reactive, and destructive to nearby molecules.
How do free radicals become stable?
Either giving up their unpaired electron or stealing one from another molecule.
What are the atomic number, mass number and atomic mass of carbon? How are they related?
atomic number = # of protons
mass number = protons + neutrons in an atom
atomic mass= average mass of all stable atoms of a given element in daltons
Atomic # is 6
(6 protons)
Mass # is
List the 12 most abundant chemical elements in the human body.
oxygen (65.0)
carbon (18.5)
hydrogen (9.5)
nitrogen. (3.2)
calcium (1.5)
phosphorus (1.0)
potassium (0.35)
sulfur
sodium
cholride
magnesium
iron
The outermost cell of an atom is called it’s __________ ____________.
valence shell
*the likelihood of a chemical bond forming depends on the number of electrons in the valence shell.
How does the octet rule- help explain why atoms interact in a predictable way?
atom goal is stability- achieved when there is 8 valence electrons.
For chemical stability (valence 8) to happen the atom either:
- empties it’s partially filled valence shell
-fills it with donated electrons
-or shares electrons with other atoms
It is predictable because the way that valence electrons are distributed determines the kind chemical bond will results (ionic, covalent, hydrogen)
Octet rule- under the right conditions two or more atoms can interact in ways that produce a chemically stable arrangement of eight valence electrons for each atom.
atomic hookups– atoms want stability and an atom with a valence shell holding 8 electrons is chemically stable.
On atom is more likely to interact with another atom if doing so will leave both atoms with 8 valence electrons.
Ionic bond
sodium : 1 valence electron
chlorine: 7 valence electrons
The force of attraction that holds together ions with opposite charges together.
Example: NaCl
a) if sodium loses one electron it can have complete octet in outermost shell
b) chlorine atom needs one electron for an octet in valence shell
c) ionic bond may form between oppositely charged ions
cation
positively charged ion formed when an atom LOSES one ore more valence electrons
When an ionic compound breaks apart into positive and negative ions in a solution, what is this called?
an electrolyte
anion
negatively charged ion
formed when an atom GAINS one ore more valence electrons
How do atoms form a covalently bonded molecule?
By sharing one, two or three pairs of valence electrons.
Sharing is covalently caring.
What are the most common chemical bonds in the body?
covalent bonds
***most of the body’s structures are formed from covalently compounded chemical bonds.
What is the main difference between an ionic bond and a covalent bond?
Ionic bond either gains or gives up a valence electron.
A covalent bond shares valence electrons.
What type of bonds share electrons equally?
non polar covalent bonds, two atoms share the electrons equally—-two identical atoms are always non-polar covalent bonds.
When the sharing of electrons between two atoms is not equal, what is this called?
polar covalent bonds
ie. water molecule
When the sharing of electrons between two atoms is unequal—the nucleus of one atom attracts the shared electrons more than the other atom.
The power of an atom to attract electrons to itself is called _________________.
electronegativity
What does it mean when something is polar?
It means it can attract or repel. (positive or negative)
A hydrogen bond is special in that it has a special type of dipole-dipole attraction. What does this mean?
dipole-dipole forces are the attractive forces of the positive end of one polar molecule to the negative end of another polar molecule.
How strong are hydrogen bonds compared to ionic and covalent bonds?
WEAKER than ionic and covalent.
* they can’t bind atoms to into molecules
Hydrogen bonds do establish important links between molecules or between different parts of a large molecule such as a protein or nucleic acid.
Yes they do
A spider walks on water or a leaf floats on water. Examples of the tendency of like particles to stay together, this is called _________ ___________.
Surface tension
cohesion in hydrogen bonds that link water molecules together
__________ ____________ occur when new bonds form or old bonds break between atoms.
Chemical reactions occur when new bonds form or old bonds break between atoms.
The basis for all chemical reactions happens in the ____________ shell.
Valence shell, the interaction between valance electrons
The starting substances two H2 and one O2 are known as ___________.
The ending substances–two molecules of H20 are the _____________.
reactants
products
What is the term used to describe all chemical reactions occurring in the body?
metabolism
What type of energy is stored in the bonds of compounds and molecules?
Chemical Energy
It’s a form of potential energy which is energy stored by matter due to its position.
The total amount of energy present at the beginning and end of a chemical reaction is the same. It can neither be created or destroyed. What is this principle known as?
The law of conservation of energy.