Micro 020: Chapter 1 Notes:
It is important to understand the molecular make up or
components of an organism because:
- It lets us know what nutrients it needs to live
- It allows us to know what metabolic processes it requires
to thrive
- It allows us to know how we can limit its growth or kill
the pathogenic ones while promoting growth of
beneficial microbiomes.
Chemical Building Blocks:
- The physical universe is composed of substances called
matters
o Matter is defined as a substance that possess mass
and takes up space.
o The most basic unit of matter is the atom
o There are different types of atoms, so these
different atoms are categorized into elemental
groups such as oxygen, hydrogen, carbon, etc.
- Atoms:
o The most basic unit of any matter
o An atom is made up of 3 parts or subatomic
particles
Proton
Neutrons
Electrons
o Hydrogen is the ONLY element that does not have a
neutron
- Protons:
, o Possess 1 atomic mass
o Possess 1 positive electoral charge
o Located in the center (nucleus) of an atom
- Neutron
o Has 1 atomic mass
o Has no electoral charge
o Located in the center (nucleus) of an atom
- Electron
o Has no Atomic Mass
o Has 1 negative electrical charge
o Is found orbiting the nucleus of an atom
- Atomic Number
o The number of proton that an atom possesses
o Atoms with the same number of protons are
grouped into the same element
An atom with 1 proton belongs in what
element?
An atom with 6 protons belongs in what
element?
- Atomic Weight (mass)
o The weight of an atom. It is calculated by adding
the mass of all protons and neutrons together.
The periodic table organizes all atoms by their
atomic mass.
- Usually, the number of electrons is the same as the
atomic number. (not always)
Example Question:
“Oxygen has an atomic number of 8. This means that it has
- 4 protons and 4 neutrons
- 8 protons
, - 4 electrons and 4 protons
- 6 protons and 2 neutrons
o The atomic number is the same as # of protons.
- Isotope: These are atoms of the same element (so they
have the same atomic number), but they possess
different number of neutrons.
o For example, Carbon 12, Carbon 12, Carbon 14 all
have 6 protons, but different number of neutrons.
How many neutrons does carbon possess?
C-12 is the most stable form of carbon and are
the most common whereas unable C13 and C-
14 are not as stable and thus are less common.
o (subtract the proton number with the “new amount)
for example C13 has 7 neutrons since C has 6
protons 13-6=7.
- Importance of Isotopes: C-14 is used to determine the
age of organic materials that is less than 75,000 years of
age.
o How is it done?
C-14 has a half-life of 5,700 years.
Every 5,700 years, C-14 will be reduced by half
- Sample question: Calculating Half life
o Carbon-14 has a half-life of about 5,700 years.
A sample of bone originally had 1 gram of
carbon-14.
How much Carbon-14 will there be in
17,100 years?
- How was question answered?:
o Divide 17,100 by 5,700. It is 3 half-lives.
o In each half-life, C-14 is reduced by half
It is important to understand the molecular make up or
components of an organism because:
- It lets us know what nutrients it needs to live
- It allows us to know what metabolic processes it requires
to thrive
- It allows us to know how we can limit its growth or kill
the pathogenic ones while promoting growth of
beneficial microbiomes.
Chemical Building Blocks:
- The physical universe is composed of substances called
matters
o Matter is defined as a substance that possess mass
and takes up space.
o The most basic unit of matter is the atom
o There are different types of atoms, so these
different atoms are categorized into elemental
groups such as oxygen, hydrogen, carbon, etc.
- Atoms:
o The most basic unit of any matter
o An atom is made up of 3 parts or subatomic
particles
Proton
Neutrons
Electrons
o Hydrogen is the ONLY element that does not have a
neutron
- Protons:
, o Possess 1 atomic mass
o Possess 1 positive electoral charge
o Located in the center (nucleus) of an atom
- Neutron
o Has 1 atomic mass
o Has no electoral charge
o Located in the center (nucleus) of an atom
- Electron
o Has no Atomic Mass
o Has 1 negative electrical charge
o Is found orbiting the nucleus of an atom
- Atomic Number
o The number of proton that an atom possesses
o Atoms with the same number of protons are
grouped into the same element
An atom with 1 proton belongs in what
element?
An atom with 6 protons belongs in what
element?
- Atomic Weight (mass)
o The weight of an atom. It is calculated by adding
the mass of all protons and neutrons together.
The periodic table organizes all atoms by their
atomic mass.
- Usually, the number of electrons is the same as the
atomic number. (not always)
Example Question:
“Oxygen has an atomic number of 8. This means that it has
- 4 protons and 4 neutrons
- 8 protons
, - 4 electrons and 4 protons
- 6 protons and 2 neutrons
o The atomic number is the same as # of protons.
- Isotope: These are atoms of the same element (so they
have the same atomic number), but they possess
different number of neutrons.
o For example, Carbon 12, Carbon 12, Carbon 14 all
have 6 protons, but different number of neutrons.
How many neutrons does carbon possess?
C-12 is the most stable form of carbon and are
the most common whereas unable C13 and C-
14 are not as stable and thus are less common.
o (subtract the proton number with the “new amount)
for example C13 has 7 neutrons since C has 6
protons 13-6=7.
- Importance of Isotopes: C-14 is used to determine the
age of organic materials that is less than 75,000 years of
age.
o How is it done?
C-14 has a half-life of 5,700 years.
Every 5,700 years, C-14 will be reduced by half
- Sample question: Calculating Half life
o Carbon-14 has a half-life of about 5,700 years.
A sample of bone originally had 1 gram of
carbon-14.
How much Carbon-14 will there be in
17,100 years?
- How was question answered?:
o Divide 17,100 by 5,700. It is 3 half-lives.
o In each half-life, C-14 is reduced by half
