1.0 Biological Molecules Flashcards
All matter is made up of what?
Atoms
What are the 3 particles an atom is made up of?
- Protons, which have a +ve charge
- Neurtons, which have no charge
- Electrons, which have a negative charge
What is the structure of an Atom
- A central nucleus contains the protons and neutrons
- The electrons circle the nucleus in orbitals or shells
If the overall charge of an atom is neutral, what is the ratio of protons and electrons
- The number of protons and electrons are the same
How many protons do atoms of the same element contain e.g. Carbon
Same
More
Less
- The same
How many protons do carbon atoms have?
- 6
How many protons do oxygen atoms have?
8
What is the atominc number
The number of protons contained in the nucleus
What is the mass number of an element
The number of protons plus the number of neutrons contained in the nucleus
What is a molecule?
- A molecule consists of 2 or more atoms joined together chemically:
- The molecules in an atom can be the same
- Eg Oxygen has 2 atoms of oxygen (O2)
- Or the atoms can be different
- Eg Carbon Dioxide has one atom of carbon and 2 atoms of Oxygen (CO2)
What is the name given to a molecule which is composed of different atoms?
- A Compound
- e.g. CO2
What is an Ion?
A charged particle
How is an ion formed?
When an atom or groups of atoms lose or gain electrons
What type of charge does an electron have?
- Negative
If an atom gains an electron what happens?
- It becomes an Ion with a negative charge
What is the name given to Ions with a negative charge
- Anions
- AN IONS
What happens when atoms lose electrons
- Ions have a positive charge
What do you call Ions with a positive charge?
Cations
CAT IONS
A sodium atom which loses an electron is written how?
- NA+
A chlorine atom which gains an electron
- CL-
How do you write a nitrate ion
N03-
How do you write a phosphate ion
PO43-
What is an isotope?
An atom composed of the same elements with a different mass number
What do some biologists use isotopes for?
- They are used as tracers because they are radioactive
How do you write radioactive isotope carbon 14
- 14C
How can 14C be used?
- If it is fed to plants you can look at the formation of compunds made in photosynthesis by tracing what happens to the 14C
Hydrogen - What is the…
Atomic number
Mass number
- Atomic number - 1
- Mass number - 1
What is the structure of a Hydrogen atom?
- 1 proton
- 1 electron
- No neutrons
How do you write a hydrogen Ion which has lost an electron?
- H+
What is pH
- The measure of the concentraton of hydrogen ions present
What if a pH is high?
- High pH
- High concentration of Hydrogen Ions
- More acidic the solution
What is the range of a pH scale
1 to 14