Chapter 2.2 Molecules and Compounds Flashcards
What is a compound?
The bond between atoms of two or more different elements
What are the two types of bonds?
- Ionic bonds
- Covalent bonds
What are covalent bonds?
Covalent bonds are electrons shared between atoms to form molecules.
What are ionic bonds?
Bonds in which electrons are transferred between atoms to form ionic compounds.
What are molecules?
Molecules are structures that are formed when two or more similar atoms are covalently bonded.
What are ions?
Ions are charged particles that form when electrons transfer from one atom to another.
What are the three types of covalent bonds?
- Single bonds= 1 line
- Double bonds= 2 shared pairs of e-
- Triple bonds= 3 shared pairs of e-
What is the inportance of the shapes of biological molecules ?
The shapes of biological molecules are related to their structural and functional roles.
- SHAPE=FUNCTION
ex De-natured proteins can affect their functional role.
Characteristics of Molecules
- All molecules have 3D shapes
- Molecules consisting of two atoms are always linear. ( Molecules like methane with five atoms have a tetrahedral shape)
- 3D shapes of molecules = Structure & function
What is a non polar covalent bond?
A covalent bond where there is an equal sharing of electrons between atoms.
What is a polar covalent bond?
- Type of bond where there is an unequal sharing of electrons.
ex. H2O wih Oxygen being more electronegative than hydrogen.
What is the importance of polarity in H2O?
Polarity in a water molecule causes hydrogen atoms of one molecule to be attracted to the oxygen atoms of another molecule. ( hydrogen bond)
Hydrogen bonds are ……….. than………..
Hydrogen bonds are weaker than ionic and covalent bonds
Where does hydrogen bonding occur in biological molecules?
DNA Strands
- Biological molecules which have polar covalent bonds between hydrogen, oxygen and nitrogen.
