1. Introduction to Biochemistry
Unit 2

2. What is matter?

3. What is matter made of?
Matter is composed of atoms

4. Atoms

5. Protons Protons have a positive charge (+)
Protons are found inside the nucleus of the atom
The number of protons equals the atomic number

6. Neutrons Neutrons are neutral charged (0)
Neutrons are found inside the nucleus of an atom

7. Protons and Neutrons
Number of Protons + Number of Neutrons = Atomic Mass
= 12

8. Electrons Electrons are negatively charged (-)
Electrons are found outside the nucleus of an atom
Electrons determine if the element has to bond

9. The Periodic Table

10. What kind of Patterns do you see?

11. Valence Electrons and Bonding
The column tells you how many valence electrons (outside) the element has
The first shell (circle) can hold 2 electrons
The other shells (circles) can hold 8 electrons

12. Your Turn: How many Valence Electrons?3 4 5

13. Ionic Bond In an ionic bond electrons are given or taken
Happens when an element has 1,2 electrons to gain or lose

14. Covalent Bond
In a covalent bond electrons are shared between 2 or more elements.
Happens when an element has 4 electrons

15.
What part of the atom helps decide if it needs to bond (protons, neutrons, electrons)?
What type of bond happens when electrons are taken or given away?
What type of bond happens when electrons are shared?

16. Insert biological levels of org pic