BIOCHEMISTRY Chemistry of life Chemistry important to understand biological functions

Some Vocab Matter- occupies space, has mass Element- pure substance- can’t be broken down into anything else-1 kind of atom Compound- 2 or more elements chemically bonded

Important Elements 96% of body is made of 4 elements Nitrogen (N) Carbon (C) Oxygen (O) Hydrogen(H) Other 4% made of Ca, P, K, S, Mg + trace elements Needed in tiny amounts- Fe, Se, I

Chemistry Review Atoms # Protons= Atomic # Neutrons (neutral) Electrons (-) # Protons= Atomic # Protons + Neutrons= Atomic Mass (nucleus)- Atoms can have different masses = ISOTOPES

Electrons- outside nucleus- in orbitals(energy levels) Responsible for bonding Atoms can gain or lose 1 or more electrons= IONS

Chemical Bonds Why do atoms bond? To fill outermost energy level (stability) Atoms can transfer electrons to another atom- IONIC BOND OR… Atoms can share electrons- COVALENT BOND (most bonds in living organisms) Hydrogen bonds- we’ll discuss later

Modeling Bonds Usually a dash is used to represent a bond between 2 atoms (see board) This bond is 1 pair of electrons being shared If two pairs are shared use 2 dashes If 3 pairs are shared- use 3 dashes

Draw these molecules Examples NH3 CH4 CO2

Types of compounds Inorganic- contain no carbon-carbon bonds 1. Carbon dioxide -used as a source of carbon in photosynthesis to fix energy into sugars -by-product of animal respiration and some natural processes 2. Minerals -many are “coenzymes”- help reactions happen -needed in varying amounts to build complex compounds for life

3. Water -most important inorganic compound for living organisms -composes 65-95% of all living organisms -provides environments for many organisms -has good heat absorbing and releasing capabilities -”Polar molecule”

Organic Compounds A. Are molecules containing carbon- carbon bonds B. Carbon forms the structural backbone of all major life sustaining compounds C. Carbon can bond with up to 4 atoms at one time

D. Can bond with other carbons to form long chains or rings. E. Four major groups 1. CARBOHYDRATES 2. LIPIDS 3. PROTEINS (ENZYMES) 4. NUCLEIC ACIDS

#1 What 3 subatomic particles compose an atom?

#2 Name 2 types of chemical bonds.

#3 What are pure substances called that cannot be broken down into any other kinds of atoms?

#4 Atomic # tells the number of ________ in an atom.

#5 What subatomic particles are responsible for chemical bonds?