Carbon is unique because:
1. It has four valence electrons in its outer orbital.
2. It can bond with other carbon atoms to form chains of great length.
CARBON
• Can have single, double, or triple bonds.
• Can make rings.
• Can make millions of different large structures.
http://www.dkimages.com/discover/previews/795/940887.JPG
Carbon Compounds
• Cells are made of large biomolecules which are built from smaller, simpler, repeating units.
Macromolecules:
• Very big molecules made of thousands of smaller molecules.
• Formed by polymerization.
• Each small molecule is a monomer.
• Monomers join to form polymer.
Four types of macromolecules in living things:
1. Carbohydrates
2. Lipids
3. Nucleic acids
4. Proteins
Carbohydrates
polysaccharide made of sugar monomers - monosaccharides. Contains C,H,O
Ex: glucose
Function:• Energy supply• Structure support• Cell recognition
Monomer of starch
• Plants store excess sugar as starch and cellulose.
Lipids• Macromolecules (polymer) made mostly
from C,H chains
• Ex: fats, steroids, waxes, phospholipids
• Monomer = glycerol, fatty acids
Function:
• store energy
• waterproof coverings, cell membrane
Ex: cell membrane, earwax.
glycerol (polar) bonds with fatty acid tails (nonpolar).
• At least one C=C bond, fatty acid is unsaturated.
• More than one C=C, polyunsaturated.
Ex: oils
• No C=C bonds, saturated.
Ex: animal fats, butter
• Cooking oils are polyunsaturated, broken down more easily.
• Solid fats like butter, animal fat are saturated, harder to break down.
Nucleic Acids
• Nucleic acids (DNA, RNA) are polymers made of monomers called nucleotides.
• 3 parts of nucleotide: sugar, phosphate group, nitrogenous base. Ex: ATP
C,H,O,N,P
Function:• store and transmit genetic information• Energy carriers (ATP)
Each nucleotide has 3 parts: nitrogen base, phosphate group, sugar
Here are 3 nucleotides joined together to make a polymer: DNA
• Two types of nucleic acids:
• Deoxyribonucleic acid - DNA• Contains sugar called deoxyribose
• Ribonucleic acid - RNA• Contains sugar called ribose
Proteins
• Polymer made of chains of amino acids = monomers• Ex: muscle, enzymes• Amino acid (monomer) ex: tryptophan• Composition: C,H,O,N
Function:• Structure, support, and transport (muscles, bone)• Communication (cell membrane)• Catalyst for chemical reactions (enzymes)
Amino Acid:
Each amino acid has 3 groups: amino, carboxyl, R
Four levels of organization
• 1st: sequence of amino acids
• 2nd: chain is twisted or folded.
• 3rd: chain itself is folded.
• 4th: several chains in one protein can be intertwined and held by H-bonds and Van der Waals forces.
MacromoleculesType Polymer Monomer Elements Function
carbohydrate
Chemical Reactions
• Chemical reaction = the process that changes one set of chemicals into another.
• Chemical rxn always involves:• breaking of bonds in reactants• making of new bonds in products.
CO2 + H2O ----------> H2CO3
Which side of the arrow are the reactants located? Which side are products located?
Energy in Reactions
• Energy is stored in the bonds that hold a compound together.
• Energy is released or absorbed whenever chemical bonds break or form.
2H2 + O2 ---------> 2H2O + ENERGY!!!
Hydrogen gas burns in oxygen and released lots of energy!
But Energy + 2H2O -------> 2H2 + O2
requires lots of energy to happen
• All living things need energy input to make chemical reactions in their bodies happen.
• Where does this energy come from?
Food!
The bonds that hold molecules together in food.
Activation Energy
• the energy needed to get a rxn (reaction) started.
• Even rxns that release energy often require energy to start them.
Ex: dynamite.
Energy Releasing Reaction
Energy Absorbing Reaction
Enzymes
• A Catalyst is something that speeds up the rate of a chemical rxn.
• Enzymes are proteins that act as catalysts to speed up chemical reactions in cells.
• Enzymes provide a site for rxn to happen called active site.
• Reactants are called substrates.
• Lock and key design. Enzymes are specific to particular substrates.
• Enzyme is the “matchmaker” for rxns.
• Enzymes are affected by temperature, pH.
• Enzymes regulate chemical pathways that make materials, release energy, and transfer information in cells.
Enzyme Animation
• http://www.kscience.co.uk/animations/anim_2.htm
Youtube Enzyme Basics, Enzymedicahttp://www.youtube.com/watch?v=AFbPHlhI13g
Catalase Floating Disk Assay
• Catalase is an enzyme found in almost all living cells. It breaks down hydrogen peroxide into water and oxygen.
• 2 H2O2 → 2 H2O + O2
• http://www.youtube.com/watch?v=ItreW0X0R50
Top Related