Chemical ReactionsProcess that changes set of chemicals into another set of chemicals
Reactants yields Products 6CO2 + 6H20 C6H12O6 + 6O2
Slow Fast
Metabolism:Chemical processes occurring within a living cell necessary to maintenance life
Catabolism - Breaking Down moleculesAnabolism – Building Molecules
Reaction Energy• Energy is Released when chemical bonds Break
• Energy is Absorbed when chemical bonds Form
• Reactions that release energy Spontaneous
• Reactions that require energy Non Spontaneous
Energy requirements in chemical reactions
Energy-Releasing Reaction
Products
Activation energy
Reactants
C6H12O6 → CO2 + H2O
Burning a Log
Enzymes• Chemical reactions in the human body require a lot of
energy • Enzymes serve as a CATALYST
• Speed up reactions that take place in cells
Reaction using Enzyme
Candy Bar
Reaction pathwaywithout enzyme
Activation energywithout enzyme
Activationenergywith enzymeReaction pathway
with enzyme
Reactants
Products
Chapter 02D.mpg
CARBOHYDRATES
Characteristics of Carbohydrates
• Consist of carbon, hydrogen, & oxygen• Energy containing molecules• Some provide structure: Celulose
• Basic building block is a monosaccharide (CH2O)n ; n = 3,5,6
• Two monosaccharides form a disaccharide
Three Monosaccharides
C6H12O6
Dehydration Synthesisof a Disaccharide
Formation of Disaccharides
Hydrolysis of a Disaccharide
Important Polysaccharides: Starch
• Consists of glucose subunits
• Plant energy storage molecule
• Glycogen is a very similar molecule in animals.
• Starch and glycogen can be digested by animals.
Important Polysaccharides: Cellulose
• Composed of glucose subunits
• Different bond formed than starch
• Structural component in plants
• Cannot be digested by animals
LIPIDS
Characteristics of Lipids
• Composed of: Carbon, Hydrogen, and Oxygen
• Includes: Fats, Oils, Phospholipids, and
Cholesterol• Phospholipids part of cell membrane• Building blocks:
• Fatty Acids and Glycerol.
• Energy storage molecules
Fatty Acid Structure
•Carboxyl group (COOH) forms the acid.•“R” group is a hydrocarbon chain.
A Representative Fatty Acid
SaturatedFatty Acid
UnsaturatedFatty Acid
Glycerol
Synthesis of a Fat
A Phospholipid
PROTEINS
Characteristics of Proteins
• Contain: • Carbon, Hydrogen, Oxygen, Nitrogen, sulfur
• Function:• Structural components of animals• Control molecules (enzymes)• Transport and messenger molecules
• Basic building block is the amino acid
Amino Acid
• Amine group acts like a base, tends to be positive.• Carboxyl group acts like an acid, tends to be negative.• “R” group is variable, from 1 atom to 20.• Two amino acids join together to form a dipeptide. • Adjacent carboxyl and amino groups bond together.
Some Amino Acids
Some More Amino Acids
Still More Amino Acids
Formation of a Dipeptide
Dehydration synthesis
Amino Acid + Amino Acid --> Dipeptide
Amino Acid + Dipeptide --> Tripeptide
A.A. + A.A. + …..+ Tripeptide --> Polypeptide
A protein consists of one or morepolypeptide chains.