1. Chemistry of Life Organic chemistry is the study of carbon compounds
ALL living things are made of carbon compounds
Can measure the amount of C remaining (half-life) to determine the age of fossils
C atoms are versatile building blocks of life
Good bonding properties
Can form 4 stable covalent bonds with many other elements H
Carbon chemistry = organic chemistry
Why is it a foundational atom?
What makes it so important?
Can’t be a good building block if you only form 1 or 2 bonds. H C H H

2. Why study carbon? All of life is built on carbon Cells ~72% H2O
~25% organic carbon compounds
carbohydrates
lipids
proteins
nucleic acids
~3% salts
Na, Cl, K…
Why do we study carbon -- is it the most abundant element in living organisms?
H & O most abundant
C is the next most abundant

3. Carbon compounds Used to build life
Smaller molecules called monomers are joined together to form larger molecules called macromolecules or polymers
4 major classes of macromolecules built on C, H, O, N, P:
carbohydrates
lipids
proteins
nucleic acids

4. Organic compounds

5. Functions of organic compounds
Carbohydrates
Source of energy and help strengthen cell walls, and communication
Lipids
Source of energy, insulation, storage, protection, forms cell membrane
Proteins
Source of energy, form traits, hormones, transporters, muscle contraction
Nucleic acids
Stores and transmits genetic information

6. Proteins Most structurally & functionally diverse group
Function: involved in almost everything
enzymes (pepsin, DNA polymerase)
structure (keratin, collagen)
carriers & transport (hemoglobin, aquaporin)
cell communication
signals (insulin & other hormones)
receptors
defense (antibodies)
movement (actin & myosin)
storage (bean seed proteins)
Storage: beans (seed proteins)
Movement: muscle fibers
Cell surface proteins: labels that ID cell as self vs. foreign
Antibodies: recognize the labels
ENZYMES!!!!

7. Proteins Protein functions depends on protein structure
Structure depends on DNA sequence
Codes for amino acid sequence
Order of amino acids determine structure and function
Forms a polypeptide chain
Amino acids joined by peptide bond
protein can be one or more polypeptide chains folded & bonded together
Rubisco = 16 polypeptide chains
Hemoglobin = 4 polypeptide chains (2 alpha, 2 beta)

8. Enzymes are important proteins
Enzymes are important proteins
substrate
Reactant or the molecule being broken down
product
end result of reaction
active site
enzyme’s catalytic site; substrate fits into active site
Active site puts “stress” on the substrate bonds
active site
products
substrate
enzyme

9. Enzymes Enzymes are substrate specific Enzyme What is an enzyme?
Enzymes are proteins that speed-up the rate of a chemical reaction- also known as a catalyst
Aid in many cellular processes
Ex: amylase in digestion
Breaks down a substrate known as starch
Bread (starch) is the substrate and amylase breaks it down into smaller products quickly
If the bread was left to breakdown on its own it could take YEARS!
Enzymes work by decreasing the activation energy also known as the start-up energy of a reaction
Enzyme
Enzymes are substrate specific

10. Pheeew… that takes a lot less energy!
Reducing Activation energy
Enzymes are catalysts
reduces the amount of energy needed to start a reaction
This increases the rate of the reaction
Pheeew… that takes a lot less energy!
uncatalyzed reaction
catalyzed reaction
NEW activation energy
reactant
product

13. In Biology, size doesn’t matter,
Protein denaturation
In Biology, size doesn’t matter,
SHAPE matters!
Proteins have “optimal” environments they function best b/c of their AA sequence
Unfolding a protein
conditions that disrupts bonding
temperature pH
salinity
alter 3-D shape
destroys functionality
some proteins can return to their functional shape after denaturation, many cannot