1. The Structure and Function of Macromolecules CHAPTER 6.4 pages 166-169
“You are what you eat!”

2. 6.4: The Building Blocks of Life
The elements of life:
Organisms are made up of cells. Cells contain molecules made up of the following elements:
CHNOPS
Carbon (C)
Hydrogen (H)
Nitrogen (N)
Oxygen (O)
Phosphorus (P)
Sulfur (S)
These elements come from the foods we eat.

3. Matter Cannot be Created nor Destroyed!
Matter is recycled!!!!
CHNOPS get into our cells through the Cycles of Matter!!

4. Carbon: All life contains Carbon!
Examples:
Glucose (C6H12O6)
& Carbon Dioxide (CO2)
MACROMOLECULES or BIOMOLECULES are LARGE molecules containing carbon.

5. Macromolecules are POLYMERS made from MONOMERS
Polymer: a chain of monomers.
Monomer: a unit of polymers.

6. DEHYDRATION SYNTHESIS:
Water is removed.
Monomers bind to form polymers.
HYDROLYSIS REACTION:
Water is added.
Polymers break down into monomers.

7. There are 4 major categories of macromolecules:
Category elements
Carbohydrates CHO
Lipids CHO
Proteins CHON
Nucleic Acids CHONP

8. CARBOHYDRATES (sugars): CHO
MONOMER
monosaccharide
POLYMER
polysaccharide
FUNCTION
Short term (fast) energy storage, structure
EXAMPLES
Glucose, sucrose (mono)
Cellulose, starch, glycogen (poly)
End in “ose”:
ex.: glucose, sucrose, fructose

9. Carbs not used as primary energy source:
Starch: energy storage in plants
Cellulose: structure in plants
Glycogen: energy storage in animal liver
Chitin: structure in animals

10. LIPIDS (fats): CHO
MONOMER
Glycerol and fatty acid
POLYMER
triglyceride
FUNCTION
Long-term energy storage, form cell membranes, steroids, insulation, waterproofing
EXAMPLES
Triglycerides, cholesterol, blubber, waxes
Foods rich in lipids: butter, oils, lard, hydrogenated fats

11. Lipids can be: Saturated: lack double bonds in fatty acid chain
solid at room temperature
Ex.: lard, Crisco
Unsaturated:
Have double bonds (“kink”) in fatty acid chain
Liquid at room temperature
Ex.: Oils, phospholipids
triglyceride
Glycerol fatty acid tail
Glycerol fatty acid tails

12. An important fat: PHOSPHOLIPID
Make up the cell membrane
Has a hydrophilic (polar) head
Has a hydrophobic (non polar) tail

13. Proteins: CHON MONOMER Amino acids (20) POLYMER
Polypeptides (proteins)
FUNCTION
Controls rates of reactions (enzymes)
Form muscles, help fight disease (antibodies), cell transport
EXAMPLES
Enzymes, antibodies, hemoglobin, muscle protein
Food sources: eggs, meat, seeds
Amino group
Carboxyl (acid) group

14. Amino acids are joined by peptide bonds to form proteins.
Proteins differ in the number and order of amino acids
Amino acids interact to give a protein its shape
The shape determines the function of a protein.
Incorrect amino acids change a protein’s structure and function
Proteins can denature (fall apart) if:
pH is too high or too low
Temperature is too high
Salinity is too high
Denatured proteins are biologically inactive

15. Nucleic acids: CHONP MONOMER Nucleotides POLYMER DNA, RNA FUNCTION
Store the genetic code
Transmit hereditary information
EXAMPLES
DNA (deoxyribonucleic acid)
RNA (ribonucleic acid)
5-C sugar
Phosphate group
Nitrogen Base
Nucleotide (monomer)

16. 6CO2 +6H2O+light energyC6H12O6 + 6O2
CHEMICAL REACTIONS: Reactants are the starting materials Products are the final materials Reactants on the left, Products on right
For example:
6CO2 +6H2O+light energyC6H12O6 + 6O2
Products
Reactants

17. Enzymes Special PROTEINS: Act as biological catalysts
speed up the rate of chemical reactions
Lower the activation energy of the reaction
Are specific to the reactions they catalyze
Reaction pathway
without enzyme
Activation energy
Activation
energy
with enzyme
Reactants
Products

18. Enzyme-substrate complex
Lock and Key Model
Explains that enzymes are specific
Enzymes only catalyze one type of reaction, using a specific substrate.
Substrate = specific molecule a specific enzyme binds to
Active site = specific place in enzyme where substrate binds
active sites
Enzyme-substrate complex
enzyme

19. ‘Lock and Key Model’ – says there is a perfect fit between active site and substrate

20. Breaking Bonds
Making Bonds

21. 5. Enzymes are Catalysts: speed up chemical reactions By lowering the Energy of Activation 6. Energy of Activation = minimum amount of energy needed for reactants to form products in a chemical reaction.

22. How do enzyme speed up reactions?
Enzymes lower the activation energy

23. 8. Factors that affect an enzyme: Temperature
Too warm, enzyme will denature
Too cold, enzymatic activity will slow down. pH
- a change in pH can change the shape of the enzyme so that substrates can’t fit into active site
Salinity
How many ions (usually salt) are present
DENATURATION:
9.Enzymes can get denatured (shape is changed, enzyme is inactivated) when these factors change.

24. 10. Competitive and Non-Competitive
Inhibition of Enzymes

25. 1. What is this graph showing?
temperature and enzyme activity
2. What is the independent variable?
temperature
3. What is the optimum temperature for the enzyme?
40°C
4. At what temperature is the enzyme completely denatured?
62°C