1. Biochemistry
Notes pt. 4

2. Organic Molecules 4 Main Macromolecules Carbohydrates Proteins Lipids
Nucleic Acids
We are here!

3. Macromolecule 2: PROTEINS
WHAT DO THEY DO?
They are the major structural molecules in living things for growth and repair : muscles, ligaments, tendons, bones, hair, skin, nails…IN FACT ALL CELL MEMBRANES have protein in them
They make up antibodies in the immune system
They make up enzymes for helping chemical reactions
They makeup non-steriod hormones which
THINK: Proteins= Membranes, Enzymes, Antibodies, Non-steroid hormones, Structural molecules : “MEANS”

4. Proteins: antibodies
Antibodies are part of the immune system. When something enters the body that isn’t supposed to be there, like certain bacteria, antibodies find the invader and stick themselves onto it. When a white blood cell finds the invader covered with antibodies, it knows it doesn’t belong there and kills it.

5. PROTEINS: Found Where? In plant foods- in the cell membranes
In animal products- in the cell membranes- in the muscles of living things- cows, chicken, fish…

6. Proteins

7. Proteins
Aside from the protein found in animal sources…protein can also be found in fruits, vegetables, grains, and nuts

8. THINK: “CHONS” Each protein is made up of…
PROTEINS
AT THE ATOM LEVEL
Each protein is made up of…
Carbon, Hydrogen, and Oxygen,
Nitrogen and sometimes Sulfur
THINK: “CHONS”

9. PROTEINS
MADE UP OF...
Proteins are made of long chains (polymers) made of monomers. All proteins are made of the monomer…
AMINO ACID

10. Protein
A protein is a polymer of just 20 kinds of monomers called amino acids.
Proteins are responsible for almost all of the day-to-day functioning of organisms.

11. What is an Amino Acid?
Each amino acid monomer consists of a central carbon atom bonded to four partners.
Three of the central carbon's partners are the same in all amino acids.

12. Consists of… The three bonds that are the same are:
Amino Group
Carboxyl Group
Carbon bonded to Hydrogen
Every amino acid will have an ‘R’ side chain, but it will be different in each amino acid

13. Differences
What is different about each type of amino acid is the "side group" that attaches to the fourth bond of the central carbon.
The side group, sometimes called the "R-group," is responsible for the particular chemical properties of each amino acid.

14. Examples…
Methionine
Serine

15. Let’s Build a Protein Amino acids are connected by peptide bonds
Each link is created by a dehydration reaction (LOSS OF WATER – WATER WILL BE A PRODUCT!!) between the amino group of one amino acid and the carboxyl group of the next amino acid in the chain.
A long chain of amino acids is called a polypeptide (many peptides)

16. So…

17. Shape Determines…
The shape of the polypeptide is determined by the sequence of amino acids, therefore determining the function

18. The sequence of letters in a word determines the word that is formed:
RAT

19. The sequence of letters in a word determines the word that is formed:
RAT TAR ART

20. Form Determines Function
One change in the sequence #6 (glutamine to valine) changes the protein formed
Sickle Cell: Most common in Black People
Hemoglobin protein that carriers O2 is mishaped Can block blood vessels, prevent O2 from getting to cells No cure

21. 4 Levels of Protein Structure
1. Primary Structure: The sequence of Amino Acids

22. 4 Levels of Protein Structure
2. Secondary Structure:
Twisting of the Polypeptide
Helix
Pleated Sheet

23. 4 Levels of Protein Structure
3. Tertiary Structure:
-The polypeptide folding back on itself
-Globular, 3-D Shape
-Determines the protein function
4. Quaternary Structure:
-The combination of multiple polypeptide structures

24. Primary
Secondary
Tertiary
Quaternary

25. Denaturation The change in form causes a change in function.
Protein shape (conformation) can be denatured (changed) by changing temperature or pH.
The change in form causes a change in function.

26. Warm Up
Using your notes, make a Venn Diagram comparing and contrasting carbohydrates and proteins

27. Biochemistry
Notes Pt. 4.2

28. Review Amino acid = Monomer
Amino acids bond together through peptide bonds to form proteins (polypeptides)
There are 20 Kinds of amino acids that differ by their R-group

29. Hydrophobic = Non Polar
Some molecules do NOT want to hydrogen bond with water and therefore avoid it.
Think oil & water
Some amino acids act this way

30. Hydrophilic = Polar
Some substances with partial or full charges like to interact with water (hydrogen bond) and tend to mix with it.
Some amino acids behave this way.

31. Proteins form different levels of structure
These determine the overall 3-D shape of the protein

32. Primary Structure
Order of Amino Acids

33. Secondary Structure How the protein folds due to hydrogen bonding
Usually a helix or pleats

34. Tertiary Structure
How the protein folds due to disulfide bonds, charges (negative & positive)and hydrophobic/hydrophilic(nonpolar & polar) regions

35. Quaternary Structure
More than one polypeptide coming together.

36. AMINO ACID SEQUENCE DETERMINES PROTEIN STRUCTURE AND FUNCTION
Remember, Remember!
AMINO ACID SEQUENCE DETERMINES PROTEIN STRUCTURE AND FUNCTION

37. Proteins Called Enzymes
Enzymes are special proteins that speed up reactions (this is called a catalyst).
Enzyme names end is “-ase”
There are many enzymes in the body that do jobs like speed up digestion. Every process going on in your body = METABOLISM

38. How Enzymes Work
In order for an enzyme to work, it needs to attach itself to a substrate like a puzzle piece (lock & key).
A specific reactant acted upon by an enzyme is called the enzyme's substrate.
The substrate fits into a particular region of the enzyme, called the active site.

39. Examples of Enzymes Salivary amylase Catalase Sucrase
In spit, helps to break down food
Catalase
Breaks down peroxide in to H2O and O
H2O2  H2O + O
Sucrase
Breaks down sucrose into simple sugars

40. Enzymes Continued Enzymes help to maintain homeostasis in the body
They make sure that all the reactions happen AND that they happen at the right time
If enzymes become heated too much or too little OR if they are put into and acidic/basic solution, they will denature
Not work as well!