1. Quiz
6. The ability of water molecules to store large amounts of energy in their hydrogen bond networks is called:
Specific heat
Adhesion
Surface tension
Cohesion
7. Which of the following solutions has the most H ions (protons) “hopping” into solution?
pH of 6
pH of 8
pH of 7
pH of 4

2. Unit 2 quiz continue today: 2.3 Homework: Reading: 2.3
Updates:
Unit 2 quiz continue today: 2.3
Homework:
Reading: 2.3
quiz continues tomorrow review 2.3

3. Quiz
Which of the following best describes the chemistry of lipid molecules in general:
Contains many oxygen atoms
Hydrophilic
Contains many nonpolar C-H bonds
Dissolves in water
9. Carbohydrates and lipids differ in several ways including:
Carbohydrates dissolve in water
Lipids do not have a monomer/polymer organization
Carbohydrates are used for an energy source
Both a and b are correct.

4. Key terms – protein, amino acid, polypeptide, fold
LEQ: What is a protein?
Activator: foldit
What are proteins?
How can identifying the structure of proteins contribute to curing diseases?
Would you play a video game, even if it meant learning something? Share with your neighbor: why or why not?
Key terms – protein, amino acid, polypeptide, fold

5. Proteins are life’s answer to “technology.”
Proteins are biological molecules:
Monomer/polymer chem.
20 standard monomers!
Some over 1,000 monomers long
Proteins can be multi-part
Hemoglobin (right)

6. Proteins are made from “essential” amino acids and rxns.
Monomer: amino acid
Common structure, unique “R” groups
below: general amino acid structure
Proteins are the molecular machines of cells and like carbohydrates, these molecules consist of subunits
The monomer of a protein is an amino acid (above, left). Amino acids are characterized the presence of an amino group (-NH2), a carboxylic acid (-COOH) and a variable R-group covalently bonded to a central carbon atom. The R-group can be understood as a variable where a combination of atoms can be substituted to change the chemical identity and nature of the amino acid.
Serine (above, right) has a chemistry that makes it polar due the presence of oxygen and hydrogen (-OH, hydroxyl group) in place of “R”. This also makes this particular amino acid hydrophilic and it readily dissolves in water and is free to interact with water proteins that include it.

7. Discussion: Comets Deliver Amino Acids to Earth?
Discuss and answer: what did scientists discover when analyzing the comet samples from the Stardust mission? How did this lead to a theory that comets may have played a part in the development of life on Earth?
Does this mean life might have originated in space, on earth, either/neither? Cite some points that support your argument.

8. R-groups: the chemical identities of amino acids
Glycine Alanine

9. Modeling Example: serine, glycine, and alanine
What makes serine hydrophilic?
How is it similar to/different from other amino acids?

10. Polypeptides consist amino acids linked by peptide bonds
Amino acids can be covalently bonded together by joining the amino group of one amino acid to the carboxyl group of an adjacent amino acid. The resulting peptide bond is strong, stable covalent bond that will support the structure of a protein.
Since there are over 20 amino acids that can be incorporated into a polypeptide, proteins have the potential to store information. Consider all of the possibilities in constructing words using just 26 letters in our alphabet. There is a similar amount of chemical diversity in structure and function that can be generated using amino acids.

11. Strong C-”X” bond breaking or forming?
Energy in or energy out of reaction?
Endothermic or exothermic

12. Modeling polypeptide primary structure: G-A-S

13. Polypeptides differ in number and order of amino acids.
characteristic sequence of every macromolecule
changes in sequence alter structure/function

14. Polypeptides can bend and fold, permitting the R groups of an amino acid to interact with the R group of an amino acid many positions away. In the above image, the dotted lines indicate the formation of hydrogen bonds between polar R-groups creating loops and folds. This is the first step in higher order structure emerging from a sequence of amino acids. This shape will be critical to the function of this molecule.

15. Folds from H-bonds enable structure to function
changes in amino acids alter structure/function

17. Summary Questions
What is the relationship between an monomer and a polymer? Use amino acids and polypeptides as an example.
What distinguishes the chemical organization of proteins from carbohydrates? Explain.

18. HW: unit guide 2.5 # 1- 5 due Friday reading 2.5
Updates:
Unit 2 quiz 2: 32.1, 2.1, 2.4, 2.2, 2.3
Homework:
HW: unit guide 2.5 # 1- 5 due Friday
reading 2.5
Unit 2 Test: Tuesday 2/24

19. Lipids, carbohydrates and proteins all have:
a. Carbon-based CHNOPS chemistry
b. hydrophobic properties
c. polar covalent bonds
d. monomers

21. Unit 2 quiz continue today: 2.3 Homework: Reading: 2.3
Updates:
Unit 2 quiz continue today: 2.3
Homework:
Reading: 2.3
quiz continues tomorrow review 2.3

22. Quiz
Which of the following best describes the chemistry of lipid molecules in general
Contains many oxygen atoms
Hydrophilic
Contains many nonpolar C-H bonds
Dissolves in water
9. Carbohydrates and lipids differ in several ways including:
Carbohydrates dissolve in water
Lipids do not have a monomer/polymer organization
Carbohydrates are used for an energy source
Both a and b are correct.

23. Unit 2 quiz continue today: 2.3
Updates:
Unit 2 quiz continue today: 2.3
Takehome essay practice: water due Monday
Homework:
Reading: 2.5
quiz begins Tuesday 2.3
Unit 2 test Thursday!

24. Quiz
10. Which of the following chemicals has a monomer chemistry consisting of amino acids?
Proteins
Lipids
Carbohydrates
Nucleic acids
11. Which of the following is the major difference between the chemistry of lipids and proteins?
Lipids have a monomer/polymer chemistry
Lipids are hydrophilic
Proteins have a monomer/polymer chemistry
Proteins are a nutrient and lipids are not.

25. Quiz
The presence of many oxygen atoms and the formation of H-bonds in carbohydrates and proteins make their chemistry:
Polar and hydrophilic
Nonpolar and hydrophobic
Acidic
Neutral or basic

26. LEQ: What is genetic information?
Activator: KWL
What do you know about DNA?
What do you want to know about DNA?
Share with your neighbor and add to board
Key terms – nucleic acid, nucleotide, DNA, RNA

27. Nucleic acids share a monomer/polymer chemistry
Monomer: nucleotides
Multi-part (see below):
Hydrophobic/hydrophilic?
Nucleotides are different from monosaccharides and amino acids because they are multi-part. Each consists of:
A phosphate group
A 5-carbon sugar (deoxyribose or ribose; the “D” and “R” in DNA and RNA, respectively).
A nitrogen-containing base (polar and perfect for hydrogen bonding)
The order of these bases is how the genetic information of a cell is encoded.

28. The nitrogen containing bases are the only difference in the four nucleotides.

29. What are nucleic acids made of?
CHNOPS…
Common bonds/groups of atoms
Parts!

30. Modeling: Build a base pair of your choice
A/T or G/C
Align molecules so they correctly hydrogen bond
Video:

31. Polynucleotides (left) have a unique sequences of bases:
Directionality (just like proteins) 5’ end, 3’ end
The figure on the right adds some important details and examines DNA once again. DNA consists of two polynucleotide strands of characteristic sequences and they also reveal the essential relationship between the 4 bases used to encode genetic information: A pairs with T; C pairs with G.

32. Explain how nucleic acids, carbohydrates, and proteins are all polymers.

33. Nucleic acids: RNA and DNA
What are they major differences?
The information in proteins is ultimately encoded in the nucleic acids found in cells. Cells contain two types of nucleic acids:
RNA – which has many jobs inside a cell including protein synthesis, performing some specialized chemical reactions, and controlling the use of genes.
DNA – which stores the biological information necessary to produce RNA and proteins.

34. DNA* stores biological information for building proteins
DNA encodes the info for making RNA, proteins
Cell processes make proteins from RNA
Letters
Sequence
Diversity
Alphabet 26
MESSAGES…
268 = 2.1 x1011
DNA nucleotides 4
GATCATAC…
48 = 65,536
Amino acids
20 standard
Gly – Val – Asp…
208 = 2.56 x 1010

35. What is the relationship between proteins and nucleic acids?
What ultimately determines the structure and function of an RNA molecule and a protein?

36. Explore: Build a DNA molecule
Model construction: Build a base pair of your choice
A-T
G-C
What made it less likely that DNA samples could be taken from Ötzi? What made it more likely that they could?
Why do you think modern humans need to develop a tolerance to lactose?

37. Summary:
Explain how both nucleic acids and proteins are polymers. Be sure to describe the monomers that make up the polymers.