1. Chemistry Review for Biology
Pre-1.9
Chemistry Review for Biology
Learning Objectives:
State the name and relative locations of subatomic particles
State that bonds are interactions between atoms due to electrons
Differentiate between chemical bonds in terms of why they occur and relative strength

2. Chemistry Basics Can either be created or destroyed?
Chemistry is all about Energy and Matter
Can either be created or destroyed?
Can be converted into other forms
Everything is made of matter
An atom is the smallest unit of an element
Has all of the properties of that element
Electron cloud (Electrons) + Nucleus (Protons + Neutrons) = Atom
# of protons (+ charge) = # of electrons (- charge)
Atoms are held together by chemical bonds to make larger matter (called “molecules”)
Chemical bond = potential (stored) energy
Living things break and build bonds

3. Bonding Basics
Covalent Bonds: atoms share electron pair(s) to form molecules.
Atom bonded to Atom(s) forms a molecule (AKA “covalent compound”)
Strongest of the bonds; it is a physical bond
All organic molecules are held together this way!
Ionic bonds: between ions to form ionic compounds
Ions: atom with a charge due to loss or gain of electrons
Weaker; not a physical bond, just an attraction due to charge!
Hydrogen bonds = weak attraction due to slight difference in charge
not a real bond
not as strong as ionic bonds or covalent.
The reason some molecules stick together

4. Questions: Which subatomic particle is involved with bonding?
Which bond type is strongest?
If energy is to be stored for later, would a covalent bond be built or broken in order to store that energy? (would you build a larger molecule or break down a large molecule into smaller ones?)
If an atom gains an electron what charge does it now have as an ion?
Which ion charge is it attracted to form an ionic bond/compound?

5. Which 4 elements are most common in organic molecules?

6. 1.9 Significance of Carbon
Learning Objectives:
Explain why carbon is essential to life on Earth
List the four major types of organic compounds/molecules
Name the monomers of carbohydrates, proteins and nucleic acids
Identify the main functions of the four major types of organic compounds/molecules

7. Intro Organic Chemistry
The chemistry of life
4 major elements: CHON (PS)
Based on Carbon
Why is carbon special?
Forms 4 covalent bonds (4 valence e-)
Bonds with itself
Can form a wide variety of molecules/compounds (sizes and shapes)

8. Define Organic Molecule
An organic molecule (AKA “covalent compound”) has C-C and/or C-H bonds and is found in and/or made by living things
QUESTION: Which of the following is organic?
CH4
H2O
C6H12O6
CO2

9. Organic Terminology Large organic molecules
Polymer = large molecule made of repeating smaller units
Monomer = the smaller subunit of a polymer; small molecule
Macromolecule = large molecule made of smaller subunits that may be different from each other
4 major classifications of organic macromolecules:
Carbohydrate Nucleic Acid
Lipid - Proteins

11. 1.10 Carbohydrates Carbohydrates play a key role:
as a source of basic energy
some are a source for structure

12. 1.10 Carbohydrates
Composed of C, H, and O in a 1:2:1 ratio (1 C, 2 H, 1 O = (CH2O)n)
Monosaccharides are the monomers
“simple sugars”
quick energy
ex: Glucose
Disaccharides = 2 monosaccharides covalently bonded
ex: Sucrose (glucose bonded with fructose)

13. 1.10 Carbohydrates Polysaccharides = 3+ monosaccharides bonded
“complex carbs”
Provide structure, energy storage
Starch, cellulose, chitin, glycogen
All are polymers of glucose…which are used by plants, animals?

14. 1.10 Carbohydrate Review Carbohydrates play a key role:
as a source of energy
Monosaccharide glucose for quick-use energy
Stored as polysaccharide glycogen (animals) or starch (plants)
4 calories/gram
some are a source for structure
Polysaccharide cellulose makes up cell walls in plant cells
Polysaccharide chitin makes up exoskeletons

15. 1.11 Proteins Monomers = amino acids
made of C, H,O,N and sometimes S
Roughly 20 types (different R group in each)
Covalent bonds between amino acids are called “peptide bonds”
When peptide bonded = “polypeptide”
primary structure = sequence of amino acids in the polypeptide
Secondary/tertiary structure = 3d shape of folding due to +/- interactions between the amino acids in the polypeptide

16. 1.11 Protein function
Determined by: amino acids sequence and folded shape
The sequence of amino acids is determined by an organisms DNA!
Uses to life:
Enzymes (make reactions go faster!), antibodies (immunity!), pigments, signals (caries messages!), animal structure (makes up muscles, skin and hair!), energy to a degree (though not as readily available as carbs and lipids)…so almost everything

17. 1.11 Protein Examples Essential amino acids: you must eat them!
Lipase: enzyme that helps digest fat
Hemoglobin: in red blood cells to carry oxygen and CO2
Collagen: resilient skin and bones

18. 1.12 Lipids Made of C, H, O Non-polar/”hydrophobic” (HATE water!!)
Made of a glycerol molecule and at least one long fatty acid tail
No double bonds in tail(s) = saturated fatty acid = carbons are saturated with hydrogens
Have double bond(s) in tail(s) = unsaturated fatty acid = there are double bonds between the carbons, so not as many hydrogens

19. 1.12 What are the Types of Lipids?
Fats Oils Waxes Steroids

20. 1.12 Lipid Categories and Functions
Triglycerides: Common lipid with 3 fatty acid “tails”
Called fat (made of saturated fatty acids) if solid at room temp, oil (unsaturated fatty acids) if liquid at room temp
Function: long-term energy storage (provide 9 cal/gram of energy!), insulation
Phospholipids have 2 fatty acid tails and phosphate “head”
Function: main component of cellular membranes
Waxes have one fatty acid
Function: waterproofing
Steroids
some hormones (regulation of processes)
Cholesterol (another part of cell membranes)

21. Essential fatty acids = must eat them!
Saturated
1.12 Lipids in Diet
Unsaturated
Essential fatty acids = must eat them!

22. 1.13 Nucleic Acids Store and transmit genetic information.
DNA, RNA
Made of monomers called nucleotides, composed of C, H, O, N, P

23. Nucleic Acid Basics Monomer = Nucleotide Polymer = Polynucleotide
Polymer Examples =
DNA, RNA
Elements =
CHONP

24. Nucleotide
3 parts:

25. DNA
Double Helix

26. DNA vs. RNA 2 strands 1 strand Thymine Uracil
Deoxyribose sugar Ribose sugar
protein blueprint/genetic code communicates genetic info/
assembles proteins