1. Molecules of Life Introduction Reading Models Carbohydrates Lipids
Proteins
Nucleic Acids

2. Introduction to Biology:
Read Chapter 1, section 1.2
Biology is the study of life.
Living things are called organisms.
Bio- “life”, -ology “study of”

3. All organisms on Earth share certain characteristics.
Cells: All organisms (so all living things) are made of cells.
Need for energy: All organisms need a source of energy to carry out life processes. Energy is important for metabolism, which is all the chemical processes that build up or break down materials.
Response to environment: All organisms must react to their environment to survive
Reproduction and development: Species must have the ability to produce new individuals passing on their DNA (genetic material) to their offspring. ALL organisms (from bacteria to plants to animals) have DNA.

4. All organisms have systems of related parts.
All living things are made of cells
Cells are made of molecules
Molecules are made of atoms
Atoms are made of protons, neutrons and electrons
Which is smaller? molecules or atoms?
atoms
Which is bigger? Molecules or cells?
cells

6. Chemistry of Life Read Ch. 2 ALL sections 2.1-2.5.
Section 2.2 and 2.3 are the most important.
Section 2.5 will be covered in more detail later this year.

7. Models:
We often represent very small structures or very large structures with idealized models or even symbols to make our study of science easier.
Which of the 3 is the biggest in real life?
Earth Layers Model DNA Model Model of an Animal Cell

8. In science, when looking at atoms, we often seen them drawn out with symbols and/or alphabet letters
These 3 pictures are all models of a molecule of water.
Compare (how are they the same) and contrast (how are they different) the models.

9. The formula for water is H20
We can simplify this even more by just writing the formula for the molecule without representing the bonds holding them together at all.
The formula for water is H20
This means there are two hydrogen atoms (represented by the letter “H”) and one oxygen atom (represented by the letter “O”)
Note: we do not put a “1” with the oxygen because it is understood. Anything other than “1” we record. + -

10. Water’s unique properties allow life to exist on earth.
Water is polar due to its regions of slight + (positive) and – (negative) charges.
Water has a high specific heat which helps regulate temperature in organisms.
Water exhibits cohesion and adhesion.
Water is often the solvent of many solutions.
Solvent—the substance that is present in the greater amount that dissolves another substance.
Solute—the substance that dissolves in a solvent.

11. Pure water has a neutral pH of 7
Pure water has a neutral pH of 7. Rain water is slightly acidic with a typical pH of 5.6
pH stands for pondus hydrogenii meaning “potential hydrogen”
pH scale measures the concentration of hydrogen ions in solutions; scale 0-14
0-6.9 is acidic
7.0 is neutral
is basic or alkaline
Most organisms, including humans, overall need to maintain a pH around neutral; however, certain organs and organelles inside our bodies operate at different pHs.

12. pH scale

13. Bonds-
The force that holds two atoms together represented by a line between two letters or other symbol in a drawing of a molecule.
Energy is needed to break bonds and is released when bonds are broken.
Circle the bonds in your notes!!

14. Molecules of Life
All living things are composed of the following basic elements:
Carbon
Hydrogen
Nitrogen
Oxygen
Phosphorous
Sulfur
Remember “CHNOPS”

15. Inorganic vs. Organic
Inorganic molecules do not contain the element carbon
Water (H20)
Organic molecules contain the element carbon
Example: Carbohydrates, Lipids, Proteins, Nucleic Acid
Exception: carbon dioxide (CO2) and carbon monoxide (CO)

16. Monomer vs. Polymer Monomer- Polymer Mono = one, mero = part
A molecule that can bind to other molecules to form a polymer
Polymer
Poly = many, meros = parts
A large molecule that contains many molecules
A large molecule made of smaller, molecules of the same type (monomers) linked together.
A protein (the polymer) is made of many amino acids (monomers)
Monomer
Polymer

17. Monomer vs Polymer
Think of a monomer like a puzzle piece and a polymer is the whole puzzle

18. Monomer vs. Polymer Monomers are hooked together by chemical bonds
A Polymer can be broken back down into monomers
When using water to BREAK bonds
Hydrolysis (“hydro”- water, “lys”- to split)
Start with one large polymer
End with 3 smaller monomers

19. Monomer vs Polymer Monomers can be linked together to form a polymer
When using water to LINK bonds
Dehydration (“de”- to remove, “hydro”- water)

20. Molecules of Life Living things have four basic carbon compounds:
Carbohydrates
Sugar, starch, cellulose
Proteins
Meat, fish, nuts
Lipids
Fats, waxes, steroids, chlorophyll
Nucleic Acid
DNA or RNA
These are the four general molecules we will study in Biology

21. Molecules of Life
Proteins
Lipids C H N O P
Carbohydrates
Nucleic Acid

22. Carbohydrates
Composed of CHO (Carbon, Hydrogen and Oxygen) in a 1:2:1 ratio
Examples: Sugar and Starch
Carbohydrates provide energy
Most sugars end in “-ose”, fructose, glucose, sucrose, cellulose

23. Carbohydrates Glucose (C6H1206 )- Is it a sugar or a starch?
Is a carbohydrate
Is it a sugar or a starch?
sugar
C6H1206 is the basic “fuel” in all living things, produced during photosynthesis
The pictures below are models of a molecule of glucose

24. Notice the C’s for carbon connected in a ring that give the molecule its general shape.
Sometimes we simplify these models even more.
The second picture is a molecule of glucose, also, but the C’s have not been drawn to simplify it.
Everywhere that 2 lines (bonds) meet represents a carbon atom.
They are numbered 1-6 to help you see them.

25. Carbohydrates Carbohydrates can be either:
1. monosaccharide- a simple, single carbohydrate (monomer)
examples: glucose or fructose
2. disaccharide- 2 monosaccharides put together (polymer)
example:
Sucrose (table sugar) = 1 glucose + 1 fructose
Maltose (malt sugar) = 1 glucose + 1 glucose
Lactose (milk sugar) = 1 glucose + 1 galactose
3. polysaccharide - numerous monosaccharides (polymer)
examples: starch, glycogen and cellulose
Starch—found in plant cells
Glycogen—how animals store carbs in muscles and liver
Cellulose—found in plant cell walls (humans CANNOT digest cellulose)

27. Proteins Composed of CHON (carbon, hydrogen, oxygen, nitrogen)
Made of small units (monomers) called amino acids.
There are 20 total amino acids that we need, our body can only make 12. From where do you think we get the other 8?
Examples:
Proteins make up muscle, skin and hair
Hemoglobin (blood) is a protein that carries oxygenated blood
Enzymes are proteins that speed of reactions in the body
Antibodies in our immune system
From the foods we eat!

29. Protein When trying to identify a protein look for: N-C-C “backbone”
central carbon
the COOH
the NH
and the R

30. Circle the components that make these amino acids (that make proteins)

31. CHALLENGE Does the picture represent dehydration or hydrolysis?
Because water is removed!

32. Lipids Composed of CHO (carbon, hydrogen, oxygen)
Monomer: 1 glycerol + 3 fatty acids
“Fat E” (typically)
Do not dissolve in water (“oil and water”)
Provide long term energy storage
Examples of lipids
Fats: acts as an insulator
Oils: some birds secrete oil to help them “waterproof” themselves
Waxes: helps plants conserve water
Steroid hormones: cholesterol, testosterone, estrogen

33. Lipids Two types of lipids: Saturated fats Unsaturated:
The carbon bonds (where the carbon molecules meet) are single, no double bonds
C-C-C-C-C-C-C-C
animal fats like butter, cream, cheese
Unsaturated:
Some of the carbon bonds are double bonded (where two bonds hold the carbons together)
C-C-C=C-C-C-C-C
Plant fats like canola oil, olive oil

35. Lipids
Phospholipids- commonly found in the membrane of cells (more on this later!)

36. Nucleic Acid
Nucleic Acids are large complex molecules containing genetic material
Contain genetic information
Made of monomers called nucleotides
Nucleotide= sugar, phosphate group, and nitrogen base
The monomers, put together, build the polymer DNA strand
Two types:
1. Deoxyribonucleic Acid- DNA
2. Ribonucleic - RNA
DNA carries instructions that regulate cells activities
RNA–uses information from DNA to make proteins

37. DNA and RNA Nucleotides have 3 parts: (label these)
Phosphate
5 carbon sugar (deoxyribose in DNA, ribose in RNA)
Nitrogen Base (Adenine, Thymine or Uracil, Guanine, Cytosine)

38. DNA Sugar- Deoxyribose Double Stranded Nitrogen Bases- RNA
Adenine
Thymine
Guanine
Cytosine
RNA
Sugar- Ribose
Single Stranded
Nitrogen Bases-
Adenine
Uracil
Guanine
Cytosine

39. ATP ATP, or adenosine triphosphate, is a special type of nucleotide.
ATP is the energy source used by cells for them to function.
Food molecules are broken down and the energy is stored temporarily in ATP until it is needed by the cell for its cellular processes.
ATP is made during cellular respiration, a process that takes place inside of cells.
C6H12O O2  6H2O + 6CO2 + ATP energy