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

2. Molecules of Life Biology is the study of life
Bio- “life”, -ology “study of”
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?
Which is bigger? Molecules or cells?

4. Molecules of Life
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

5. Molecules of Life
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.

6. Molecules of Life 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 molecules (represented by the letter “H”) and one oxygen molecule (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.

7. Molecules of Life
Practice- what could be the formula for the models below?

8. CHALLENGE! What is the formula for this model/molecule?

9. Molecules of Life Bonds-
The force that holds two atoms together represented by a line between two letters or other symbol in a drawing of a molecule
Circle the bonds in your notes!!

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

11. Inorganic vs. Organic
Inorganic molecules do not contain the element carbon
Water (H2O)
Organic molecules contain the element carbon
Example: Carbohydrates, Lipids, Proteins, Nucleic Acid
Exception: carbon dioxide (CO2) and carbon monoxide (CO)

12. 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

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

14. 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

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

16. 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

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

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

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

20. 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.

21. 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

23. Proteins Composed of CHON (carbon, hydrogen, oxygen, nitrogen)
Made of small units (monomers) called amino acids.
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

25. Protein When trying to identify a protein look for: central carbon
the COOH
the NH
and the R

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

27. CHALLENGE
Does the picture represent dehydration or hydrolysis?

28. Lipids Composed of CHO (carbon, hydrogen, oxygen)
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
Steroids

29. 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

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

32. 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

33. Nucleic Acids Nucleotides: Phosphate
5 carbon sugar (deoxyribose in DNA, ribose in RNA)
Nitrogen Base (Adenine, Thymine, Guanine, Cytosine)

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

35. Nucleic Acids Contain genetic information
More details about DNA and RNA later!