Molecules of Life Introduction Reading Models Carbohydrates Lipids Proteins Nucleic Acids

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?

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

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.

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.

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

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

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!!

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

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)

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

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

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

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)

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

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

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

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

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.

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

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

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

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

CHALLENGE Does the picture represent dehydration or hydrolysis?

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

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

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

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

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

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

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