Biomolecules

Texas Expected Knowledge and Skills (TEKS) 9A – Compare the functions of different types of biomolecules, including carbohydrates, lipids, proteins, and nucleic acids.

Biomolecule: Any molecule that is present in living organisms. Ex: Carbohydrates, Lipids, Nucleic Acids and Proteins

Levels of organization Carbohydrates, proteins, lipids, and nucleic acids!!!! Levels of organization Biomolecule

Compound: a thing composed of two or more separate elements (such as carbon, nitrogen, oxygen etc.) Organic Compound: most compounds that contain carbon and are found in living organisms

Four Classes of Organic Compounds: Carbohydrate Lipid Protein Nucleic Acid

Monomer vs Polymer Monomer-single unit Polymer: many single units joined together Example: A brick house: the brick is the monomer; the house is the polymer

Dehydration Synthesis / Hydrolysis Dehydration Synthesis: removing water to form polymers. Hydrolysis: adding water to break down polymers into monomers

Class demonstration of dehydration synthesis and hydrolysis 3 student volunteers Blue piece of paper shaped like a water drop Using a blue piece of paper shaped like a water drop. Three students individually represent a monomer. Have students link arms by the elbows to create a polymer. Using the blue paper, add the water between their elbows to break the bond and create monomers. Remove water from the area and have them re-link their arms. I also use the description of oatmeal. If you add a bunch of water to your bowl of oatmeal, the little pieces of oats will all float apart and separate into “monomers” but if you could snap your fingers and remove the water, it would clump together like a polymer. You can use mud/sand as an example too.

https://youtu.be/YO244P1e9QM

Carbohydrates Monomer: Glucose, monosaccharide, simple sugar Elements: C H O (carbon, hydrogen, oxygen) Functions in living organisms: “Quick” energy – main source of energy, short term energy Examples: glycogen, glucose, starch Memory Helpers: Saccharides – “sack of sugar” “Ring pop” sugars have a ring structure of CHO End in “ose” most of the time (i.e. glucose, sucrose, galactose)

Lipids Monomer: Triglyceride = glycerol + 3 fatty acids Elements: C H O (carbon, hydrogen, oxygen) Functions in living organisms: Long term reserve energy, main component of cell membranes, Insulation & organ protection (fat) Examples: fat, wax, cholesterol, oil, steroids Memory Helpers: CHO in a chain like a chain of “fatty bacon”

Proteins Monomer: amino acid Elements: C H O N (S) (carbon, hydrogen, oxygen, nitrogen, sulfur) Functions in living organisms: Muscle, enzymes, cell structure, transport Examples: Enzymes Memory Helpers: Bonded by peptide bonds – “peppy proteins” Protein

Nucleic Acids Monomer: nucleotide Elements: C H O N P (carbon, hydrogen, oxygen, nitrogen, phosphorus) Functions in living organisms: Stores genetic information which codes for traits Examples: DNA, RNA, ATP

Enzymes = Proteins Enzymes accelerate, or catalyze, chemical reactions No living organism can function WITHOUT Enzymes Enzymes: 1. Build molecules: Synthesis Enzymes 2. Break Down Molecules: Digestive enzymes 3. Speed up reactions: Catalysts 4. Lowers activation energy

What is an enzyme? Proteins found within cells that are reusable and help speed up reactions. Substrate – the substance upon which an enzyme acts. Ex. Enzymes break down or build up substrates (other monomers or polymers needed by the body)

Enzymes = Proteins Activation energy – the amount of energy it takes to get a reaction started. Enzymes LOWER the activation energy! Reactions happen faster with enzymes present.

Enzymes are substrate-specific! Two theories: Lock and Key: the active site of an enzyme is precisely shaped to hold specific substrates Induced-fit: the active site and substrate don't fit perfectly together; instead, they both alter their shape to connect.

Lock and Key Theory To function, the enzyme needs to be the right shape for the job.

Enzymes are reusable but… Two things can affect the enzyme action. Temperature pH If the temp. and pH is too extreme the enzyme will denature. Denature: permanently change the shape of the enzyme. Will no longer work! A 3D model of pepsin, an enzyme that digests food proteins into peptides

Enzymes Enzymes are named for the reaction they help, and often end in “ase” sucrase breaks down sucrose proteases breakdown proteins lipases breakdown lipids DNA polymerase builds DNA Notice that the end of each enzyme name says “ase.” This will be a clue in the future to know that you’re dealing with an enzyme, and therefore, a protein!

Key Points on Enzymes Enzymes are substrate-specific Enzymes are reusable Enzymes are proteins Each enzyme works best at a certain pH and temperature Enzymes can be denatured by pH and temperature