Biomolecules Texas Expected Knowledge and Skills TEKS 9

Biomolecules

Texas Expected Knowledge and Skills (TEKS) 9 A – 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 Biomolecule Carbohydrates, proteins, lipids, and nucleic acids!!!!

• 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

https: //youtu. be/YO 244 P 1 e 9 QM

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) 4 calories / gram of carbohydrate

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” 9 calories / gram of carbohydrate

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: 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: 1) Lock and Key: the active site of an enzyme is precisely shaped to hold specific substrates 2) 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… A 3 D model of pepsin, an enzyme Two things can affect the enzyme action. that digests food proteins into peptides 1. Temperature 2. p. H • If the temp. and p. H is too extreme the enzyme will denature. • Denature: permanently change the shape of the enzyme. Will no longer work!

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 p. H and temperature • Enzymes can be denatured by p. H and temperature