Testing For Macromolecules

Lipids

Lipids: Structure Lipids are made up of… There is no monomer Lipids are composed of: 1 molecule of glycerol 3 fatty acids Phospholipids 2 fatty acids 1 phosphate group

Lipids: Structure* Properties of Lipids caused by: Saturated vs. Unsaturated fatty acids Polar head and nonpolar tail regions (phospholipids) Hydrophilic and hydrophobic regions

Lipids: Function Make up the cell membrane, providing cell structure Provide insulation (fat keeps body warm) Long-term energy storage

Lipids: Food Sources As you might have guessed, fatty foods contain lipids. Lipids are found in meat and fish, oils, avacados, eggs & nuts.

Lipids: Indicator Test Paper Bag Test: Smear substance onto paper bag If see-thru, it contains lipids

Proteins

Proteins: Structure Proteins are made up of… Monomer (basic unit): amino acids 20 different kinds!* Polymer (chain of units): protein More specifically- polypeptides dipeptide Amino acids linked by peptide bonds

Proteins: Structure* 20 Amino Acids: Some of these are polar & hydrophilic, others are non-polar and hydrophobic. Proteins can contain both kinds.

Proteins: Structure Proteins have complex structures. The shape of a protein determines its function!

Proteins: Function Enzymes- proteins that speed up chemical reactions Hemoglobin: protein within red blood cells that binds oxygen Insulin: protein that regulates glucose levels in the blood stream

Proteins: Denaturation Denaturation: the unfolding of a protein that results in loss of function Causes: extreme pH or temperatures

Proteins: Food Sources Proteins are found in meat, fish, legumes, nuts, milk, eggs, grains and soy products. There are 6 amino acids that our bodies cannot make- we can only get these from food.

Proteins: Indicator Test Biuret’s Solution: Turns from blue to purple if protein is present

Carbohydrates

Carbohydrates: Structure Carbohydrates are made up of… Monomer (basic unit): simple sugars (or monosaccharides) Ex.: glucose Disaccharide: 2 monosaccharides covalently bound together. Ex: Maltose, Sucrose, Lactose Polymer (chain of units): complex carbohydrates (or polysaccharides) Ex.: starch, cellulose, glycogen

Carbohydrates: Function Provide body with energy! What should you eat before playing the big game? Candy bar or pasta? Candy bar: contains simple sugars, provides a short burst of energy Pasta: contains starch which takes longer to break down, provides longer-lasting energy *We can’t digest cellulose- it is used as fiber, or roughage instead. Ex. : corn Complex carb (ex. Starch) Broken down to disaccharides Broken down further Simple sugars (ex. Glucose)

Carbohydrates: Food Sources Simple carbs (simple sugars) are found in most candy and sweet drinks, fruit, vegetables, and milk. They are quickly digested and give a short burst of energy. Complex carbs (like starches) are found in pasta, bread, potatoes, legumes & corn. They take longer to digest, and provide energy longer.

Carbohydrates: Indicator Tests Simple Sugars: Benedict’s solution Blue solution turns orange/green/brown Complex Carbs: Lugol’s solution/Iodine Turns from orange-red-brown to black-purple

Nucleic Acids

Nucleic Acids: Structure Nucleic Acids are made up of… Monomers (basic unit): nucleotides Nitrogenous Base: A, T/U, C, G Phosphate group 5-Carbon Sugar: deoxyribose (DNA) Ribose (RNA) Polymers (chain of units): DNA or RNA

Nucleic Acids DNA vs. RNA

Nucleic Acids: Function Stores and transmits genetic information

Nucleic Acids: Food Sources We get nucleic acid components from vitamins and minerals in our diet. These in turn, come from fruits, vegetables, grains, meats, & almost anything else you can think of with some nutritional value (no junk food!).

Digestion & Reconstruction When macromolecules are eaten, they are digested and broken down into their subunits (monomers). Analogy: taking apart an old brick building Inside the cells, these subunits are reconstructed into the macromolecules we need. Analogy: using bricks to build a new building

Digestion Products Macromolecule eaten: Broken down in stomach to: Carbohydrates Simple sugars (i.e. glucose) Lipids Fatty acids & glycerol (glycerol further broken down to glucose) Proteins Amino acids Nucleic Acids Nucleotides