Ch. 4 - Biological Molecules

Carbohydrates, Protein, Lipids

Carbohydrates are made of up simple sugars (e.g., Glucose) Primarily composed of Carbon, Hydrogen and Oxygen Simplest forms are known as monosaccharides - glucose Two are known as disaccharides Multiple form polysaccharides - glycogen, starch, cellulose

Proteins are made of up amino acids Primarily composed of Carbon, Hydrogen, Oxygen, and Nitrogen

Fats/Lipids are made of up fatty acids and glycerol Primarily composed of Carbon, Hydrogen and Oxygen

Iodine Test Reagent: Iodine solution (iodine in potassium iodide). Method: Take 2 ml of test solution. Add a few drops of iodine solution. Observe color change. Result: Positive: Blue-black color (starch present). Negative: Solution remains yellow-brown (no starch).

Benedict’s Test Reagent: Benedict’s solution Method: Take 2 ml of test solution. Add 2 ml Benedict’s reagent. Heat in boiling water bath for 2–5 minutes. Observe color change. Result: Positive: Green → Yellow → Orange → Brick-red (depending on sugar concentration). Negative: Remains Blue.

Biuret Test Reagent: Biuret reagent Method: Take 2 ml of test solution. Add 2 ml of Biuret reagent. Mix well. Observe color change. Result: Positive: Violet/Purple color (protein present). Negative: Solution remains Blue (no protein).

Ethanol-Emulsion Test Reagent: Ethanol + Water. Method: Take 2 ml of test solution. Add 2 ml of ethanol and shake well. Add 2 ml of distilled water. Observe for emulsion. Result: Positive: White/milky emulsion forms (lipids present). Negative: Solution remains clear (no lipids).

DCPIP Test Reagent: DCPIP solution (blue dye). Method: Take 2 ml of DCPIP solution in a test tube. Add test solution drop by drop. Shake gently after each drop. Observe color change. Result: Positive: Blue color of DCPIP decolorizes (Vitamin C present). Negative: Blue color remains (no Vitamin C).

Deoxyribonucleic acid 1. Double helix shape 2. Building block is nucleotide - sugars, nitrogenous bases and phosphate A - two hydrogen bonds - T G - three hydrogen bonds - C

• Determines the sequence of bases • Determines the sequence of amino acids that make up protein • Determines the proteins to be made, which result in the changing or determining of a phenotype

Magnification - how many times larger an image is from the original formula: size of image/size of actual object