Biology - Digestive system, Breaking down food, Enzymes

Mechanical Digestion

Physical action that makes chunks of food smaller

Chemical Digestion

Enzymes converting insoluble molecules into soluble molecules

Hydrochloric acid

Destroys micro-organisms in contaminated food, Lowers the pH allowing enzymes to function as optium rate

Bile

Produced in the liver, it is Alkaline which neutralises the stomach acid as food enters the duodenum

Bile Emulsification

Bile emulsifies fat to form small droplets, increasing the surface area and suspending them in water

Where Mechanical Digestion occurs

Oesophgus

Where both types of digestion occurs

Mouth, Stomach

Where Chemical Digestion occurs

Small intestine, Pancreas

Muscular tissue

Contracts and relaxes to allow Mechanical Digestion

Glandular Tissue

Releases Hydrochloric acid and enzymes for Chemical Digestion

Adaptions of Small Intestine

Long in length to to increase time for absorption

Villi & Microvilli

Increases surface area for absorption, Thin, Short diffusion pathway, Good blood supply to increase concentration gradient for diffusion

Glucose - Color change

Benedicts solution, Red to Blue

Equipment for Glucose

Benedict’s solution, pipette, test tube, water bath, thermometer

Starch - Colour change

Iodine solution, brown/orange to blue/black

Equipment for Starch

Iodine solution, pipette, spotting tile

Protein - Color change

Biuret Solution, blue to lilac

Lipids - Color change

Ethanol & Water, colorless to milky-white emulsion

Equipment for Lipids

Ethanol & Water, test tube, test tube rack

Enzymes

Each Enzyme has a specific shape, with a complementary substrate forming an Enzyme Substrate Complex

Amylase

Turns into Glucose

Protease

Amino acids

Lipease

Fatty acids + Glycerol

What happens to Enzymes that are at extreme pHs

Denatures so the substrate can no longer bind to the active site

Enzyme catalyst

speeds up chemical reactions