digestion (march 11)

change of insoluble (non dissolvable) large molecules to soluble small molecules

large insoluble small soluble

carbohydrate ————→ simple sugar

proteins ——————→ amino acid

lipids ———————→ fatty acid

nucleic acid ————-→ nucleotide

the digestive system: group of organs work together to change large insoluble to small soluble.

there are 2 types of digestion:

1. mechanical (changing the size) : cutting smashing grinding chewing crushing.

2. chemical: breaking down food into smaller molecules using enzymes and acids, allowing nutrients to be absorbed into the bloodstream. (enzymes can be changed by temperature and ph)

digestive systems:

1. main organs (the organs which the food go through): mouth, oesophagus, small intestine, large intestine

2. accessory organs (the organs which the food dong go through but still effect it): salivary glands, liver, gallbladder, pancrease

1. mouth:

   • has 2 types of digestion mechanical (chewing) and chemical (saliva)

   • mouth has a ph of 6.5-7

   • food + saliva = bolus

   • the mouth produces amylase

2. oesophagus:

   • connects the mouth and stomach

   • has a flap like thing called epiglottis preventing the food (bolus) from going down the windpipe.

3. stomach:

   • breaks down protein to amino acid

   • acid→gastric juice→ hydrocloric acid (HCL) kills bacteria

   • chyme → partially digested food.

4. small intestine:

   • length of 7m

   • blood capillaries absorb nutrients from the digested food, which are then transported to the liver for processing.

   • thinnest blood vessel

   • villi: tiny, finger-like projections that increase the surface area for absorption of nutrients.

   • microvilli: even smaller projections on the surface of villi that further enhance nutrient absorption by providing an extensive surface area.

     

5. large intestine:

   • absorption ← excess food into solid waaste

   • microbes = useful

   • E.coli ← useful bacteria

accessor organs:

pancreas→ insulin→ control the blood sugar level

diabetic:

1. pancreas stop produsing insulin

2. body stop responding to insulin

Enzyme:

1. slaiva (6.8-7 ph)

sliva is water mucus and digestive enzymes

• salivary amylase : An enzyme that breaks down starches into sugars, initiating the digestive process in the mouth.

• lingual lipase : An enzyme secreted by the salivary glands that begins the digestion of fats in the mouth, although its activity is more pronounced in the stomach.

• lysozyme: An enzyme that helps to break down bacterial cell walls, providing an antibacterial function in the oral cavity.

carbohydrate → carbohydrase

protien → protase

lipid→ lipase

nucleic Acid →nuclease

2. stomach (1.5-3.5)

• gactric juice is HCL and pepsin

• pepsin changes protien into amino acid by breaking the polypeptide bond

3. pancreas

• amylase: strach → Monosacharid

• lipase: lipid → fatty acids and glycerol.

• trypsin: protein → amino acids.

• nuclease: nucleic acids → nucleotides.