Digestion

Ingestion- eat the food Digestion- series of chemical

rxs to convert food to smaller molecules

Absorption- small molecules are absorbed through the cells of your digestive system into blood or lymphatic vessels

Transport- circulatory system delivers the small molecular nutrients to body cells

process of making food absorbable

it must be changed into simpler chemical compounds

nutrients can't be used by the body until they are absorbed into the cells & tissues

They can't be absorbed unless they are small & soluble

MOLECULAR FORM INGESTED

FORM AFTER DIGESTION

Protein Triglycerides poly, di and

monosaccharides

DNA and RNA

Amino acids Glycerol and

fatty acids Monosaccharid

es Nucleotides

Breaking food into smallest components

ex. albumin in egg whites

contain amino acid serine

needed in pancreas to produce insulin

You can think of the digestive system as two sets of structures

First set called the alimentary canal:

consists of organs that food passes through directly

it’s a one-way tube with two openings

accessory organs outside of but connected to the alimentary canal

these organs produce digestive enzymes

Liver, pancreas, gall bladder, salivary glands, etc.

Increase rate of rx at lower T° (37°C)

Lower energy of activationAmylase in salivary glands of mouth

Pepsin (a protease) in stomach cells

Lipase in pancreas cells

Salivary Amylase

Pepsin(a protease)

Lipase

Source Salivary glands

Stomach cells

Pancreas cells

Substrate Amylose (starch)

Proteins (polypeptide

s)

Lipids

Products Maltose & glucose

Amino acids Glycerol & fatty acids

Optimum pH Neutral (pH 7)

Acidic (pH 3) Neutral (pH 7)

Be able to draw and label!!!!!!!!!!

Mouth- amylase (in saliva) mechanical digestion of all

food (teeth chewing & grinding)

chemical digestion of carbohydrates begins

esophagus- passageway to stomachsmooth muscle- peristalsis

Gastric Juices:Pepsin – protease enzymeHCl – creates optimium pH for pepsin to be active & helps degrade and breakdown food

Mucus – lines and protects stomach from HCl

mechanical digestion of food (churning of stomach walls)

1st portion called duodenum Accessory organs secrete

juices:Bile – produced in liver, stored in gall bladder (emulsifies fats)

Trypsin (protease), lipase, amylase and bicarbonate from pancreas

absorption: small soluble nutrients (sugars, amino acids, fatty acids)

Contain capillaries and lacteals (small vessel of the lymph system)

Small molecules taken into capillaries, except fatty acids which are absorbed into lacteals

lacteal

inside are two types of vessels, capillaries & lacteal

the capillaries web around the lacteal

protein & carbohydrates (amino acids & simple sugars) are absorbed by capillaries

lipids (fatty acids & glycerol) are absorbed in the lacteal

Nutrient molecules used by cells: For energy (e.g. glucose) For buiding larger molecules (e.g.

amino acids)

Assimilation= the process of bringing nutrients to a body cell and using it to build larger molecules

2. You ingest a glucose molecule in the starch of a breakfast cereal. State as many specific locations as you can for this single glucose molecule from the time it is in your mouth to the time it enters a muscle cell of your right forearm.