Digestion

What is the role of gastric in digestion?

Gastrin is a hormone secreted by the stomach that induces glands to produce hydrochloric acid for digestion.

Small Intestine

-Nutrient absorption of digestive end products (monomers) into the blood through structures called villi

Gallbladder

-Stores bile -gall stones can form

Esophagus

-Tube off the pharynx that contracts (called peristalsis) to push food to stomach

Chemical Digestion

Breaking down of complex molecules into smaller (carbs, lipids, proteins)

Amylase

Carbs

The principal function of mechanical digestion is the...

Production of more surface area for enzyme action

Trypsin

Proteins

Digestion

process that breaks down food

Epiglottis

Flap to cover trachea or airway

Mouth (Oral Cavity)

-Ingestion of food -Physical digestion -Beginning of carbohydrate digestion (salivary amylase from the salivary gland)

Trace the movement of food through the human digestive track

Food enters the oral cavity and proceeds past the epiglottis down the esophagus to the stomach. After being liquified in the stomach, the food travels through the small intestines then the large intestine. Parts of the food that remain undigested are eliminated through the anus.

How does acid affect pepsinogen?

Hydrochloric acid changes inactive pepsinogen into active pepsin.

2 types of digestion

Intracellular Extracellular

Physical Digestion

Large pieces are broken down into smaller ones -both earthworms and birds use a gizzard to grind up food using sand or stones

Digestive enzymes which hydrolyze molecules of fat into fatty acid and glycerol molecules are known as...

Lipases

Enzymes which speeds up the hydrolysis of fats are known as...

Lipases

For the given statement, choose the human organ that performs the function described by the statement. The chemical digestion of carbohydrates begins in this organ

Oral Cavity

For the given statement, choose the human organ that performs the function described by the statement. The chemical digestion of protein usually begins in this organ

Stomach

Incomplete digestive system

one mouth opening (mouth or oral cavity) -starfish

Extracellular

outside a cell -animals -Enzymes are secreted into a digestive cavity where food is broken down and the nutrients are passed to cells

Intracellular

within a cell -plants, paramecium (protists) -Enzyme breaks down food into small molecules the cell can use

Liver

-Produces and releases bile to emulsify (breakdown from large to small) lipids

Large Intestine

-Water absorption -Water for egestion (removal) from the body

2 parts to digestion

-physical -chemical

Complete digestive system

2 opening (mouth and anus) -earthworm

What is the role of the small intestine in the digestion of proteins and fats?

When proteins enter the small intestine, they are acted on by pancreatic juice that raises the pH so that enzymes such as trypsin can break peptide bonds to produce amino acids from polypeptides. When fats enter the small intestine, they are mixed with bile that breaks down fat droplets into small particles that can be further broken down by enzymes such as lipase.

Stomach

-Breaks down food into a paste-like consistency -Contains hydrochloric acid (pH near 2) -Hormone gastrine is produced to stimulate acid production -Secretes pepsin (active form of pepsinogin) to begin protein digestion -Mucus lining for protection -Sores called ulcers can form

Pancreas

-Produces pancreatic juice to make the small intestine basic (pH near 8) -Releases the enzymes pancreatic amylase (carbs) trypsin (proteins), lipase (lipid) into the small intestine

Explain the digestion of carbohydrates. Be sure to include the regions of the digestive tract where carbohydrates digestion of proteins and fats.

Digestion of carbohydrates begins in the mouth. The enzyme amylase contained in saliva breaks down bonds in starch molecules and adds water to the food. No further carbohydrate digestion occurs in the stomach due to its acid pH. Completion of digestion takes place in the small intestine, resulting in the formation of glucose.

Explain how digestive systems in different multi-cellular animals are adaptive.

Digestive systems in multi-cellular animals are adapted to the animal's diet. For example, stomach of cows, horses and rabbits have side pockets that contain microorganisms that aid in the digestion of cellulose in their diets. Since meat is easier to digest, the digestive tracts of carnivores are relatively short.

During chemical digestion, large food molecules are broken down to smaller food molecules by the process of...

Hydrolysis

2 types of animal systems

Incomplete digestive system Complete digestive system

Lipase

Lipid

Which substances are released into the small intestine and aid in the digestion of the intestinal contents?

bile, pancreatic juice, and intestinal juice