3.3.4.3 Digestion And Absorption

Question 1

What is the definition of ::
Ingestion

Answer 1

Solid food taken through the mouth

Question 2

What is the definition of
Digestion

Answer 2

Mechanical and chemical breakdown of large insoluble to small soluble molecules

Question 3

What is the definition of
Absorption

Answer 3

Soluble molecules taken into bloodstream

Question 4

What is the definition of
Egestion

Answer 4

Deffication

Question 5

Label the digestive system

Answer 5

Check biology folder

Question 6

What is the definition of
Peristalsis

Answer 6

Wave-like muscles contractions that move food through the digestive tract

Question 7

What is the definition of
Ileum

Answer 7

The last part of the small intestine , connects to the Cecum helps in digestion

Question 8

What is the definition of
Disaccharides

Answer 8

Two monosaccharides

Question 9

What is the definition of
Emulsification

Answer 9

Two solutions that are immiscible and cannot mix forming a suspension

Question 10

What is the definition of
Villi

Answer 10

Small tenticles that move food , while also increasing surface area

Question 11

What is the definition of
Lumen

Answer 11

A small channel in the middle of a blood vessel (e.g vein / artery) or intestine

Question 12

What is the definition of
Chylomicrons

Answer 12

A droplet of fat in blood or lymph after absorption from intestine

Question 13

What is the definition of
Lacteal

Answer 13

Lymph in micro villi

Question 14

What is the definition of
Bile Salt

Answer 14

Helps with digestion of fats and fat and fat soluble vitamins (a ,d, e)
Made in the liver stored in the gall bladder

Question 15

Describe the function of
Mouth / salivary glands

Answer 15

Called buccal cavity
Mechanical digestion
Mastication (chewing)

Saliva consists of mucin (binds food together) (glycoprotein)
Salivary amylase (digestion of starch to maltose )
Mineral salts buffer at ph of 7

Question 16

Describe the function of
Oesophagus

Answer 16

Circular and longitudinal muscles contract involuntary in peristalsis

Question 17

Describe the function of
Stomach

Answer 17

Muscular sack with layer that produces enzymes
Stores and digests foods
Acid conditions (1/2ph) enzymes optimum ph
Churning (mechanical digestion ) this increases surface area
While in stomach , mixes with gastric juice
Chemical digestion :
Pepsin - digests proteins
Rennin - digests proteins
Hydrochloric acid
Mucus - amylase , mucin , mineral salts

Question 18

Describe the function of
Duodenum

Answer 18

This is the first 20cm after the stomach and receives sec reactions from the liver and pancreas
Digestion takes place
Input of pancreatic juices
Lipids broken down into fatty acids
Proteins broken down into amino acids
Large surface area due to villi
Digestion of carbohydrates takes place in cells

Question 19

Describe the function of
Liver

Answer 19

Produces bile , stored in gall bladder transported through bile duct
Bile made from bile salts and mineral salts
Bile salts help with breaking large globules of lipids into smaller globules of lipids , increasing SA and reducing surface tension(emulsification)
Mineral salts neutralise HCl from stomach restores to ph 7

Question 20

Describe the function of
Pancreas

Answer 20

Produces pancreatic juice :
Amylase
Lipase
Trypsin
Amylose to maltose if not done already
Lipase into fatty acids
Trypsin continues to break down proteins

Question 21

Describe the function of
Illium

Answer 21

Edopeptiases and exopeptidase

Endopeptidase works in the middle (Endo) on a polypeptide chain

Exopeptidase works on the ends of peptide chains to make singular amino acids

Endo increases the amount of ends which allows more exo to act therefore more amino acids produces per second

Sucrase hydrolyses sucrose into fructose and glucose

Maltose hydrolyses into two glucoses

Glucose and amino absorbed over epithelium of villi by diffusion and active transport into capillaries of villi

Absorption of fatty acids and glycerol

Question 22

Describe the function of
Large intestine

Answer 22

Absorption of water

Question 23

Describe the function of
Rectum

Answer 23

Storage of faeces and then removed

Question 24

What is the definition of
Endopeptidases

Answer 24

Which hydrolyse peptide binds between amino acids in the central region of the molecule forming a series of peptide molecules . Found in the stomach

Question 25

What is the definition of :
Exopeptidase

Answer 25

Which hydrolyse the peptide bonds on the terminal amino acids of the peptide molecules to release dipeptidases and signal amino acids . Found in duodenum

Question 26

What is the definition of
Dipeptidases

Answer 26

Which hydrolyse the bond between the dipeptidases to release amino acids these enzymes are membrain bound and found on epithelial cells lining the ileum

Question 27

What are the 5 adaptions for absorption

Answer 27

1. Villi have high SA
2. Thin walls
   3.muscle contractions maintain concentration gradient
   4.blood vesicles carry away absorbed material maintaining a conc gradient
3. Micro villi further increase SĄ

Question 28

Are chylomicrons water soluable

Answer 28

Yes

Question 29

Blurb about lipid absorption

Answer 29

1. Triglycerides broken down into monoglyceride and fatty acids by pancreatic lipase it associates with bile salts which form micelles
   Micells - a ball of fatty acids and monoglycerids which enter epithelial cells
2. Micells come in contact with plasma membrain releasing non-polar fatty acids and monoglycerids which diffuse through
3. FA (fatty acids )MG (monoglycerids) transported to endoplasmic reticulum, recombined to make triglycerides (TG)
4. TG associats with cholesterol and lipoproteins (in endoplasmic reticulum and Golgi apparatus) to make chylomicrons ,enter lacteals pours lymph system