Digestion, Absorption, and Transport

Question 1

Absorption is

Answer 1

The transfer of nutrients from the lumen of the small intestine to the blood or lymphatic capillaries surrounding the GI tract

Question 2

Describe the path food follows as it travels through the GI tract

Answer 2

Mouth, oesophagus, stomach, duodenum, jejunum, ileum, colon, rectum, anus

Question 3

Describe what occurs to food in the mouth

Answer 3

Amylase in saliva chemically breaks down food

Mastication is the physical breakdown of food by teeth

Question 4

After swallowing food, it is called?

Answer 4

Bolus

Question 5

What occurs between the mouth and stomach

Answer 5

Bolus passes the upper oesophageal sphincter passing down the oesophagus through the lower oesophageal sphincter into the stomach

Question 6

What happens to Bolus in the stomach

Answer 6

The stomach adds acidic juices and grinds up the Bolus using peristaltic contractions to turn it into a semi liquid called chyme

Question 7

What regulates flow of chyme into the small intestine

Answer 7

The pyloric sphincter

Question 8

What role does the liver play in digestion

Answer 8

It produces bile salts to help break down fat

Question 9

Carbohydrates are digested into what in order to be absorbed

Answer 9

Glucose and other monosaccharides

Question 10

Proteins are digested into what to be absorbed

Answer 10

Amino acids

Question 11

Lipids are digested into what to be absorbed

Answer 11

Glycerol and fatty acids

Question 12

Where is bile stored

Answer 12

Gall bladder

Question 13

Where does carbohydrate digestion occur

Answer 13

In the mouth (amylase) and in the duodenum

Question 14

Why would it take longer to digest starch as amylopectin instead of amylose?

Answer 14

Because amylopectin starch is more highly segmented

Question 15

What is the difference between glucose and galactose

Answer 15

The -OH points down in glucose but up in galactose

Question 16

Maltose is broken down into what

Answer 16

Two glucose molecules

Question 17

Sucrose is broken down into what

Answer 17

Fructose and glucose

Question 18

Lactose is broken down into what

Answer 18

Galactose and glucose

Question 19

What is fibre composed of. How is it digested

Answer 19

Composed of glucose

It isn’t digested although can be partially fermented

Question 20

Why is insoluble fibre important in a diet

Answer 20

It provides bulk to the diet and speeds up transit through the bowel

Question 21

Where are lipids digested

Answer 21

Begins in the mouth when they are warmed to body temperature

Most occurs in the small intestine with lipase after being emulsified in bile salts

Question 22

Where are proteins digested

Answer 22

Uncoiled in the stomach thanks to acid. Pepsin also in the stomach breaks it down into smaller peptide chains
Protease enzymes in duodenum reduces chains break down peptide chains into dipeptides
Dipeptidase enzyme on intestinal lining breaks them down one further into amino acids to be absorbed

Question 23

What nutrients don’t need to be digested

Answer 23

Vitamins
Minerals
Water

Question 24

Where do nutrients get absorbed into

Answer 24

Glucose and amino acids into blood capillaries

Lipids into lymphatic system

Question 25

What does the portal vein do in the digestive system

Answer 25

Nutrients collect here and it connects the blood vessel to the liver

Question 26

What does the liver do in regards to absorption

Answer 26

Controls the regulation of nutrients to the body

Question 27

What are chylomicrons? Why are they important in absorption?

Answer 27

Packages of lipoprotein.

Important because lipid are not water soluble

Question 28

Why contributed to the small intestines large surface area

Answer 28

Villi and microvilli

Question 29

What are the three transport systems used in absorption

Answer 29

Simple diffusion
Facilitated diffusion
Active transport

Question 30

What is the function of the large intestine (Colon)

Answer 30

Water absorption

Question 31

Where is insulin produced and what is it used for

Answer 31

Produced by beta cells in the pancreas and encourages cells to uptake glucose to store it when blood glucose levels are high

Question 32

Where is glucagon produced and what is it used for?

Answer 32

Produced in alpha cells in the pancreas and encourages cells to release glucose from glycogen stores when blood glucose is low

Question 33

Briefly explain type 1 diabetes

Answer 33

Beta cells faulty and insulin is not produced

Question 34

Briefly explain type 2 diabetes

Answer 34

Insulin is produced but cell receptors are faulty preventing them from taking up glucose

Question 35

Digestion is

Answer 35

The mechanical and chemical breakdown of food, extraction of nutrients and breakdown of macronutrients