Digestion and Absorption

Question 1

List the order of the digestive system

Answer 1

Mouth, Oesophagus, Stomach, (Liver), (Gall Bladder), (Pancreas), Small Intestine, Large Intestine, Rectum, Anus

Question 2

What makes salivary glands secrete saliva (Mouth)

Answer 2

The smell of food or looking at food

Question 3

What happens when you actually taste the food (Mouth)

Answer 3

Saliva Increases

Question 4

What enzyme does saliva contain (Mouth)

Answer 4

Amylase

Question 5

What happens while your physically breaking down the food into tiny pieces, small enough to be digested (Mouth)

Answer 5

Even more saliva is produced to begin chemical breaking down of food into amylase

Question 6

Describe the oesophagus

Answer 6

A muscular tube, which carries food down to the stomach.

Question 7

How does the oesophagus push food down into the stomach

Answer 7

Contraction of muscles behind the bolus (chewed food) force it forward. Waves of contractions force the bolus towards the stomach​ - this is called peristalsis

Question 8

What does the stomach do to the food, once the food has reached it

Answer 8

Physically churns food while it is being mixed with enzymes and acid.​

Question 9

What secretes the acid and enzymes in the stomach, and what is the name of the enzyme / pH of the acid

Answer 9

Cells in lining of stomach secrete a strong acid (pH 2) and an enzyme called pepsin which continue to break down the food. ​

Question 10

When is the food in the stomach passed on to the small intestine

Answer 10

When the acids and enzymes have changed the food to the consistency of liquid or paste (The food is now known as chyme)

Question 11

What do gastric glands do while food is in stomach

Answer 11

Secrete gastric juices into the stomach

Question 12

What is the livers role in the digestive system

Answer 12

To process the blood containing the nutrients absorbed from the small intestine.

This organ also detoxifies potentially harmful chemicals found in the blood.​

Question 13

What is made at the liver and how is this relevant for digestion

Answer 13

Bile is made here and is secreted from bile ducts into the small intestine to help digest fat.

Question 14

Describe a bile duct

Answer 14

A sac for storing excess bile.

Question 15

What happens if small intestine doesn’t need the bile sent to it

Answer 15

The bile travels back to the bile duct, until it is needed

Question 16

What are the roles of bile

Answer 16

it helps absorb fats in the diet.​

it carries waste from the liver that cannot go through the kidneys

Question 17

What types of enzymes does the pancreas produce

Answer 17

carbohydrases (eg. Amylase), proteases and lipases. (Pancreas is the chief factory for digestive enzyme)

Question 18

How are enzymes, produced in the pancreas, secreted and where are they secreted into

Answer 18

They are secreted via the pancreatic duct into the first segment of the small intestine (called the duodenum)​

Question 19

What are proteins broken down into

Answer 19

Amino acids

Question 20

What are fats broken down into

Answer 20

Fatty acids and Glycerol

Question 21

What are carbohydrates broken down into

Answer 21

Sugars

Question 22

What else does the pancreas produce other than enzymes

Answer 22

insulin (hormone which lowers blood sugar levels), secreting it directly into the bloodstream.

Question 23

What does the small intestine use to break down foods

Answer 23

enzymes released by the pancreas and bile from the liver.​

Question 24

How does the small intestine push food through it

Answer 24

Small Intestine muscles contract, in a process called peristalsis.

Question 25

What state is the food in when it starts out in the small intestine

Answer 25

A semi - solid state

Question 26

What state is the leftover - food in the small intestine in after the nutrients from it have been absorbed into the bloodstream

Answer 26

A liquid state

Question 27

How is small intestine adapted to absorb nutrients into the blood?

Answer 27

Each villus along the lining of the small intestine is covered with microvilli, giving a large surface area for the absorption of nutrients. Each villus has a blood supply so nutrients are absorbed directly into the blood​

Question 28

What is the function of the large intestine

Answer 28

Processing waste so that emptying the bowels is easy and convenient.​

Question 29

What occurs as stool passes through large intestine

Answer 29

Water is removed from it

Question 30

How long does it take for stool to pass through large intestine

Answer 30

About 36 hours

Question 31

What does the stool in large intestine mostly consist of

Answer 31

Food Debris and Bacteria

Question 32

When does large intestine empty it's contents into the rectum

Answer 32

When the last section of the large intestine becomes full of stool, or faeces

Question 33

What does the rectum do

Answer 33

Receives stool from the large intestine.​ Lets the person know there is a stool to be evacuated.​ Holds the stool until evacuation happens.​

Question 34

How does rectum let the person know something needs to be expelled

Answer 34

Sensors send a message to the brain. The brain then decides if the contents can be released or not.

Question 35

What happens if the brain decides contents from rectum can be expelled and also what happens if it decides contents can't be expelled

Answer 35

If they can, the sphincters relax, expelling its contents. If the contents cannot be expelled, the sphincters contract and this part accommodates so that the sensation temporarily goes away. ​

Question 36

What does the anus consist of

Answer 36

Pelvic floor muscles and two sphincters

Question 37

Define Digestion

Answer 37

The process in which large molecules are hydrolysed by enzymes into small molecules which can be absorbed and assimilated.​

Question 38

Is the digestive system an exchange surface and why?

Answer 38

Yes, as nutrients are absorbed into bloodstream via digestive system

Question 39

What are the two forms of digestion

Answer 39

Physical and Chemical

Question 40

What is physical digestion

Answer 40

Food is broken into small pieces by structures like teeth to aid ingestion and increase surface area for chemical digestion.

Question 41

What is chemical digestion

Answer 41

hydrolysis (by adding water to the chemical bonds) of large insoluble molecules into small soluble ones by enzymes.​

Question 42

What is the substrate for the enzyme amylase

Answer 42

Starch

Question 43

What product does amylase produce after it's bound with its substrate

Answer 43

Disaccharide Maltose

Question 44

What is the substrate for the enzyme maltase

Answer 44

Maltose

Question 45

What product does maltase produce after it's bound with its substrate

Answer 45

Alpha Glucose

Question 46

What is the substrate for the enzyme sucrase

Answer 46

Sucrose

Question 47

What product does sucrase produce after it's bound with its substrate

Answer 47

Glucose and Fructose

Question 48

What is the substrate for the enzyme lactase

Answer 48

Lactose

Question 49

What product does lactase produce after it's bound with its substrate

Answer 49

Glucose and galactose

Question 50

What is the difference between how amylase forms it's product and how maltase, sucrase and lactase form theirs

Answer 50

Amylase breaks multiple glyosidic bonds by hydrolysis, whereas the others break just a single glyosidic bond by hydrolysis

Question 51

Name the enzymes produced from the - Mouth, Stomach, Pancreas and the intestine wall

Answer 51

Mouth - Produces salivary amylase Stomach - Produces protein digesting enzymes Pancreas - Secretes pancreatic amylase Intestine wall - maltase

Question 52

Explain what is secreted by the - Mouth, Stomach, Pancreas and the intestine wall

Answer 52

Mouth - salivary Amylase Stomach - Hydrochloric acid Pancreas - Alkaline salts Intestine wall - Enzymes located on membrane of microvilli- membrane bound disaccharides.

Question 53

What is the role of each of the secretions from the - Mouth, Stomach, Pancreas and the intestine wall

Answer 53

Mouth (salivary Amylase) - Contains mineral ions to maintain optimum pH Stomach (Hydrochloric acid) - Acid denatures amylase and prevents further hydrolysis Pancreas (Alkaline salts) - Digests remaining starch to maltose and maintains optimum pH Intestine wall (Enzymes located on membrane of microvilli- membrane bound disaccharides) - Hydrolysis of maltose to alpha glucose

Question 54

Where are the enzymes - endopeptidase, Exopeptidase and Dipeptidases produced

Answer 54

Endopeptidase and Exopeptidase = Stomach, pancreatic juice (optimum pH of 1.5 - 2.0 for endopeptidase) Dipeptidases = Membrane bound on microvilli of ilium, pancreatic juice

Question 55

What is the substrate for the enzyme Endopeptidase

Answer 55

Peptide bonds between amino acids in central region of protein

Question 56

What product does endopeptidase produce after it's bound with its substrate

Answer 56

Peptide molecules

Question 57

What is the substrate for the enzyme Exopeptidase

Answer 57

Peptide bonds at terminal amino acids

Question 58

What product does exopeptidase produce after it's bound with its substrate

Answer 58

Single amino acids and dipeptides

Question 59

What is the substrate for the enzyme dipeptidase

Answer 59

Peptide bonds of dipeptides

Question 60

What product does dipeptidase produce after it's bound with its substrate

Answer 60

Amino acids