Nutrition

Question 1

What does the liver make to help digestion?

Answer 1

Bile

Question 2

Where is bile stored?

Answer 2

Gall Bladder

Question 3

When is bile secreted onto the food?

Answer 3

As it’s leaving the stomach and entering the duodenum

Question 4

What does Bile do?

Answer 4

It emulsifies lipids, produces a large surface area and lipid droplets
and provides an alkaline solution to neutralise acidic chyme

Question 5

Where is lipase produced?

Answer 5

pancreas

Question 6

when is lipase secreted?

Answer 6

onto the emulsified lipids in the duodenum

Question 7

what does lipase do?

Answer 7

digests ester bonds in the lipids

Question 8

what bonds do protease enzymes digest?

Answer 8

peptide bonds

Question 9

what do endopeptidases do?

Answer 9

digests peptide bonds within the polypeptide leaving di or tri - peptides

Question 10

what do exopeptidases do?

Answer 10

hydrolyse the terminal peptide bonds releasing single amino acids

Question 11

what is released to aid digestion and maintain a low ph in the stomach and for what?

Answer 11

Hydrochloric acid maintains at ph1.5 for proteases to work at their optimum

Question 12

What is partly digested food called in the stomach?

Answer 12

Chyme

Question 13

What are the 4 layers of the gut wall?

Answer 13

Mucosa
Submucosa
Muscularis externa
serosa

Question 14

what is the structure of the mucosa?

Answer 14

Glandular epithelium + connective tissue containing blood and lymph vessels. surrounds lumen

Question 15

what is the structure of the submucosa?

Answer 15

connective tissue containing blood and lymph vessels + elastic fibres and collagen

Question 16

what is the structure of the muscularis externa?

Answer 16

circular and longitudinal smooth muscle fibres

Question 17

what is the structure of the serosa?

Answer 17

loose connective tissue

Question 18

what is digestion?

Answer 18

the breakdown of complex, insoluble, organic molecules, into small, simple soluble molecules

Question 19

what is mechanical digestion?

Answer 19

the physical breakdown of large food particles into smaller particles

Question 20

what is chemical digestion?

Answer 20

the hydrolysis of complex molecules into simple soluble molecules - catalysed by enzymes

Question 21

what is mastication?

Answer 21

the mechanical grinding of food into smaller pieces by teeth, chewing

Question 22

what is the purpose of mastication?

Answer 22

smaller food particles are easier to swallow
creates a larger surface area for chemical digestion by salivary amylase

Question 23

what is peristalsis?

Answer 23

the movement of food down the alimentary canal

Question 24

how does peristalsis occur?

Answer 24

brought about by wavelike contraction and relaxation of circular and longitudinal muscle in the muscularis externa

Question 25

where does the circular muscle contract?

Answer 25

behind the bolus

Question 26

where does the longitudinal muscle contract?

Answer 26

in front of the bolus

Question 27

what do carbohydrases do?

Answer 27

catalyse the hydrolysis of glycosidic bonds in carbohydrates

Question 28

what do proteases do?

Answer 28

catalyse the hydrolysis of peptide bonds in proteins and polypeptides

Question 29

what do lipases do?

Answer 29

catatlyse the hydrolysis of ester bonds in triglycerides

Question 30

what are the stages of carbohydrate digestion?

Answer 30

Starch broken down to dextrins that are broken down into maltose - both in saliva and pancreatic juice maltose is broken down into glucose - membranes of microvilli of ileum endothelium

Question 31

How is the mouth and buccal cavity involved in carbohydrate digestion?

Answer 31

food is masticated and mixed with saliva from salivary glands.

Question 32

what is the optimum ph of the buccal cavity?

Answer 32

6.7-7.3

Question 33

what is the optimum ph of the duodenum?

Answer 33

7

Question 34

what is the optimum ph of the ileum?

Answer 34

Between 7 and 8

Question 35

what is the role of the salivary amylase?

Answer 35

Breaking down carbohydrates into simpler sugars

Question 36

what is the role of the lysozyme?

Answer 36

Fighting infections

Question 37

what is the role of the mucus?

Answer 37

trapping unwanted substances like bacteria and dust before they can get into the body -- particularly the sensitive airways

Question 38

what is the role of the chloride ions?

Answer 38

Neuronal signaling

Question 39

what is the role of the chloride ions?

Answer 39

Neuronal signalling

Question 40

what is the role of the duodenum?

Answer 40

receive secretion from pancreas and liver, Brunner's glands secrete intestinal alkaline juice to neutralise acidic chyme

Question 41

What is the role of amylase?

Answer 41

Amylase is a digestive enzyme that acts on starch in food, breaking it down into smaller carbohydrate molecules

Question 42

What is the role of alkaline salts?

Answer 42

digestion and absorption of nutrients and also serve as a means for excretion of several waste products from the blood

Question 43

What is the role of lipase?

Answer 43

breaks down dietary fats into smaller molecules called fatty acids and glycerol

Question 44

What is the role of protease?

Answer 44

responsible for breaking down proteins into amino acids that our bodies need

Question 45

What is the role of maltase?

Answer 45

catalyses the breakdown of a molecule of maltose into two molecules of glucose which can be absorbed into the blood

Question 46

What is the role of lactase?

Answer 46

digests lactose

Question 47

What is the role of sucrase?

Answer 47

catalysing the hydrolysis of starch, sucrase, and isomaltase, among other dietary carbohydrates

Question 48

what is absorption?

Answer 48

the passage of soluble products of digestion into the bloodstream, most occurs in the small intestine

Question 49

How is the small intestine adapted for absorption?

Answer 49

Has villi that has a large surface area, is long (about 5m) also increases surface area

Question 50

what does the mucus do?

Answer 50

lubricates food protects the endothelium from effects of digestive enzymes