digestive system

Question 1

what is an organic compound

Answer 1

molecules with a carbon chain including hydrogen atoms

may include oxygen, nitrogen and sulfur

Question 2

state the 3 organic compounds

Answer 2

• carbohydrate
• proteins
• fats/lipids

Question 3

what are carbohydrates made up of

Answer 3

simple sugars

carbon, oxygen and hydrogen

Question 4

what is a monosaccharide

Answer 4

a simple sugar

e.g. glucose, fructose, galactose

Question 5

what is a disaccharide

Answer 5

2 simple sugars

e.g. sucrose, maltose, lactose

Question 6

what are polysccharides

Answer 6

3 simple sugars

e.g. glycogen, cellulose, starch

Question 7

what are proteins made of

Answer 7

amino acids (about 20 types)

always= carbon, hydrogen, oxygen and nitrogen. sometimes= sulfur and phosphorus

Question 8

what are dipeptides

Answer 8

2 amino acids joined by a peptide bond

Question 9

what are polypeptides

Answer 9

over 10 amino acids joined by a peptide bonds

Question 10

examples of di/polypeptides

Answer 10

hormones, enzymes, muscles, keratin

Question 11

function of carbohydrates

Answer 11

the main source of energy for the body

used for cellular respiration (release of energy)

Question 12

function of proteins

Answer 12

the are the structural components

influence metabolism

can be a source of energy is no carbs/fats are present

Question 13

what are fats made of

Answer 13

fatty acids and glycerol

oxygen, hydrogen, carbon

Question 14

what is a monoglyceride

Answer 14

1 fatty acid molecule and glycerol

Question 15

what is a diglyceride

Answer 15

2 fatty acid molecules and a glycerol

Question 16

what is a triglyceride

Answer 16

3 fatty acid molecules and a glycerol

Question 17

examples of lipids

Answer 17

phospholipids, oils and fats

Question 18

function of lipids

Answer 18

glycerol is used in cellular respiration to produce energy

fatty acids are important in the cell membrane and steroids (cholesterol/sex hormones)

Question 19

6 major nutrients of the body

Answer 19

1. water
2. vitamins
3. minerals
4. carbs
5. proteins
6. fats

Question 20

what is chemical digestion

Answer 20

chemicals (enzymes) that break down large/complex molecules into smaller/simple molecules to be absorbed

Question 21

what is mechanical digestion

Answer 21

physical break down of food into smaller pieces allowing more efficient chemical digestion

increase surface area to volume

Question 22

chemical digestion of the mouth

Answer 22

salivary gland contain salivary amylase which break down starch (carbs)

Question 23

mechanical digestion of the mouth

Answer 23

mastication (chewing)

Question 24

define peristalsis and how it occurs

Answer 24

the bolus enters the oesophagus and the circular muscle behind the bolus contracts.

peristalsis is the wave like muscle contraction that move the food down the oesophagus.

Question 25

chemical digestion of the stomach

Answer 25

the stomach lining (mucosa) secrets gastric juices which breaks proteins into shorter peptides and nucleic acids into RNA and DNA

Question 26

mechanical digestion of the stomach

Answer 26

3 muscle layers (longitudinal, circular and oblique) allowing the stomach to contract in different ways turning the contents into a soupy liquid called chyme

Question 27

what are gastric juices made of

Answer 27

mucus, HCl and pepsinogen

Question 28

what happens to pepsinogen when released into the stomach

Answer 28

pepsinogen is inactive so the acidity of HCl turns it into pepsin (gastric protease) which is active

Question 29

what is the cardiac and pyloric sphincter for

Answer 29

cardiac relaxes to allow food into the stomach but doesnt allow acid to leave stomach pyloric allows chyme to move to duodenum when its ready via peristalsis- stops food from going through until its chyme

Question 30

where is bile produced

Answer 30

the liver

Question 31

where is bile stored where is bile secreted from/to

Answer 31

gall bladder common bile duct to duodenum

Question 32

what is the function of bile

Answer 32

emulsify fats/lipids mechanical

Question 33

where do pancreatic juices come from and secreted from/to

Answer 33

pancreas common bile duct to duodenum

Question 34

what do pancreatic juices consist of

Answer 34

1. pancreatic amylase- carbs 2. trypsin (pancreatic protease)- proteins 3. pancreatic lipase- lipids 4. deoxyribo/ribonuclease- dna rna

Question 35

where do intestinal juices come from

Answer 35

mucosa/lining of small intestine

Question 36

what do intestinal juices consist of

Answer 36

1. amylase- carbs 2. peptidase- proteins 3. intestinal lipases- fats

Question 37

how does the small intestine create a large surface area

Answer 37

1. length (6-7m) 2. mucosa (inner lining) has folds 3. villi from mucosa (small finger like projections) 4. micro-villi of villi

Question 38

how does mechanical digestion occur in the small intestine

Answer 38

segmentation circular contractions of circular muscles breaking up bolus/mix it with bile

Question 39

what is absorbed into through the small intestine

Answer 39

vitamins, minerals, water, organic compounds in their simple units (fatty acid+glycerol, monosaccharides, amino acids)

Question 40

how do villi assist absorption

Answer 40

one cell thick centre of villi have lacteals that absorb fats and fat soluble vitamins blood capillaries actively absorb amino acids+monosaccharides water/water soluble= osmosis to blood capillaries

Question 41

what is the function of the large intestine

Answer 41

absorb water and vitamins stores faeces elimination

Question 42

what is the alimentary canal

Answer 42

continuous tube running from the mouth to the anus making up the digestive system

Question 43

identify the accessory organs

Answer 43

pancreas liver gall bladder/common bile duct

Question 44

define accessory organs

Answer 44

assist digestion but are not on the alimentary canal