2.5 Nutrition

Question 1

oesophagus

Answer 1

a muscular tube that takes food from the mouth to the stomach

Question 2

alimentary canal

Answer 2

the digestive tract running from the mouth to the anus

Question 3

peristalsis

Answer 3

the contraction and relaxation of muscles all along the alimentary canal that pushes food along

Question 4

amylase

Answer 4

an enzyme produced in the salivary and pancreas that speeds up the breakdown of starch into maltose

Question 5

digestion

Answer 5

the breakdown of larger, insoluble molecules into smaller, more soluble ones

Question 6

duodenum

Answer 6

the first part of the small intestine where food is broken down by the pancreatic juices:
lipids–> fatty acids + glycerol by lipases
proteins –> peptides/amino acids by proteases such as trypsin and carbohydrates like starch, that get broken down into maltose by amylase

Question 7

ileum

Answer 7

second part of the small intestine where the products digestion are absorbed

adapted with one cell thick wall
high surface area
high concentration gradient

Question 8

bile

Answer 8

made in the liver, stored in the gall bladder and works in the duodenum where it:
emulsifies lipids and with pancreatic juices, neutralises stomach acid

Question 9

colon

Answer 9

first part of the large intestine where water is reabsorbed

Question 10

lipase

Answer 10

a group of enzymes produced in the pancreas that speeds up the breakdown of maltose into glucose

Question 11

pancreas

Answer 11

an organ that produces and secretes enzymes such as amylase, lipases and proteases that makes up the pancreatic juices and releases them into the duodenum

Question 12

rectum

Answer 12

last part of the large intestine, where faeces are stored

Question 13

stomach

Answer 13

food enters here after travelling down the oesophagus
stomach acid makes conditions acidic, perfect for pepsin which works here as it has an optimum pH of 2
the acid kills any pathogens on the food
muscular walls contract to move food around and increase the chance of food coming into contact with enzymes

Question 14

surface area

Answer 14

the total area occupied by the surface of an object

Question 15

villi

Answer 15

small finger-like projections on the surface of the ileum that increase the surface area for maximum absorption
the walls of the villi are folded themselves (microvilli) to increase surface area further

Question 16

proteases

Answer 16

a group of enzymes that speed up the breakdown of proteins into peptides/amino acids