digestion Flashcards
why do we break down and reassemble major nutrients
most of the molecules in food are too large
function of carbohydrates
energy, glucose is main respiratory substrate
sources of carbohydrates
potatoes, rice, bread, fruit, sweets
function of protein
growth and repair
sources of protein
meat, eggs, cheese
function of lipids
energy, make up cell membrane
essential for growth
sources of lipids
butter, oily fish
starch is a _____ of glucose
polymer
what are glucose molecules used for
respiration
glycogen
what are proteins made up of
amino acids
where is excess amino acid broken down
liver
esters
type of organic compound formed in the reaction between an alcohol and a carboxylic acid.
food test for sugar
add benedict’s solution to food and heat in a water bath
sugar food test result
changes colour to red
food test for starch
add iodine to food being tested
starch food test result
if it contains starch will turn blue/black
food test for protein
biuret test
purple colour if protein is present
food test for fat
Sudan III test
add equal amounts of food and water, add drops of Sudan III.
result for fat food test
red stained layer forms on surface of water if fat is present
function of human digestive system (2)
breaks down complex food substances
provides the very large surface area for maximum absorption of food
mouth
mechanical digestion
amylase for carbs
stomach
digestion of protein; small molecules such as alcohol absorbed
duodenum
digestion of carbohydrate and protein; begins the digestion of lipids
ileum
Completes the digestion of carbohydrates and proteins into single sugars and amino acids
large intestine
absorption of water
what are enzymes
biological catalysts
catalysts
lower activation energy and speed up reactions
at what temp do enzymes in our body work best
37°
function of saliva in digestion
lubrication to help swallow
contains amylase to break down starch
