Human nutrition-Biological molecules,food tests, balanced diet Flashcards
what are biological molecules
biological molecules are things such as carbs, lipids and proteins. They are long complex molecules made of smaller units.
what are carbs made of
simple sugars such as maltose or glucose .
name 2 large, complex carbs
starch and glycogen
what smaller unit is starch made out of
maltose (and other simple sugars such as glucose)
What elements make up carb molecules
CHO
What are proteins made of
amino acids
what elements made up amino acids
CHON
What are lipids
fats and oils
what are lipids made up of
lipids are made up of fatty acids and GLYCEROL
what elements make up lipids
CHO
what do carbs provide in a diet
energy
why are proteins needed in a diet
needed for growth and tissue repair
and to provide energy in emergencies
what do lipids provide in a diet
provide insulation and provide energy
what is fibre needed in a diet
to aid the movement of food through the body for excretion
why do we need water in a diet
to stay hydrated and to replace water loss through sweating, urinatating etc
what are the different mineral ions we need in a diet and what do we need them for
calcium-to help made bones and teeth
iron-to help make haemoglonib for healthy blood
why are the different types of vitamins we need in our diets
vitamin A
vitamin C
Vitamin D
what does vitamin D help with
calcium absorption
what does vitamin C help with
prvention of scurvy
what does vitamin A help with
vision and helps to keep skin and hair healthy
give and example of proteins
chicken, pork
give an example of carbs
pasta and rice
give an example of lipids
butter and oily fish
give an example of food that contain iron
red meat, spinach
give an example of a food that has vitamin a in
Liver
give an example of a food that has vitamin c in
oranges
give and example of a food that has vitamin d in
eggs
what an example of fibre
fruit, wholemeal bread
calcium example?
milk
what can the Benedict’s test be used for
TO FIND GLUCOSE -SUGAR
what can iodine solution be used to find
TO FIND STARCH- CARBS
what can emulsion test be used to find
TO FIND LIPIDS-FATS
what can the biuret test be used to find
TO FIND PROTEINS
what is the test for starch and can you explain it
the test for starch is the iodine solution test
- get a small crushed up sample of you food and put it on a tile
- place a few drops 2-3 of iodine solution onto you sample
- if starch present it will be blue-black, if not if will stay brown yellow
what is the test for lipids and can you explain it
the test for lipids is the emulsion test
1.crush up a food sample and put it into a test tube that is half filled with ethanol
2.shake the test tube to dissolve the food into the ethanol
4.pour the mixture into a test tube half filled with water
4.if fair is present it will go white
if not present it will be clear
what is the test for protein and can you explain it
the test for proteins in the biuret test
1.put 2cm3 of food sample into test tube
2.add 2cm3 of sodium hydroxide
3.add 2cm3 of copper sulphate solution
4.shake and leave 1 min
5.if protein present will go purple
if not will be dark blue
whats the test for sugars and can you explain it
the test for sugar is the Benedict’s test
- 2cm3 into a test tube
- add 2cm3 of benedicts solution
- place in a water bath for 3 mins
- if sugar present brick red, if not clear blue
what does the amount of energy needed for a person depend on
- their age
- their activity levels
- if they are pregnant
How do carbs, protein and get broken down into simple sugars,fatty acids and amino acids?
By digestive enzymes
Why do bigger molecules get broken down into the smaller molecules?
In order to pass through the walls of the digestive system
what enzymes convert starch to maltose to glucose
starch—–> enzyme amylase maltose
maltose—>enzyme maltease—-> glucose
what enzyme coverts proteins into amino acids
protease
what enzyme convert lipids to fatty acids/ glycerol
lipase
what is the function of bile
bile emulsifies (breaks down) fats ingto ti y droplets to make digestion faster. Bile also neutralises hydrochloric acid which in the stomach
where is bile produced
liver
how does food move through the gut
by peristalsis
what is peristalsis
peristalsis is the squeezing action of muscle tissues within the alimentary canal which move food through the gut
where is bile stored
gall bladder
where is bile used
small intestine
where is the enzyme amylase produced
in the salivary glands in the mouth
what do the large intestine do
store execss water from food
what do the small intestine do
absorb nutrients and produces protease, amylase and lipase
whats the difference between excretion and egestion
excretion is the removal of metabolic waste where as egestion is the removal of undigested food
what are faeces stored and expelled
stored in the colon rectum
expelled through the anus
what is ingestion
the taking in of food from the mouth
what is chemical digestion
the breakdown of food using chemicals such as enzyme
what is mechanical digestion
the breakdown of food using movement such as chewing
whats malnutrition
malnutrition refers to a poor diet
