Human Nutrition Flashcards
What elements do carbohydrates contain?
Describe carbohydrates molecules
contain hydrogen, carbon, oxygen
Starch / glycogen are large complex molecules made from smaller units like glucose / maltose
Enzyme and break down product of maltose
Enzyme - maltase
Break down product - glucose
Enzyme and break down product of starch
Enzyme - amylase
Break down product - maltose
Enzyme and break down product of proteins
Enzyme - protease
Break down product - amino acids
Enzyme and break down product of lipids
Enzyme - lipase
Break down product - fatty acids and glycerol
What are proteins made up of?
What elements do they contain?
made up of amino acids
contain oxygen, hydrogen, carbon, nitrogen
What are lipids made up of?
What elements do they contain?
built from fatty acids and glycerol
contain hydrogen, oxygen, carbon
Describe the test for glucose
add Benedict’s solution to a sample
heat sample
sample will turn blue - green - yellow - orange - brick red
Carbohydrates
Found in :
Function :
Carbohydrates
Found in : pasta, rice
Function : provide energy
Lipids
Found in :
Function :
Lipids
Found in : butter, oily fish
Function : provide energy, energy store and insulation
Proteins
Found in :
Function :
Proteins
Found in : meat, fish
Function : growth and repair tissue, emergency energy
Vitamin A
Found in :
Function :
Vitamin A
Found in : liver
Function : improve vision, healthy skin/hair
Vitamin C
Found in :
Function :
Vitamin C
Found in : Oranges
Function : prevent scurvy
Vitamin D
Found in :
Function :
Vitamin D
Found in : eggs, made by body when sunlight exposed
Function : calcium absorption
Mineral Ion Calcium
Found in :
Function :
Mineral Ion Calcium
Found in : milk, cheese
Function :make bones and teeth
Mineral Ion Iron
Found in :
Function :
Mineral Ion Iron
Found in : red meat
Function : makes haemoglobin for healthy blood
Water
Found in :
Function :
Water
Found in : food and drink
Function : needed for every bodily function
Fibre
Found in :
Function :
Fibre
Found in : wholemeal bread
Function : aids movement of food through gut
what is a balanced diet ?
gives all essential nutrients in right proportions
what are the six essential nutrients ?
carbohydrates, proteins, lipids, vitamins, minerals, water (fibre)
what are the factors of energy requirements?
activity level - active people need more energy
age - children and teens need lots of energy to grow
pregnancy - as they need to provide for baby
what is calorimetry ?
measuring energy food contains by burning it
where is bile made/stored/used?
produced in liver
stored in gall bladder, then released into small intestine
what is another word for gut ?
alimentary canal
what is the function of the mouth?
salivary glands produce amylase enzymes in saliva
teeth break down food mechanically
what is the oesophagus ?
muscular tube that connects mouth to stomach
what is the function of the liver ?
produces bile
what is the function of the gall bladder?
stores bile
what is the function of the large intestine ?
absorbs excess water from food
what is the function of the Anus ?
removes undigested material (faeces)
what is the function of the stomach ?
pummels food with muscular walls
produces the protease enzyme, pepsin
produces hydrocloric acid to kill bacteria and give right pH for pepsin to work (pH 2)
what is the function of the pancreas?
produces enzymes (protease, amylase, lipase) which are released into small intestine
what is the function of the small intestine ?
produces enzymes (lipase, protease, amylase) to complete digestion absorbs nutrients into body
what is peristalsis ?
how does it work?
way food is moved through gut
muscular tissue along alimentary canal which uses waves of circular muscle to move food, or else it would get clogged up
what are the five main stages of digestion ?
ingestion, digestion, absorption, assimilation and egestion
what is ingestion?
intake of food (drink) in mouth
what does digestion do?
how does it do it?
break-down of large, insoluble molecules to small, soluble molecules to be absorbed
mechanical - teeth and stomach muscles
chemical - enzymes and bile
what is absorption ?
give 2 examples of absorption
process of moving molecules through walls of intestines into blood
digested food absorbed in small intestine
water absorbed in large intestine
what is assimilation ?
absorbed digested molecules move into body cells
what is egestion ?
removal of undigested material through the anus
how is the small intestine adapted to absorb food?
walls covered in millions of tiny villi
each cell on surface of villus has its own micro villi
this increases surface area - able to absorb more
villi have permeable layer and good blood supply so quick absorption
what are the functions of bile?
bile is alkaline so neutralises acid (enzyme optimum pH)
bile also emulsifies (breaks down) fat - bigger surface area so faster digestion
Explain how insulin controls the level of glucose in the blood
The pancreas secretes a hormone called insulin when glucose levels are too high in the blood. The liver is the target organ, which turns excess glucose into glycogen. When the blood sugar level returns to normal, negative feedback turns the secretion of insulin off
energy in food (J) =
mass of water (g) x water temp change x 4.2
energy per gram of food (J/g) =
energy (J) / mass (J)
