B4 & B7.1 - biological molecules, Human diet Flashcards
elements that make up carbohydrates, lipids, protein
carbohydrates- carbon, hydrogen, oxygen
lipids- carbon, hydrogen, oxygen
protein- carbon, hydrogen, oxygen, nitrogen
4 food sources for carbohydrates, lipids, protein
carbohydrates- rice, potato, pasta, bread
lipids - meat, fish, cheese, beans
protein- red meat, egg yolk, soy beans, chocolate
importance of carbohydrates
-easy available energy released during respiration
-excess stored as glycogen in liver and muscles
-if not used, converted into fat
- 16 KJ/g
importance of lipids
-insulation
-long term energy store
-organ protection
-sex hormone production
-buoyancy
- 39 KJ/g
what are monosaccharides, and eg
simple sugars, glucose, glycogen
importance of protein
-growth
-tissue repair
-making enzymes
-emergency energy
- 17 KJ/g
what are basic units of carbohydrates
simple sugars
-say glucose in exam
in what form is sugars transported in humans and plants
plants - sucrose
humans - glucose
2 main groups of carbohydrates
-polysaccharides
-sugars (disaccharides, monosaccharides)
how does starch go to glucose
-starch broken down by Amylase into maltose
-maltose broken down by Maltase into glucose
are carbohydrates soluble
simple sugars - soluble
polysaccharides - insoluble
what do you call a fat molecule
triglyceride
what is triglyceride broken down into
3 fatty acids and glycerol
what breaks down triglyceride
lipase
are lipids soluble
no
define protein molecules
a long chain of amino acids
how does protein go to amino acids
-protein is broken down by protease into polypeptides
-polypeptides are broken down by peptidase into amino acids
what happens to amino acids
arranged in sequence depending on the DNA
are proteins soluble
some are
what do you use to test for starch
iodine reagent
what do you use to test for reducing sugar
benedicts reagent
what do you use to test for lipids
ethanol emulsion
what is the test for lipids called
emulsion test
what do you use to test for protein
biuret reagent
what is the colour of iodine reagent before the starch experiment
orangey brown
what is the colour of benedict reagent before the reducing sugars experiment
blue
what is the colour of ethanol reagent before the fats experiment
colourless
what is the colour of biuret reagent before the protein experiment
blue
what is the colour of iodine reagent for positive starch
blue- black
what is the colour of benedicts reagent for positive reducing sugars
-green (trace)
-yellow (low)
-orange (moderate)
-brick red (high)
what is the colour of ethanol reagent for positive fats
cloudy white emulsion
what is the colour of biuret reagent for positive protein
purple
What must you do as a safety procedure to when doing experiment for starch, reducing sugars, lipids and protein
-wear googles
-try to prevent direct contact with skin- wash immediately if it does
-Ethanol is flammable so keep away form naked fire
steps to test for starch
1-put googles
2 -add a few drops of iodine on food
3 -check for colour change-
orangey brown or blue- black
step to test for reducing sugars
1-put googles
2 -add a few drops of distilled water if food is dry
3 -add benedicts reagent
4 -put the test tube in a beaker of water that is 80C with a heat below for 3 mins
5 -check for colour change
step to test for lipids
1-put googles
2 -add ethanol reagent
3 -place bung and shake thoroughly to mix it
4 -add distilled water in another tube
5 - add the ethanol from the tube to the distilled water- do not put the food too
6 -check for colour and emulsion
step to test for protein
1 -put googles
2 -add a few drops of distilled water if food is dry
3 -add biuret reagent slowly
4 -check for colour change
Which test do you add distilled water if the food is dry
-benedicts
-biurets
What do lipids include
-fats
-oil
what is the difference between fats and oil
-fats are solid at room temp.
-oils are liquid at room temp.
define a balance diet
a balanced diet include carbohydrates, lipids, protein, vitamins, minerals, fiber and water in the correct proportions to meet energy and specific dietary needs.
when does malnutrition happen
when the diet does not provide all the nutrients in the correct proportions
humans factors that affect the dietary need of humans
-age
-gender
-activity
-pregnancy/ breast feeding
2 important things about diet and energy for people
not everyone’s balanced diet and energy requirements are the same
1 Calorie in Kilo Jules
1C = 4.2 KJ
7 important part of a balanced diet
-carbohydrate
-lipids
-protein
-vitamins
-minerals
-fiber
-water
what must out energy intake be equal to
energy output
Define Basal Metabolic Rate (BMR)
energy consumed in 1 day by process required to stay alive
4 processes that required energy to simply stay alive
-breathing
-excretion
-thinking
-keeping a constant body temperature
define micronutrients
nutrients need in small amounts
define macronutrients
nutrients needed in large amounts
which are the 2 micronutrient
vitamins and mineral
which are the 3 macronutrients
carbohydrates, lipids, protein
define fibers
indigestible carbohydrates
define cellulose
-is an insoluble fiber in plant cells
define solvent
a substance which solutes dissolve in
solute + solvent = solution
3 uses of water
-enzymes dissolve in water for chemical reaction or digestion (most)
-dissolves substances to be transported in blood (eg. nutrients)
-dissolve toxic waste for excretion (eg. urea)
what happens when vitamin C is heated
can get degraded
what are vitamin C and D soluble in
C - water soluble
D - fat soluble
food sources of vitamin c
-citrus fruits eg. oranges, kiwi
-fresh green vegetables
food sources of vitamin d
-liver
-egg yolks
-dairy products
importance of vitamin c
-keeps tissues intact by forming collagen protein for skin, hair and immunity
importance of vitamin d
helps body to absorb calcium
what does vitamin c deficiency cause
-scurvy - bleeding gums, teeth problems, immunity problems
-is deadly
-poor wound healing
what does vitamin d deficiency cause
- rickets - soft bones from being unable to absorb calcium
-poor formation of bones or teeth
symptoms:
-fatigue
-muscle weakness
when does the body make vitamin d
when exposed to sunlight
2 minerals
-calcium
-iron
food sources of calcium
-milk
-cheese
-eggs
-(dairy products)
food sources of iron
-red meat
-liver
-spinach
-chocolate
importance of calcium
-keep bones and teeth strong
-help blood clotting
importance of iron
-needed to make hemoglobin in red blood cells to carry oxygen to cells
what does calcium deficiency cause
-Osteoporosis (brittle bones), usually in old people
-rickets
what does iron deficiency cause
-anemia - tiredness, weak, pale skin, lack energy
-reduced oxygen transport
food sources of fiber/ roughage
-vegetables
-fruits
-brown bread and rice
-oats
importance of fibers
-needed for peristalsis
define peristalsis
muscles contraction during digestion
what does the lack of fiber cause
-constipation - rectum and large intestine swelling
-bowel cancer - from bacteria in poop
what does lipids in excess casue
-obesity
-blockage of heart vessels
-heart diseases
-joint damage
-diabetes
what does carbohydrates deficiency cause
-lack of energy
-fatigue
-prone to illnesses
what does protein deficiency cause
-Kwashiorkor- swollen abdomen, muscles wastage, stunted growth
what does lipids deficiency cause?
-anorexia
-weight loss
-fat soluble vitamins deficiency (A, D)
sources of water
-tea
-water
-juice
-coffee
what does lack of water cause
-dehydration
-dies within a few days
what causes a person to be overweight
-energy input is greater than use of energy
-excess energy is converted to fat so overweight
precautions for fats test
-no naked flames
-ethanol is flammable
3 ways to prevent rickets
-vitamin D supplements
-eat more dairy products
-more exposure to sunlight
define reducing sugars
maltose
why is it not possible to confirm presence of fat in milk using ethanol & water test
milk is white like the emulsion
