chapter 3:Nutrients(part 1:Biomolecules) Flashcards
what are the 3 nutrients?
starch,proteins and fats
what are the 3 biomolecules?
carbohydrate,proteins and fats
what types of carbohydrates are there?
simple and complex carbohydrates
food provides us with nutrients, vitamins and minerals .Other than for providing energy and keeping us healthy and free from diseases .How can it help us?
it provides raw materials to make new protoplasm needed when making new cells or repairing cells
1.what is the basic unit of carbohydrates ?
2.what ratio do the hydrogen and oxygen atoms exist in ?
3.what elements are there in carbohydrates ?
1.glucose
2. 2:1
3.carbon,hydrogen and oxygen
there are several types of carbohydrates with the same chemical formula .They have different atomic arrangements ,so they have different physical and chemical properties .What are MONOsaccharides ?what are the examples ?and what is the food test?
they are single sugar carbohydrate consisting of 6 carbon atoms per molecule.The examples include:Glucose,fructose and galactose .The food test is :Benedict’s test
what are DIsaccharides ?what are the examples?and what is the food test?
they are double sugar carbohydrates consisting of 12 carbon atoms per molecule.The examples include:
1.glucose+glucose=maltose(ggm ,Good Getaway Mate!)
2.glucose+fructose=sucrose(gfs,Good For Service)
3.glucose+galactose=lactose(ggl,Get Good Luck!)
Food test:Benedict’s test
what are POLYsaccharides ?AKA complex carbohydrates?what are the examples ?and what is the food test?
consists of numerous single sugar units in PLANTS,examples include:cellulose->essential component used to synthesise cell walls AND starch->store energy mostly found in leaves,storage organs like underground roots.
It also consists of numerous single sugar units in ANIMALS.One example is:Glycogen->store energy mostly found in liver and muscles .
Food test:iodine test
what are the functions/roles of carbohydrates ?
In both plants and animals:
1.is a relatively immediate source of energy .Specifically,glucose is used as a substrate for respiration to release energy for cellular activities
2.(pentose)sugar is used as a component to form DNA
In plants only:
1.Cellulose is used to form supporting structures like cell walls in plant cells.
2.sugars are used to synthesise nectar in flowers of plants
why store glucose in the form of starch and glycogen ?
.have compact shapes->take up less space in cells
.are large molecules which will not diffuse out of cells->no loss of carbohydrates not utilised for respiration
.are insoluble in water->do not affect water potential of cells
.can be easily converted back to glucose when needed for respiration
what are the basic units of proteins?and what elements are there in proteins?
the basic unit are amino acids .And the elements are carbon,hydrogen,oxygen and nitrogen
what are the functions/roles of proteins?what is the food test?
1.to synthesise new protoplasm-for growth and repair of cells
2.To synthesise enzymes and hormones
3.to form antibodies required to defend the body against diseases .
Food test:Biuret test
what is the basic unit of fats?and what are the elements?
Basic unit:1 glycerol+3 fatty acids.Elements:Carbon,hydrogen and oxygen
what is the difference between saturated and unsaturated fats?
saturated fats is solid at room temperature like butter,ghee.Unsaturated fats is liquid at room temperature like oils
what are the functions or roles of fats?
1.Fats is required to synthesise essential parts of cell membranes
2.Fats can provide heat insulation to prevent excessive heat loss
3.fats is the main store of energy(more compact form than starch and higher energy value)
4.Is the secondary source of energy after carbohydrates
5.a solvent that can dissolve essential fat-soluble substances such as hormones and vitamins so they can be transported.
6.A layer of oil secreted on the surface of skin reduces evaporation of water from skin
what is the name of the food test for starch and what is the procedure ?
Name:iodine test
Procedure:
1.add 2 drops of iodine solution to solid sample
what are the results for iodine test?
Solution remains brown->starch is absent
solution turns blue-black->starch is present
what is the name of food test for reducing sugar? And procedure?
Name:Benedict’s Test
Procedure:
1.Add 2 cm cube of sample into a test tube
2.add 2 cm cube of Benedict’s solution.Shake to mix
3.Place the test tube in a boiling water bath for 3 mins
what are the results for Benedict’s test ?
Remains blue->Reducing sugar absent
Brick-red precipitate formed->Large amount present
orange/yellow ppt formed->
moderate amount present
Green ppt formed->little amount present
what is the food test for protein?and procedure?
Name:biuret test
Procedure:
1.Add 2 cm cube sample into a test tube
2.Add 2 cm cube of biuret solution.Shake well and allow to stand for 5 mins
what are the results for biuret test?
solution remains blue->protein is absent
turns violet->present
what is the food test for fats?and procedure?
Name:Ethanol Emulsion Test
Procedure:
1.Add 2 cm cube of sample into a test tube
2.Add 2 cm cube of ethanol.Shake to mix
3.Add 2 cm cube of water.Shake to mix
what are the results for Ethanol Emulsion test?
Solution remains clear->Fat is absent
White emulsion formed->present
