3 | Nutrients Flashcards
Chemical composition of water
H2O
Uses of water in animals
SHMKT
- a component of Sweat to be evaporated to remove latent heat of vapourisation to cool the body down (regulates body temp)
- needed in Hydrolysis reactions
- Medium in which chemical reactions occur
- Key component of protoplasm, lubricants, digestive juices, blood and tissue fluid
- Transport dissolved substances around the body (solvent for transport of substances)
→ digested products, metabolic waste products, hormones (water in blood plasma)
Uses of water in flowering plants
PTT
- raw material for Photosynthesis
- needed for Turgor pressure to maintain cell structure
- Transport of mineral salts and sucrose in xylem vessels and phloem vessels
Type of chemical reactions
Condensation reaction
Hydrolysis / hydrolytic reaction
What is a condensation reaction
A chemical reaction in which 2 simple molecules are joined together to form a large molecules with the removal of one molecule of water.
What is a hydrolysis / hydrolytic reaction
A reaction in which a water molecules is needed to break down a larger, complex molecule into smaller, simple molecules
What is a carbohydrate?
Carbohydrates are organic molecules made up of
- carbon
- hydrogen
- oxygen
ratio of hydrogen to oxygen atoms in carbohydrates → 2:1
What are monosaccharides
cannot be further digested into smaller molecules
C6H12O6
Examples of monosaccharides
Glucose
Fructose
Galactose
What are disaccharides
made up of 2 molecules of monosaccharides bonded together C12H22O11
Examples of disaccharides
Maltose (glucose + glucose)
Sucrose (glucose + fructose)
Lactose (glucose + galactose)
What are polysaccharides
made up of many monosaccharide molecules bonded together
Examples of polysaccharides
starch
cellulose
glycogen
3 types of complex carbohydrates
(made up of glucose molecules bonded differently)
Starch
Cellulose
Glycogen
Structure, function, occurrence of starch?
Structure: Linear
Function: Storage (large molecules, insoluble in water, compact shapes, easily hydrolysed)
Occurrence: Storage organs in plants
Structure, function, occurrence of cellulose?
Structure: linear
Function: protection from mechanical damage
Occurrence: cell walls of plants
Structure, function, occurrence of glycogen?
Structure: branched
Function: storage (large molecules, insoluble in water, compact shapes, easily hydrolysed)
Occurrence: Stored in the livers and muscles of mammals
Functions of carbohydrates?
SCLFNN
- Substrate for respiration to release energy for cell activities
- Converted into other organic compounds such as amino acids and fats
- used to synthesise Lubricants such as mucus
- Form supporting structures such as cell walls in plants
- form part of Nucleic acids such as DNA
- used to synthesise Nectar in flowers
What are fats made up of
Fats are organic molecules made up of
- Carbon
- Hydrogen
- Oxygen
Properties of fats
- Fats contain much less oxygen in proportion to hydrogen and the proportions of the elements in fats are not fixed.
- Fats can be broken down into simpler molecules by hydrolysis and it produces fatty acids and glycerol.
Function of fats
PRISE
- form the main part of Protoplasm such as the cell membrane
- Reduce water loss from the skin surface
- act as an Insulating layer to prevent excessive heat loss
- a Solvent for fat soluble vitamins and some hormones
- a source and store of Energy
What are proteins made up of
Proteins are organic molecules made up of
- carbon
- hydrogen
- oxygen
- nitrogen
- sulfur (may or may not be present)
Properties of proteins
- Each protein molecule is made up of smaller basic units called amino acids
- amino acids are made up of
– amino group
– acid group
– side chain - peptide bonds link up amino acids to form a polypeptide
- one or more polypeptide chains fold to form a three-dimensional structure held by hydrogen bonds called proteins.
Functions of protein
- Synthesis of new protoplasm for growth and repair of worn out body cells
- Synthesis of enzymes and some hormones
- Synthesis of antibodies
Elements of carbohydrates
C:H:O
usually 1:2:1
(H is double of O)
Elements of fats
made up of C, H, O with more C&H
Elements of proteins
made up of C, H, O, N
Example / source of carbohydrates
- starch (potatoes, bread)
- cellulose (leafy vege.)
- glycogen
Example / source of fats
- peanuts
- oil
- butter
- animal fats
Example / source of proteins
- meat
- eggs
- beans
- enzymes
Monomer / basic unit of carbohydrates
glucose
Monomer / basic unit of fats
fatty acids + glycerol
Monomer / basic unit of proteins
amino acids
Diagram of carbohydrates
Notes
Starch
- made up of maltose
- made up of glucose
Diagram of fats
Notes
1 fat molecule = 1 glycerol, 3 fatty acids
Diagram of proteins
Notes
Like lego blocks
Diff proteins are formed out of the 20 amino acids
Function of carbohydrates
- Cellulose forms cell walls in plants, a source of fibre for humans
- Glycogen is stored in liver and muscle cells, when energy is needed, it breaks down into glucose
- Glucose used in respiration (mitochondria) to release energy
Function of fats
- Energy storage (x2 the amt of sugars)
- Insulation (blubber)
- Found in cell membranes
Function of proteins
- Synthesis of new cells for growth and repair
- Enzymes allow numerous reactions to take place
- Antibodies to fight pathogens
What is the reagent for test for starch?
Iodine
What is the test for starch?
Add a few drops of iodine solution
What will be the observation and conclusion of starch test?
+ve: Blue-black colouration observed
-ve: solution remains brown
What are reducing sugars?
All monosaccharides and disaccharides (except sucrose)
Reagent for test for reducing sugars?
Benedict’s solution, in boiling water bath
Test for reducing sugars?
- Add equal vol of benedict’s solution to sample solution
- Leave test tube in boiling water bath for 5 mins
Observation and conclusion for test for reducing sugars?
+ve:
- green precipitate – traces amt
- yellow/orange precipitate – moderate amt
- orange red precipitate – a large amt
-ve: solution remains blue
Reagent for test for fats
Ethanol
Test for fats?
- Add 2cm3 of ethanol to the sample and shake thoroughly
- Decant ethanol into another test tube with 2cm3 of water.
Reagent for test for proteins?
Biuret’s reagent
copper sulfate + sodium hydroxide
Test for proteins?
Add biuret solution
OR
- Add 1cm3 sodium hydroxide solution to 2cm3 of sample solution
- Add 1% copper sulfate solution drop by drop, shaking after every drop
Observation and conclusion for test for proteins
+ve: violet colouration observation
-ve: solution remains blue
