Monomers Polymers And Carbohydrates Flashcards
What is a monomer?
Small repeating units from which polymers/ larger molecules are made
What is a polymer? +examples
A large molecule made up from many repeating monomers. Eg DNA, RNA, cellulose, proteins
What is a condensation reaction?
Joins two molecules together with the formation of a chemical bond and involves the elimination of a molecule of water. Makes polymer from monomers
What is a hydrolysis reaction?
- breaks the chemical bond between monomers/ two molecules using a water molecule
- opposite of condensation
What are the elements monomers and polymers of carbohydrates
Elements- C,H,O
Monomers- monosaccharides
Polymers- Polysaccharides
What are the elements monomers and polymers of proteins
Elements- C,H,O,N (some have S)
Monomers- amino acids
Polymers- polypeptides
What are the elements monomers and polymers of nucleic acids
elements- C,H,O,N,P
Monomers- nucleotides
Polymers- DNA, RNA
Are lipids/triglycerides polymers?
No they are not because they are not made from repeating monomers= CHO
ATP- CHONP
How is a disaccharide formed?
When two monosaccharides join together in a condensation reaction where a glycosidic bond forms between them as a molecule of water is removed
Name the disaccharides
maltose, sucrose, lactose
maltose formation
glucose + glucose
sucrose formation
glucose + fructose
Lactose formation
glucose + galactose
What is a glycosidic bond?
Bond formed by condensation reaction joining molecules in a carbohydrate
structure of glucose
Has 6 carbon atoms in each molecule(hexose sugar)
Elements= C,H,O
has two forms alpha glucose and beta glucose
What are the two types of glucose?
alpha glucose and beta glucose. They’re isomers so have the same formula as each other, but with the atoms connected in a different way.
Structure and info on alpha glucose
OH on bottom.
Maltose, sucrose, lactose
Starch and glycogen
Structure of beta glucose and where is it found
OH on top
Only found in cellulose
How can sugar be classified
Reducing or non reducing
What is included under reducing sugars?
All monosaccharides and some disaccharides eg maltose and lactose
How to test for reducing sugars
Add benedict’s reagent (blue) to a sample.
Heat in a water bath that has been brought to the boil.
Reducing sugar present = coloured precipitate.
Higher concentration of reducing sugar the further the colour change goes- green-yellow-orange-brick red
Can filter solution and weigh precipitate or remove precipitate and use a colorimeter to measure the absorbance of the remaining Benedict’s reagent.
How to test for non-reducing sugars
If result of reducing sugars test negative
Have to break them down into monosaccharides
Get a new sample of test solution, adding hcl and heat in water bath brought to boil
Neutralise sample by adding sodium hydrogen-carbonate
Carry out Benedict’s test as you would for reducing sugar
How is a polysaccharide formed?
when more than two monosaccharides join together by condensation
Cellulose: Functions/bonding/What is it made of?
Provided rigidity and strength to plant cell walls
1-4 glycosidic bonds
Made of long unbranched chains of beta glucose
When the beta molecules bond they form straight chained cellulose chains which are linked by hydrogen bonds to form strong fibres (micro fibrils)
