Biology notes that will help you get an A*
Notes have been made to cater to the AQA Biology Mark Scheme
Contains everything on the spec for Biological Molecules:
- Carbohydrates
- Lipids
- Proteins
- Enzymes
- DNA
- ATP
- Inorganic Ions
- Water
Intro
Monomer = single repeating unit that can be combined and bonded with other monomers to create a
polymer
Polymer= A long chain of monomers that have been chemically bonded together in a repeating pattern
The process in which they are formed is polymerisation.
An organic molecule is made up of elements that are found in living things such as carbon, hydrogen,
nitrogen, oxygen, phosphorus and sulfur.
Biological molecules
Polypeptides (proteins) are made up of amino Polysaccharides (carbohydrates) are made up of
acids and there is a peptide bond between units of sugars such as glucose, fructose and
each monomer. Proteins are used for growth galactose. There is a glycosidic bond between the
and repair, hormones, antibodies and enzymes. monomers. Carbohydrates are used for respiration.
Lipids are made up of 3 fatty acids and a Polynucleotides (DNA and RNA) are made up of
glycerol. They are used for insulation, nucleotides which have phosphodiester bonds. They
protecting organs, cell membranes and as are used to store genetic information and transfer
energy stores. genetic information from DNA to ribosomes.
Condensation reaction: Hydrolysis reaction:
Joins monomers to form a polymer Breaks polymers down into monomers
: Joins 2 molecules together
&
-
Separates 2 molecules
↑
Removes a water molecule Breaks the chemical bond
-
Chemical bond is formed : Requires addition of a water molecule
, Carbohydrates
Carbohydrates are made from monosaccharides and all contain the elements C, H and O.
I
Monosaccharides and disaccharides are simple carbohydrates
Monosaccharides Disaccharides
Consist of only one sugar molecule Monosaccharides combined in pairs form
They are soluble and sweet-tasting disaccharides
Have the general formula (CH O) where
n can be a number from 3 to 7 (isomers) Glucose + glucose = maltose
Examples are glucose, galactose and fructose Galactose + glucose = lactose
Fructose + glucose= sucrose
Glucose:
A hexose sugar (6 carbon atoms) Polysaccharides:
CHO -
Examples are glycogen, starch and cellulose
Has 2 isomers: alpha and beta -
They are polymers
Bonding via condensation polymerisation:
HO
so
H Oh
a-glucose
5
H
/ 0 H I
B-glucose OH
·
H
/
& HO H
OH HO
glycosidic bond
Cellulose:
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller hennanabiii. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for £8.99. You're not tied to anything after your purchase.
