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Page 1

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Molecules, Biodiversity, Food and Health

Biological Molecules
Proteins
Amino Acids
Structure
Monomer of proteins
Join to form backbone of polypeptide
20 types naturally occurring
Differences caused by R-groups
Synthesis
Plants: Convert nitrates into amino group and bond to organic part made from photosynthesis products
Animals: Proteins broken down, 8 essential…

Page 2

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Molecules, Biodiversity, Food and Health
Collagen
Structure
3 polypeptide chains wound around each other
H-bonds between chains = strength
Each collagen - strength
Collagen fibril collagen fibre

Function
Arteries - collagen layer prevents bursting walls at high
pressure
Tendons mostly made of collagen
Bones formed from collagen
Cartilage and connective…

Page 3

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Molecules, Biodiversity, Food and Health
Polysaccharides
Polysaccharide Structure Function
Starch Made of 2 polymers: Storage in plants
Amylose: polymer of glucoses joined by a-1,4-glycosidic bonds. Forms
helix with 6 molecules per turn & about 300 per helix



Amylopectin: polymer of glucoses jonied by a-1, 4-glycosidic bonds but
with branches of…

Page 4

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Molecules, Biodiversity, Food and Health
Cell membranes
All biological membranes are made of a phospholipid bilayer
Phospholipids have a hydrophobic head and hydrophilic tail
Partial permeability - substances don't move across the barrier
indiscriminately

Scents
Most naturally occurring fats and oils are the fatty acid esters of
glycerol
Esters with…

Page 5

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Molecules, Biodiversity, Food and Health
Tests
Carbohydrates
Starch
Add solution of potassium iodide to sample
If starch is present, the solution changes from yellow-
brown blue-black




Reducing sugars
Monosaccharide and disaccharide (molecule can react
with other molecule by giving electrons to them
When reducing sugar is heated to 80° with…

Page 6

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Molecules, Biodiversity, Food and Health

Nucleic Acids
Polynucleotides
DNA
Structure
Deoxyribonucleic acid
- Phosphate group
- Deoxyribose
- Organic base
Base can be a purine ­ two rings
- Adenine
- Guanine
Base can be a pyrimidine ­ one ring
- Cytosine
- Thymine
These components link together to form…

Page 7

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Molecules, Biodiversity, Food and Health
RNA
Structure
Ribonucleic acid
- Phosphate group
- Ribose sugar
- Organic base
Single stranded
Contains uracil instead of thymine
RNA uses information from the DNA to make
proteins
- Determines the primary structure of a
protein


DNA replication
Semi-conservative replication
DNA replication takes place…

Page 8

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Molecules, Biodiversity, Food and Health

Enzymes
Enzyme action
Structure
Structure
Globular proteins
- Specific tertiary structure
Biological catalysts

Location
Intracellular
- Catalyse reaction in the cell
- E.g. hydrolases inside lysosomes
Extracellular
- Released from cells onto food
- Break down organisms into nutrients
- E.g. amylase which hydrolyses starch…

Page 9

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Molecules, Biodiversity, Food and Health
Changing conditions
Effect of changing concentration
Enzyme concentration
As enzyme concentration increases, more active sites become
available
- A maximum reaction rate will be reached when all the substrate molecules
occupy active sites
The substrate concentration becomes the limiting factor


Substrate concentration
As substrate concentration…

Page 10

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Molecules, Biodiversity, Food and Health
Inhibitors
Enzyme inhibitors
A substance that slows down or stops an enzyme-controlled reaction
It is possible for other molecules to bind with the active site is it is similar to the substrate
Creates competition for it and the substrate for the site
Inhibitors that seriously…

Comments

Zechariah

I love this please make  one for unit 1 which is cell exchange and transport OCR!!!!!!!!

Recommend this BRILLIANT

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