natures chemistry Flashcards
How are proteins formed?
Through a condensation reaction
What is a condensation reaction?
When amino acids join together and water is removed. A peptide link is formed.
What are essential amino acids?
They are amino acids that the body needs but cannot be made, therefore it’s taken in through the diet
How do you break down proteins
Through a hydrolysis reaction
Proteins are….
Major structural material found in animal tissues
2 types of proteins
Fibrous- long, spiral chains folded into long thin shapes. Strong and insoluble in water
Globular- involved in regulation. Spiral chains and folded into spherical shapes and soluble in water
During cooking …
Proteins are denatured
What groups do amino acids have?
A carboxyl group (COOH)
An amino acid group (NH2)
what’s another name from glycerol?
propane-1,2,3-troil
fatty acids are …
saturated. so they are closely packed together therefore the melting and boiling points are higher cause the bonds are closer and stronger LDF’s
oils are …
unsaturated. so they have kinked bonds so they aren’t closely packed together therefore they have weaker LDF’s
oxygen to hydrogen ratio
oxidation is increase
reduction is decrease
primary alcohol oxidation
primary alcohols to aldehyde - done by acidified dichromate solution
aldehyde to carboxylic acid - done by tollens reagent
secondary alcohol oxidation
secondary alcohol to ketone - done by acidified dichromate solutions
tertiary alcohol oxidation
no oxidation
primary alcohol placement
carbonyl functional group joined to carbon
secondary alcohol placement
carbonyl functional group joined onto 2 other carbons
tertiary alcohol placement
carbonyl functional group joined onto 3 other carbons
many flavour and aroma molecules are …
aldehydes
oxidation of foods gives it a …
rancid flavour
antioxidants prevent…
unwanted oxidation from occurring
antioxidants are;
easily oxidised
they themselves are oxidised instead of the compounds they are protecting
easily identified as the substance being oxidised in a redox reaction
What’s the test to find unsaturated compounds
Bromine test
Formation of an ester
Alcohol + carboxylic acid -> ester + water
Methanol + ethanoic acid -> methyl ethanoate + water
Saturated-
Single bonds
Unsaturated-
Double bonds
What happens to saturated bonds with bromine water
Saturated do NOT decolourise bromine, stays orange
What happens to unsaturated bonds with bromine water
Unsaturated bonds decolourise bromine solution quickly
Isomers are compounds…
With the same molecular formula but different structural formulae
Physical properties of compounds can be predicated by considering…(4)
-presence of OH or NH bonds
- spatial arrangement of polar covalent bonds
-polarities of solute and solvent
-molecular size of molecules
What is the OH group
Hydroxyl
What is the COOH group
Carboxyl
What do carboxylic acids name finish with
-oic acid
What’s the name to describe water that has high levels of dissolved metal ions
Hard water
What do aldehydes finish with and what is there structure
-al
COH
What do ketones finish with and what is there structure
CO
-one
What functional group do aldehydes and ketones have
Carbonyl functional group
O
=
-C-
Antioxidants are…
-substances that are easily oxidised
- they are oxidised instead of the compounds they protect
- can be identified as the substance being oxidised in a redox reaction
What does exposure to UV light cause
It provides sufficient energy for bonds to be broken
Causes sunburn and accelerates skin aging
Sun-block prevents Uv from reaching the skin
What are free radicals
They are atoms or molecules with an unpaired electron
UV light breaks the bonds to form free radicals
They are highly reactive due to the unpaired electron
Definition of an emulsifier
It prevents polar and non-polar substances from separating into layers
