Carbohydrates and Proteins Pack 1

Smaller units from which larger molecules are made up of

Polymers are molecules made from a large number of monomers joined together

• Any of the three;
• Monosaccharides
• Amino acids
• Nucleotides

A condensation reaction is one which joins two molecules together with the formation of a chemical bond and involves elimination of a water molecule.

A hydrolysis reaction is one which breaks a chemical bond between two molecules and involves the use of a water molecule.

Monomers (of which larger carbohydrates are made up of)

Polymers

Condensation Reactions

Monomers

Hydrolysis reactions

• Carbon
• Hydrogen
• Oxygen
• Nitrogen

Proteins are polymers made up of one or more chains of amino acid monomers known as polypeptides.

• An amino group
• a carboxylic group
• A Variable group

The R group/variable group

It's properties it has

dipeptide

peptide bond(s)

a strong covalent bond

Amino group ; R Group ; carboxylic acid group

a polypeptide chain

• 1. Primary structure
• 2. Secondary Structure
• 3. Tertiary Structure
• 4. Quaternary Structure

This is the sequence of amino acids in a polypeptide chain

(amino chain)

This is further folding of the polypeptide chain. As they fold they allow the formation of weak H-bonds which produce particular secondary structures


(hydrogen bonds between amino acids)

• a-helix
• B-pleated sheet

fibrous proteins such as keratin (hair and nails)

globular proteins such as enzymes

further folding where the whole chain (including secondary structures) folds into a specific shape. 

It is stabilised by ionic bonds, hydrogen bonds and disulphide bonds.


(alpha helix and beta-pleated sheets attract)

A covalent bond between sulphur-containing amino acids

high temperatures and extremes of pH

Hydrogen bonds break first, as they are very weak bonds. The disulphide bonds are stronger and can withstand higher temperatures.

When the bonds break, the tertiary structure is lost and the protein loses its function.

The specific shape of the tertiary structure of the protein

This is found in proteins made up of more than one polypeptide chain -----> 2 alpha chains or 2 beta chains

(more than one chain joined together)

Fibrous and globular

These form long chains running parallel to each other with cross-bridges between the chains. This produces very stable molecules.

Collagen is a protein found in tendons which join muscle to bone

unbranched polypeptide chain

the polypeptide chain forms an a-helix. 

lots of amino acid glycine helps close packaging

the polypeptide chain is further twisted

3 polypeptide chains are wound together with covalent bonds between amino acids of adjacent chains

• Collagen is found in tendons which join muscle to bone.
• Tendons need to be very strong and not elastic.
• Cross-links between adjacent polypeptide chains in the fibres proved strength and stability.
• The points where one collagen molecule ends and another one starts are spread throughout the fibres, rather than being at the same point

Enzymes and haemoglobin

metabolic functions

• add potassium hydroxide and copper sulphate (buret solution) to a sample of the solution to be tested
• if the solution turns lilac then a protein is present
• if the sample does not contain protein, only the pale blue colouration of the copper sulphate is seen

carbon, hydrogen and oxygen

basic molecular units/monomers of which other carbohydrates are composed

glucose, galactose and fructose

soluble and sweet

hexose

It contains 6 carbon atoms

C₆H₁₂O₆

C₅H₁₀O₅

C₃H₆O₃

Photosynthesis

respiration

different structural form

a-glucose and B-glucose

The hydroxyl group points down in a-glucose and points upwards in B-glucose