Protein 1.1.2 Sample Answer (2014) PDF

# Protein 1.1.2 ## Low Cost Protein Foods (3 @ 3mk) | Name Protein Food | Meal | Healthy Eating | |:---|:---|:---| | Eggs (32cents each) | Lunch | Cheese Omlette / Fresh Green Salad, 3 | | Pulse Vegetables (Tin Kidney Bean) | Meat Substitute | Bean Chilli / Brown Rice (Kidney, Butter, Black Beans)...

# Protein 1.1.2 ## Low Cost Protein Foods (3 @ 3mk) | Name Protein Food | Meal | Healthy Eating | |:---|:---|:---| | Eggs (32cents each) | Lunch | Cheese Omlette / Fresh Green Salad, 3 | | Pulse Vegetables (Tin Kidney Bean) | Meat Substitute | Bean Chilli / Brown Rice (Kidney, Butter, Black Beans) 3 | | Quinoa (500g / €1.09 Tesco) | Dinner | Grilled Chicken / Quinoa / Chor grilled vegetables 3 | ## Classification of Protein (Simple / Conjugated) - 3 groups @ 4mus each - 6 points @ 2mus each - 24mus. ### Simple - Animal (4) - Globular (2) - Ovalbumin (egg white) - Keratin (nails) - Lactalbumin (milk) - Fibrous (2) - Collagen (skin) - Plant (4) - Glutelins (2) - Glutenin (wheat) - Gliadin (wheat) - Prolamines (2) - Zein (maize) - Oryzenin (rice) ### Conjugated - Lipoproteins - LDL (low density Lipoprotein) - low cholesterol (blood) - Lecithin (egg yolk) - RNA (genetic material) - Nucleoproteins - DNA (cells) - Chromo proteins - Haemoglobin (blood) - Myoglobin (muscle) - Phospho proteins - Casein (milk) - Vitellin (egg yolk) ## Supplementary Value / Complementary Role (8mk) [See Sample answer Q1.B. Protein 2020] ## Structure (Primary/secondary / Tertiary) (3 @ Smk) ### Primary Structure - Primary structure of protein refers to the order sequence that amino acids appear on a protein chain. - Example of a protein chain 'sequence' - Val = Valine - Leu = Leucine - Iso = Isoleucine - Gly = Glycine ``` Va - Leu - Iso - Gly - Leu ``` - The linkage between the amino acids on each protein chain is called peptide linkage where one molecule of water is eliminated in a condensation reaction each time any two amino acids chemically join together. ### Secondary Structure - Secondary structure of protein refers to further linking on the protein chain ie. beyond peptide linkage. Usually due to the formation of disulphide bonds / bridges and hydrogen bonds resulting in protein chains having spiral or helix structures. - Disulphide bridges can form between two neighbouring protein chains. ``` Cysteine HSCH₂ - C = O / N H H R = HSCH₂ (contains SH group ie. Sulphur Containing group) ``` - The SH group of the amino acid cysteine on one protein chain "bonds" with the SH group of another cysteine on a neighbouring chain forming a disulphide bond / bridge. This results in the protein chains having a double helix structure. ``` PROTEIN CHAIN No.1 -Cyst -va -leu -iso - cyst - SH | SH | SH | SH PROTEIN CHAIN No. 2 -Cyst - Iso -ly - leu - cyst - ``` - Hychoger bonds are weaker than disulphide bonds / bridges. - They form when the H (Hychoger) of the serine on one protein chain (amino group) of the Olt (Hydroxyl group) of the COOH (carboxyl group) of tyrosine on the neighbouring protein chain. ``` Protein Chain No.1 Serine - H - O - tyrosine ↑ Hydroger Bond. ↓ serine - H - O - tyrosine Protein Chain No. 2. ``` ### Tertiary Structure - Tertiary structure refers to the pattern of folding on protein chains, where the protein chains have a three dimensional (3D) structure. This structure is maintained by the presence of cross links. - Globular proteins have a 3D structure that is roughly spherical and resembles a ball of wool or twine eg. Casein - milk / Ovalbumin - egg white. ``` AP AR AA AA இ AA ``` - Fibrous proteins have a 3D zig zag structure which gives the protein elastic properties' eg. - gluten (wheat) / - collagen (skin) ``` eg. Gluten is Composed of Two interlocking, coctide chains. ``` ``` Glutenin XXXXXXXXXX Gliadin ```