Importance of proteins

Question 1

what are the 5 points for importance of proteins?

Answer 1

1. Protein structure and enzymes
2. Resting potential
3. Immunity
4. Control of blood glucose
5. Control of water potential of the blood

Question 2

what is the AO1 for proteins and enzymes?

Answer 2

• describe the primary/secondary/tertiary structure of proteins
• eg the primary structure of a polypeptide is a chain of amino acids linked by peptide bonds through condensation reactions
• tertiary structure is formed though hydrogen/ionic/disulphide bonds
• enzymes have a tertiary structure that determines the active site of the enzyme
• allowes ES complexes to form

Question 3

what is the AO2 for importance of enzymes?

Answer 3

• enzymes act as biological catalysts, lowering the activation energy to allow metabolic pathways to occur at body temperature
• enzymes are important in the digestion of carbohydrates
• describe the digetsion of carbohydrates using salivary and pancreatic amylase, as well as membrane bound disaccharides to produce glucose, fructose and galactose so that they are small enough to be absorbed into the bloodstream

Question 4

what is the AO1 for use of proteins in the resting potential?

Answer 4

• transport proteins embedded in the neurone membrane eg sodium potassium pump and potassium ion leakage channels
• describe their involvemnt in maintaining the resting potential and production of electrochemical gradient with potential diffferences across membrane being -70mV
• membrane impermeable to sodium ions so they build up on outside

Question 5

what is the AO2 for importance of producing the resting potential using proteins?

Answer 5

• the proteins are important as they allow the establishment of resting potential
• this allows for the action potential to take place as there is a high concentration of sodium ions outside the axon so sodium ions can diffuse into the axon to reach threshold potential and all voltage gated sodium ion channels open causing depolarisation
• allows transmission of impulses between neurones

Question 6

what is the AO1 for role of proteins in immunity?

Answer 6

• the role of proteins in terms of antibodies and antigens
• antibodies are proteins - describe their quaternary structure and there production through the humoral response and secretion by the plasma b cells
• each one has a specific variable region so it can bind to particular complementary antigens

Question 7

what is the AO2 for the importance of proteins in immunity

Answer 7

• these antibodies are controlling your immunity
• allows for agglutination, neutralisation of toxins from pathogens, act as markers attracting phagocytes to engulf pathogens in phagocytosis
• provides long term immunity
• have roles in both passive and active immunity

Question 8

what is the AO1 for proteins role in control of blood glucose?

Answer 8

• insulin is a protein hormone and insulin receptor is a protein
• they are involved in controlling blood glucose concentration
• explain how insulin lowers blood glucose concentration

Question 9

what is the AO2 for importance of proteins in blood glucose control?

Answer 9

• the importance is that it lowers blood glucose concentration so that you dont have too negative of water potential, which would cause water to leave the cells, moving to the blood by osmosis and it would increase blood pressure
• wouldn’t be able to create glycogen stores without insulin
• unregulated blood gluocse leads to type 1 diabetes

Question 10

what is the AO1 for the importance of proteins in control of water potential

Answer 10

• ADH is a protein hormone that binds to receptors on the cell surface membrane of the collecting duct and the distal convoluted tubule
• production in the hypothalamus, and the release from the posterior pituitary into the blood
• causes aqauporins to move to surface making membrane more permeable to water so more water reabsorbed back into blood by osmosis so you lose less water in urine

Question 11

what is the AO2 for the importance of proteins in control of water potential of the blood

Answer 11

• controlling water reabsorption to maintain that constant level of water potential of the blood, because if it was too negative you are going to be dehydrated and that can cause dehydration crenation of cells
• if too much water in the blood - results in water moving into the cells by osmosis causing them to split or lysis