proteins food chemistry, its structure ,efficiency, deficiency, net protein utilization

protein:
structure
quality
efficiency and deficiency ratio
excess protein in the diet

1. GROUP MEMBERS Rimal Benash (0114) [Protein Deficiency] Zakia Akram (0115) [Excess protein in the diet] Muhammad Saad (0100) [Net protein utilization] Izhar sarfraz (0105) [Protein efficiency ratio] Nawal Haroon (0129) [Quality of protein] Wajeeha Batool (0089) [Protein Structure]

2. PROTEIN STRUCTURE PRESENTED BY: WAJEEHA BATOOL (0089)

3. Biomedical importance Besides forming long chain polypeptide, unit of protein, amino acid have additional functions Nerve transmission Biosynthsis of porphyrines, purine, pyrimidines and urea Short polymer of AA-Peptides Neuroendocrine system harmones, hormone releasing factors, neuromodulators or neurotransmitters Microrganisms;D-L amino acids Therapeutic value :antibiotics bactrim and grameidines A Some may be toxic

4. Structure of proteins Protein catalyze metabolic reactions power cellular motion and forms structural integrity to hair, bones, tendons and teath Human Protein therefore reflects the sophistication and diversity of their biological roles Maturation of a newly synthesized polypeptide into a biological functional protein Require folding into a specific three-dimensional arrangement or conformation During maturation, post translation modification may add new chemical group or remove it transiently

5. Four orders of protein structure The modular nature of protein synthesis and folding are embodied in the concept of orders of protein Structure: Primary protein: linking amino acid residues is a polypeptide chain Secondary structure: stable arrangement of amino acid residues giving rise to recurring structural patterns into geometrically orders unit ; twisting resulting in a-helix or pleated Tertiary structure: the three-dimensional assembly of secondary structural unit to form larger functional units Quaternary structure: it’s the arrangement in a space of protein having two or more polypeptide subunits

6. Four orders of protein structure

7. EXCESS PROTEIN IN THE DIET PRESENTED BY: ZAKIA AKRAM (0115)

8. Protein in diet: Protein is an essential part of healthy diet Reduces fats Helps in weight loss Increases satiety Provides feeling of fullness Helps in retains muscles

9. Excess protein in diet May tout weight loss Or weight gain Bad breathe (ketosis) Constipation Diarrhoea Dehydration Kidney damage Heart/cancer risks Calcium loss

10. Short time interventions Bad breath : This could be in part because your body goes into a metabolic state called  ketosis , which produces chemicals that give off an unpleasant fruity smell. Constipation : High-protein diets that restrict carbohydrates are typically low in  fibre Increasing your water and  fiber intake can help prevent constipation. Tracking your bowel movements may be helpful Dehydration: Hi gh protein diet caused the kidney to produce a more concentrated urine.

11. Short time interventions Diarrhoea : if you’re lactose-intolerant or consume protein sources such as fried meat, fish, and poultry.  Eat heart-healthy proteins instead Calcium loss : Diets that are high in protein and meat may cause calcium loss. This is sometimes associated with osteoporosis and poor bone health. Kidney problems: A high-protein diet may worsen kidney function in people with kidney disease because your body may have trouble eliminating all the waste products of protein metabolism.

12. Long term interventions Cancer risks : C ertain high-protein food such as red meat-based protein are linked to an increased risk of cancer. Eating more red or processed meat is associated with colorectal, breast, and prostate cancer Normal protein range Individual Normal protein intake Excess protein intake Sedentary man 56g/day Above 56g/day Sedentary women 46g/day Above 46g/day High protein diet is required in elderly Scientists are still working on long term side effects of High protein diet

13. PROTEIN DEFICIENCY PRESENTED BY: RIMAL BENASH (0114)

14. What is protein deficiency ? Protein deficiency is when your intake is unable to meet your body’s requirements PRIMARY SYMPTOMS OF PROTEIN DEFICIENCY: Hunger Muscle loss Depression Fatigue Hair loss Fluid retention Slow healing injuries Difficult sleeping

15. Severe protein deficiency may affect your skin, causing redness, flaky skin and depigmentation. It may also cause brittle nails and hair loss. Protein is essential for muscle growth and maintenance. Loss of muscle mass is one of the first signs of inadequate protein intake. Eating too little protein may impair your body’s ability to fight infections, such as the common cold. Your bones too are also at risk. Protein helps maintain the strength and density of bones. Not consuming enough protein content might weaken your bones and increase the risk of fractures. Another common symptom of protein deficiency is fatty liver, or fat accumulation in liver cells. The most severe protein deficiency may lead to diseases like kwashiorkor and marasmus

16. QUALITY OF PROTEIN PRESENTED BY: NAWAL HAROON (0129)

17. Protein quality Protein quality  is the digestibility and quantity of essential amino acids for providing the  proteins  in correct ratios for human consumption. Two types of measurements are used to estimate protein quality: Biological assays Chemical analysis BIOLOGICAL ASSAYS: A biological assay is a biological testing procedure for estimating the concentration of a pharmaceutically active substance in a formulated product or bulk material. It is further divided into: Biological Value (BV) Net Protein Utilization (NPU)  Protein Efficiency Ratio (PER) Net Protein Retention (NPR) Protein Retention Efficiency (PRE) Relative Protein Value (RPV)

18. Biological Value (BV): is the proportion of absorbed protein retained in the body (i.e. taking no account of digestibility ) Net Protein Utilization (NPU): is the proportion of dietary protein that is retained in the body under specified experimental conditions (i.e. it takes account of digestibility; NPU = BV × digestibility). By convention NPU is measured at 10% dietary protein ( ) at which level the protein synthetic mechanism of the animal can utilize all of the protein so long as the balance of essential amino acids is correct. When fed at 4% dietary protein, the result is NPU standardized. If the food or diet is fed as it is normally eaten, the result is NPU operative (NPU op). Protein Efficiency Ratio (PER): is the gain in weight of growing animals per gram of protein eaten . Net Protein Retention (NPR): is the weight gain of animals fed the test protein, minus the weight loss of a group fed a protein‐free diet, divided by the protein consumed.  

19. Protein Retention Efficiency (PRE): is the NPR converted into a percentage scale by multiplying by 16: it then becomes numerically the same as Net Protein Utilization. Relative Protein Value (RPV): is the ability of a test protein, fed at various levels of intake, to support nitrogen balance, relative to a standard protein . CHEMICAL ANALYSIS: Chemical Score is based on chemical analysis of the protein; it is the amount of the limiting amino acid compared with the amount of the same amino acid in egg protein . Protein Score: is similar to Chemical Score, but uses an amino acid mixture as the standard, also known as amino acid score . Essential amino acid index: is the sum of all the essential amino acids compared with those in egg protein or the amino acid target mixture .

20. NET PROTEIN UTILIZATION PRESENTED BY: M. SAAD (0100)

21. What is Net Protein Utilization? The Net Protein Utilization (NPU) of a food is the percentage of protein contained in that food which is retained by the body after the food has been eaten.  • Simple equation for NPU:               Net Protein Utilization= Nitrogen Retained / Nitrogen Retained X100      •This is equivalent to Biological Value (BV) x Digestibility

22. Biological Value (BV) = Nitrogen Retained / Nitrogen x100    Definition Of Biological Value: Biological value (BV) is a measure of the proportion of absorbed protein from a food which becomes incorporated into the proteins of the organism's body.  It captures how readily the digested protein can be used in protein synthesis in the cells of the organism . For accurate determination of BV:  ⦁    The test organism must only consume the protein or mixture of proteins of interest (the test diet) ⦁    The test diet must contain no non-protein sources of nitrogen. ⦁    The test diet must be of suitable content and quantity to avoid use of the protein primarily as an energy source.

23. Some texts explain the relationship between Net Protein Utilization (NPU) and biological value (BV) as: Net protein utilization= Biological Value(BV) x Digestibility    According to above: Digestibility= Nitrogen Retained / Nitrogen Intake As a value, NPU can range from 0 to 1 (or 100), with a value of 1 (or 100) indicating 100% utilization of dietary nitrogen as protein and a value of 0 an indication that none of the nitrogen supplied was converted to protein.  Certain foodstuffs, such as eggs or milk, rate as 1 on an NPU chart.          

24. PROTEIN EFFICIENCY RATIO PRESENTED BY: IZHAR SARFRAZ (0105)

25. Protein efficiency ratio  (PER) is the easiest method of assessing the quality of proteins.   From 1919 until very recently, the PER had been a widely used method for evaluating the quality of protein in food. PER is the gain in body weight divided by the amount of protein consumed: PER= weight gain/protein intake. The animal proteins are called first class proteins because they can maintain nitrogen balance by supplying all the essential amino acids. Plant proteins (on the other hand) are low class proteins because they don’t maintain nitrogen balance.

26. Thus, a protein can have a high biological value if it has the following characteristics: It should contain all the essential amino acids in sufficient amounts. The essential amino acids should be present in an optimal proportion. The protein should be easily digestible. The food industry in Canada currently uses the PER as the standard for evaluating the protein quality of foods.

27. Role of Protein in Performance Protein  is important for any athlete, and fuels many functions within the body. S uch as body tissue growth and maintenance. H ormone and enzyme synthesis. B alanced fluids and electrolyte levels. E xercise-associated muscle damage repair.