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

2. 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]

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

4. 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

5. 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

6. 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

7. Four orders of protein structure

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

9. 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

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

11. 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: High protein diet caused the
kidney to produce a more concentrated urine.

12. 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.

13. Long term interventions
• Cancer risks : Certain 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

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

15. 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

16. 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

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

19. 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)

20. • 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 (𝑁𝑃𝑈10) 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.

21. • 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.

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

24. 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

25. 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.

26. • 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.

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

29. 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.

30. 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.

31. Role of Protein in Performance
Protein is important for any athlete, and fuels many functions
within the body.
Such as body tissue growth and maintenance.
Hormone and enzyme synthesis.
Balanced fluids and electrolyte levels.
Exercise-associated muscle damage repair.