1. Food /exercise diary or essay option-questions?
-if consuming the recommended number of
servings for each food group for one’s
age and gender one is most likely meeting
all of one’s dietary nutrient requirements.
-hence no worries about consuming foods
without a food label
No discussion of pathology in the 2104 essay
option- any questions on essay or dietary assessment
option?
94/80
AA displacement

2. LECTURE 6A PROTEINS
10 Oct. 2018

3. Proteins defined but proteins also have nitrogen
contain carbohydrate, hydrogen and oxygen just like lipids and carbohydrates
but proteins also have nitrogen
shape and hence function depends on amino acid side chains

6. Amino definition Building blocks Non-essential Essential
Amino acids
   
Amino definition
Building blocks
Non-essential
Essential
Conditionally essential

8. Protein structure considerable variety of proteins
variety comes from lots of different shapes and hence functions of protein
loss of shape-loss of function
heat, acid, beating, chemically (e.g. urea)
get easier digestion and occasionally colour change

9. Stomach-acid and pepsin Small intestine lumen-oligopeptides,tri- and
 IDATME of proteins and amino acids
Ingestion - oral, tube (whole protein, or protein hydrosylates or amino acids), IV (amino acids only)
Digestion
Stomach-acid and pepsin
Small intestine lumen-oligopeptides,tri- and
dipeptides, and amino acids formed
Small intestine wall-tri- and dipeptides formed
into single amino acids
Issues of dietary enzymes and pre-digested proteins

10. IDATME of proteins and amino acids Digestion

11. IDATME of proteins and amino acids continued
Animal proteins are generally very digestible and plant proteins are generally less digestible than animal proteins
Proteins vary in their digestibility due to variable dietary protein structures as well as other food ingredients and hence accessibility to protein digestive enzyme active sites
Complete plant proteins
-soy - very digestible - close to many animal proteins’ digestibility
-quinoa - about 10 % less digestible than soy

12. IDATME of proteins and amino acids continued
Digestibility affects availability (WWFQ) of essential and non-essential and conditionally essential amino acids

13. IDATME of proteins and amino acids continued
Absorption
-carriers

14. Blood-amino acids alone or as part of proteins
IDATME of proteins and amino acids continued
Transport
Blood-amino acids alone
or as part of proteins

15. PROTEIN METABOLISM DNA to Protein
DNA to Protein

16. Figure 6.7: Animated! Protein Synthesis.
Fig. 6-7, p. 188

17. Figure 6.7: Animated! Protein Synthesis.

18. PROTEIN METABOLISM
Proteins broken down to amino acids and amino acids then broken down to urea and water
Also have synthesis of non-essential amino acids in the body
Essential and non-essential amino acids and conditionally essential amino acids are made into proteins

19. PROTEIN EXCRETION
Faeces- undigested protein and unabsorbed amino acids
Urine- urea and water
Sweat- metabolic water formed by amino acid catabolism
Respiration- CO2 and water from amino acid catabolism
Saliva?-whole proteins

20. STRUCTURE IN THE BODY Primary Secondary Tertiary Quaternary Globular
STRUCTURE IN THE BODY
Primary
Secondary
Tertiary
Quaternary
Globular
Fibrous
Undone - heat, chemically, mechanically, pH

23. PROTEINS ESSENTIAL OR NOT?
Yes- functions

24. PROTEIN FUNCTIONS P
CHAPERONES

25. PROTEIN FUNCTIONS CONTINUED
ENZYMES
proteases
carbohydrases
lipases

26. PROTEIN FUNCTIONS CONTINUED NUTRIENT AND STORAGE PROTEINS
nutrient proteins
ovalbumin
casein
storage proteins
ferritin

27. PROTEIN FUNCTIONS CONTINUED
TRANSPORT PROTEINS
lipoproteins
hemoglobin
glucose transporters
amino acid transporters
sodium potassium transporter

28. PROTEIN FUNCTIONS CONTINUED CONTRACTILE OR MOTILE PROTEINS
actin
myosin

29. PROTEIN FUNCTIONS CONTINUED STRUCTURAL PROTEINS
collagen
elastin
keratin

30. PROTEIN FUNCTIONS CONTINUED DEFENCE PROTEINS
antibodies
fibrinogen
thrombin

31. PROTEIN FUNCTIONS CONTINUED
REGULATORY PROTEINS
insulin-part of blood glucose level control
parathyroid hormone-helps control calcium and phosphorous levels in the body

32. PROTEIN FUNCTIONS CONTINUED RECEPTOR PROTEINS
insulin
LDL receptor

33. PROTEIN FUNCTIONS CONTINUED SIGNALLING PROTEINS
insulin sets off signalling cascade for
glycogen synthesis

34. PROTEIN FUNCTIONS CONTINUED
Energy

35. PROTEIN FUNCTIONS CONTINUED
In summary proteins:
Bind (B)
Catalyse (C)
Build (B)