1. Suggestion box
Please me your questions about nutrition-Answers presented following week
on line notes are not complete transcripts of lectures

2. Student help –tutors- I am your best tutor
Nutritional assessments or essays-any questions?- anything at all that I may clarify or or otherwise help with nutritional assessments or essays?
Waist circumference
Exam question for December 2018
Self-assessment handouts

3. http://www. theglobeandmail

4. Lecture 3a- 19 Sept. 2018
CARBOHYDRATES I

5. Overview of lecture 3a
Carbohydrates
-introduction
-structure and classification
-IDATME of carbohydrate
-lactose intolerance
-utilisation-carbohydrate metabolism

6. Introduction to carbohydrates p. 96-97
-commonly referred to as sugars but this is not completely accurate
-contain carbon
-contain hydrogen and oxygen in the same proportion as water

7. Introduction to carbohydrates continued p 97
- yield energy (glucose) and store energy (glycogen)
-very important for nerve function among many other functions

8. Structure and classification
Simple p
monosaccharides
disaccharides

13. Carbohydrate structure classification continued
Complex
oligosaccharides–
3-10 sugar units

14. Carbohydrate structure classification continued
Complex continued
Polysaccharides p
many sugar units strung together
glycogen
starch
fibre

15. Figure 4.9: Starch and Cellulose Molecules Compared (Small Segments).
The bonds that link the glucose molecules together in cellulose are different from the bonds in starch (and glycogen). Human enzymes cannot digest cellulose. See Appendix C for chemical structures and descriptions of linkages.
Fig. 4-9, p. 102

17. Figure 4.8: Glycogen and Starch Molecules Compared (Small Segments).
These units would have to be magnified millions of times to appear at the size shown in this figure. For details of the chemical structures, see Appendix C.
Fig. 4-8, p. 101

19. Carbohydrates digestion
p. 101
mouth-amylase
stomach-acid-minimal

20. Carbohydrate digestion continued
small intestine
-most of carbohydrate digestion in body occurs in the small intestine:
-small intestine uses:
pancreatic carbohydrases
and small intestinal carbohydrases

21. Figure 4.10: Carbohydrate Digestion in the GI Tract.
Fig. 4-10, p. 104

22. Carbohydrate digestion continued
minimal digestion by humans of fibres and some resistant carbohydrates (e.g. resistant starches)

23. Carbohydrate digestion continued

24. Lactose intolerance
intolerance is not an allergy-allergies due to proteins and other agents that produce an allergic response

25. Lactose intolerance is due to :
reduction in the activity of lactase
- reduction can be up to % loss over time
strong genetic component

26. Symptoms of lactose intolerance
gas, acids from bacterial digestion of lactose
resulting in cramps, abdominal distension, diarrhea and bloatingG

27. Consequences of lactose intolerance
-have to find alternate non-dairy calcium sources or
-use an oral lactase or
-use a lactase added to dairy product

28. Carbohydrates absorption
glucose-active transport
fructose-facilitated diffusion

29. Carbohydrates transport
glucose via blood

30. Metabolism-Utilisation of Carbohydrates
Insulin–glucose into cells for energy or to glycogen (primarily muscle and liver)
-glycogen-storage form of glucose primarily in muscle and liver
Glucagon- glycogen to glucose in cell – glucose leaves the cell and enters the blood where it goes to other cells to be used as energy

31. Figure 4.12: Maintaining Blood Glucose Homeostasis.
Fig. 4-12, p. 109

32. Carbohydrate excretion
urine (in diabetes there can be glucose in the urine) and water-a metabolite of glucose in everyone
faeces-whole carbohydrate
breathing metabolite of glucose- CO2
saliva?
sweat (water- a metabolite of glucose)

33. -blood glucose homeostasis in the body
Next lecture
-blood glucose homeostasis in the body
-functions of carbohydrates in the body