1. Why do we need food? What is in the food that you eat?
Biochemistry of food!
Why do we need food?
What is in the food that you eat?

2. Section 8.1 Carbohydrates, Fats, and Proteins Objectives
Name the three classes of nutrients that supply your body with energy.
Explain how the body obtains energy from foods.
Describe the roles that carbohydrates, fats, and proteins play in your body.

3. Quick Quiz Which of these statements are always true?
Which are sometimes true? Which are always false?
Foods that are high in calories are unhealthy.
You should avoid foods with sugars in them.
You should avoid fats in your diet.
Vegetarian diets are low in protein.
Snacking is bad for you.

4. Nutrition
Nutrition = the process of obtaining the food necessary for health and growth.

5. Foods Supply Nutrients
Nutrients = substances that helps with body processes
6 classes of nutrients: carbohydrates, fats, proteins, vitamins, minerals, and water.
Carbs, fats, and proteins can all be used by the body as sources of energy.

6. Foods Supply Energy The foods you eat are your body’s energy source.
You need energy to maintain your body temperature, keep your heart beating, and enable you to understand what you read.

7. Fuel for Your Body
When your body uses the nutrients in foods, a series of chemical reactions occurs inside your cells. As a result, energy is released.
Metabolism is the chemical process by which your body breaks down food to release as energy.
Metabolism also involves the use of this energy for growth and repair of body tissue.

8. What are Calories?
Calories = amount of energy released when nutrients are broken down
The more calories a food has, the more energy it contains.

11. Carbohydrates made of C, H, O
MAIN source of short-term energy for your body

12. CARBS! Carbs = sugar 3 types of carbs: Monosaccharides Disaccharides
Polysaccharides
Saccharon = Latin for “sugar”
Saccharin = brand name for artificial sweetener
Saccharomyces = Baker’s yeast (for making bread)

13. Examples of carbs: (Everything here is full of sugar!)

14. Understanding: Monosaccharide monomers are linked together by condensation rxns to form disaccharides & polysaccharide polymers.
Monosaccharides single sugars Molecular formula = C6H12O6 e.g. glucose, galactose, fructose, ribose

15. Disaccharides
Double sugars Molecular formula = _____________??? e.g.

16. Polysaccharides
Many sugars Polymers e.g.

17. Complex Carbohydrates
Simple Carbohydrates
Simple carbohydrates are sugars that enter the bloodstream rapidly and provide quick energy.
Simple carbs provide calories but few vitamins and minerals.
Complex carbohydrates are made up of sugars that are linked together chemically to form long chains.
Starch – a food substance that is made and stored in most plants
Provide long-lasting energy
Complex Carbohydrates

18. Carbohydrates can be… Simple Carbs Complex Carbs
- Fruits - Honey - Milk - Sugars added to cookies, candies, soft drinks
-Grains (bread & pasta)
Vegetables (potatoes & beans)
Rice
Cereals
Wheat
Tortillas
Whole-wheat rolls

19. Fiber Fiber = type of complex carb found in plants (can’t be digested)
A high-fiber diet
helps prevent constipation
may reduce colon cancer
May prevent heart disease

20. Insoluble vs Soluble Fiber
Binds with water to help produce bowel movements (prevent constipation).
Associated with reduced risk of colon cancer.
Good sources: wheat products, leafy vegetables, and fruits.
Eating foods with soluble fiber reduces your blood cholesterol level and your risk of developing heart disease.
Good sources: wheat, bran, barley, rye, oats, whole grain pasta,breads, cereals…

21. Fiber

22. Your Body’s Energy Reserves
At a meal, you usually eat more carbohydrates than your body can immediately use.
The extra glucose is converted into a type of starch called glycogen.
Glycogen is stored in the muscles and when you need energy, it is converted to glucose.
If you eat so many carbohydrates that the body’s glycogen stores are full, then the excess carbohydrates are stored as fat instead.

23. Daily Carbohydrate Intake
Nutritionists recommend that 45-65% of a person’s daily calorie intake come from carbohydrates.
It is better to eat foods rich in complex carbohydrates rather than simple carbohydrates.

24. Fats
Made of C, H, O
Fats supply energy, form cells, maintain body temp, and protect nerves.
provides long-term energy and helps body store and use vitamins

25. Unsaturated Fats
Unsaturated Fats have at least one unsaturated bond in a place where hydrogen can be added to the molecule.
Unsaturated fats are usually liquid at room temp
Unsaturated fats are classified as either monounsaturated fats or polyunsaturated fats.

26. Saturated Fats
Fats that have all the hydrogen the carbon atoms can hold are called saturated fats.
Saturated fats are usually solid at room temp
Too much saturated fat in your diet can lead to heart disease.

27. Understanding: Fatty acids can be saturated, monounsaturated or polyunsaturated

28. Saturated (max # of H’s) vs Polyunsaturated (less room for H’s)

30. Daily Fat Intake
Nutritionists recommend that 20-35% of your calories come from fat, primarily unsaturated fat.

31. Cholesterol
Cholesterol is a waxy, fatlike substance found only in animal products.
Need certain amount of cholesterol to make cell membranes, nerves, sex hormones, and substances that help digest fat

32. Trans Fats
Trans fats are made when manufacturers add hydrogen to fat molecules in veg oils.
Trans fats are found in margarine, chips, and commercially baked goods.
Trans fat seems to have many of the negatives of saturated fat.

33. Understanding: Unsaturated fatty acids can be cis or trans isomers
Understanding: Unsaturated fatty acids can be cis or trans isomers * Double bond in a CIS unsaturated fatty acid produces a kink in the molecule because a double bond cannot rotate. So they can’t line up next to each other in an ordered fashion as the trans isomers, and so don’t solidify as readily as trans fatty acids. CIS = Liquid at room temp – OILS!

34. Trans fatty acids

35. Fatty Acids
CIS
TRANS
Straight chain Line up evenly Higher melting point Solid at room temp Margarine, butter, processed, fried Produced artificially by partial hydrogenation of vegetable or fish oil Bad for you!
Kink at every double bond Can’t line up evenly Lower melting point Liquid at room temp OILS Natural fat Good for you!

38. Just Say No to Trans Fats!

39. Lies!

41. Leading causes of death in US

43. Application: Scientific evidence for health risk of trans-fats and saturated fats
CHD IS THE #1 KILLER OF MEN AND WOMEN IN THE US!!! Coronary Heart Disease (CHD) = coronary arteries (that supply blood to the heart itself) become partially blocked by fat, leading to blood clot & heart attack!

44. Atherosclerosis

45. Proteins
Made of C, H, O, N
Needed for growth, and to build and repair body tissues

48. Amino Acids
* = building blocks that make up proteins

49. Essential Amino Acids
The nine amino acids that the body cannot manufacture are called essential amino acids.

50. Complete and Incomplete Proteins
Protein from animal sources is complete protein.
It contains all nine essential amino acids.
Most protein from plant sources is incomplete protein.
It lacks one or more of the essential amino acids.

51. Proteins for Vegetarians
Daily Protein Intake
Nutritionists recommend that 10-35% percent of your calories come from proteins.
People who don’t eat meat can combine two or more plant protein sources that, taken together, provide all the essential amino acids.
Proteins for Vegetarians

52. Vocabulary
nutrient
A substance in foods that the body needs to regulate bodily functions, promote growth, repair body tissues, and obtain energy.
metabolism
The chemical process by which the body breaks down food to release energy.
calorie
Unit for the amount of energy released when nutrients are broken down.
carbohydrate
A nutrient made of carbon, hydrogen, and oxygen and that supplies energy.
fiber
A way of dealing with an uncomfortable or unbearable feeling or situation.

53. Vocabulary
fat
A nutrient made of carbon, hydrogen, and oxygen; supplies energy, forms cells, maintains body temperature, and protects nerves.
unsaturated fat
A fat with at least one unsaturated bond in a place where hydrogen can be added to the molecule.
saturated fat
A fat that has all the hydrogen the carbon atoms can hold. A fat that has all the hydrogen the carbon atoms can hold.
cholesterol
A waxy, fatlike substance that is found only in animal products.

54. Vocabulary
trans fat
The type of fat produced when manufacturers add hydrogen to the fat molecules in vegetable oils.
protein
A nutrient that contains nitrogen as well as carbon, hydrogen, and oxygen; needed for the growth and repair of body tissues.
amino acid
Small units that are bound together
chemically to form proteins.

55. Questions Which 3 classes of nutrients supply the body with energy?
Define the term metabolism. How is metabolism related to the nutrients in food?
What roles do the following nutrients play in the body? A. carbohydrates B. fats C. proteins
What is cholesterol? How does diet affect cholesterol levels in the blood?
Name a circumstance during which you might use your body’s stores of glycogen.
How do saturated fats differ from unsaturated fats? Name 2 sources of each type of fat.
Suppose that you ate 2,500 calories/day. Of those calories, 1,200 calories were from carbs, 875 from fats, and the rest from protein. What % of your total day’s calories came from carbs, from fats, and from protein?