Learning Objectives

At the end of this session, 1.I can categorize the biological molecule as a carbohydrate or lipid according to their structure and function (STEM_BIO11/12-Ii-j-15).2.I can explain the role of each biological molecule in specific metabolic processes(STEM_BIO11/12-Ii-j-16).

Words to rememberMacromolecules Polysaccharides Saturated fatty acids

Polymer Starch Unsaturated fatty acids

Monomer Glycogen Trans fat

dehydration Cellulose Phospholipids

Hydrolysis Chitin Steroids

Carbohydrates Lipids cholesterol

Monosaccharides fats

disaccharides Fatty acids

Glycosidic bond Triacylglycerol

Activity: Food Nutrition Labels 1. How many servings are in this container?2. Would you agree that this is the reasonable amount of

food you would consume per serving? How many total food calories (C) are in this container?

3. How much fat is present in one serving? What kind of fat?4. What is the importance of consuming fats in our diet?5. How much carbohydrates are present in one serving?6. What kind of carbohydrates? What is the importance of

consuming carbohydrates in our diet?7. Decide on whether this food sample can be eaten often or

sparingly and justify.

What is calorie?• A measure of energy in food

• An average man needs about 2500 kCal/day (10.500KJ)

• Estimated calorie needs per day by age, gender & physical activities

Rice Nutritional

Facts

Elements found in human being.

96%

99%

What are Carbohydrates?• Macromolecules or biomolecules• general formula of CnH2mOm• 2:1 ration of H and O• Example

glucose - C6H12O6

sucrose - C12H22O11.• Raw materials for other molecules and source

of energy• 1 gm of Carb = 16 KJ or 3.24 Kcal of energy

How carbohydrates are formed?• Made from repeating units, the

monomer that are covalently bonded (glycosidic bond) to form polymer through the process of dehydration (one molecule losses hydrogen atom and the other losses hydroxyl group to form water) or condensation.

Dehydration Synthesis of Sugars

• Polysaccharides are formed by monosaccharide addition through succeeding dehydration

• Example: formation of glycogen in the

liver and starch in plant ground tissues

How polysaccharides are broken down?

• By breaking the glycocidic bonds through hydrolysis (water mediated) and release of energy.

• The opposite process of dehydration

• Occurs in digestive tract through mechanical and chemical digestions (enzyme mediated)

Three main categories of carbohydrates

•Monosaccharides•Disaccharides•Polysaccharides

Monosaccharides

Disaccharides

What is Lipids?• Large biomolecules but not a polymer• All non-polar• Composed of O but abundance in C-

H bonds• Provide 37KJ/ 8.86 Kcal energy/gm• Cushion vital organs, insulation,

precursor for testosterone, important in plasma membrane structure

Three Types of Lipids• Fats (triacylglycerols or

triglycerides)

• Phospholipids

• Sterols/Steroids

Types of Phosphatidyl

Where fats are stored in the body?

Identify the food items whether it is carbohydrate or fats.

Group Assignment

• Bring the following:Group 1 - Potato Group 2 – White Peanut Group 3 - Ripe banana Group 4 – Hardboiled Egg

• Image of cell membrane showing the position of cholesterol. http://study.com/cimages/multimages/16/fluidmosaic.png

• Structure of different types of phosphatidyl. http://oregonstate.edu/instruct/bb451/451material/stryer7/CH12/figure_12_05.jpg

• Image of phospholipid bilayers. http://academic.brooklyn.cuny.edu/biology/bio4fv/page/phosphb.htm

• Saturated and unsaturated fatty acid structures. http://www.scienceprofonline.com/images/fat-saturated_unsaturated.jpg

• Fat cells. http://www.weightlossforall.com/fat-storage-body.htm