1 Biological Molecules Focus on Carbohydrates (See pages 31-41)

2 MACROMOLECULE(Polymers)MONOMER CarbohydratesMonosaccharides (Simple Sugars) Proteins Amino Acids Lipids (Fats) Fatty Acids and Glycerol Nucleic Acids (DNA/RNA) Nucleotides

3 General Reactions 5H 2 O POLYMER MONOMERS Dehydration Synthesis Hydrolysis

4 Carbohydrates Carbohydrates are polymers of monosaccharides (simple sugars). Carbohydrates are polymers of monosaccharides (simple sugars). They are the first macromolecule to be metabolized within the cells of the body (ie. they are involved in cellular respiration before fats and proteins, meaning that they are the PRIMARY source of energy for the body). They are the first macromolecule to be metabolized within the cells of the body (ie. they are involved in cellular respiration before fats and proteins, meaning that they are the PRIMARY source of energy for the body). Cellular Respiration (Mitochondria): Cellular Respiration (Mitochondria): Glucose + 6O 2 6CO 2 + 6H 2 O + ATP (C 6 H 12 O 6 )

5 Glucose is a simple sugar and the main monomer of carbohydrates (polysaccharides) in the body. Glucose is a simple sugar and the main monomer of carbohydrates (polysaccharides) in the body. Carbohydrates are broken down by the digestive system, first in the mouth, then in the small intestine. Carbohydrates are broken down by the digestive system, first in the mouth, then in the small intestine. The final result of digestion is GLUCOSE which is small enough to enter the bloodstream and eventually, cells. The final result of digestion is GLUCOSE which is small enough to enter the bloodstream and eventually, cells. Aside from providing energy, carbohydrates also associate with both the phospholipids and proteins of cell membranes, in order to provide each cell with an “I.D. tag” for cell-to-cell recognition. Aside from providing energy, carbohydrates also associate with both the phospholipids and proteins of cell membranes, in order to provide each cell with an “I.D. tag” for cell-to-cell recognition.

6 There are three levels of carbohydrate structure based purely on size differences: There are three levels of carbohydrate structure based purely on size differences: 1. Monosaccharides (One simple sugar): Three major types: A. Glucose – the primary energy source for the body. Most polysaccharides are the body. Most polysaccharides are eventually broken down to glucose by eventually broken down to glucose by our digestive system. our digestive system. -- found naturally in green plants -- found naturally in green plants -- chemical formula = -- chemical formula = (C 6 H 12 O 6 )

7 Structure of Glucose: Each vertex in the above right drawing represents a carbon ( C ) molecule (they are numbered 1 to 6). OR

8 B. Galactose – found in milk -- possesses the same chemical -- possesses the same chemical formula as glucose but has formula as glucose but has one different arrangement of –H one different arrangement of –H and –OH on carbon #4. and –OH on carbon #4. C. Fructose – found in fruits -- same formula as glucose, but a -- same formula as glucose, but a much different –H, –OH, and C much different –H, –OH, and C arrangement. arrangement.

9

10 Glucose, galactose, and fructose are all structural ISOMERS of each other, meaning that they each possess the same chemical formula, but exhibit a different arrangement of the atoms. Glucose, galactose, and fructose are all structural ISOMERS of each other, meaning that they each possess the same chemical formula, but exhibit a different arrangement of the atoms.

11 Sugar Ray Leonard After his first fight he ditched his old nickname: Monosaccharide Ray Leonard

12 2. Disaccharides (Two Sugars): -- formed when two monosaccharides undergo DEHYDRATION SYNTHESIS (producing a water molecule as well). Three Major Types: A. Maltose – Made up of two glucose molecules (studied in Biology 12) B. Sucrose – Made up of one glucose and one fructose molecule C. Lactose – Made up of one glucose and one galactose molecule

13 Maltose Formation by Dehydration Synthesis + +H 2 O GLUCOSE MALTOSE

14 Oxygen “Bridge” Formula for Maltose: C 12 H 22 O 11 – which is equal to 2 x Glucose minus one water…

15 The EMPIRICAL formula for carbohydrates is CH 2 O. The EMPIRICAL formula for carbohydrates is CH 2 O. However, a ‘carb’ made up of two glucose molecules forms one water molecule during its construction. However, a ‘carb’ made up of two glucose molecules forms one water molecule during its construction. Similarly, a “carb” made up of 50 glucose molecules forms 49 water molecules. Similarly, a “carb” made up of 50 glucose molecules forms 49 water molecules. To find the formula of any “carb,” all one needs to know is either how many glucose molecules are involved OR how many water molecules are formed. To find the formula of any “carb,” all one needs to know is either how many glucose molecules are involved OR how many water molecules are formed. Eg. A “carb” with 17 glucose molecules has a formula of: 17 x (C 6 H 12 O 6 ) – 16 x (H 2 O) = C 102 H 172 O 86 Eg. A “carb” with 17 glucose molecules has a formula of: 17 x (C 6 H 12 O 6 ) – 16 x (H 2 O) = C 102 H 172 O 86 So, the empirical formula is only a guide, it’s not exact. So, the empirical formula is only a guide, it’s not exact.

16 3. Polysaccharides (Long chains of sugars): -- a POLYMER of monosaccharides. -- three polysaccharides are common in living things (all are polymers of glucose, but differ in their branching patterns): A. Starch – storage form of glucose in plants. -- few side branches (very simple arrangement) -- the existing side branches all span in the same direction -- relatively straight molecule but adopts an energy-efficient helical shape. energy-efficient helical shape. -- see figure 2.19 p easy to digest

17 B. Glycogen – storage form of glucose in animals. -- more branched than starch (see fig p. 33) -- also easy to digest as the branching allows digestion to occur at several points simultaneously. -- the liver converts excess glucose to glycogen and stores it. -- muscles also convert glucose to glycogen and store it.

18 C. Cellulose – the structural component of plant cell walls. -- possesses a much different type of linkage between glucose molecules (see fig p. 33). -- humans are unable to digest cellulose molecules; they pass right through our digestive tract as fibre or roughage.

19 -- cows (and other ruminant animals) are able to digest cellulose due to the presence of symbiotic bacteria that exist in their stomachs, bacteria which humans do not house.

20 I’ll RUN WILD on you Atkins…eat your CARBS, brother!!! Damn, I’m lookin’ good! Probably because of my diet!

21