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Essential Idea
Compounds of carbon, hydrogen and oxygen are used to supply and store energy.
Understandings.
• Monosaccharide monomers are linked together by condensation reactions to form disaccharides and polysaccharide polymers.
IB Assessment Statement
• List three examples each of monosaccharides, disaccharides and polysaccharides. The examples used should be: glucose, galactose and fructose; maltose, lactose and sucrose; starch, glycogen and cellulose.
Sugars: monosaccharides
• Monosaccharides have molecular formulas that are usually multiples of CHusually multiples of CH22OO
• Monosaccharide is a molecule made up of one type of sugar
• Glucose is the most common monosaccharide
Copyright Pearson Prentice Hall
Monosaccharide: Glucose
Copyright Pearson Prentice Hall
Monosaccharide: Ribose
• A disaccharide is formed when a dehydration reaction joins two monosaccharides
Animation: Disaccharides
Disaccharides: Two Sugars
• Disaccharide examples:
– Lactose formed from a bond between Galactose and glucose
Animation: Disaccharides
Disaccharides: Two Sugars
• Disaccharide examples:
– Sucrose formed from a bond between fructose and glucose
Animation: Disaccharides
Disaccharides: Two Sugars
Application
• Application: Structure and function of cellulose and starch in plants and glycogen in humans.
Skill:
• Use of molecular visualization software to compare cellulose, starch and glycogen.
• Starch
– Formed from many glucose molecules
– Used for energy storage in plants
Animation: Disaccharides
Polysaccharides: Many Sugars
• Glycogen
– Formed from many glucose molecules
– Energy storage for animals
Animation: DisaccharidesAnimation: Disaccharides
Polysaccharides: Many Sugars
• Cellulose
– Formed from many glucose molecules
– Structural support for plants
Animation: DisaccharidesAnimation: Disaccharides
Polysaccharides: Many Sugars
Polysaccharide Comparisons
Know the structures of the following carbohydrate
• Monosaccharides
•Disaccharides
•Polysaccharides
• glucose, galactose, fructose
•maltose, lactose and sucrose
•Starch, glycogen, cellulose
IB Assessment Statement
• State one function of glucose, lactose and glycogen in animals, and of fructose, sucrose and cellulose in plants.
Carbohydrate functions in Animals
• Glucose – used as a substrate for respiration or converted to glycogen for storage.
• Lactose – produced by mammary glands and secreted in milk as an important part of the diet of young mammals
• Glycogen – energy storage
Carbohydrate functions in Plants
• Glucose – a product of photosynthesis.
• Fructose – produced as an intermediate substrate during glucose breakdown during respiration. Used in production of sucrose
• Cellulose – component of cell walls/ structural support in plants
• Starch – energy storage
Carbohydrate tutorial
Click on the Carbohyrdate tutorial below
•http://www.wisc-online.com/objects/ViewObject.aspx?ID=AP13104
IB Assessment Statement
• Outline the role of condensation & hydrolysis reaction the relationships between monosaccharides, disaccharides and polysaccharides;
Hydrolysis vs. Condensation
Hydrolysis
•Adds water
•Breaks down polymers into monomers
•Example: Breaks down starch into glucose
Condensation
•Removes water
•Forms new bonds between monomers forming polymers
•Example: glucose and fructose are bonded together to form sucrose
Building and Breakdown disaccharides and Polysaccharides
• Condensation (dehydration)and Hydrolysis Reactions
One Type of Condensation (dehydration) Reactions
1. Occurs between monosaccharide and forms disaccharides and polysaccharides
• When two monosaccharides join together a hydrogen is released from one monosaccharide & a hydroxide is removed from another
• Hydrogen and hydroxide bond together to form water
Animation: DisaccharidesAnimation: Disaccharides
Disaccharides & Dehydration/ Condensation Reaction
Condensation (dehydration) Reactionin carbohydrates
glucose glucoseStarch
glucoseFructose
Sucrose
One type of hydrolysis reactions
1. Breakdown of disaccharide or polysaccharides into monosaccharide
FlashcardsMake a flashcard of the following:1st side but the name:
• glucose, • Lactose • Glycogen (describe structure) • fructose, • sucrose • Cellulose (describe structure) • Ribose• Starch (describe structure)
2nd side put•State one function of glucose, lactose, ribose and glycogen in animals, •and of fructose, sucrose, ribose and cellulose in plants.•Draw/ describe the structure of the molecule
Understandings.
• Triglycerides are formed by condensation from three fatty acids and one glycerol.
Lipids are a diverse group of hydrophobic molecules
• Lipids occur in living things as animal fat and plant oils
• The unifying feature of lipids is having little or no is having little or no attraction for waterattraction for water
• Lipids are hydrophobic becausethey consist mostly of hydrocarbons, which form nonpolar covalent bonds
• The most biologically important lipids are fats, phospholipids, and steroids
Fats and Oils
Fats are constructed from two types of smaller molecules: glycerol (an alcohol) and fatty acids
•Glycerol is a three-carbon alcohol with a hydroxyl group (--OH) attached to each carbon
•A fatty acid consists of a carboxyl group (--COOH) attached to a long carbon skeleton
Structure of fat and oils
Glycerol
Fatty acid
• Fats and oils are compounds called triglycerides
• In a fat, three fatty acids are joined to glycerol by an ester linkage a triglyceride
• In cells, enzymes catalyze the formation of triglyerides, and also the breakdown of glycerides by hydrolysis
Below is a figure representing the Structure of Triglycerides
Ester linkage
Fat molecule (triacylglycerol)
IB Assessment Statements
• Outline the role of condensation and hydrolysis in the relationships between between fatty acids, glycerol and triglycerides; and between amino acids and polypeptides.
Condensation reaction between glycerol & fatty acids form lipids
Glycerol
Fatty acid
Phospholipids
• Phospholipids has a similar chemical structure to triglycerides.
• In a phospholipid, one of the fatty acids is replaced by a phosphate group (--PO4)
• The over structure of a phospholipid consists of
– two fatty acids
– and a phosphate group
– attached to glycerol
• The two fatty acid tails are hydrophobic, but the phosphate group and its attachments form a hydrophilic head
LE 5-13
Structural formula Space-filling model Phospholipid symbol
Hydrophilichead
Hydrophobictails
Fatty acids
Choline
Phosphate
Glycerol
Hyd
rop
ho
bic
tai
lsH
ydr o
ph
ilic
hea
d
• When phospholipids are added to water, they self-assemble into a bilayer, with the hydrophobic tails pointing toward the interior
• The structure of phospholipids results in a bilayer arrangement found in cell membranes
• Phospholipids are the major component of all cell membranes
Cell Membrane
WATERHydrophilichead
Hydrophobictails
WATER
Lipid Tutorial Below:
Click below for the lipid tutorial
•http://www.wisc-online.com/objects/ViewObject.aspx?ID=AP13204
Understandings.
• Fatty acids can be saturated, monounsaturated or polyunsaturated.
• Unsaturated fatty acids can be cis or trans isomers.
Mono vs Poly UNSATURATED FATs
• Monounsaturated Fats-
– One double bond in the hydrocarbon chain
• Polyunsaturated Fats
– More than one double bond exists in the hydrocarbon chain
Saturated vs Unsaturatedfatty acids
• Polyunsaturated fats are hydrogenated or partially hydrogenated,
• Hydrogenated means that double bonds in the fatty acid are broken and hydrogen are added.
• Poly and Mono Unsaturated fats becomes saturated through the process of hydrogenation.
Saturated (trans) vs. Unsaturated (cis)
• Mono and Poly Unsaturated fatty acids are naturally curved.
• Saturated fatty acids are straight.
Trans vs. Cis
• Cis fatty acids are unsaturated, contain a double bond in the fatty acid chain and are curved.
– An example of a cis fatty acid is Omega -3
• Trans fatty acid are saturated, no double bonds and straight.
– Vast majority of trans fatty acid are the result of food process (i.e. hydrogenation)
CHD is coronary heart disease
Why are Trans fats bad? VIDEOS
• Simple video
– https://www.youtube.com/watch?v=mYM7B2RfpdE
• GOOD VIDEO BELOW:
– https://www.youtube.com/watch?v=7kLLI2GluDE
• Lipid Video
– https://www.youtube.com/watch?v=ulIjtl4FPDQ
• Biochemistry & human physiology of fat in the blood ( 1 hour long lecture)
– https://www.youtube.com/watch?v=_oLXa4SfsVs
Omega-3 and Omega 6 Fatty Acids
The name omega 3 and omega 6 comes from which numbered carbon has the double bond.
Nature of Science
• Evaluating claims—health claims made about lipids in diets need to be assessed. (5.2)
Why are Trans fats bad?• The Shape of trans fats make them bad for your
cardiovascular system.
– Saturated trans fats are linear and thus they lay flat against your arteries making is more difficult for them to flow with your passing blood.
– These linear, saturated, trans fatty acids combine with cholesterol and form a substance called plaque and can be deposited along the walls of your arteries blocking or slowing blood flow. It this happens in the coronary arteries you can have a heart attack.
Application
•Application: Lipids are more suitable for long-term energy storage in humans than carbohydrates.
Energy Content in Food
• Fats contain more than twice as much energy per 100 grams than carbohydrates and proteins
• Carbohydrates: 1,760 kJ per 100 g
• Proteins: 1,720 kJ per 100 g
• Fats: 4,000 kJ per 100 g
Skills
• Determination of body mass index by calculation or use of a nomogram.
• A.2.5 Calculate body mass index (BMI) from the body mass and height of a person
• A.2.6 Distinguish, using the body mass index, between being underweight, normal weight, overweight and obese
• • Underweight – below 18.5 • Normal weight – 18.5 to 24.9
• • Overweight – 25 to 29.9 • Obese – above 30.0
Body Mass Index