Essential Idea Compounds of carbon, hydrogen and oxygen are used to supply and store energy.

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



• Disaccharide examples:

– Sucrose formed from a bond between fructose and glucose



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


Polysaccharides: Many Sugars

• Glycogen


– Energy storage for animals

Animation: DisaccharidesAnimation: Disaccharides


• Cellulose


– Structural support for plants



Polysaccharide Comparisons

Know the structures of the following carbohydrate

• Monosaccharides

•Disaccharides

•Polysaccharides

• glucose, galactose, fructose

•maltose, lactose and sucrose

•Starch, glycogen, cellulose


• 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


• 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


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

Essential Idea Compounds of carbon, hydrogen and oxygen are used to supply and store energy.

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