2.3 Carbohydrates and lipids: Compounds of carbon, hydrogen and oxygen are used to supply and store energy.

Nature of science: Evaluating claims—health claims made about lipids in diets need to be assessed.

Understandings: Monosaccharide monomers are

linked together by condensation reactions to form disaccharides (sucrose, lactose, and maltose) and polysaccharide polymers.

Fatty acids can be saturated, monounsaturated or polyunsaturated.

Unsaturated fatty acids can be cis- or trans- isomers.

Triglycerides are formed by condensation from three fatty acids and one glycerol.

Applications and skills: Application: Structure and function of cellulose and starch (amylose

and amylopectin) in plants and glycogen in humans. Potatoes have been genetically modified to reduce the level of amylose to produce a more effective adhesive.

Application: Scientific evidence for health risks of trans-fats and saturated fatty acids. There are social implications of obesity.

Application: Lipids are more suitable for long-term energy storage in humans than carbohydrates.

Application: Evaluation of evidence and the methods used to obtain the evidence for health claims made about lipids.

Skill: Use of molecular visualization software to compare cellulose, starch and glycogen.

Skill: Determination of BMI by calculation or use of a nomogram.

International-mindedness: Variation in the prevalence of different health problems around the world could be discussed including obesity, dietary energy deficiency, kwashiorkor, anorexia nervosa and coronary heart disease. Theory of knowledge: There are conflicting views as to the harms and benefits of fats in diets. How do we decide between competing views?

Topic 2: Molecular biology (21 hours)

What are the names of these molecules?What terms can we use to describe them?Compare and contrast them.

Biology Journal 9/12/2014

Maltose Sucrose Lactose

Glucose Glucose GlucoseGalactose

Fructose GlucoseC6H12O6

Hexagon ringC6H12O6

Hexagon ringC6H12O6

Hexagon ring C6H12O6

Hexagon ring

Oriented differently than glucose

C6H12O6

Hexagon ring

C5H10O5

Pentagon ring

Disaccharide

Carbohydrate (CnH2nOn)Disaccharide

Carbohydrate (CnH2nOn)Disaccharide

Carbohydrate (CnH2nOn)

3 Fatty acids

Glycerol

Carboxyl groups

What is the name of this molecule? Label its parts. If this molecule were created by your body, what would that reaction be called?

Biology Journal 9/11/2014

Name these molecules (by specific name, if you can), and describe them in as much detail as you can…

Biology Journal 9/9/2014

RiboseC5H10O5

CarbohydrateMonosaccharide

Fatty AcidLipid

Polyunsaturated fat

Fatty AcidLipid

Monounsaturated fat

CelluloseCarbohydrate

Polysaccharide

Fatty AcidLipid

Saturated fat

Complete this Venn diagram!

Biology Journal 9/10/2014

Cis-Fatty Acid Both Trans-Fatty Acid

Complete this Venn diagram!

Biology Journal 9/10/2014

Cis-Fatty Acid Both Trans-Fatty AcidHas a bend in the C-chain at the C=C

Has a double bond in the C-chain

Is unbent at the C-chain at the C=C

H’s are on same side of C=C

Same chemical formula

H’s are on opposite sides of C=C

Are more likely to be liquids

Same amount of calories

Are more likely to be solids

Not associated with cardiovascular disease

Associated with cardiovascular disease

Naturally occurring Created artificially through chemistry

Compare and contrast Amylose and cellulose in a Venn diagram.

Cellulose Both Amylopectin

Biology Journal 9/15/2014

Cellulose Both Amylopectin

Plant cell walls

Polysaccharide. Carbohydrate. All glucose molecules.

Plant energy storage molecule (“starch,” along with amylose)

Glucose molecules have alternating orientation

Created through anabolic condensation. Broken down through catabolic hydrolysis.

Glucose molecules are oriented in same direction

Made by plants

A chemical reaction occurs, synthesizing 5 glucose molecules. a. What 2 terms can be used to describe this reaction?b. What is the name of the product?c. What is the other product and how many molecules

of it are made?

(a) Condensation anabolism (synthesis, or “building up”)(b) cellulose (c) 4 H2O molecules are made

H H OH

H2O

OH H HOH OH

H2O H2OH2O

Review!

A chemical reaction is shown below. 1. Name each reactant and product.2. What kind of reaction is this?3. Where should water be present in the reaction?

How many molecules of water?

+ →H2O

• Hydrolysis (water is split)• It “fills in” each monomer

Dipeptide Monopeptide(amino acid)

Monopeptide(amino acid)

Catabolic Hydrolysis Reaction

Review!

Molecule Type Monomer Dimer Polymer Examples

Carbohydrates Starch…

Proteins Monopeptide(one amino acid)

Enzymes, collagen,

elastin, keratin

Lipids(aka fats) CH2 n/a lipid

Complete the table!Review!

Molecule Type Monomer Dimer Polymer Examples

Carbohydrates Monosaccharide Disaccharide Polysaccharide

Starch, lactose, glucose, ribose

ProteinsMonopeptide

(one amino acid)

Dipeptide Polypeptide, Protein

Enzymes, keratin, elastin,

Lipids(aka fats) CH2 n/a lipid Fatty acids,

triglyceride

Review!

Biology Journal 8/29/2013

What is the name of the polysaccharide that animals use to store energy?Plants make 2 different polysaccharides. What is the name of the one that humans can digest? What is the name of the one that humans can’t digest?

Biology Journal 8/27/2013

What is the name of the monosaccharide below? These 2 molecules bond in a condensation reaction to form a disaccharide called lactose. Show this reaction by circling the atoms that are “released” as water, and draw the product.

H2O+ → +

Biology Journal 8/27/2013

What is the name of the monosaccharides shown below? These 2 molecules bond in a condensation reaction to form a disaccharide called lactose. Show this reaction by circling the atoms that are “released” as water, and draw the product.

a. triglyceride

a. What is the name of this molecule?b. Label its parts

3 Fatty acids

Glycerol

Carboxyl groups

Skeletal line drawing of triglyceride

3 Fatty acids

Glycerol

Carboxyl groups

Review!

This is adrenaline, which is stored in your adrenal glands, and released as part of the “fight or flight response.”

C

CC

C

C

CC CH2

H

H

H

C9H13NO3

HC

Rules for Skeletal Line Drawings:1. Lines are covalent bonds (2 lines indicates a double bond and 3 indicates a triple bond)2. C’s are “corners”3. H’s attached to C’s are not drawn (remember: C makes 4 bonds) 4. Other elements, and H’s attached to them, are shown with their symbol

H3

Review!

Which molecule is:i. riboseii. Generalized fatty acidiii. Generalized amino acid

Review!

Carbohydrates and Sugars

2.3• Monosaccharide monomers are linked together by condensation reactions to

form disaccharides (sucrose, lactose, and maltose) and polysaccharide polymers.• Structure and function of cellulose and starch (amylose and amylopectin) in

plants and glycogen in humans. Potatoes have been genetically modified to reduce the level of amylose to produce a more effective adhesive.

Lactose• Disaccharide• 1 galactose and 1 glucose• Milk sugar from mammals• People with lactose

intolerance don’t make the enzyme that breaks the glycosidic bond between the 2 glucose molecules.

We get raw sucrose from plants like sugar cane and sugar beets.

Sucrose• Disaccharide• 1 glucose and 1

fructose• Common table sugar

made from plants

Maltose• Disaccharide• 2 glucoses• “Malt” sugar made by plants– Used as a sweetener in things like cereal, pasta, and

many kinds of alcohol, like beer

Glycogen• Polysaccharide • All glucoses • “Blood sugar” • Its like starch, but

highly branched and compact.

Glycogen is often attached to a protein your body makes called glycogenin

Starch (Amylose and Amylopectin)• Polysaccharide. “Starch” is a mixture of 2 carbohydrates:

amylose and amylopectin.• All glucoses, bonded with glyosidic bonds, and oriented in

the similar directions.• Provides most of the calories in “carbs” that we eat.• Found in plants like potatoes, rice, grains, oats, fruit…

Cellulose• Polysaccharide made out of glucoses• Glucoses “flip flop” their orientation. Notice the elbow!• Plant cell walls. Makes up many plant parts like wood and

leaves, so its found in salads, vegetables, and has no calories.

Where fat comes from

Lipids

2.3 Lipids are more suitable for long-term energy storage in humans

than carbohydrates.

Which of these fats are saturated and which are unsaturated?

Double bonds cause bends or “kinks” in the carbon chain. •Saturated fats = no kinks = usually solids at room temp.•Unsaturated fats = kinks = usually liquids at room temp.

Lard: Not KinkyBody Oil: Very Kinky

Which of these fats is unsaturated?Which of these will be a liquid at room temperature?

Which of these fats is a solid, and a liquid? Where do they come from?

Which has more saturated fat? 2% milk or soy milk

Which has more saturated fat?

Lipids are the most efficient molecule to store energy. Animals store their extra energy as lipids.

Review Questions

Make a skeletal line drawing of a cis-monounsaturated fatty acid.

1.Name a polysaccharide that comes from plants.2.Name a disaccharide that comes from plants.3.Name a polysaccharide that comes from animal.4.Name a disaccharide that comes from animals.

1.Starch (amylose, amylopectin), cellulose 2.Sucrose, Maltose3.Glycogen4.Lactose

Characteristic Water (H2O) Methane (CH4)

Hydrogen Bonds

Attraction to water

Specific Heat

Heat of Evaporation

Contrast water and methane according to their properties.

Characteristic Water (H2O) Methane (CH4)

Hydrogen Bonds Yes! (it’s polar) No! (it’s nonpolar)

Attraction to water Hydrophilic Hydrophobic

Specific HeatHigh! (hydrogen bonds make water molecules resist temperature change)

Low! (there are no hydrogen bonds to resist temperature change)

Heat of Evaporation

High! (water takes a lot of heat when it evaporates, because it must overcome hydrogen bonds)

Low! (methane does not have hydrogen bonds to overcome, so it evaporates using less energy)

Make a skeletal line drawing of a trans-polyunsaturated fatty acid.

The double bonds are all trans. This fatty acid has 3 unsaturations. Yours may have 2 or more.

Draw four water molecules and label which side is slightly positive, which side is slightly negative, and show where hydrogen bonds form.

Hydrogen bonds

What molecule do animals typically use for long-term energy storage? Explain why.• Animals tend to store their energy as lipids.• Mammals store their energy as triglycerides

• Lipids store energy more efficiently than carbohydrates or proteins.

• Lipids have the greatest amount of energy (calories, kilojoules…) per unit of volume (liters, mL…).

• Lipids have more energy per mass. Thus, an animal doesn’t have to “carry around” a large weight to store a lot of energy.

1. What are the names of these molecules?2. A chemical reaction joins these molecules together. What

are 2 terms to describe this reaction?3. What will the other product of this reaction be? How

many molecules of this product will be made?3 saturated fatty acids1 glycerol

2. The reaction is: condensation, anabolism3. The product is a triglyceride and 3 H2O molecules.

1. Which of these are trans fats? Which of these are cis fats?2. Which are solids at room temperature? Which are liquids

at room temperature?

Trans fatSolid

Cis fatLiquid

Lipid A Lipid B

Compare and contrast cellulose and glycogen.

Cellulose Both Glycogen

Cellulose Both GlycogenMade by plants

Polysaccharide. Carbohydrate. All glucose molecules.

Made by animals

Glucose molecules have alternating orientation

Created through anabolic condensation. Broken down through catabolic hydrolysis.

Glucose molecules are oriented in same direction

Plant cell walls

Glucoses connected by glyosidic bonds

Human blood sugar

1. Trans fats are associated with increased chances of hypertension, cholesterol, and other cardiovascular diseases.2. Trans fats are intentionally placed in food so that the food has a long shelf life, and the fat does not separate from the food, like peanut oil separates from peanut butter.

1.What are health effects of trans fats?2.Why are trans fats produced and put into

food?

Compare and contrast adhesion and cohesion in water.In both, hydrogen bonds cause water to be attracted to something.

Cohesion is the characteristic of water to be attracted to itself, and stick together. Surface tension is a result of cohesion.

Adhesion is the characteristic of water to stick to other substances. Capillary action is an example of adhesion.

a. Does water have a high or low specific heat?

b. Describe one biological consequence of this characteristic of water.

a. Water has a high specific heat.b. As a consequence of this:

Living things can more easily maintain a relatively constant temperature.

Aquatic habitats maintain a relatively constant temperature.

Water is an excellent coolant, because it takes a lot of heat away from an organism when it evaporates.

2.3 Carbohydrates and lipids: Compounds of carbon, hydrogen and oxygen are used to supply and store energy.

Nature of science: Evaluating claims—health claims made about lipids in diets need to be assessed.

Understandings: Monosaccharide monomers are

linked together by condensation reactions to form disaccharides (sucrose, lactose, and maltose) and polysaccharide polymers.

Fatty acids can be saturated, monounsaturated or polyunsaturated.

Unsaturated fatty acids can be cis- or trans- isomers.

Triglycerides are formed by condensation from three fatty acids and one glycerol.

Applications and skills: Application: Structure and function of cellulose and starch (amylose

and amylopectin) in plants and glycogen in humans. Potatoes have been genetically modified to reduce the level of amylose to produce a more effective adhesive.

Application: Scientific evidence for health risks of trans-fats and saturated fatty acids. There are social implications of obesity.

Application: Lipids are more suitable for long-term energy storage in humans than carbohydrates.

Application: Evaluation of evidence and the methods used to obtain the evidence for health claims made about lipids.

Skill: Use of molecular visualization software to compare cellulose, starch and glycogen.

Skill: Determination of BMI by calculation or use of a nomogram.

International-mindedness: Variation in the prevalence of different health problems around the world could be discussed including obesity, dietary energy deficiency, kwashiorkor, anorexia nervosa and coronary heart disease. Theory of knowledge: There are conflicting views as to the harms and benefits of fats in diets. How do we decide between competing views?

Topic 2: Molecular biology (21 hours)Study your review Guide!

• Make Sure that these sentences

make sense!• For every word, make sure you can

define it, give an example, and

apply it!