Topic 2: Molecular biology (21 hours) 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?

What are the names of these molecules? Biology Journal 9/12/2014 What are the names of these molecules? What terms can we use to describe them? Compare and contrast them. Maltose Sucrose Lactose Disaccharide Disaccharide Disaccharide Carbohydrate (CnH2nOn) Carbohydrate (CnH2nOn) Carbohydrate (CnH2nOn) Glucose Glucose Glucose Glucose Fructose C6H12O6 Hexagon ring C6H12O6 Hexagon ring Galactose C6H12O6 Hexagon ring C6H12O6 Hexagon ring C5H10O5 Pentagon ring C6H12O6 Hexagon ring Oriented differently than glucose

Biology Journal 9/11/2014 What is the name of this molecule? Label its parts. If this molecule were created by your body, what would that reaction be called? Carboxyl groups 3 Fatty acids Glycerol

Biology Journal 9/9/2014 Name these molecules (by specific name, if you can), and describe them in as much detail as you can…

Ribose C5H10O5 Carbohydrate Monosaccharide Fatty Acid Lipid Polyunsaturated fat Cellulose Carbohydrate Polysaccharide Fatty Acid Lipid Monounsaturated fat Fatty Acid Lipid Saturated fat

Complete this Venn diagram! Biology Journal 9/10/2014 Complete this Venn diagram! Cis-Fatty Acid Both Trans-Fatty Acid

Complete this Venn diagram! Biology Journal 9/10/2014 Complete this Venn diagram! Cis-Fatty Acid Both Trans-Fatty Acid Has 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

Cellulose Both Amylopectin Biology Journal 9/15/2014 Compare and contrast Amylose and cellulose in a Venn diagram. Cellulose Both Amylopectin

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

Review! A chemical reaction occurs, synthesizing 5 glucose molecules. What 2 terms can be used to describe this reaction? What is the name of the product? What is the other product and how many molecules of it are made? Review! H OH H OH H OH H OH H2O H2O H2O H2O Condensation anabolism (synthesis, or “building up”) cellulose 4 H2O molecules are made

Catabolic Hydrolysis Reaction A chemical reaction is shown below. Name each reactant and product. What kind of reaction is this? Where should water be present in the reaction? How many molecules of water? Review! Catabolic Hydrolysis Reaction Monopeptide (amino acid) Monopeptide (amino acid) Dipeptide → + H2O Hydrolysis (water is split) It “fills in” each monomer

Enzymes, collagen, elastin, keratin Complete the table! 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

Review! Disaccharide Monopeptide Dipeptide Polypeptide, Protein CH2 Molecule Type Monomer Dimer Polymer Examples Carbohydrates Monosaccharide Disaccharide Polysaccharide Starch, lactose, glucose, ribose Proteins Monopeptide (one amino acid) Dipeptide Polypeptide, Protein Enzymes, keratin, elastin, Lipids (aka fats) CH2 n/a lipid Fatty acids, triglyceride

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. What is the name of this molecule? b. Label its parts Carboxyl groups 3 Fatty acids Glycerol a. triglyceride

Skeletal line drawing of triglyceride Review! Carboxyl groups 3 Fatty acids Glycerol

Rules for Skeletal Line Drawings: Lines are covalent bonds (2 lines indicates a double bond and 3 indicates a triple bond) C’s are “corners” H’s attached to C’s are not drawn (remember: C makes 4 bonds) Other elements, and H’s attached to them, are shown with their symbol Review! This is adrenaline, which is stored in your adrenal glands, and released as part of the “fight or flight response.” H C C C C H C H2 C C H C C H H3 C9H13NO3

Review! Which molecule is: i. ribose ii. Generalized fatty acid iii. Generalized amino acid

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.

Sucrose Disaccharide 1 glucose and 1 fructose Common table sugar made from plants We get raw sucrose from plants like sugar cane and sugar beets.

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.

Lipids Where fat comes from 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. Body Oil: Very Kinky Lard: Not Kinky

Which of these fats is unsaturated 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 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.

Name a polysaccharide that comes from plants. Name a disaccharide that comes from plants. Name a polysaccharide that comes from animal. Name a disaccharide that comes from animals. Starch (amylose, amylopectin), cellulose Sucrose, Maltose Glycogen Lactose

Contrast water and methane according to their properties. Characteristic Water (H2O) Methane (CH4) Hydrogen Bonds Attraction to water Specific Heat Heat of Evaporation

Characteristic Water (H2O) Methane (CH4) Hydrogen Bonds Yes! (it’s polar) No! (it’s nonpolar) Attraction to water Hydrophilic Hydrophobic Specific Heat High! (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 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.

What are the names of these molecules? A chemical reaction joins these molecules together. What are 2 terms to describe this reaction? What will the other product of this reaction be? How many molecules of this product will be made? 1 glycerol 3 saturated fatty acids

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

Which of these are trans fats? Which of these are cis fats? Which are solids at room temperature? Which are liquids at room temperature? Lipid A Lipid B Trans fat Solid Cis fat Liquid

Compare and contrast cellulose and glycogen. Both Glycogen

Cellulose Both Glycogen Made 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

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

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.

Does water have a high or low specific heat? Describe one biological consequence of this characteristic of water. Water has a high specific heat. 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.

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