Carbohydrates and Lipids (2.3)
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Notes: Metabolism and MacromoleculesJeopardy Review
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Introduction to Biomolecules
Roughly only 11 elements are found in living things. Of those 99% are Carbon, Hydroden, Oxygen, and Nitrogen (or CHON).
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From these elements, 4 major categories of macromolecules are created:
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For information on what you should be able to draw and identify see: Metabolism 2.1
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Alpha vs Beta Bonds
HOW molecules are linked together is just as important as WHAT is linked together. Stringing a bunch of carbon together in one way gives us starch, but string it together in a different way, you get cellulose. This is the difference between what is digestable an what is NOT. Hence bond types!
Atom bondingGlucose molecules, as well as many carbohydrates in living things tend to bond either in what is refered to as 1,4 linkages or 1,6 linkages. This means the carbon-1 of one molecule bonds to the carbon-4 of a different molecule. Or in the case of 1,6 linkages carbon-1 to carbon-6.
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Alpha and Beta bonds
Linking alpha glucose molecules together vs linking beta glucose molecules together causes different formations. In an alpha bond both -OH groups are in the downward position (Maltose, glycogen, etc). But in a beta bond, the carbon-1 is in the upward position this creates a situation where everyother molecule is flipped upside down, causing the entire chain to lay straight (cellulose).
Types of Carbohydrates
Carbohydrates: molecules (generally in ring form) that are made up of Carbon, Hydrogen, and Oxygen.
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Simple sugars are either monosaccharides or disaccharides
Complex Carbohydrates are polysaccharides (3 or more monosaccharides linked together) NOTE: the differences in the bond linkages and types of bonds formed.
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Jmol: Molecular Visualization
Jmol is a molecular visualization software that can be used to build molecules.
A few must knows:
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Tutorials
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Types of Lipids
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Lipids are a category of molecule of diverse macromolecules. Their main characteristic being that they are insoluable in water. As a result they must be treated differently in the body. See Water (2.2) and Digestion (6.1) for more information
They contain a wide variety of molecules including:
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Triglycerides
Triglycerides are a specific type of fat molecule that is stored in the adipose tissues (our fat cells) of our cell.
To understand triglycerides, we need to take a look at different kinds of fatty acid chains. 3 basic kinds: Saturated, Unsaturated (mono or poly), and Trans |
SaturatedSaturated fatty acids contain no double bonds, and are "saturated" with hydrogen atoms.
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UnsaturatedUnsaturated fatty acids contain double bounds, and therefore are not saturated with hydrogen. They come in two main forms:
These are generally liquid at room temperature and therefore are generally oils over solid fats. |
TransTrans fatty acids are unnatural double chained fats. They are transformed from unsaturated fatty acids, usually to make an oil solid at room temperature
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Evaluating Health Claims with Lipids
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Lipids have a bad rap- mostly because of the "Lipid Hypothesis," first introduced into American society in the 1950s.
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Using actual published data is important in solving claims like these. Especially with all of the varying opinions around. But remember that even published data is imperfect. So evaluating the claims, methods and conclusions of each study is important.
Ultimately, we are trying to answer the following:
Questions to ask to help you answer the overaching questions:
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SO... DO LIPIDS CAUSE HEART DISEASE?Here area a few articles and published journal articles to get you started:
Eat Fat, Get Thin? Maasai Tribe: Saturated fat diet, yet still healthy Saturate Fats and CHD 'unproven' 20-year Nurse study shows correlation Evidence for Saturated Fat and Sugar Related Heart Disease Saturated and Trans Fat & Heart Diease -Meta Analysis Remember: Correlation does NOT equal causation! Student discussion on Google Docs General consensus of most of my students:
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Carbs vs Lipids with Energy
Eating helps us gain energy.
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Body Mass Index
Body Mass Index (BMI) = is a nomogram measured using the mass of a person in kilograms and the persons height in meters. Please note that measurements are in metric NOT english units!!!
BMI is generally used as a measurement of health. With 4 different categories: underweight, normal, overweight, or obese. While this is a general indicator is it not definitive as muscle tends to weigh more than fat- so being really muscular and in good health may make your BMI higher than normal. The rising concern with obesity in some countries (like the USA) has made obesity more pominant. The medical conditon called Metabolic Syndrome has led to other contributors for a diagnosis of obesity and concern: waist circumference, body fat (estimated through skinfolds on waist), as well as blood pressure and heart rate. Factors contributing to this rising epidemic include lack of exercise, poor dietary habits, and excess sugar intake, etc. Complications include the development of heart disease and type 2 diabetes.
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