1. Biochemistry II Functional Groups, Lipids, Nucleic Acids & Metabolism

2. Functional Groups  A functional group is a portion of a molecule that is a recognizable / classified group of bound atoms.  In organic chemistry it is very common to see molecules comprised mainly of a carbon backbone with functional groups attached to the chain.

3. Functional Groups  The functional group gives the molecule its properties, regardless of what molecule contains it  They are centers of chemical reactivity.  The functional groups within a molecule need to be identified when naming as well.

4. Functional Groups  These are things like  Hydroxyl groups which form alcohols,  Carbonyl groups which form aldehydes or ketones,  Carboxyl groups which form carboxylic acids  Amino groups which form amines.  There are about 20 key functional groups in organic chemistry Crash CourseCrash Course

6. A Simple Analogy  One way you can think of functional groups are like wood and hardware.  Most biological molecules are composed of carbon which can be analogous to a piece of wood.  Once you start to add hardware to the wood, it begins to take on a certain appearance and function.

7. Stay with me…..  If you take your piece of wood and add hinges and a doorknob it will begin to look like a door.  If you add legs to your piece of wood, it begins to look like a table.  Functional groups are like the hinges or legs added to your original piece of wood or carbon molecule

9. Lipids (aka Triglycerides)  Fats, oils, and other water-insoluble compounds are called lipids.  Waxes and steriods also fall into this category  Natural fats and oils exist as triesters of glycerol with fatty acids, which are long-chain carboxylic acids (C 12 through C 24 ). This form of lipid is known as a triglyceride.

11. Solubility of Lipids  Lipids tend to dissolve readily in organic solvents, such as ether and chloroform, rather than in highly polar solvents such as water.  This property sets them apart from most biological substances such as carbohydrates and proteins. Saturated vs. Unsaturated Fats

12. Where are Lipids found?  The hydrolysis of oils or fats by boiling with an aqueous solution of an alkali-metal hydroxide is called saponification  Saponification is used to make soap.  Phospholipids, or lipids that contain phosphate groups, are abundant in cells.

13. Phospholipid Bilayer  In water, phospholipids spontaneously form a spherical double layer, called a lipid bilayer, in which the hydrophobic tails of phospholipid molecules are sandwiched between two layers of hydrophilic heads

15. Nucleic Acids  The fourth type of organic compound in all living things is DNA and RNA. Substantially covered in your biology class.  Composed of a sugar phosphate backbone and base pairs (Uracil, Thymine, Guanine, Adenine, Cytosine)  They are the blueprint for making proteins that control EVERYthing in an organism.

17.  Adenosine triphosphate (ATP) is a molecule that transmits energy in the cells of living organisms.  In living cells, ATP is the energy carrier between the spontaneous reactions that release energy and nonspontaneous reactions that use energy.

18.  The entire set of chemical reactions carried out by an organism is known as the organism’s metabolism.  In metabolism, unneeded cellular components and the nutrients in food are broken down into simpler compounds by chemical reactions collectively called catabolism.

19. Catabolism  The degradation of complex biological molecules such as carbohydrates, lipids, proteins, and nucleic acids during catabolism provides the energy and the building blocks for the construction of new biological compounds needed by the cell.

20. Anabolism  The synthesis reactions of metabolism are called anabolism.  In anabolism, the products and the energy of catabolism are used to make new cell parts and compounds needed for cellular life and growth.  Simple compounds produced by catabolism are used in the synthesis reactions of anabolism.

22. Free Radicals  The body generates free radicals as the inevitable byproducts of turning food into energy.  Others are in the food you eat and the air you breathe.  Some are generated by sunlight’s action on the skin and eyes.

23.  Free radicals have a voracious appetite for electrons.  This electron theft can radically alter the “loser’s” structure or function.

24.  Free radical damage can change the instructions coded in a strand of DNA.  It can make a circulating low-density lipoprotein (LDL, sometimes called bad cholesterol) molecule more likely to get trapped in an artery wall.

25.  It can alter a cell’s membrane, changing the flow of what enters the cell and what leaves it.  Free radical damage is involved in the early stages of artery-clogging atherosclerosis and may contribute to cancer, vision loss, and a host of other chronic conditions.

26. Antioxidants  Antioxidants work by generously giving electrons to free radicals without turning into electron- scavenging substances themselves.

27.  The most familiar ones are vitamin C, vitamin E, beta-carotene, and the minerals selenium and manganese. vitamin C vitamin Ebeta-carotene  They’re joined by glutathione, coenzyme Q10, lipoic acid, flavonoids, phenols, polyphenols, phytoestrogens, and many more.  How do vitamins work? How do vitamins work?

28.  But using the term “antioxidant” to refer to substances is misleading.  It is really a chemical property, namely, the ability to act as an electron donor.

29.  Some substances that act as antioxidants in one situation may be pro-oxidants— electron grabbers—in a different chemical situation.  Another big misconception is that antioxidants are interchangeable.  They aren’t. Each one has unique chemical behaviors and biological properties.

31. The Bottom Line  Free radicals contribute to chronic diseases.  This doesn’t automatically mean that substances with antioxidant properties will fix the problem.  At the same time, abundant evidence suggests that eating whole fruits, vegetables, and whole grains—all rich in networks of antioxidants and their helper molecules—provides protection against many contributing factors to disease and aging.  Simply Put....... Simply Put.......