Important Biological Compounds. organic molecules

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1 Important Biological Compounds organic molecules

2 Carbon containing compounds are the building blocks of life. All the functions of the cell are based on chemical reactions.

3 Carbon containing compounds are the building blocks of life. The term organic refers to Carbon containing compounds.

4 Organic Chemistry The study of compounds containing Carbon

5 The Story of Carbon Unique and unparalleled of all the elements in its ability to form large, complex & diverse molecules.

6 C enters the realm of living systems through plants radiant energy H 2 O sugar (glucose) C 6 H 12 O 6 they process CO 2 Atoms are rearranged during photosynthesis

7 Why so many organic compounds?

8 Carbon can: Form up to 4 (covalent) bonds

9 Carbon can: Form stable bonds with itself.

10 graphite There are strong covalent bonds between carbon atoms in each layer. But, only weak forces exist between layers.

11 in diamonds each carbon atom is the same distance to each of its neighboring carbon atoms. In this rigid network atoms cannot move.

12 fullerenes the buckyball C 60 Buckyballs were discovered in a piece of the 4.6-billion-year-old meteorite that landed in Mexico in The Carbon 60 molecules, shaped like a geodesic sphere, were first synthesized in laboratories in This is now the third form of pure carbon known to exist naturally.

13 "In Science the credit goes to the man who convinces the world, not to the man to whom the idea first occurs." Sir Francis Darwin.

14 Carbon can: Form stable bonds with other elements. chocolate capsaicin

15 Carbon can: Form double and triple bonds with other elements limonene

16 Carbon can: Form double and triple bonds.

17 the end of the story?...

18 Carbon can: be arranged in a variety of ways

19 Carbon can form: chemical compounds which have a common chemical formula, but not a common structure. This gives isomers different chemical properties

20 structural isomers C 5 H 12 show a different arrangement in covalent bonds Usually occur in differences in the arrangements of the carbon skeleton. Locations of double bonds may vary also

21 Differ in covalent arrangement OR location of double bond

22 Geometric isomer cis-2-butene trans-2-butene differences in arrangements of atoms around a double bond. (doublebonded carbons do not exhibit rotation). When molecules/functional groups are found on the same side of a double bond, this is known as the "Cis" configuration When atoms/functional groups are located on opposite sides of a double bond, this is called the "trans" configuration

23 Example in the biological world This is a schematic diagram of a rod cell. The stacked disks contain rhodopsin, the complex of opsin protein and 11-cisretinal. The nerve fires a signal to the brain as a result of retinal isomerization passed along to a connecting nerve cell, creating an electrical impulse interpreted as visual information by the brain.

24 Upon absorption of a photon in the visible range, 11-cis-retinal can isomerize to alltrans-retinal. Note how the size and shape of the molecule change as a result of this isomerization.

25 optical isomers when 4 different atoms/functional groups occur around a single carbon This results in molecules which are "mirror images" of each other, but NOT IDENTICAL. The resulting molecules do not function the same.

26 Purves, fig. 2.21, pg. 32 Amino acids & proteins often show this feature. Biological systems usually can identify and use the correct form, the other is usually ignored.

27 dextro = right levo = left The two forms of an enantiomer are known as the "L" form or the "D" form

28 Example in the biological world Thalidomide Laboratory tests after the thalidomide disaster showed that the 'S' enantiomer was teratogenic but the 'R' isomer was an effective sedative. It is now known that even when a selective sample of thalidomide is created, it can cause racemizing. This means that both enantiomers are formed in a roughly equal mix in the blood. So, even if a drug of only the 'R' isomer had been created, the disaster would not have been averted.

29 phocomelia Pregnant women who took thalidomide had high frequency of children with phocomelia.

30 Families of Organic Compounds hydrocarbons substituted hydrocarbons

31 hydrocarbons Formed of only C and H

32 Hydrocarbons: hydrophobic (generally insoluble) stable, non-polar release E when undergoing rx s.

33 Derivative hydrocarbons (substituted) Properties of organic molecules not only depend on the structure of the C skeleton, but on the molecules attached to the skeleton Gives each organic molecules particular chemical properties

34 substituted Hydrocarbons Atoms of other elements can be joined to the carbons in place of one or more hydrogens. sucrose Oxygen, nitrogen, sulfur and the halogens are the most common atoms that replace hydrogens.

35 Remember: If you change the shape OR kind of atoms in a molecule, it becomes a new chemical with new chemical properties. That s why there can be millions of different organic compounds even if they all contain Carbon!

36 ketone aldehydes

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38 the functions of organic compounds: Structural: used as building blocks for cellular and extracellular structures. Storage: store chemical energy for future use by the organism. Enzymes: lowers activation energy, allowing chemical reactions to proceed.