Chemical properties of a carbon atom
Carbon is very abundant on the planet, and it forms the backbone of every single organic molecule. Without carbon, life would not be possible. The reasons for this are the specific features of the carbon atom.
Chemical properties of a carbon atom
Carbon can also form multiple bonds: Single, double and triple covalent bonds
Draw an atom of carbon, showing all Carbon can form long chains electrons, protons and neutrons
or rings of molecules.
Covalent bonds are the strongest type of bond between atoms. Stable molecules can be formed.
Carbon can form molecules with many different elements (metallic and non-metallic)
Carbon atoms contain four electrons in their outer shell allowing them to form four covalent bonds with other atoms.
Carbon-containing macromolecules
Organic
Compounds
Carbohydrates
Lipids
Proteins
Nucleic acids
They are composed of
carbon, hydrogen and oxygen. The ratio of C:H:O is 1:2:1.
They are composed of
carbon, hydrogen and oxygen. With C:H:O at a ratio of 1:2:less than 1.
Contain one or more chains of amino acids. All of the amino acids in the chains contain carbon, hydrogen, oxygen and nitrogen. Some of them also contain sulphur.
Nucleic acids are chains of subunits called nucleotides, which contain carbon, hydrogen, oxygen, nitrogen and phosphorus.
Carbon-containing macromolecules
Carbohydrates are the largest group of organic compounds found in living things. Depending on the number of building blocks that combine, carbohydrates can be classified as mono-, di- or polysaccharides.
Monosaccharides
Monosaccharides can be classified by the number of carbons they possess. E.g. three-carbon sugars are called trioses, five carbon sugars are pentoses, six-carbon sugars are called hexoses. Pentoses and hexoses are unique in that they can exist in straight chain form, but they can also fold into rings.
Can you spot the hexoses and pentoses?
Glucose, fructose, galactose
Describe the features of monosaccharides:
Most are ring structures
One C-atom outside of the ring They all have OH groups
The atoms C, H, O are always a ration of 1:2:4
Monosaccharides
Glucose exist as linear form, but can also fold into a ring structure:
1.
Use a molecular model kit, construct a model of structure A.
2.
Twist the model so that carbon 1 comes near the oxygen attached to carbon 5 as
shown in structure B.
3.
Break the double bond on carbon 1 and remove the hydrogen attached to the
oxygen attached to carbon 5.
4.
Attach carbon 1 to oxygen on carbon 5 and reposition the detached hydrogen as
shown in structure C.
Monosaccharides
Structural isomers have typically different chemical properties, and the type of isomer often result different bonding patterns when combined with other monomers.
http://bio1151.nicerweb.com/Locked/media/ch05/05_07GlucoseStruc.jpg
The functional group (-OH) on the carbon 1 can be positioned in two different orientations. These two orientations result in the formation of an isomer for glucose – the molecular formula is the same, but the structural one is different.
Glucose has two isomers: alpha (α) D-Glucose and beta (β) D-Glucose:
Glucose is polar and hydrophilic, and therefore soluble in aquaeous solutions (like blood or plant sap). It therefore can be easily transported
Solubility:
Chemical stability:
Monosaccharides have strong covalent bonds and therefore are very stable. This property is useful for food storage.
Energy:
Glucose gives out energy when oxidized during cellular respiration.