Macromolecules (Carbohydrates, Lipids, Proteins & Nucleic Acids)
Carbohydrates:
General formula: C H2 O
Examples are sugars, grains, breads, fruits, etc.
The basic building blocks of carbohydrates are carbon rings.
Monosaccharide: a single carbon ring. Examples are glucose, galactose and fructose
Disaccharide: two monosaccharides joined together.
Polysaccharide: three or more (may be thousands) of monosaccharides joined together.
There are two kinds of chemical reactions involved in making and breaking down large molecules; dehydration synthesis and hydrolysis.
1. Dehydration Synthesis: the process that organisms use to combine molecules together. As the name indicates, water is removed during this process. A disaccharide or polysaccharide would be constructed using dehydration synthesis.
2. Hydrolysis: the process that organisms use to break apart larger molecules. Water must be added for hydrolysis to occur.
The energy that comes from carbohydrates is found in the bonds (made by electrons) between atoms in the carbon rings. When an organism digests (breaks down) the food it eats, this energy is released and can be used by the organism.
Carbohydrate Fact Table
Example / Type / Plant or Animal Source? / FunctionStarch / Polysaccharide / Plant / Plants store excess energy as starch
Glycogen / Polysaccharide / Animal / Animals store excess energy as glycogen
Cellulose / Polysaccharide / Plant / Plants use cellulose as a building material
Chitin (kite’ in) / Polysaccharide / Fungi & some animals / Fungi use chitin in cell walls
The exoskeletons of lobster, crayfish, etc. are made of chitin
Glucose / Monosaccharide / Plant & Animal / Glucose is found in the cells and bloodstream of all living organisms and is used as energy
Lipids: Lipids are fats, oils, steroids and waxes. They are nonpolar, which means that they are not charged and would not be attracted to water, which is polar.
Lipids are used as long – term energy storage, and also serve other functions.
Example / FunctionFats / Used as long – term energy storage in animals. Also serve as insulation.
Phospholipids / Used in animals and plants to make cell membranes
Waxes / Used to make waterproof barrier on skin and in ears
Steroids / Act as chemical messengers or hormones. Steroids are a large group of essential chemicals in the human body, not to be confused with the chemicals that are used to increase muscle mass.
Monomer: fatty acid
Proteins: Proteins are extremely important macromolecules that serve as structural building material for the bodies of organisms as well as catalysts (enzymes) that aid all chemical reactions in the body.
Monomer of a Protein: Amino Acids are the building blocks or monomers of proteins. There are 20 common amino acids, which form long chains. The way the chains are put together and the exact sequence of amino acids determines the characteristics of the protein.
Peptide Bonds: Each amino acid is connected to other amino acids by peptide bonds. The long chain of amino acids is thus called a polypeptide.
Types of Proteins: The two main types of proteins are globular and structural.
Globular: globular proteins are enzymes, which act as catalysts to lower the amount of energy required for a chemical reaction. Every basic function of your body depends on enzymes.
Structural: structural proteins serve as building blocks for muscle, bone, skin, tendons, vessels, hair and so forth.
Nucleic Acids: Nucleic acids are the fourth type of macromolecule. The two
kinds of nucleic acids are DNA and RNA, deoxyribonucleic acid and ribonucleic acid, respectively. The monomer of DNA and RNA are nucleotides, which are strung together in extremely long chains.
DNA: the hereditary information of any living organism is carried in DNA.
DNA is found in the nucleus of the cells.
RNA: RNA is responsible for making a blueprint of
DNA. The RNA then codes for the proteins that your body needs.