Review of biochemistry

Carbon Compounds All organic molecules contain the element carbon. All living things are composed of water, and organic molecules. Organic compounds contain carbon atoms that are covalently bonded to other elements The structure of a biomolecule will help determine its properties and functions Carbon is a special element, because it has four electrons in its valence level to share. It can form four covalent bonds because of this.

Carbohydrates Lipids Proteins Nucleic Acids Four Main Groups There are four main groups of biomolecules. They are: Carbohydrates Lipids Proteins Nucleic Acids A biomolecule is any molecule that is produced by an organism

Fossil Fuels are hydrocarbons.                                                                                                                                                                                                                                                                                                                         The simplest organic compounds contain molecules composed of carbon and hydrogen…also known as “hydrocarbons”. The compound methane contains one carbon bonded to four hydrogens. CH4 In chemistry we use a molecular formula to show how many atoms of each element are present in a molecule. A molecular formula does not show the structure of the molecule. Scientists often use structural formulas to show the number and arrangement of atoms in a compounds. Fossil Fuels are hydrocarbons.

What are the four groups of organic molecules we need to know about? Why isn’t water an organic molecule? What element does methanol and ethanol contain, that other hydrocarbons don’t?

Carbohydrates Carbohydrates are biomolecules that are composed of carbon, hydrogen, and oxygen in approximately a ratio of 1:2:1 Carbohydrates include sugars (monosaccharides, and disaccharides) starches (polysaccharides), and complex polysaccharides like cellulose and glycogen.

Carbohydrates are... The most abundant of the biomolecules a key source of energy found in most foods especially fruits, vegetables, and grains The building blocks, or monomers of carbohydrates are single sugars called monosaccharides

Lipids Lipids are large biomolecules composed mainly of carbon and hydrogen, with small amounts of oxygen. They are nonpolar molecules that are not soluble in water. Types of lipids include: Fats Are lipids that can store a great deal of energy Contains three fatty acids bonded to a glycerol molecule backbone (don’t worry…I’ll show you this) Oils Phospholipids Steroids Waxes Other lipids include some light-absorbing compounds called pigments

1) Polarity- lipids are non-polar and so are insoluble in water, meaning they must be stored in cells in special ways. Functions of Lipids 2) High-energy store - they have a higher proportion of H atoms relative to O atoms and so yield more energy than the same mass of carbohydrate 3) Thermal insulation – fat conducts heat very slowly so having a layer under the skin keeps metabolic heat in. 4) Electrical insulation – the myelin sheath around axons prevents ion leakage, and increases signal speed. 1 gram of fat provides 9 kcal while 1 gram of carbohydrate or protein provides 4 kcal 5) Waterproofing – waxy cuticles are useful, for example, to prevent excess evaporation from the surface of a leaf. 6) Hormone production – steroid hormones. Estrogen requires lipids for its formation, as do other substances such as plant growth hormones.

Lipids… Since lipids are indeed, not polymers, but macromolecules made of many different subunits…they do NOT contain monomers. And since each type of lipid contains a different set of building-blocks, what you need to know is that lipids are composed of subunits known as glycerol, and fatty acids. Since there are three fatty acids joined to this glycerol molecule, it is known as a triglyceride.

Place carbohydrates in order from smallest to largest in terms of molecular size. What are the monomers of carbohydrates? How do lipids and carbohydrates vary in their structure? What are three types of lipids? Which lipids store the most energy?

Proteins Proteins have many structures, resulting in a wide range of functions Proteins do most of the work in cells, such as enzymes The monomers of proteins are called amino acids Primary Structure…

The Work Proteins Do Receptor proteins Enzymatic Proteins Enzymes catalyze the hydrolysis of food polymers Structural Proteins Ovalbumin Storage Proteins Keratin Transport Proteins Hormonal proteins Receptor proteins Contractile and motor proteins Defensive proteins Actin and Myocin Enzymes: Selective acceleration of chemical reactions… Digestive enzymes catalyze the hydrolysis of the polymers in food. Support : Insects and spiders use silk fibers to make their cocoons and webs. Collagen and elastin provide a fibrous framework in animal connective tissues. Keratin is the protein of hair, horns, and feathers. Storage of amino acids: Ovalbumin is the protein of egg white, used as an amino acid source for the developing embryo. Casein, the protein of milk, is the major source of amino acids for baby mammals. Plants have storage proteins in their seeds Transport of other substances: Hemoglobin, the iron-containing protein of vertebrate blood, transports oxygen from the lungs to outer parts of the body. Other proteins transport molecules across cell membranes. Hormonal: Coordination of an organism’s activities: Insulin, a hormone secreted by the pancreas, helps regulate the concentration of sugar in the blood of vertebrates. Receptor: Response of cell to chemical stimuli: Receptors built into the membrane of a nerve cell detect chemical signals released by other nerve cells. Contractile and Motor: Movement: Actin and myosin are responsible for the movement of muscles. Other proteins are responsible for the undulations of the organelles called cilia and flagella Tubulin: Protein that makes flagella rotate like a screw, found in eukaryotes Flagellin: Globular Protein arranged in a helical chain found in prokaryotes Defensive: Protection against disease: Antibodies combat bacteria and viruses

What are the monomers of proteins? What is the primary structure of a protein? Describe one job that proteins do.

Nucleic Acids: Structure and Function The nucleic acids include the amazing DNA molecule. It is the source of constancy and variation among species, and is the foundation for the unity and diversity of all life on Earth. Our text book title is taken from this notion

Nucleic Acids Nucleic acids store and transmit hereditary information The amino acid sequence of a polypeptide is programmed by a unit of inheritance called a gene Genes are made of DNA, a nucleic acid Genes Are the units of inheritance Program the amino acid sequence of polypeptides Are made of specific nucleotide sequences on DNA Monomers of Nucleic Acids are called Nucleotides

The Roles of Nucleic Acids There are two types of nucleic acids involved in inheritance and protein synthesis Deoxyribonucleic acid (DNA) Ribonucleic acid (RNA) DNA Stores information for the synthesis of specific proteins Found in the nucleus of cells Directs RNA synthesis (transcription) Directs protein synthesis through RNA (translation) RNA Single stranded nucleic acid which carries the code for protein synthesis Found in nucleus, and outside of nucleus in association with ribosomes

ATP Another type of nucleic acid is ATP. It is a source of energy for cells.

What are two functions of nucleic acids? What are monomers of nucleic acids known as?