Chemistry of living things
1. Living things are made up of elements and compounds
- Elements are pure substances that cannot be broken down into any simple substances by ordinary means
- Compounds are made up of two or more elements that are chemically combined
- There are two main categories of compounds
- Inorganic compounds- compounds that may or may not contain the element carbon.
- Most inorganic compounds do not contain carbon
- However carbon dioxide is an exception
- Examples of inorganic compounds includes table salt, ammonia, rust and water
- Organic compounds- most compounds in living things contain the element carbon combined with oxygen and hydrogen
- There are over three million different organic compounds in living things
- Organic compounds that are basic to life include carbohydrates, fats and oils, proteins enzymes and acids
- Carbohydrates
- The main sources of energy for living things
- Made of elements C, H, and O
- Include sugars and starches
- Fats and oils
- They are energy rich compounds made from C, H and O
- They are scientifically called lipids
- Proteins
- Organic compounds made from C, H, and O
- They also contain nitrogen, and sometimes sulfur and phosphorus
- The buildings blocks of proteins are called amino acids.
- There are about 20 different amino acids
- These amino acids combine in many different ways to produce thousands of proteins
- Proteins are necessary for growth and repair of body structure
- Enzymes
- A special type of protein that regulates chemical activities in the body
B. Enzymes act as catalysts by initializing, speeding up, or slowing down chemical reactions in the body.
H. Nucleic Acids
- The blueprints of life are nucleic acids
- They are very large compounds that store information that helps the body make proteins
- They control the way that amino acids are put together so that the correct protein is formed
- One nucleic acid is DNA
- Deoxyribonucleic acid stores the information needed to build a protein
- DNA also carries messages about an organism that are passed from parent to offspring.
- Another nucleic acid is RNA
- Ribonucleic acid reads the message carried by DNA and guides the protein making process
- Together these two nucleic acids contain the information and carry out the steps that make each organism unique