3.3 Chemical Compounds in Cells

1. 3.3 Chemical Compounds in Cells cells function similarly in all living organisms.

2. Elements and Compounds • Air is a mixture of elements • Key Concept: “An element is any substance that cannot be broken down into simpler substances.” • Elements found in living things- carbon, hydrogen, oxygen, nitrogen, phosphorus, sulfur • An element is made up of atoms, the smallest unit of an element

3. Elements and Compounds • Key concept: “When two or more elements combine chemically, they form a compound.” • Most elements form compounds (in living things) • The smallest unit of a compound is a molecule • Carbon dioxide is a chemical compound

4. Elements and Compounds • Water is a compound • Water makes up more than 2/3 of your body • Key concept: “Most chemical reactions within cells could not take place without water.” • Water dissolves chemicals, helps cells to keep their size and shape, and keeps the temperature from changing quickly • Key concept: ”Carbohydrates, lipids, proteins, and nucleic acids are important groups of organic compounds in living things.”

5. Elements and Compounds • Inorganic Compounds- does not have the element carbon (example: water, table salt) • Organic Compounds- have carbon (example: carbon dioxide) • Key concept: “Most chemical reactions within cells could not that take place without water.”

6. Carbohydrates • Carbohydrate- an energy-rich organic compound made of carbon, hydrogen, and oxygen • Sugars are produced during the food making process in plants • Plant cells store extra energy in starch (carbohydrates) • Examples: potatoes, pasta, rice • Key concept: “In addition to providing energy for the cell, carbohydrates are important components of some cell parts.” • The cellulose found in the cell wall is a type of carbohydrate • When you eat carbohydrates your body breaks it down into starch and sugar

7. Lipids • Lipids- energy–rich organic compounds made of carbon, hydrogen, oxygen • More energy than carbohydrates • Cells store energy in lipids • Types of lipids: fats, oils, and waxes • Key concept: “In addition to their functions as an energy source, lipids also make up most of the cell membrane.”

8. Proteins • Proteins- large organic molecules made of carbon, hydrogen, oxygen, nitrogen, sometimes sulfur • Protein molecules are made of amino acids. • Amino acids combine to make thousands of different proteins • A lot of the structure of cells is made of proteins • Make parts of cell membrane and many of the organelles in the cell

9. Proteins • Key concept: “The proteins known as enzymes perform important functions in the chemical reactions that take place in cells.” • Enzyme- type of protein that speeds up a chemical reaction in a living thing • Enzymes are needed for many chemical reactions that are needed for life, those chemical reactions either would take longer or wouldn’t happen at all if enzymes weren’t there

10. Nucleic Acids • Nucleic acids- very long organic molecules made of carbon, oxygen, hydrogen, nitrogen, phosphorus • Key concept: “Nucleic acids contain the instructions that cells need to carry out all the functions of life.” • 2 kinds of nucleic acids: DNA and RNA • DNA- (deoxyribonucleic acid) genetic material that carries information that passes from parent to child • RNA- (ribonucleic acid) a nucleic acid that is important in the production of proteins • RNA is found in the cytoplasm and the nucleus

11. Section 3: Chemical Compounds in Cells What are elements and compounds? How is water important to the function of cells? What are the functions of carbohydrates, lipids, proteins, and nucleic acids?