Unit 2 Lesson 2 Chemistry of Life Copyright © Houghton Mifflin Harcourt Publishing Company 1

Unit 2 Lesson 2 Chemistry of Life Florida Benchmarks SC.6.N.1.1 Define a problem from the sixth grade curriculum, use appropriate reference materials to support scientific understanding, plan and carry out scientific investigations of various types, such as systematic observation or experiments, identify variables, collect and organize data, interpret data in charts, tables, and graphics, analyze information, make predictions, and defend conclusions. Copyright © Houghton Mifflin Harcourt Publishing Company 2

Unit 2 Lesson 2 Chemistry of Life Florida Benchmarks SC.6.L.14.1 Describe and identify patterns in the hierarchical organization of organisms from atoms to molecules and cells to tissues to organs to organ systems to organisms. LA.6.4.2.2 The student will record information (e.g., observations, notes, lists, charts, legends) related to a topic, including visual aids to organize and record information and include a list of sources used. Copyright © Houghton Mifflin Harcourt Publishing Company 3

It’s Elementary What are atoms and molecules? Unit 2 Lesson 2 Chemistry of Life It’s Elementary What are atoms and molecules? All cells (and all matter) are made up of atoms and molecules. An element is a substance that cannot be broken down into a simpler substance. The smallest unit of an element that maintains the properties of that element is called an atom. Copyright © Houghton Mifflin Harcourt Publishing Company 4

What are atoms and molecules? Unit 2 Lesson 2 Chemistry of Life What are atoms and molecules? What are the six main elements that make up the human body? Copyright © Houghton Mifflin Harcourt Publishing Company 5

What are atoms and molecules? Unit 2 Lesson 2 Chemistry of Life What are atoms and molecules? A molecule is a group of atoms held together by chemical bonds. Some molecules are made of only one type of atom. Most molecules are made of two or more types of atoms. Copyright © Houghton Mifflin Harcourt Publishing Company 6

What are atoms and molecules? Unit 2 Lesson 2 Chemistry of Life What are atoms and molecules? Cells are mostly made of compounds. Compounds are substances made up of two or more elements joined by chemical bonds. Compounds have different properties than the elements that make them. Copyright © Houghton Mifflin Harcourt Publishing Company 7

Cell Fuel What are some important molecules in cells? Unit 2 Lesson 2 Chemistry of Life Cell Fuel What are some important molecules in cells? Organisms use nutrients for energy and as building materials. A lipid is a fat molecule or a molecule that has similar properties. Lipids store energy in cells. Your cells get lipids from the foods you eat. Copyright © Houghton Mifflin Harcourt Publishing Company 8

What are some important molecules in cells? Unit 2 Lesson 2 Chemistry of Life What are some important molecules in cells? A protein is a molecule made up of amino acids. Protein-rich foods are broken down into amino acids, which make new proteins to build and repair body structures. Proteins called enzymes help chemical processes happen in cells. Copyright © Houghton Mifflin Harcourt Publishing Company 9

What are some important molecules in cells? Unit 2 Lesson 2 Chemistry of Life What are some important molecules in cells? Carbohydrates are molecules that include sugars, starches, and fiber. Cells use carbohydrates for energy and energy storage. Carbohydrates can be simple carbohydrates or complex carbohydrates. Copyright © Houghton Mifflin Harcourt Publishing Company 10

What are some important molecules in cells? Unit 2 Lesson 2 Chemistry of Life What are some important molecules in cells? Nucleic acids are molecules that carry information in cells. Nucleotides are the smaller molecules that make up nucleic acids. DNA is a nucleic acid that carries information that cells need to make other molecules. Copyright © Houghton Mifflin Harcourt Publishing Company 11

Waterworks What are phospholipids? Unit 2 Lesson 2 Chemistry of Life Waterworks What are phospholipids? A lipid that contains phosphorus is called a phospholipid. The head of a phospholipid is attracted to water. The tail repels water. A double-layer cell membrane, made of phospholipids, regulates molecules entering and leaving a cell. Copyright © Houghton Mifflin Harcourt Publishing Company 12

What are phospholipids? Unit 2 Lesson 2 Chemistry of Life What are phospholipids? What causes a cell membrane to have a double-layer structure? Copyright © Houghton Mifflin Harcourt Publishing Company 13

Unit 2 Lesson 2 Chemistry of Life Why is water important? Water moves through a cell membrane by osmosis. Water moves into and out of a cell, from areas of higher concentration to areas of lower concentration. Too little water causes cells to shrink. Too much water causes cells to burst. Copyright © Houghton Mifflin Harcourt Publishing Company 14