Transcript Water
Chemicals That are Important for life Chapter 1 Lesson 2 A little background… • Not all chemicals are harmful to living things • Water is one of the most important life chemicals • Other important chemicals include proteins, carbohydrates, fats, vitamins, and minerals • Plants make their own food using energy from the sun and chemicals they get from the air and soil. • The chemicals that are needed for life and come from foods are called nutrients. Importance of Water • Life as we know it cannot exist without water. • Special properties of water allow it to break things apart into tiny particles. • When the particles of water and broken down substance become equally mixed, they form a solution. – A solution is a mixture in which the particles are mixed equally. • Think about drinks you enjoy. Tea, Koolaid, and hot chocolate are all solutions! Water is inside every one of your cells! • Water’s ability to break down particles is important to cells • Cells are so small that the particles that enter them must be very tiny • Have you accidentally bitten your lip or tongue? – The salt and iron you taste is part of the solution of chemicals that make up your blood. • Fact: Humans can live several weeks without food, but only a few days without water. Carbohydrates • Carbohydrates or carbs are sugars and starches with living things use for energy. • Some examples include: – Sugars • Fruits like oranges and apples • Sugar from sugarcane • Dairy products like milk and yogurt – Starches • Vegetables like potatoes and corn • Grains like breads, rich, and pasta Were do carbs come from? • Plants use the energy from sunlight to make carbohydrates. – Plants pull carbon dioxide from the air and water to make carbohydrates. • Animals get their carbohydrates from plants they eat. • Carbs are divided into two groups: – Simple carbohydrates are all sugar – Complex carbohydrates are made of sugars, starches, and fiber. • These are much better for you! Energizing Carbs! = • Carbs are the fuel your body needs to carry out life activities. • Carbs work like gas in a car – Carbs are broken down in your body (Like gas is burned in a car) – Energy is released – The energy makes your body go! • Fact: Coffee does not actually give you energy. It makes you use the energy you have from carbs faster. So, drinking coffee is like pressing down harder on the gas pedal of a car. Fats • Fats are a chemical that stores large amounts of energy. • The energy is released when the fat is broken down. • Of all the important chemicals, fat has the most energy. • Fats protect your body by keeping it insulated (warm) and padded. • Some examples include: – – – – Meat Cheese Butter Peanut butter Fats and oils • Fats are related to oils. • Fats are solid at room temperature. • Oils are liquid at room temperature. • Some examples include: – Corn oil – Olive oil – Canola Oil – Peanut Oil Proteins • Proteins are a chemical used by living things to build and repair body parts and regulate body activities. • Some examples include – Meat: • • • • • Beef Chicken Pork Lamb Fish – Non-meat options • • • • Eggs Beans Nuts Cheese Powerful Proteins • Provide energy for living things • Help repair damaged cells and build new ones – Hair, muscles, and skin are mostly made of protein • Help control body activities such as – – – – – Heart rate Digesting food Fighting infections Controlling body chemistry Keeping the body running smoothly Proteins are a basic part of living cells • Cells put together molecules (mainly proteins) to carry out cellular functions. • Proteins are made of long chains that are smaller than molecules called amino acids. • There are 20 different amino acids that can be arranged to create different types of protein. • Proteins fold into shapes to perform different functions. – If a protein folds the wrong way or has a missing part, it may not be able to do its job. • Ex) proteins with incorrect structures in the brain cause Alzheimer’s disease DNA and Proteins • DNA in the cell nucleus contains the code needed to produce proteins. • When a cell receives a signal from the body that a protein is needed, the DNA inside the nucleus reproduces the code for the protein. • The code is carried by RNA out into the cell. • Ribosomes read the RNA and join together the amino acids using the RNA code. • Fact: A change in one atom of the DNA molecules an change the protein that is produced. Importance of Nutrients • To keep your body working, you need a regular supply of water, carbohydrates, proteins, and fats from the foods you eat. • Different foods give you different nutrients, so it is important to eat many kinds of healthy foods. Your body also needs minerals and vitamins. • Minerals and vitamins are chemicals found in foods that are needed by living things in small amounts. – Examples of Minerals include: • Iron • Zinc • Calcium – Examples of Vitamins include: • E • B12 • C Basic Life Activities Chapter 1 Lesson 4 You’re getting a puppy!!!! • What plans will you need to make? • What will you need to buy for it? Getting Food • All living things need food • Animals get their food from plants and other animals • Plants make their own food using the sun’s energy. They make carbohydrates from carbon dioxide and water. Using Food and Removing Waste • Animals eat food and digest it. • Digestion: the process by which living things break down food. • The broken down particles are taken to cells • Cells release the energy that is stored in the chemicals of food through a process called Respiration. – Oxygen is used to release stored energy. • Respiration also produces waste products. • Excretion is the process that removes waste from living things. – Exhaling and going to the bathroom are two ways animals remove their waste. Movement • Movement is a conmen activity for living things • Plants do not move from place to place, but their stems and leaves bend and move as they grow. Plants growing and moving • There is constant moments inside living things – – – – Material in animals and plants is always changing Liquids are flowing Food is digested Materials are moving in and out of cells Sensing and Responding • Animals and plants have organs that pick up, or sense, signals from their surroundings • These signals include: – Light – Touch – Sound – Chemicals Homoeostasis • Organisms have the ability to maintain their internal conditions. – Example: • Your body’s ability to keep you temperature within a normal range Growth, Development, and Reproduction • Growing is part of being alive – All animals and plants grow • Many things develop as they grow – Development means becoming different over time. – Example: • Tadpoles hatch from eggs and slowly develop into frogs • All living things produce offspring though reproduction – Some living things reproduce by themselves – Other living things need two parents to produce offspring