What Is Life? Chapter 1

1. What Is Life? Chapter 1 Characteristics of Living Things Life Comes From Life Needs of Living Things Living, Non-living & Dead

2. Characteristics of Living Things: All living things… • Are made of cells. • Have the Chemicals of Life. • Use Energy. • Are able to grow and develop. • Will respond to a stimulus. • Are able to reproduce.

3. Cellular Organization • Cells: The basic unit of structure and function in an organism. • Organism: A living thing that shares all of the characteristics of living things. • Unicellular: single celled organisms (bacteria) • Multicellular: Many celled organisms

4. Chemicals of Life • Water (most abundant) • Carbohydrates (energy source) • Proteins & Lipids (building materials) • Nucleic Acids (genetic material)

5. Carbohydrates: • The main source of energy for living things. • Sugar and starch • Fruits

6. Proteins: • Eggs, meat, fish, beans, nuts and poultry. • Made up of Amino Acids. • Needed for the growth and repair of body structures. • Hair and muscles. • Provide energy.

7. Nucleic Acids: • The blue prints of organic chemicals. • Large compounds. • Help to make proteins. • DNA and RNA are Nucleic Acids.

8. Energy Use: • Metabolism: The chemical reactions performed by a living organism. Needed for growth, to store energy, and repair cells. • Ingestion: How a living thing takes in or produces food. • Digestion: The process of breaking down food into simpler substances.

9. Energy continued: • Respiration: The process of a living thing taking in food to produce energy. • Excretion: The removal of waste products.

10. Response: • Stimulus, (Stimuli: plural): The signals to which an organism reacts. • Response: The action or movement or change caused by a stimulus.

11. Growth & Development • Growth: the process of becoming larger. • Development: the process of change that occurs during an organism’s life to produce a more complex organism.

12. Reproduction: • Sexual Reproduction: requires two parents. Most multicellular organisms reproduce this way. • Asexual Reproduction: reproduce with only one parent. Bacteria, yeast and some plants reproduce this way.

13. Changing an old theory: • Spontaneous Generation: Before the 1600’s people believed that life could spring from non-living things. • Francesco Redi: an Italian doctor in 1668 helped to disprove Spontaneous Generation.

14. Louis Pasteur • Mid-1800’s • French Chemist • Proved that Spontaneous Generation was not true. • He compared bacterial growth in boiled and un-boiled broth. • Pasteurization

15. Needs of Living Things: • Food • Water • Living Space • Stable Internal Conditions

16. Food • Autotroph: a kind of living thing that can make it’s own food. Auto means “self” and troph means “feeder”. • Heterotrophs: a kind of living thing that cannot make their own food. Hetero means “other”. They must obtain energy by feeding on others.

17. Stable Internal Conditions • Homeostasis: To maintain a stable internal condition. Organisms must be able to keep the conditions inside their bodies stable, even when conditions in the surroundings change.

18. Living Things: • Have all 6 characteristics of living things or have the potential to (seeds). • Cells • Chemicals of Life • Use Energy • Respond to their surroundings • Grow and Develop • Reproduce

19. Non-living Things: • Do not have all of the 6 Characteristics of living things. It may have some, but not all! • It may never have been alive (rock), OR • It may have been alive once (tree), but went through a chemical or physical process and was changed (chair).

20. Dead: • It once was alive, but no longer is. • It may still have cells or chemicals of life, but they no longer function.

21. The End Created by Mrs. Scibelli Science Explorer From Bacteria to Plants