2. SCIENCE GATEWAY Biological Systems and Life Processes REVIEW AND PRACTICE BIOLOGY

3. Life What does it mean to be alive?

4. Biological Systems Homeostasis

5. ENERGY/MATTER TRANSFORMATIONS RESPIRATION AND PHOTOSYNTHESIS

6. –Process by which plants and animals obtain energy from foods –Organisms break down food into smaller molecules, which combine with oxygen –Energy stored in sugars (glucose) is released as ATP RESPIRATION

7. Process occurs in two phases: 1.Glycolosis: breakdown of glucose into pyruvic acid Occurs in cytoplasm in eukaryotes 2.Oxidation of pyruvic acid to carbon dioxide and water Occurs in mitochondria RESPIRATION

8. After the breakdown of glucose, waste products, such as CO 2 and water, leave through cell membrane RESPIRATION

9. –Chemical reactions produce the nucleotide, ATP –ATP stores energy –Energy is released from ATP when needed –ATP is used for all the energy-consuming activities of the cell

10. RESPIRATION

11. OVERALL REACTION Respiration C 6 H 12 O 6 + 6O 2 → 6CO 2 + 6H 2 O + energy GlucoseOxygenCarbon DioxideWater Similar to combustion reaction (burning)

12. PHOTOSYNTHESIS 6CO 2 + 6H 2 O + energy → C 6 H 12 O 6 + 6O 2 Process of producing food in plants Chloroplasts (cells) use energy from the sun to produce glucose Uses CO 2 and water Releases oxygen as waste

13. PHOTOSYNTHESIS Light Reaction Chlorophyll traps the energy available in sunlight ATP is produced –ATP stores energy for cell processes Water is split into hydrogen and oxygen Some oxygen is used in respiration A great deal of oxygen is released to the environment

16. Dark Reaction CO 2 and other chemicals combine to form glucose, using energy from ATP Some of the glucose produced is used in respiration Some glucose is used for growth Excess glucose is stored in roots, stems and leaves of plants

17. RELATIONSHIP BETWEEN PHOTOSYNTHESIS AND RESPIRATION Respiration ALL plants and animals carry on respiration Uses oxygen Releases water and CO 2 Photosynthesis Plants with chlorophyll carry on photosynthesis Produces oxygen Uses water and CO 2

18. LIFE FUNCTIONS

19. BASIC LIFE FUNCTIONS All living organisms need to perform certain functions to remain alive Living organisms contain systems designed to carry out these essential functions

20. BASIC LIFE FUNCTIONS Six basic functions: DDigestion RRespiration RReproduction RResponse EExcretion GGrowth

21. BASIC LIFE FUNCTIONS DIGESTION The process of changing food into a usable form to provide energy

22. RESPIRATION The process of using food Breaking down stored food and combining it with oxygen to provide energy The exchange of gases to produce food and energy BASIC LIFE FUNCTIONS

23. REPRODUCTION The process by which new organisms (offspring) are produced BASIC LIFE FUNCTIONS

24. RESPONSE How organisms react to changes in their surroundings BASIC LIFE FUNCTIONS

25. EXCRETION The process by which the body gets rid of liquid waste The lungs, kidneys, and skin function to excrete waste produces created by the body

26. BASIC LIFE FUNCTIONS GROWTH The repair and production of new and larger cells within a living organism

27. TO BE LIVING An organism must perform all life functions to be considered living However, these life functions may be carried out in different ways

28. BACTERIA Prokaryotic organisms –Single-celled organisms that lack a nucleus Identified by shape, type of cell wall, movement, and the ways in which they obtain energy Most reproduce by binary fission, creating two identical cells May participate in conjugation –Genes move from one cell to another

29. ARE VIRUSES ALIVE? Not considered alive by many biologists Not composed of cells Not able to reproduce independently; must use host cell Infect living cells Can make copies of themselves Made of a DNA or RNA core surrounded by protein coat HIV Virus

30. WWHHHEEE!!!! That’s a lot of knowledge! Think you can remember? GATEWAY – HERE I COME!

31. ARE YOU READY???!!!! test