1. TAKS presentation for Spring 2007 Cells and organization of living systems

2. Organization of living systems All matter made of atoms Atoms organized into molecules Molecules organized into cells (Living things are made of cells) Cells organized into tissues Tissues organized into organs Organs organized into organ systems Organ systems organized into organisms

4. Two types of cells Prokaryotic cells Eukaryotic cells

5. Prokaryotic Cells Lack nucleus and most other organelles (structure within cell – performs specific function) Include Eubacteria and Archaebacteria Archaebacteria – ancient bacteria Eubacteria – true bacteria Good bacteria and pathogenic bacteria

6. Eukaryotic cells Have nucleus and other organelles

7. Organelles in Eukaryotic cells Nucleus – contains DNA; command center of cell Mitochondria – found in all eukaryotes – breaks down food molecules (i.e. – glucose) to release energy (cellular respiration) Equation for cellular respiration: C 6 H 12 O 6 + 6O 2  6CO 2 + 6H 2 O + ATP Ribosomes – where proteins are made Endoplasmic reticulum – path along which molecules move from one part of the cell to another Golgi apparatus – processes and packages substances produced by the cell

8. Lysosome – digests molecules, old organelles, and foreign substances Cilia and flagella – propel cells through the environment; move materials over cell surface Vacuole – storage of water, waste, and/or enzymes Microfilaments and microtubules – forms cytoskeleton of cell for support, movement, and division of cells Chloroplast – found in cells of plants and some protists – use energy in sunlight to make the sugar glucose (photosynthesis). Glucose fuels all life’s processes (plant and animal). Cell wall – (plants) supports/protects cell

9. Plant and Animal cells

10. How cells keep themselves alive Maintain stable internal environment - homeostasis

11. Ways to maintain homeostasis Passive transport – no ATP used –Diffusion –Osmosis –Facilitated diffusion Carrier proteins Ion channels Active transport – ATP used –Carrier proteins Cell membrane pumps (sodium-potassium) –Endocytosis –exocytosis

12. Interdependence In multicellular organisms cells work together in organs and organ systems to help one another maintain homeostasis

13. Organ Systems Circulatory – transports oxygen and nutrients to cells and carries wastes away from cells Respiratory – moves oxygen into the body and carbon dioxide out of the body Digestive – breaks down food and absorbs nutrients Nervous – detects changes outside and inside your body and controls the way your body responds to these changes Skeletal – movement, protection, shape, support, storage of minerals and produces blood cells

14. Muscular – movement, posture, and production of heat Endocrine – produces chemical messengers called hormones; some hormones help to maintain homeostasis while others control development and growth Integumentary – forms protective barrier around body, prevents water loss, controls body temperature, and gathers information about your surroundings Immune – protects body from infection

15. Lymphatic – takes fluid from the spaces between cells and returns it to the circulatory system; filters bacteria and other microorganisms from this fluid Reproductive – males – sperm production; females – eggs Excretory – removes wastes from the body and helps maintain homeostasis