Notes: Life and the Cell

1. Notes: Life and the Cell Name _____________________________ Date ____________ Period _____

2. Organisms • Organism – any living thing • In order to be considered an organism (living thing) it must: • Be made up of cells • Use energy • Adapt to surroundings • React to changes • Change, develop, or grow • Produce more organisms

3. 6 Characteristics Described… • Be Made up of Cells • Cell– building block of living things • Some organisms have one cell(unicellular), some organisms have many cells(multicellular) • Use Energy • Organisms use energy for life processes • Energy – the ability to do work • Adapt to Surroundings • Organisms are suited for living in their environment • Adaptation – change that increases an organism’s chance for survival

4. 6 Characteristics Described… • React to Changes • Response – any reaction to a change • Stimulus – change that causes a response • Behavior – way in which an organism responds to stimuli • Homeostasis – the keeping of an organism’s body stable in a changing environment • Organisms can respond to changing conditions in their environment in order to keep their body’s conditions stable • Thermoregulation – keeping body’s temperature constant • Oxygen regulation– keeping oxygen levels constant

5. 6 Characteristics Described… • Change or Develop or Grow • Organisms grow • Organisms change in appearance • Produce More Organisms • Reproduction – process by which organisms produce more organisms • Offspring – the new organism that is produced

6. Needs of Organisms • In order to stay alive, all organisms require 5 things. They compete for these things in order to stay alive. These are: • Energy • Autotroph – organism that makes its own food • Heterotroph – organism that cannot make its own food; must consume food to survive • Water • Air– can be oxygen or carbon dioxide • Temperature – all organisms have a preferred temp • Living space– must provide all of the needs of an organism

7. Where do organisms come from? • Early scientists thought that spontaneous generation occurred • Spontaneous Generation– the idea that living things come from nonliving things • Examples – mice came from bales of hay • In the 1600’s most peoplebelieved this to be true • Two scientists disproved this • FrancesoRedi– proved that animals come from other animals; they reproduce • Louis Pasteur– proved that microorganisms (like bacteria) reproduce as well

8. Living things come from other living things! • Reproduction – the process by which organisms produce new organisms • Offspring – new organism produced by a living thing • Types of Reproduction – • Asexual Reproduction – reproduction needing only oneparent • Bacteria and other one-celled organisms reproduce this way • Sexual Reproduction – reproduction needing two parents • Animals, plants, and other multi-celled organisms reproduce this way

9. Asexual Reproduction Fission Budding • There are two typesof asexual reproduction: • Fission – new organisms are produced when a parent splits in two equal halves • Budding – the growth of a new organism from the parent organism • In asexual reproduction the offspring is identical to the parent

10. Sexual Reproduction In sexual reproduction cells from two parents join and a new organism develops from the joined cells The offspring has features of both parents

11. Living things are made of cells. Animal Cell: Plant Cell: • Cell – the basic unit of structure and function in living things • A cell is a building block for life • All living things are made of cells (either one or many)

12. Discovery of Cells: • Robert Hooke – He observed cork under a microscope and saw small boxes or “cells” • Anton von Leeuwenhoek – he was the first person to see living cells while looking at a drop of waterunder a microscope • Based on their and others’ observations, the cell theory was developed • Cell Theory: • All living things are made up of one or more cells • Cells carry out all life processes • Cells come only from other living cells

13. Types of Cells • All cells can be divided into two basic groupsbased on their characteristics • Eukaryotic Cells: • The genetic material is in the nucleus • There are organelles • Found in all multi-cellular (plants, animals, fungi) and a few unicellular organisms (fungi, protista) • Prokaryotic Cells: • There are NO organelles • The genetic material is in the cytoplasm (there is NO nucleus) • Found in most unicellular organisms (bacteria & archaea)

14. Parts of a Eukaryotic Cell: • Cell Membrane – a protective covering that encloses the entire cell; it acts as a boundary between cells • Part of the factory: security • Cytoplasm – gel-like fluid within the cell; most of the work of the cell is carried out here • Part of the factory: factory floor • Organelle – a small structure within the cell that has a specific jobin the cell

15. Organelles of the Cell – Page 1 Nucleus • Nucleus – Control center of the cell; contains DNA • Part of the factory – boss • The nucleus is surrounded by a nuclear membraneand has a nucleolus inside of it • Nuclear Membrane– the thin structure that surrounds and protects the nucleus • Nucleolus – the small structure inside the nucleus that makesribosomes

16. Organelles of the Cell – Page 2 Ribosome EndoplasmicReticulum • Endoplasmic Reticulum – Small network of tubes that substances move along; connected to the nucleus • Part of the factory – Assembly Line • Rough ER– has ribosomes on it • Smooth ER– does NOT have ribosomes on it • Ribosome – small, round structure that makes protein • Part of the factory – Production

17. Organelles of the Cell – Page 3 • Golgi Apparatus– Packages and sends materials to other parts of and out of the cell • Part of the factory – Packaging / Shipping • Lysosome – Small round structure that breaks down nutrients and old cell parts (animal cells only) • Part of the factory - Custodian

18. Organelles of the Cell – Page 4 Chloroplast Mitochondrion • Chloroplast – takes in sunlight to make sugar (food) through the process of photosynthesis • Found only in plant cells • Chlorophyll – substance inside the chloroplast that absorbs sunlight • Mitochondria – use food and oxygen to make energy for the cell through the process of cellular respiration • Part of the factory – Power Plant

19. Organelles of the Cell – Page 5 Vacuole CellWall Vacuole • Vacuole – sac that stores water, food, and waste • Part of the factory – Storage • Plant Cells – have one large, central vacuole • Animal Cells – have many small vacuoles • Cell Wall – thick outer layer that surrounds the cell membranes of plant cells; provides support to the plant • Part of the factory - Walls

20. Cell Processes • All cells undergo processes in order to stay alive • They take in materials, release materials, and transport materials throughout their cell • They do this through the processes of passive transportand active transport • They obtain energy and use energy • They do this through the processes of photosynthesis and cellular respiration

21. Materials Move Across Membranes Diffusion Osmosis • Passive Transport – the movement of materials across a cell membrane without the use of energy • Diffusion – process by which molecules spread out, or move from areas of where there are many of them to where there are fewer of them • Molecules move from higher to lower concentration • Osmosis – the diffusion of wateracross a membrane

22. Materials Move Across Membranes Cont… Exocytosis Endocytosis • Active Transport– Process of using energy to move materials across a membrane • Endocytosis – material is captured in a pocket of the membrane and moved into the cell • Exocytosis – a pocket in the cell fuses with the membrane and releases material out of the cell

23. All Cells Need Energy to Survive • Cells get all of their energy from the sugar molecule glucose • Autotroph – an organism that makes its own food; also called a producer • Examples – plants, algae, phytoplankton • Heterotroph – organism that must consume food to get energy; also called a consumer; it cannot makeits own food • Examples – animals, fungi

24. Autotrophs Get Food from Light • PhotosynthesisReaction: • Water + Carbon Dioxide + Light Energy  Glucose + Oxygen • Photosynthesis – process that plants and other autotrophs use to turn the energy from light into chemical energy in the form of glucose • Occurs in chloroplasts • Chlorophyll – light-absorbing pigment that traps energy from the sun; found in chloroplasts

25. All Cells Get Energy from Glucose • CellularRespiration – process through which cells use oxygen to releaseenergy stored in glucose • Occurs in the mitochondria • CellularRespirationReaction: Glucose + Oxygen  Chemical Energy + Water + Carbon Dioxide • Fermentation – process through which cells release energy stored in glucose withoutoxygen

26. Cells Work Together in Multicellular Organisms • All multicellularorganisms begin life as a single, fertilized egg cell • As cells divide through asexual reproduction, the specialize to perform specific jobs • Example – muscle cells, skin cells, brain cells • Specialized cells will worktogether and become increasingly organized: • Similar cells join to form tissues • Similar tissues join to form organs • Similar organs work together to form organsystems • Organsystems work together to form organisms • Cells Tissues  Organs  Organsystems  Organisms

27. Notes Reflection Responses In 5 lines name and describe the six characteristics of organisms. __________________________________________________ __________________________________________________ __________________________________________________ __________________________________________________ __________________________________________________ In 5 lines describe how prokaryotic and eukaryotic cells are different. __________________________________________________ __________________________________________________ __________________________________________________ __________________________________________________ __________________________________________________

28. Notes Reflection Responses In 5 lines name and define 3 organelles of a cell. __________________________________________________ __________________________________________________ __________________________________________________ __________________________________________________ __________________________________________________ In 5 lines describe how cells in a multicellular organism work together. __________________________________________________ __________________________________________________ __________________________________________________ __________________________________________________ __________________________________________________