The Twelve Days of Middle School Science

The Twelve Days of Middle School ScienceDay 1: Cell Theory(& structure, organelles & functions, processes)Cell Theory1. All organisms (living things) are made of one or more cells. (Unicellular or multicellular)2. The cell is the basic unit of all LIVING things. Hierarchy of all matter:(?)Quarks & Leptons Protons/ Neutrons/Electrons Atoms Elements Molecules Compounds Proteins, Sugars, Acids, Lipids, Minerals Cells (LIFE) Tissues Organs Organ Systems Organisms Populations Communities Ecosystems Biome Biosphere Earth Solar System Galaxy Local Group Galaxy Clusters Universe Multiverse?3. All cells come from existing cells. (Mitosis=production of body cells or Meiosis=production of sex cells) Two Classifications* of CellsProkaryotic Cells 1st form of lifeHave NO nucleus DNA is free (called the nucleloid) ONLY form Unicellular organisms (one-celled)Example: Bacteria (e. coli, staph, salmonella)Eukaryotic CellsEvolved from prokaryotesHave a nucleus with bundled DNACan form unicellular or multi-cellular organisms.Example: Amoebas, plants animals, fungi, protists

*Note: There many TYPES of cells (skin, muscle, hair, sex, etc.,); these are the two categories that ALL cells fall under! It is the DNA within cells that controls what type of cell they will be.

Cell Organelles

Organelle & Function*Cell Membrane: Outer cell lining for protection*Cytoplasm: Jelly-like liquid that organelles float in*Nucleus: Control center that contains organisms DNANuclear Membrane: encloses and protects nucleus; DNA can travel through to get to the ERNucleolus: Produces ribosomes*DNA: The hereditary material of organismsChromosome: Thread-like structure of DNA that holds genes*Vacuoles: Store nutrients and waste *Mitochondria: Jelly-bean shaped producers of energy (ATP) for cell*Ribosomes: Where proteins are made*Endoplasmic Reticulum: Cell transportation system (rough=has ribosomes on top, smooth=no ribosomes)*Golgi Apparatus/Body/Complex: Packaging center which stores, modifies and secretes proteins and lipidsMicrotubules: protein filaments involved in cell movement, shape, and cell division (mitosis/meiosis).Centrioles: contain microtubules and involved in cell division (animals only)Lysosomes: responsible for intracellular digestion, kamikazes

* = KNOW THESEEVALUATE:What shape are the mitochondria?How is the cell similar to a body system?Is the animal cell an open or closed system? Why?

PLANT-SPECIFIC organelles: *Cell Wall: Gives plant cells shape and structure (rigidity), made of cellulose*Chloroplast: Site where photosynthesis in plant cells occurs

EVALUATE:What are some similarities between plant and animal cells?What do you notice about the vacuole of the plant cell?Why do you think plants evolved to have cell walls and animals did not?

Plant OrganellesCellular ProcessesRespiration the release of energy from sugar. Can be aerobic (with oxygen) or anaerobic (w/o oxygenthis is called fermentation)**Photosynthesis** - process by which plants change light energy (sunlight) into chemical energy (sugar)

Mitosis when cells split to create new body cellsMeiosis when cells split to reproduce sex cells (ex: egg & sperm)

Cellular Processes, Cont.Diffusion - Movement of molecules from an area of great concentration to an area of lesser concentration.

Osmosis diffusion of water through cells

Summary of the Cell

Assessment & HomeworkGo to Ms. Cedillos website (8th Grade Science The Twelve Days of Middle School Science)Look under Day 1 for these notes and other resourcesHOMEWORK: STUDY cell structure & organelle functions we will have an assessment over this tomorrow