A Theory Widely accepted Supported by experimental evidence and observations
Cell Theory Every living thing is made of one or more cells Cells carry out the functions needed to support life Cells come only from other living cells
Pasteur Experiment Confirmed the cell theory Did not support spontaneous generation-the idea that living things formed from non-living things
Classification of Cells Archaea- “ancient” usually found in extreme environments. Prokaryotic cells Bacteria-prokaryotic cells Eukarya- are eukaryotic cells, more complex, includes all multicellular organisms and some unicellular organisms (protists and paramecium)
Multicellular Organism Cells Tissues Organs Organ systems
Carbohydrates Provides the cell with energy by breaking down sugar
Lipids Are fats and oils that are used for energy and for making organelles in the cell Lipids can’t mix with water important for the cell
Proteins Made up of amino acids and are used by the cell for proper cell functioning proteins help the cell transport materials in and out of the cell
Nucleic Acids Provide the cell with the instructions for the maintenance, growth, and reproduction of the cell.
Cell Membrane Made up of fats, provides a barrier between materials inside the cell and outside the cell. Selectively permeable (semi- permeable)-only some things are allowed in/out of the cell.
Importance of Cell Membrane Allow needed materials into the cell Prevents unwanted materials from getting into the cell Lets unneeded materials out of the cell Cell Membrance animation Cell Membrance animation
Passive Transport When molecules move freely across the cell membrane. No energy is required from the cell.
Diffusion Movement of material from an area of high concentration (crowded) to an area of low concentration (uncrowded ).
Osmosis Diffusion of water across a membrane Diffusion Osmosis Diffusion Osmosis
Active Transport When the cell uses energy to move material across the cell’s membrane.
Endocytosis When the cell uses energy to move large molecules into the cell.
Exocytosis When the cell uses energy to move large molecules out of the cell.
How does this picture represent Active Transport?
Photosynthesis Plants use energy from the sun to make food Takes place in the chloroplasts by the chlorophyll Materials needed: 1. Water (H 2 O) 2. Carbon dioxide (CO 2 ) 2. Carbon dioxide (CO 2 ) Materials produced: 1. Glucose-sugar (C 6 H 12 O 6 ) 2. Oxygen (O 2 )