bio unit 2

• cells are the basic units of all living organisms, all cells are surrounded by a cell membrane and contain dna
• Cell theory: all things have cells, cells are the basic unit of structure & function in all living things, all cells come from other cells
• all cells contain small organelles that have a specific function
• Prokaryotic: no nucleus, no membrane bound organelles, dna is circular, unicellular, ex: bacteria, anarachea
• Eukaryotic: has a nucleus & membrane bound organelles, dna is spiral, multicellular, ex: protists, fungi, plants/animals
• all of an organisms cells have the same dna, what the dna tells each cell to do: differentation
• stem cells: early in development all are the same. dna will activate a certain gene (section of dna) that tells the cell what to do. specialized cells: have certain function, can never be reversed
• types of stem cells - Embryonic: early fertilized, can be anything (undifferentiated), Adult stem cells (somatic): can become type of cell they live near, found in bone marrow, undifferentiated
• cell membrane regulates what enters and leaves the cell to maintain homeostasis, also called plasma membrane, phospholipid bilayer, concentration gradient, fluid mosaic
• phospholipids make up cell membrane, have a phosphorus head (hydrophilic), fatty acid tail (hydrophobic)
• larger molecules (charged molecules; ions) need a protein channel to pass through membrane
• cells have to stay in a liquid environment to survive
• Passive transport: no ATP needed, 3 types. Diffusion: small particles move from high to low concentration. Osmosis: movement of water from high to low concentration. Facilitated Diffusion: molecules to big have to pass thru protein channels
• 3 ways osmosis can effect cells. Isotonic solution: solute is same inside & outside of cell; stable. Hypertonic solution: more solute in water, water flows out of cell & shrinks. Hypotonic solution: more solute in cell, water comes in & cell will explode.
• Active transport: requires a protein channel to move from low to high concentration, requires the use of ATP
• types of active transport. Exocytosis: waste & other products being pushed out of cell. Endocytosis: taking items into the cell, 3 kinds are phagocytosis, pinocytosis, receptor-mediated
• Photosynthesis: making glucose, chlorophyll captures light energy > CO2 taken into plant through stomata > plant adaptations help process (leaf size & covering (wax to hold water), little hairs (stop evaportation)
• cellular respiration: converting glucose into energy (atp), occurs in mitochondria
• 2 stages of cellular respiration. Cytoplasm (glucose broken down without O2 needed (anaerobic), produces little atp). > Mitochondria (small molecules broken down more, O2 needed (aerobic), makes lots of atp)
• types of anaerobic respiration (fermentation). Lactic acid fermentation: gives energy when not enough O2, produces little atp, sore muscles. Alcholic fermentation: used in yeast & bacteria, byproducts are CO2 & alcohol, produces little atp, used for foods.