Physics 2 Vesicle Mediated Transport & Plant Biology PDF

## Vesicle Mediated Transport - Used to facilitate the movement of substances - **Endocytosis:** Membrane forms pocket around substances the cell wants to take in; transports particles to specific parts of the cell - **Phagocytosis:** Takes large, solid particles - **Pinocytosis:** Takes s...

## Vesicle Mediated Transport - Used to facilitate the movement of substances - **Endocytosis:** Membrane forms pocket around substances the cell wants to take in; transports particles to specific parts of the cell - **Phagocytosis:** Takes large, solid particles - **Pinocytosis:** Takes small, fluid droplets - **Receptor Mediated Endocytosis:** Receptors bind to companies and take them in - **Exocytosis:** The reverse of endocytosis. Vesicles fuse with the membrane and eliminate particles out of the cell. ## Tonicity - **Tonicity:** Ability of a solution to move water in/out of a cell through osmosis. Comparison of the amount of water inside to outside of the cell. - **Solute:** Substance that dissolves - **Solvent:** Substance that does dissolving - **Solution:** Solute + Solvent together - **Hypotonic:** Solute inside the cell is greater than outside. Causes water to move into the cell (cell swells up/bursts). - **Hypertonic:** Solute outside the cell is greater than inside. Causes water to leave the cell (cell shrinks/shrivels). - **Isotonic:** Solute inside and outside is equal. Causes water to move in/out equally. - **Tonicity of the cell is always opposite to the tonicity of the solution:** Hypotonic cell = Hypertonic solution ## Cell Size & Function - **Why cells are so small:** Diffusion over long distances is slow. Minimizing the distance for access to oxygen, substances, nutrients, etc. is faster. - **Plant Structure & Specialization:** - Four organs in plants: roots, stem, leaves, flowers - **Photosynthesis:** Occurs in chloroplasts of plant cells. - $6CO_2 + 6H_2O + light (energy) -> C_6H_{12}O_6 + 6O_2$ - **Cellular Respiration:** Occurs in mitochondria of cells - $C_6H_{12}O_6 + 6O_2 -> 6CO_2 + 6H_2O + Energy (ATP)$ ## Parts of a Leaf Cell - **Epidermal tissue:** Flat single layer of cells on the upper/lower leaf. Protects the leaf, has no chloroplasts. (The clear layer prevents evaporation through the leaf). - **Palisade tissue:** Long, narrow columns of cells under the epidermal tissue. The main area of photosynthesis, has chloroplasts. - **Spongy tissue:** Round, loosely packed cells under the palisade tissue. Main area of water/gas exchange, minor photosynthesis, some chloroplasts. - **Stomata:** Tiny openings on the bottom of the leaf. Allows exchange of CO2, O2, and H2O. - **Guard cells:** Cover the stomata to allow substances in/out. - **Vascular tissue:** Tubes arranged in vascular bundles. - **Xylem:** Carries water/minerals from roots to leaves. - **Phloem:** Carries sugars from leaves to the rest of the plant. ## Plant Growth Responses - **Phototropism:** Allows the stem to curve away/towards light. - **Positive:** Growth towards light. - **Negative:** Growth away from light. - **Gravitropism:** Growth due to gravity. - **Positive:** Growth into soil, towards the force of gravity. - **Negative:** Growth upwards, against the force of gravity. - **Nastic Response:** Plants respond to touch. ## Heating Curve of Water - Diagram of a heating curve of water with the following phases: solid, liquid, and gas. ## Types of Systems - **Open:** Energy and matter cross the systems boundary (cell). - **Closed:** Only energy, not matter crosses the boundary (Earth). - **Isolated:** No energy or matter crosses the boundary (Universe). ## Types of Heat Transfer - **Conduction:** Heat transfer through direct contact (touching). - **Convection:** Heat transfer in fluid currents (liquid/gas). - **Radiation:** Heat transfer using waves (no contact). ## Albedo - **Albedo:** The ability of a surface to reflect light. - **Light colors = High albedo** - **Dark colors = Low albedo**