- Slides: 33
Transport in the Cell Active and Passive Transport
How can molecules move through cells? • Semi-permeable membrane: allows certain molecules to move in or out depending on their properties – Ex: if they are too big, they can’t go in easily • Membrane is made of (composition): – Bi-lipid layer • 2 layers of lipids – Proteins that transport materials across – Carbohydrates that act as identifiers
Fluid Mosaic Model-membrane is a fluid with a bunch of different components
Before we begin you must understand…. • Concentration-how much solute is in a solvent • Why must molecules move? – To maintain homeostasis – Homeostasis-state of balance in which the internal body remains in a normal range – Molecules must move to maintain this
Biology 11/5 HW-Concept Map 1. Take out 7. 3 wkst and 7. 3 notes. 2. Pick up your binder in the back. Put 7. 3 reading guide in wkst section.
2 types of transport in the cell • Passive transport – Molecules move down the concentration gradient • Area where there is a lot of molecules to where there is very little – Energy involved: NO • Active transport – Molecules move up the concentration gradient • Area where there is a few molecules to where there is a lot – Energy involved: YES
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Type of Passive Transport Diffusion-movement of molecules from an area of high concentration to an area of low concentration until equilibrium is reached – Equilibrium-equal distribution • Molecules will move equally after this is reached. – Simple molecules can move • Carbon dioxide, oxygen
Osmosis-Type of passive transport • Water moves from an area of high concentration to an area of low concentration – No energy involved – AKA: diffusion of water
Hypertonic and Hypotonic • Hypotonic-More water outside the cell than inside – Distilled water – Water comes into the cell – Why? To balance out the concentration of solutes • Hypertonic-More water inside the cell than outside – Salt water – Water leaves the cell – Why? to balance out the concentration of solutes
Isotonic • Molecules are equal inside and outside the cell – Molecules move evenly across the membrane
Biology 11/14 HW-finish concept map Agenda: Stations; finish notes You should be: 1. Take out 7. 3 notes 2. Take out paper with station information.
Station Exploration • You will visit different stations. • At each station, there will be directions telling you what conditions each item was place in or what to do with each item. • On your paper, you need to write down a brief description of what you see and why. – Examples of answers for why: hypertonic, hypotonic, diffusion, osmosis, decrease in turgor pressure, molecule movement
Why is water so important to a plant? • Water fills the vacuole and the contents of the cell are pushed against the cell wall • Produces turgor pressure • Gives the plant rigidity and the ability to stand erect
Facilitated Diffusion-3 rd type of passive transport • Molecules move from an area of high concentration to an area of low concentration with the help of a carrier protein – Molecules attach to a specific protein – The protein allows it to move through the membrane – Needed when molecules are too big or have an electrical charge (ions!!) • Glucose (large molecules), Na+, Ca+, K+, Cl-
Active Transport-A reminder! • Requires energy from the cell • Move molecules from an area of low concentration to high
Endocytosis • Process for bringing things into the cell • Used for large particles (bigger than molecules, still microscopic) • Requires energy
Phagocytosis Pinocytosis • “Cell Drinking” • “Cell Eating” • Small bits of liquid • Very large or other substances particles taken in by cell (engulfed) taken in
Exocytosis • Process for moving large amount of material out a cell
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Bio 11/13 HW-finish wkst; Lab due Friday; test and flashcards Friday (25 from 7. 3 and 10 from 7. 4) 1. Turn in analysis questions. Put transport review in wkst section. This is a great study tool for the test. Put lab info in lab section. 2. Take out 7. 4 notes-we will finish this.
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Section 7. 4 • Unicellular-one celled – Bacteria, algae, yeast – One cell does all the work • Multicellular-many celled – Plants, humans – Specialized cells do certain things
Specialization • Cell develop differently to perform different tasks • All cells at one time in your body are the same (stem cells) – Then they differentiate in fetal development • • Become different cells with different functions Muscle cells-allow movement Red blood cells-carry oxygen Guard cells in plants open and close stomata on a leaf.
Smallest level Group of tissues Group of organs that perform a specific function Group of similar cells Largest level