1. Animal & Plant Cell Review
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2. 5.1 Matter & Energy Pathways in Living Systems
5.2 Photosynthesis Stores Energy in Organic Compounds
5.3 Cellular Respiration Releases Energy from Organic Compounds
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3. Ch. 5 Photosynthesis & Cellular Respiration
In this unit, you will:
Relate photosynthesis to the storage of energy in organic compounds
Explain the role of cellular respiration in releasing potential energy from organic compounds
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4. Plant and Animal Cells
Plants, animal, fungi & protists are made up of eukaryotic cells
Eukaryotic cells have a nucleus
Cells that make up animals have some structures that distinguish them from plant cells
Plant cells have a cell wall
Plant & animal cells have organelles
Plant cells are larger than animals cells
Plant cells have chloroplasts
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5. Plant Cells
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6. Animal Cells
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7. Organelles
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8. The Cell Membrane
The cell membrane is a boundary that separates the internal environment of a cell from its external environment
Composed of:
Double layer of phospholipid molecules
Structure:
Head region: dissolves easily in water
Tail region: insoluble in water
Arranged into two, sandwich-like layers
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9. Cell Membrane Peripheral protein Integral proteins
Cholesterol
Part of phospholipids attracted to water
Part of phospholipids repelled by water
Glyco-protein
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10. Passive Transport: Diffusion
The cell membrane is selectively permeable
Allows some molecules to pass through it while preventing others from doing so
Small molecules and ions move through the cell membrane by diffusion
Diffusion is the natural movement of molecules or ions from a region where they are more concentrated to one where they are less concentrated
Does not require energy from the cell
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11. Diffusion
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12. Diffusion
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13. Movement of Substances
The natural tendency of a substance to move from an area of high concentration to an area of lower concentration is often described as “moving down” or “following” its concentration gradient
Differences in some quality between two adjacent regions
Examples: concentration in pressure, electrical energy, pH
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14. Concentration Gradients
Low Concentration
High Concentration
Equilibrium
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15. Cell and Membrane
Water inside of the cell is referred to as intracellular fluid
Water outside of the cell is referred to as extracellular fluid
Cellular fluid diffuses freely through the cell membrane
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16. Passive Transport: Osmosis
The diffusion of a solvent across a semi-permeable membrane that separates two solutions is called osmosis
Does not require energy from the cell
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17. Osmotic Movement
If the water concentration inside of the cells equals the water concentration outside of the cell, equal amounts of water move in and out of the cell at the same rate (cell is isotonic)
If the water concentration outside the cell is greater than than the water concentration inside of the cell, water moves into the cell (cell is hypotonic)
If the water concentration inside the cell is greater than the water concentration outside of the cell, then water moves out of the cell (cell is hypertonic)
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18. Osmotic Movement Isotonic Solution Hypertonic solution
Hypotonic solution
Water moves in and out of the cell equally. Cell remains the same size.
Water moves out of the cell. Cell shrinks in size.
Water moves into the cell. Cell increases in size and bursts.
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19. Facilitated Diffusion
Some substances require assistance from the cell to diffuse across cell membranes
Some cells are too big (ex. Glucose)
Transport proteins recognize and move only one type of dissolved molecule or ion (based on shape, size and electrical charge)
Carrier proteins helps the movement of glucose across a concentration gradient
Specific shape
Channel proteins transport charged particles across a membrane
Tunnel shape
No energy from the cell is required
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20. Facilitated Diffusion
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21. Active Transport
Active transport uses energy to enable a cell to take in a substance that is more concentrated inside the cell than outside the cell
Energy for active transport comes from a molecule called adenosine triphosphate (ATP)
When one of three phosphates is split from ATP in a chemical reaction, energy is released that is harnessed to power a cellular function
Also known as the sodium-potassium pump
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22. Active Transport
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23. Endocytosis
Some cells use a specialized method to move substance across a cell membrane
When the cell membrane folds inwards, creating a bubble-like sac called a vesicle, trapping and enclosing a small amount of matter from outside the cell is called endocytosis
Three forms:
Pinocytosis
Phagocytosis
Receptor-assisted endocytosis
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24. Endocytosis
Pinocytosis: the intake of a small droplet of extracellular fluid along with any dissolved substances or tiny particles that it may contain
Phagocytosis: the intake of a large droplet of extracellular fluid, often including bacteria or bits of organic matter
Receptor-assisted endocytosis: the intake of specific molecules that attach to special proteins in the cell membrane
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25. Endocytosis
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26. Exocytosis The removal of substances from the cell Steps:
A vesicle from inside the cell moves to the cell surface
Vesicle membrane fuses with the cell membrane
Contents of the outward-bound vesicle are secreted into the extracellular fluid
Important in the secretion of hormones
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27. Exocytosis
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28. Cell Transport Summary
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29. Video Video – Membranes & Transport Crash Course
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