Chapter 7 Cellular Structure and Function

Transcription

1 Section 1: Cell Discovery and Theory Section 2: The Plasma Membrane Section 3: Structures and Organelles Section 4: Cellular Transport Click on a lesson name to select.

2 7.2 The Plasma/Cell Membrane Thin, flexible boundary between the cell and its environment Allows nutrients into the cell and wastes to leave.

3 Composed of the phospholipid bilayer. Consists of a glycerol backbone, two fatty acid chains, and a phosphate group.

4 Selective Permeability or semi-permeable Lets some things in but not others. Sugars are too big. Ex.-fish net, coffee filter See picture p. 187

5 Fluid Mosaic Model The phospholipid bilayer allows other molecules (proteins, carbs, and cholesterol) to float in the membrane.

6 Proteins Transmit signals inside the cell Act as a support structure Provide pathways for substances to enter and leavelike sugars.

7 Carbohydrates Identify chemical signals

8 Cell Structure and Function SPI Distinguish between prokaryotic and eukaryotic cells. EQ-What is the main differences between these types of cells?

9 Parts of Prokaryotic Cells 1. Cell Wall in 99% of them 2. Cell Membrane 3. Cytoplasm 4. Ribosomes 5. DNA 6. Capsule (sometimes) 7. Flagella or cilia Capsule

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11 SPI Identify the cellular organelles associated with major cell processes. EQ-What are the functions of the cell parts?

12 7.3 Structures and Organelles Plant and Animal Cell Structures Animal Cell Plant Cell Cellular Pursuit

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14 Animal Cell

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16 Plant Cell

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24 Membrane Transport SPI Predict the movement of water and other molecules across selectively permeable membranes. Essential Question: What type of transport is used by a potato placed in different solutions?

25 7.4 Cellular Transport Passive Transport Movement of particles across the cell membrane without using energy-always flows from high to low concentration Three Modes of Passive Transport 1. Diffusion 2. Facilitated Diffusion 3. Osmosis

26 1. Diffusion High to low movement of many particles. Ex.=smell of baking cookies Initial Conditions Low Diffusion High High Low

27 Diffusion is controlled by Temperature Concentration Pressure Equilibrium= Diffusion in = diffusion out Molecules continue to move, but the overall concentration remains the same.

28 Diffusion in a Cell--selective permeability - water and oxygen move this way.

29 Concentration gradient A difference between concentrations in a space. Molecules always move down the concentration gradient, toward areas of lesser concentration. Ex. food coloring in water or air freshener in a room.

30 2. Facilitated Diffusion Movement of materials across proteins channels. Allows ions, sugars and salts to pass. Different solutes pass through based on size, shape, and polarity.

31 Channel Proteinsallows substances to cross through a channel Carrier Proteinschange shape to help move particles across

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33 3. Osmosis Diffusion of water across a selectively permeable membrane Three Types of Solutions Isotonic Hypotonic Hypertonic

34 Water molecules move to the area with higher concentration of solute (sugar in the picture) and therefore a lower concentration of water.

35 A simple rule: Salt is a solute, when it is concentrated inside or outside the cell, it will draw the water in its direction. This is why you get thirsty after eating something salty.

36 Isotonic Solution: Iso=same Water diffuses into and out of the cell at the same rate. Plant Cell Blood Cell 11,397x

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38 Hypotonic Solution: hypo=less Solute concentration is higher inside the cell. Water diffuses into the cell so it swells. Plant Cell Blood Cell 13,000x

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40 Hypertonic Solution: hyper=more Solute concentration is higher outside the cell. Water diffuses out of the cell so the cell shrinks. Plant Cell Blood Cell 13,000x

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43 Compare and contrast active and passive transport. EQ-What are the main differences between passive and active transport?

44 Active Transport When substances move against the concentration gradient- low to high Uses Carrier Proteins or pumps and energy-atp

45 3 Types of Active Transport 1. Na + /K + ATPase pump Moves Na + ions out of the cell and K + ions into the cell

46 2. Endocytosis=Enter Process by which the cell surrounds and takes particles into the cell Requires energy 2 types: 1. phagocytosis- cell eating for large particles 2. pinocytosis-engulfs liquid or small particles

47 3. Exocytosis=Exit Secretion of material out of the plasma membrane-uses vesicles Requires energy