ch 7 cells 2016 - mr. b's science...
TRANSCRIPT
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1 ReviewWhat is a cell
Explain What three statements make up the cell theory
Infer How did the invention of the microscope help the development of the cell theory
2 Review How do microscopes work
Apply Concepts What does it mean if a micrograph is “false‐colored”
CH 7 CELL STRUCTURE AND FUNCTION
7.1 Life is Cellular
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Robert Hooke
1665 used microscopes
Looked in cork
Used the word “cell.”
Anton van Leeuwenhoek
Early master
lens maker
Made early
microscopes
Looked at pond
water.
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Cell Theory
1. The cell is the basic unit of life
2. All living things are made up of at least one cell
3. All cells come from other cells.
Compound Light Microscope
Light waves pass through small organisms or thin slices of larger ones
Up to 1500 times magnification
Ours magnify 400 times
Used to see bacteria
cells, and a few organelles.
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Stains and Dyes
Increases contrast and detail
Can see more organelles.
Transmission Electron Microscope (TEM)
Magnifies up to 1 million times
Shows internal structures
Specimen has to be dead.
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Scanning Electron Microscope (SEM)
Magnifies up to 1 million times
Shows the surface of the specimen
Used for cell surfaces, organelle membranes, viruses
Specimen may be living.
Cell Types
Eukaryote
Prokaryote
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Prokaryotes
Lack nucleus
Lack membrane bound organelles
Bacteria.
Eukaryotes
Have a nucleus
Have membrane bound organelles
Everything but bacteria.
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Nucleus
Contains the DNA
Control center of cell.
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Cell Membrane Plasma Membrane
Controls what goes in and out of cell
Protective boundary
Semi fluid
Similar to skin.
1 Review What is the function of lysosomes
Review what is the difference between rough and smooth ER
Infer You examine an unknown cell under a microscope and discover that the cell contains chloroplasts. From What type of organism does the cell likely come
2 Review Why is the cell membrane sometimes referred to as a fluid mosaic? What part of the cell membrane acts like a fluid? And what makes it like a mosaic?
Explain How do the properties of lipids help explain the structure of a cell membrane
Infer Why do you think it’s important that cell membranes are selectively permeable?
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CH 7 CELL STRUCTURE AND FUNCTION
7.2 Cell Structure
Organelles
Cellular structures that act as if they are specialized organs.
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Nucleus
Contains the DNA
Control center of cell.
Nucleolus
Synthesis and assembly of
tRNA and rRNA
Contains one or more.
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Centrioles
Major role in mitosis
Animal cells.
Ribosome
Site of protein synthesis
Made of RNA
May be attached on Endoplasmic Reticulum or free.
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Golgi Apparatus
Modifies
Sorts
Packages.
Golgi Apparatus
Modifies
Sorts
Packages.
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Golgi Apparatus
Modifies
Sorts
Packages.
Chloroplast
Site of photosynthesis
Plant cells.
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Mitochondria
Site of Cellular Respiration
Converts sugar into ATP
“Makes” energy
“Powerhouse of the cell”.
Cell MembranePlasma Membrane
Controls what goes in and out of cell
Protective boundary
Semi fluid
Similar to skin.
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The Properties of Lipids
Fatty acid tail are hydrophobic, or “water‐hating”
Opposite end of the molecule is hydrophilic, or “water‐loving.”
Selectively permeable
Some materials can pass through the membrane and some cannot.
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1 ReviewWhat happens during diffusion
Explain Describe the process of osmosis
Compare and Contrast What is the difference between diffusion and facilitated diffusion
2 Review How is active transport different from passive transport
Explain Describe the two major types of active transport
CH 7 CELL STRUCTURE AND FUNCTION
7.3 Cell Transport
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Concentrations
Oil on water
Koolaid in water
Air freshener in a room
Many more examples….
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Passive Transport
Goes from High concentration to Low Concentration
Follows concentration gradient
Simple diffusion
Facilitated diffusion
Does NOT use energy.
Diffusion
Movement of molecules from are of high concentration to low concentration.
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Simple Diffusion
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Facilitated Diffusion
Molecules use special protein channels to diffuse across the membrane
Does NOT use energy
Aquaporins
Protein Channel for water.
Osmosis
Diffusion of water across a membrane.
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Isotonic
Same concentration on both sides
Hypotonic
Low concentration
Hypertonic
High concentration.
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Osmotic Pressure
Force of the net movement of water in or out of a cell.
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Active Transport
Goes from LOW concentration to HIGH concentration
Goes AGAINST the concentration gradient
Requires energy
Why would this be used/where?
Molecular Transport
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Bulk Transport
Endocytosis
Taking material in
Phagocytosis Food
Pinocytosis Liquid
Exocytosis
Removal of material
1 ReviewWhat is cellular specialization
Explain How do cellular junctions and receptors help an organism maintain homeostasis
2 Description Use an area in your life‐ school sports, etc…, to construct an analogy that explains why specialization and communication are necessary for you to function well.
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CH 7 CELL STRUCTURE AND FUNCTION
7.4 Homeostasis and Cells
Homeostasis
Relatively constant internal physical and chemical conditions
To keep constant unicellular organisms grow, respond to the environment, transform energy, and reproduce.
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Unicellular organisms are most numerous
Eukaryotes may also be unicellular.
Multicellular Organisms
Cells are independent but work together
Cells specialize
Cells communicate.
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Levels of Organization
Tissue
Group of similar cells that performs a particular function.
Levels of Organization
Organ
Groups of tissues that work together.
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Levels of Organization
Organ system
Group of organs that work together to perform a specific function.