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Structure and Function Chapter 4

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1 Structure and Function Chapter 4
THE CELL Structure and Function Chapter 4 What importance do cells have to life?

2 Early Research Mid 1600’s Started using microscopes
Robert Hooke- used the scope to look at cork Coined the term cells, because of what the cork looked like under the scope. Van Leeuwenhoek- 1st to look at living cells. Looked at pond water and saw organisms (very tiny) living in the water.

3 The Cell Theory 1. All living things are made of cells. 2. Basic unit of structure and function. 3. New cells come from existing cells.

4 Exploring the Cell - Use fluorescent labels to follow molecules through cells. - Can build 3-D cells images of cells and their parts. -Use light, electrons and high resolution scopes to see cells, structures, DNA, proteins and other molecules.

5 Cell Types Prokaryote Eukaryote 1st to evolve Lacking Nucleus
Simple Cell Ex: Bacteria Eukaryote Cells contain Nucleus Larger and more complex Highly Specialized Both Have DNA and Cell Membranes

6 Eukaryote Cell Structure
2 Parts 1. Nucleus- Brain of the cell 2. Cytoplasm- Entire cell outside of the nucleus. Holds organelles for cell.

7 Animal Cell

8 Plant Cell

9 Cell Structures 1. Cell Membrane- -thin, flexible outer layer - lipid bilayer (2 layers of lipids) - Integral proteins(in membrane) - Peripheral Protein (touch membrane) -Mosaic because molecules in membrane.

10 Semi-Permeable Cell Membrane (fluid) Gate Keeper- controls what comes in and out of cell. (picky)

11 2. Cell Wall-. - Plant Cells. - made of cellulose
2. Cell Wall Plant Cells - made of cellulose - rigid support for cell/plant - outside of the membrane 3. Cytoplasm- - area between nucleus and membrane -contains organelles -jelly-like substance

12 4. Nucleus-. - brain of the cell. - surrounded by the nuclear envelope
4. Nucleus- - brain of the cell - surrounded by the nuclear envelope - double membrane - contains nuclear pores (sm holes) - Main Function- store DNA in form of chromatin during cell division chromatin coils up to form chromosomes. - Contains nucleolus - synthesizes and partially assembles ribosomes.

13 5. Cytoskeleton-. - framework of the cell, made of proteins
5. Cytoskeleton- - framework of the cell, made of proteins - 2 structures: microfilaments- (“threads”) - aid in movement and muscle contraction microtubules- (“straws”) - assemble/disassemble to form spindle fibers during cell division. (extremely important to cells)

14 6. Cilia and Flagella-. - hairlike. - on cell surface. - aid movement
6. Cilia and Flagella- - hairlike - on cell surface - aid movement Cilia- shorter and numerous (respiratory system) Flagella- longer and less numerous (protists)

15 Organelles - small structures with specialized function - Found in the cytoplasm 7. Mitochondrion - mitochondria (plural) - “powerhouse” of the cell - Converts energy from nutrients to ATP - Double membrane –inner membrane cristae - has its own DNA (from mother) -more in active tissue (muscle, liver)

16 8. Ribosomes-. - protein synthesis (proteins are made)
8. Ribosomes- - protein synthesis (proteins are made) - most numerous organelle - NOT membrane bound - synthesized and partially made in nucleolus - finished being made in cytoplasm when proteins are made. - may be “free-standing” or attached to Endoplasmic Reticulum.

17 9. Endoplasmic Reticulum (ER). - “subway” of the cell
9. Endoplasmic Reticulum (ER) - “subway” of the cell - Transports material within cell - Rough ER- covered with ribosomes and prepares proteins for transport. - Smooth ER- no ribosomes - synthesizes steroids (glands) - regulates calcium (muscle) - breaks down toxins (liver)

18 10. Golgi Apparatus-. - Made of a series of parallel. compartments
10. Golgi Apparatus- - Made of a series of parallel compartments. - Modifies/ repackages proteins - manufactures lysosomes - plays a role in secretion 11. Lysosomes- - most common in animals, not plants - contains digestive enzymes - help to break down carbs, proteins, lipids

19 12. Centrioles-. - found in a pair. - near nucleus
12. Centrioles- - found in a pair - near nucleus - aid in cell division by aligning chromosomes Vacuoles- - store food, water, waste (not at same time) - plant cells have a large central vacuole - animals have numerous, smaller vacuoles - plant vacuoles perform lysosome job.

20 14. Chloroplasts-. - exclusive to plants. - have a double membrane
14. Chloroplasts- - exclusive to plants - have a double membrane - captures energy from sunlight and converts it into chemical energy during photosynthesis. - “solar power” in plants - contains green pigment called chlorophyll. - Type of Chromoplasts- colored plastids - orange- carotene

21 Plant Cells Animal Cells
Cell Wall No Cell Wall Cell Membrane Chloroplasts Mitochondria NO Centrioles Centrioles Single Large Vacuole Many small lysosomes Oblong Shape Round/Irregular Shape Nucleus not centrally located Nucleus usually centrally located Endoplasmic Reticulum

22 Relationships Between Organelles
Nucleus (DNA makes RNA) Nucleolus – Makes Ribosomes Cytoplasm- Holds Organelles 2. ER- ribosomes attach, transports proteins Proteins modified by GOLGI Golgi manufactures LYSOSOMES Lysosome digest particles, worn out organelles Spare parts from lysosome, ready to use in future from directions from NUCLEUS MITOCHONDRIA provides energy for ALL

23 7.3- Cell Boundaries What is the cell boundary of animal cells?
What is the cell boundary of plant cells? What role do these structures have?

24 Cell Boundaries Functions
Cell Membrane- regulates what enters and leaves the cell. Cell Wall- Provides support and protection for the cell.

25 2 Types of Transport Passive Transport- movement of molecules/material through the cell membrane and requires NO energy. 2. Active Transport- movement of molecules/material through the cell membrane and REQUIRES energy.

26 Passive Transport Diffusion- movement of molecules from an area of high concentration to low concentration. Osmosis- movement of solutions across a membrane. Facilitated Diffusion- form of diffusion which requires a carrier protein. Ex: Glucose

27 Diffusion Concentration- amount of solute dissolved in a solution
Concentration Gradient- difference in molecule concentration across a space. Movement of molecules from an area of HIGH concentration to LOW concentration. Ex: Match being lit. Movement is ‘with’ or ‘down’ the gradient Molecules move to reach equilibrium.

28 Movement from high Equilibrium to low Reached
Diffusion Continued Movement from high Equilibrium to low Reached

29 Diffusion Continued Kinetic Energy- powers diffusion
- energy of moving particles Examples: - ink dropped into water - gas exchange in cells (oxygen) - fragrance of candles in a room

30 Osmosis Movement of water (solutions)
Cell must have a selectively permeable membrane. Movement depends on concentration. (use salt water as an example) Hypertonic- more solute (salt) [OVER] Hypotonic- less solute (salt) [Below] Isotonic- same amounts of solute (equal salt in the cell and outside of the cell)

Inside of Cell Inside of Cell Inside of Cell Outside Outside Outside Solutions are: HYPOTONIC HYPERTONIC ISOTONIC - ate salt, need water no salt to absorb water

32 Osmosis Examples Plants- “like” HYPOTONIC
- turgor pressure- membrane pushing against cell wall. Gives us crisp veggies. Protists- often in HYPOTONIC environment. - contractile vacuole pumps out excess water Animals- can be in HYPOTONIC environment. - cells take on water until they burst- CYTOLYSIS If in HYPERTONIC environment - Plasmolysis- cells lose water and shrink.

33 Facilitated Diffusion
Form of diffusion Requires a carrier protein (protein channel) Carrier protein binds to molecule and changes shape to carry molecule across. Protein returns to normal shape when finished. No ATP (energy) used Glucose is best example.

34 Active Transport Molecular Transport- movement of molecules from area of lesser to greater concentrations. Endocytosis- taking in of material into the cell by infolding of the cell membranes. Exocytosis- forces material out of the cell through the cell membrane.

35 Molecular Transport -Movement of molecules from an area of lesser concentration higher concentration Movement is ‘up’ or ‘against’ the gradient Paddling up stream Normally moves calcium, potassium, and sodium ions across cell membrane. Uses ATP Ex: Na/K pumps - moves 3 Na+ OUT and 2 K+ IN

36 Endocytosis Endocytosis- “infolding” to allow cells to bring molecules into it. Cell membrane pinches around a molecule or fluid. 2 types 1. Phagocytosis- membranes surround LARGE PARTICLES and pull it in. 2. Pinocytosis- membranes surround FLUIDS and pull it into the cell

37 Exocytosis Exocytosis- cells release large amounts of material from the cell. - vacuole attaches to cell membrane and dumps its contents out of the cell.

38 7-4 Diversity of Cellular Life
- What are the different types of life found on Earth?

39 Living Organisms Unicellular Organisms- a cell is the entire organism. 1 cell does everything multicellular organisms do. Multicellular Organisms- made of many cells Cell specialization- cells develop in different ways to perform different tasks.

40 Cell Specialization Animal Cells - Red Blood Cells- transport oxygen
- Pancreatic Cells- produce proteins (enzymes) - Muscle Cells- humans ability to move Plant Cells - Guard Cells- regulates how much carbon dioxide, oxygen, water vapor is released through the stomata.

41 Levels of Organization
Cells- Tissues- similar cells grouped into units that perform a particular function. Ex: muscle, epithelial, nervous and connective Organs- groups of tissues working together. Ex: heart Organ Systems- group of organs that work together. Ex: Pulmonary system- heart and lungs


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