Unit 3: Cellular Structure and Function Mr. Hulse BVHS 2013-2014 Unit 3: Learning Targets 1-9 History of the Cell Robert Hooke (1665) 1 st person to see a cell Observed a piece of cork using a microscope Saw small, empty boxes Unit 3 LT 1: Explain the three (3) main ideas of cell theory History of the Cell Robert Hooke (1665) 1 st person to see a cell Observed a piece of cork using a microscope Saw small, empty boxes These boxes reminded him of the small rooms monks live in called cells His observations were of non-living cells Unit 3 LT 1: Explain the three (3) main ideas of cell theory 1
Robert Hooke Unit 3 LT 1: Explain the three (3) main ideas of cell theory History of the cell Antonie van Leeuwenhoek 1 st person to describe living cells (1673) Animalcules name he gave to the many things he observed Unit 3 LT 1: Explain the three (3) main ideas of cell theory The Cell Theory 1. All living organisms are composed of cells. 2. The cell is the basic unit of life 3. Cells come from pre-existing cells Unit 3 LT 1: Explain the three (3) main ideas of cell theory 2
The Cell All cells have structures in them called organelles The organs of the cell These specialized structures allow and provide the cell to complete specific specialized functions Unit 3 LT 2: Explain the difference between prokaryotic and eukaryotic cells Prokaryote or Eukaryote? Prokaryote Only bacteria cells NO: nucleus NO: organelles with membranes DNA is contained as 1 single circular strand Eukaryote All other types of cells YES: Nucleus YES: Organelles with membranes DNA is contained as many coiled chromosomes Unit 3 LT 2: Explain the difference between prokaryotic and eukaryotic cells Cell Wall and Plasma Membrane The cell is surrounded by a water-proof plasma membrane This is the outer layer of the cell Controls what enters and exits the cell General structure Phospholipid Bi-layer Plants have an additional layer known as a cell-wall Unit 3 LT 4: Describe the structure of cellular membranes. 3
Cell Wall and Plasma Membrane The phosphate group (orange) is polar and hydrophilic The fatty-acid tails (yellow) are non-polar and hydrophobic Unit 3 LT 4: Describe the structure of cellular membranes. Cell Wall and Plasma Membrane Hydrophilic Capable of hydrogen bonding Water loving Hydrophobic Not capable of hydrogen bonding Water repelling Unit 3 LT 4: Describe the structure of cellular membranes. Cell Wall and Plasma Membrane Unit 3 LT 4: Describe the structure of cellular membranes. Unit 3 LT 5: Identify the functions of proteins in cellular membranes 4
Cell Wall and Plasma Membrane Membranes are semi-permeable Not everything can pass through the membrane Fats and other lipids can move straight through Other large compounds and macromolecules require membrane proteins Unit 3 LT 4: Describe the structure of cellular membranes. Membrane Proteins Peripheral Proteins On the outside edges of the membrane Integral Proteins Inside/through the phospholipid bilayer These proteins act as channels for other molecules to pass through Unit 3 LT 5: Identify the functions of proteins in cellular membranes. Organelles 5
The Organelles: 1. Cytoplasm 2. Nucleus/Nucleolus 3. Mitochondrion 4. Smooth ER 5. Rough ER 6. Ribosomes 7. Lysosomes 8. Golgi Apparatus 9. Cytoskeleton 10. Cilia and Flagella 11. Chloroplast 12. Vacuole 1. Cytoplasm The entire region from nucleus to plasma membrane composed of cytosol and the many suspended organelles Cytosol - Gel-like fluid 1. Cytoplasm 6
2. Nucleus/Nucleolus Protects and stores DNA in the cell Has 2 membranes Why 2? These membranes have nuclear pores allowing large molecules to pass through Both plant and animal cells have nuclei 2. Nucleus/Nucleolus In the middle of the nucleus, we find our nucleolus Site of protein synthesis Where ribosomes are made Does not have a membrane 3. Mitochondrion Kidney-bean-like structure serving as energy supplier to the cell Site of cellular respiration Glucose + O 2 = ATP Has 2 membranes In both plant and animal cells 7
Smooth and Rough Endoplasmic Reticulum(ER) Smooth and Rough Endoplasmic Reticulum(ER) 4. Smooth Endoplasmic Reticulum (ER) NO ribosomes covering surface Synthesis of lipid molecules For example hormones testosterone and estrogen 8
5. Rough Endoplasmic Reticulum (ER) Ribosomes cover the outside surface Package and export proteins produced by the ribosomes Salivary glands are rich in rough endoplasmic reticuli and ribosomes 6. Ribosomes Produce proteins Has 0 (zero) membranes Made of protein and rrna Made in the nucleolus of the cell Both plant and animal cells contains ribosomes How fast can this all occur??? 9
7. Lysosomes Membrane-bound sacs Contain digestive enzymes Break down macromolecules (proteins, nucleic acids, and carbohydrates) Immune, nutrition, and repair roles 7. Lysosomes Does not necessarily have to be food (digestion) Could be bacteria or virus infected cell (immune) Could be an old or damaged cell (repair) 8. Golgi Apparatus Modifies, stores, and routes proteins FedEx/UPS of the cell Processing and shipping center Arranged as series of flattened sacs Transports through use of vesicles 10
9. Cytoskeleton Cytoskeleton is a network of fibers extending throughout the cytoplasm Microtubules are larger, hollow tubes that provide rigid shape and organization to a cell Microfilaments are thinner, solid rods that provide flexibility and enable the cell to change shape Microtubule Microfilament 9. Cytoskeleton 10. Cilia and Flagella Cilia Hair-like structure surrounding cell Made of short bundles of microtubules Use a back-and-forth waving motion Oars on a rowboat Flagella Long, thin, and whiplike Made of many microtubules Wave in an S pattern similar to a snake 11
10. Cilia and Flagella Mucociliary Escalator 11. Chloroplast Found ONLY in plant cells Makes energy from sunlight for the plant cell Site of photosynthesis Has 2 membranes 12
11. Chloroplast Fluid filled space is called Stroma Thylakoid site of photosynthesis Stacks of thylakoids are called Grana 12. Vacuole Large membranebound sacs Store undigested nutrients Often holds excess water In plants absorbs water and allows for the cells to grow in size Provides turgidity: Larger due to swelling Wilted plant 13
Cell Wall and Plasma Membrane The phosphate group (orange) is polar and hydrophilic The fatty-acid tails (yellow) are non-polar and hydrophobic Unit 3 LT 4: Describe the structure of cellular membranes. Cell Wall and Plasma Membrane Hydrophilic Capable of hydrogen bonding Water loving Hydrophobic Not capable of hydrogen bonding Water repelling Unit 3 LT 4: Describe the structure of cellular membranes. Cell Wall and Plasma Membrane Membranes are semi-permeable Not everything can pass through the membrane Small lipids and water can move straight through passive transport - osmosis and diffusion Other large compounds and macromolecules require membrane proteins Active transport Unit 3 LT 4: Describe the structure of cellular membranes. 14
Cell Wall and Plasma Membrane Unit 3 LT 4: Describe the structure of cellular membranes. Unit 3 LT 5: Identify the functions of proteins in cellular membranes. Membrane Proteins Peripheral Proteins On the outside edges of the membrane Integral Proteins Inside/through the phospholipid bilayer These proteins act as channels for other molecules to pass through Unit 3 LT 4: Describe the structure of cellular membranes. Unit 3 LT 5: Identify the functions of proteins in cellular membranes. Passive Transport Definition: the free movement of particles or HIGH CONCENTRATION substances across a membrane The movement will go from an area of high concentration to an area of low concentration Does NOT require the use LOW CONCENTRATION of energy (ATP) natural 15
Concentrations? The amount of dissolved solutes per volume of solution REVIEW: Solvent and Solutes? Solutes the particle that is dissolved within a solution Solvent the substance that dissolves the particles These measurements set up a Concentration Gradient Concentration Gradient Definition: a gradual change in concentration of solutes in a solution PASSIVE TRANSPORT OSMOSIS Movement of water across a semipermeable membrane from an area of low solute concentration to an area of high solute concentration DIFFUSION Movement of particles from an area of high concentration to an area of low concentration 16
Diffusion: Definition: Movement of particles from an area of high concentration to an area of low concentration Facilitated Diffusion Remember! The cell membrane is semipermeable meaning NOT EVERYTHING can simply diffuse across the membrane How do we get these compounds in and/or out of the cell? Membrane Proteins! Unit 3 LT 5: Identify the functions of proteins in cellular membranes. transport and how each of these relates to solute concentration. Unit 3 LT 5: Identify the functions of proteins in cellular membranes. transport and how each of these relates to solute concentration. 17
Osmosis: Definition: Movement of water across a semipermeable membrane from an area of low solute concentration to an area of high solute concentration 18
Types of Solutions Isotonic: Having an equal amount of dissolved solutes within and outside the cell Hypertonic: Having a higher amount of solutes dissolved outside the cell Hypotonic: having a lower amount of dissolved solutes outside the cell Active Transport Movement across a membrane AGAINST its concentration gradient not-natural As a result - Active transport requires the use of energy (ATP) Examples of why this would be necessary? 19
Sodium and Potassium ion pumps generate a charge along nerve cells! 3 Sodium (Na+) ions leave cell 2 Potassium (K+) ions enter the cell Result? Interesting information Polarization of the nerve cell creating an action potential Interesting information Interesting information 20