AP Biology Cells
Monday, Sept. 23rd • Learning Target: Students will recall their knowledge of cells and understand why cells are small. • Go Over Test. • Brain Storm – Everything you remember about cells. • Prep for lab on Wednesday – Part 1 Diffusion and Osmosis
Tuesday, Sept. 24th • Learning Target: Students will understand the relationship between cell volume, surface area, rates of diffusion and cell efficiency • Why are cells so small? • Differences between the categories of cells. • Compare and Contrast Different Types of Cells. • Prep for Cell Surface to Volume Lab. • Lab – Part 1 • Write up in Notebook
In graph one as surface area… volume …rate. • In graph 2 as the length of the side … the surface to volume ratio … • Based on the data table what conclusions can you make about surface area and volume.
Terms: CytosolNucleoid Cell Wall Plasma Membrane Endoplasmic Reticulum Central Vacoule Chromosomes Chloroplasts Mitochondria Ribosomes Golgi Apparatus Centrosome Nucleus Nucleolus Cytoskeleton Cytoplasm
Wednesday, Sept. 25th • Learning Target: Students will understand the relationship between cell volume, surface area, rates of diffusion and cell efficiency • Complete: Surface Area to Volume Lab • Lab – Part 1 • Write up in Notebook • Due: Friday, Sept. 27th
Students will investigate the relationship of among surface area, volume, and the rate of diffusion by designing an experiment with the use of agar gells. • Table of Contents: Cell Size and Diffusion Rates • Title • Introduction: Brief statement of purpose, background knowledge of the concepts, and hypothesis. (less the 100 words) • Materials and Procedures: Brief explanation of what you will do and what you will use. • Results/ Data Collection and Analysis: Data Tables, Graph with title, X and Y Labeled. • Conclusions and Discussion: Results summarized, Errors identified, compare to hypothesis, conclusions stated, suggestions for improvement • Questions: What are questions for further investigation? What new questions arise?
Questions to Address • Which surface area-to-volume ratio gave the fastest diffusion rate? • Which surface area-to-volume ratio had the greatest diffusion depth? • How might a cell’s shape influence the rate of diffusion? • What factors affect the rate of diffusion and how can these be tested?
Thursday Sept. 26th • Learning Target: Students will understand the relationship of cell size and diffusion rates. Students will be able explain the endosymbiotic theory and the evidence for it. • Go over Lab • Endosymbiosis
Thought Questions… • Why are prokaryotic cells so much smaller than eukaryotic cells? • Which type of cell was first on the planet? Why? What was the order of cellular diversity? • Which type of cell has been more successful in terms of evolution, survival and populating the planet? • How did we evolve from prokaryotic life into eukaryotic life?
Define and draw your interpretation of the evolution from prokaryotic life to eukaryotic life. • Define the evidence we have for this process? • What three main categories of life does it create? • Pgs. Biology in Focus 484 - Red Book 529, 541
What we know: • Prokaryotic Life originates between 3.5 to 3.9 billion years ago • Chemiosmotic Mechanism of ATP Synthesis • Use Molecular Hydrogen, Methane Hydrogen Sulfide for energy • VERY DIFFERENT BUT THE SAME
What we know: • Prokaryotes evolve from chemiosmotic mechanisms to photosynthesis • Creates a Oxygen rich atmosphere. • BAD and GOOD
Eukaryotic Life 2.7 BYA • Cytoskeleton – • Big Deal • Evolutionary Advantages to folding of membranes?
Figure 4.16 Endoplasmic reticulum Nucleus Engulfing of oxygen- using nonphotosynthetic prokaryote, which becomes a mitochondrion Nuclear envelope Ancestor of eukaryotic cells (host cell) Mitochondrion Engulfing of photosynthetic prokaryote At least one cell Chloroplast Nonphotosynthetic eukaryote Mitochondrion Photosynthetic eukaryote
Endosymbiosis Evidence: Mitochondria and Plastids (chloroplasts) • Enzymes and Transports systems same as modern prokaryotes • Replicates by binary fission same as prokaryotes • Contain their own DNA (Plasmids same as prokaryotes) • Contain their own ribosomes to make their own proteins
Three Distinct Lineages… • Domain Eukarya (Eukaryotic) • Domain Bacteria (Prokaryotic) - Normal • Domain Archea (Prokaryotic) – EXTREMOPHILES • Thermophiles – TEMP. • Halophiles – SALT • Methanogens – USE Carbon Dioxide and Hydrogen gas to make energy – creates methane gas – sewage treatment, guts
Friday, Sept. 27th • Learning Target; Students will be able to identify and explain the functions of the various structures that make up the endomembrane system. • Reading Check • Turn in Lab Notebooks • http://www.youtube.com/watch?v=yKW4F0Nu-UY • Discussion: Endomembrane System
Write a Narration for the video. • Must include the following structures with their functions. • Typed • Due: Tuesday • Cytoskeleton, Cell membrane, plasma membrane, microtubules, microfilaments, intermediate filaments, motor proteins, mitochondria, nucleus, nuclear pores, nuclear envelopes, Endomembrane system, Ribosomes, Golgi Apparatus, Cis face, Trans face, Vesicle, exocytosis, Smooth ER, Rough ER, extracellular matrix, transport vesicles, motor protein, glycoproteins, mitochondria, centrosomes.
Figure 4.15-1 Nucleus Rough ER Smooth ER Plasma membrane
Figure 4.15-2 Nucleus Rough ER Smooth ER cis Golgi Plasma membrane trans Golgi
Figure 4.15-3 Nucleus Rough ER Smooth ER cis Golgi Plasma membrane trans Golgi
Figure 4.13 Vesicle containing two damaged organelles 1 m Mitochondrion fragment Peroxisome fragment Lysosome Peroxisome Digestion Mitochondrion Vesicle Lysosomes: Autophagy
Compare and contrast the roles of smooth ER with rough ER. What type of cells would expect to find the two different types. • A protein that functions in the ER but requires modification in the Golgi apparatus before it caqn achieve function. Describe the protein’s path through the cell, starting with the mRNA molecule that specifies the protein. • Compare and contrast mitochondria and chloroplasts with regard to structure and function.
Tuesday, Oct. 1st • Objective: Students will understand the basic structure and function of the cytoskeleton, cell wall, extracellular matrix, cellular junctions and the cell membrane. • task card. • Discussion Cell Membrane
Table 6.1 The Structure and Function of the Cytoskeleton • Write a Haiku poem that describe the cytoskeleton. Remember Haiku’s are 5, 7, 5 syllable poems.
Primary cell wall Central vacuole of cell Middle Lamella (Pectin) 1 µm Plasmodesmata Figure 6.28 Plant cell walls Central vacuole of cell Plasma membrane Secondary cell wall
Polysaccharide molecule EXTRACELLULAR FLUID Collagen fibers . proteoglycan Carbo- hydrates Core protein Fibronectin Proteoglycan molecule Plasma membrane Integrins CYTOPLASM Micro- filaments Integrin Figure 6.29 Extracellular matrix (ECM) of an animal cell
TIGHT JUNCTIONS At tight junctions, the membranes of neighboring cells are very tightly pressed against each other, bound together by specific proteins (purple). Forming continu- ous seals around the cells, tight junctions prevent leakage of extracellular fluid across a layer of epithelial cells. Tight junction Tight junctions prevent fluid from moving across a layer of cells 0.5 µm DESMOSOMES Desmosomes (also called anchoring junctions) function like rivets, fastening cells together into strong sheets. Intermediate filaments made of sturdy keratin proteins anchor desmosomes in the cytoplasm. Tight junctions Intermediate filaments Desmosome Gap junctions 1 µm GAP JUNCTIONS Gap junctions (also called communicating junctions) provide cytoplasmic channels from one cell to an adjacent cell. Gap junctions consist of special membrane proteins that surround a pore through which ions, sugars, amino acids, and other small molecules may pass. Gap junctions are necessary for commu- nication between cells in many types of tissues, including heart muscle and animal embryos. Extracellular matrix Space between cells Gap junction Plasma membranes of adjacent cells 0.1 µm Figure 6.31 Exploring Intercellular Junctions in Animal Tissues
Compare different aspects of cell structure • What structures best reveal evolutionary unity? • Provide examples f diversity related to specialized modifications.
Recreate the diagram on your whiteboard label as much as you possibly can with structure and function. • Label the hydrophobic and hydrophilic regions.
The term fluid mosaic model is often used to describe the cell membrane what is meant by this term and list and what factors contribute to its fluidity? Be specific to the role of cholesterol • Describe three ways in which molecules can move across a cell membrane.
Unsaturated Phospholipids • Increase fluidity • Cholesterol • Temperature buffer • Integral Proteins?
Wednesday, Oct. 2nd • Objective: Students will understand the fundamental processes that drive movement across the cell membrane. • Discussion • Lab Prep.
Passive Transport – No energy, High To Low Conc. Diffusion What types of molecules? Why? Things that affect the rate of diffusion
Why differentiate between simple diffusion and facilitated diffusion? • What are the characteristics of the proteins? Why are they necessary?