Cells Cell Theory Prokaryotic Cells Eukaryotic Cells Membranes

Cells Cell Theory Prokaryotic Cells Eukaryotic Cells Membranes Cell Division author unknown address unknown accessed unknown

The Cell Theory A. Cell Theory B. Cell Size C. Multicellular Organisms D. Stem Cells Institute for Social Marketing http: //www. ism. stir. ac. uk/projects_cancer. htm accessed 28. 01. 08

Theory of Knowledge THE NATURE OF SCIENTIFIC THEORIES COULD BE INTRODUCED HERE: THE ACCUMULATION OF EVIDENCE THAT ALLOWS A HYPOTHESIS TO BECOME A THEORY; WHETHER A THEORY SHOULD BE ABANDONED WHEN THERE IS EVIDENCE THAT IT DOES NOT OFFER A FULL EXPLANATION; AND WHAT EVIDENCE IS NEEDED FOR A THEORY TO BE REJECTED OR ADAPTED. A. Cell Theory 1. The cell theory states that: a. living organisms are composed of cells b. cells are the smallest unit of life c. cells come from preexisting cells 2. Evidence for the cell theory is a result of international collaborative efforts_ University of Cincinnati Clermont College http: //biology. clc. uc. edu/fankhauser/Labs/Cell_Biology/Cells_Lab/CELLS. htm accessed 28. 01. 08 TOK Click

3. Unicellular organisms carry out all the functions of life a. metabolism b. response c. homeostasis d. growth e. reproduction f. nutrition_ California State University, Stanislaus http: //arnica. csustan. edu/Biol 1010/classification. htm accessed 25. 01. 08

B. Cell Size Theory of Knowledge THE BIOLOGICAL ENTITIES IN THE ADJACENT LIST ARE BEYOND OUR ABILITY TO PERCEIVE DIRECTLY. THEY MUST BE OBSERVED THROUGH THE USE OF TECHNOLOGY SUCH AS THE LIGHT MICROSCOPE AND THE ELECTRON MICROSCOPE. IS THERE ANY DISTINCTION TO BE DRAWN BETWEEN KNOWLEDGE CLAIMS DEPENDENT UPON OBSERVATIONS MADE DIRECTLY WITH THE SENSES AND KNOWLEDGE CLAIMS DEPENDENT UPON OBSERVATIONS ASSISTED BY TECHNOLOGY? 1. Compare the relative sizes of molecules, cell membrane thickness, viruses, bacteria, organelles and cells, using the appropriate SI unit a. molecules (1 nm) b. thickness of membranes (10 nm) c. viruses (100 nm) d. bacteria (1 µm) e. organelles (up to 10 µm) f. most cells (up to 100 µm)_ Sustain. Pack http: //www. sustainpack. com/nanotechnology. html accessed 28. 01. 08 author unknown address unknown accessed unknown TOK Click

2. Cells have an individual threedimensional nature/shape that should be appreciated_ Internet FAQ Archives http: //www. faqs. org/nutrition/Hea-Irr/HIV-AIDS. html accessed 28. 01. 08

3. An important factor limiting the size of cells is the surface area to volume ratio a. the rate of heat production/waste production/resource consumption of a cell is a function of its volume b. the rate of exchange of materials and energy (heat) is a function of its surface area_ The Voltage Gate http: //thevoltagegate. blogspot. com/2007_01_01_archive. html accessed 15. 01. 09 Play

C. Multicelluar Organisms 1. Multicellular organisms show emergent properties arise from the interaction of component parts: the whole is greater than the sum of its parts_ University of Winnipeg http: //io. uwinnipeg. ca/~simmons/16 cm 05/1116/16 protis. htm accessed 28. 01. 08

2. Cells in multicellular organisms differentiate to carry out specialized functions by expressing some of their genes but not others (differentiation) a. genes are needed for cells to develop into specialized cells_ Answers. com http: //www. answers. com/topic/embryogenesis? cat=health accessed 28. 01. 08

b. each cell has a copy of every gene c. only the genes that are needed to differentiate are expressed d. once a cells begins to develop along a pathway, it cannot change paths (committed)_ MB Scientific http: //www. mbscientific. com/1_Morphogenesis. Gene. Angle. htm accessed 28. 01. 08 Campbell, Mitchell, Reece Biology, Concepts and Connections 2000 Click

Theory of Knowledge THIS IS AN OPPORTUNITY TO DISCUSS BALANCING THE HUGE OPPORTUNITIES OF THERAPEUTIC CLONING AGAINST THE CONSIDERABLE RISKS—FOR EXAMPLE, STEM CELLS DEVELOPING INTO TUMOURS. ANOTHER ISSUE IS HOW THE SCIENTIFIC COMMUNITY CONVEYS INFORMATION ABOUT ITS WORK TO THE WIDER COMMUNITY IN SUCH A WAY THAT INFORMED DECISIONS ABOUT RESEARCH CAN BE MADE. D. Stem Cells 1. Stem cells retain the capacity to divide and have the ability to differentiate along different pathways 2. Outline one therapeutic use of stem cells, for example: a. stem cells were used to restore the insulation tissue of neurons in laboratory rats (2005) b. resulting in subsequent improvements in their mobility_ Public Stem Cell Banking http: //publicstemcellbanking. com/ accessed 28. 01. 08 TOK

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Prokaryotic Cells A. Structure and Function B. Reproduction author unknown address unknown accessed unknown

A. Structure and Function 1. Prokaryotic cells are single celled and do not have a nucleus 2. They are small and simple in structure_ author unknown address unknown accessed unknown Play

3. Draw and label a diagram of the ultrastructure of Escherichia coli (E. coli) as an example of a prokaryote a. cell wall, plasma membrane, cytoplasm, pili, flagella, ribosomes, and nucleoid (region containing naked DNA)_ author unknown address unknown accessed unknown Play

3. Know the function of the cell wall, plasma membrane, cytoplasm, pili, flagella, ribosomes and nucleoid (region containing naked DNA)_ Designs for Wellbeing http: //www. relax-well. co. uk/MRSA-information-10. html accessed 06. 02. 08 Play

B. Reproduction 1. Prokaryotic cells divide by binary fission_ NOVA Science Now http: //www. pbs. org/wgbh/nova/sciencenow/3401/04 -bact. html accessed. 6. 02. 08 Play

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Eukaryotic Cells A. Overview of the Cell B. Manufacture & Breakdown C. Energy, Support, Movement D. Comparing Cells E. Extracellular Matrix author unknown address unknown accessed unknown Click Play

A. Overview of the Cell 1. An organelle (mini organ) is a discrete structure within a cell and has a specific function 2. General Functions a. manufacture b. breakdown c. energy processing d. support and movement_ The Internet Encyclopedia of Science http: //www. daviddarling. info/encyclopedia/P/plant_cell. html accessed 29. 02. 08

B. Manufacture & Breakdown 1. Nucleus- control center a. surrounded by a nuclear envelope b. contains DNA (chromatin) which directs the cell’s activities author unknown address unknown accessed unknown c. nucleolus makes ribosomes_ Click

2. Endoplasmic reticulumnetwork of passageways a. rough ER (dotted with ribosomes) produces proteins for export b. smooth ER builds lipids author unknown address unknown accessed unknown 3. Ribosomes assemble proteins a. free ribosomes are not attached_ author unknown address unknown accessed unknown Click

4. Golgi apparatus packages products in membrane-bound vesicles a. modifies, stores, and transports_ author unknown address unknown accessed unknown Click Play

5. Vacuole- large membranebound sacs that store: a. undigested food & water b. color pigments & poisons 6. Lysosome- a vacuole that contains digestive enzymes a. breaks down nutrients, bacteria, and old organelles_ author unknown address unknown accessed unknown Play

C. Energy. Support. Movement 1. Chloroplasts convert energy from the sun into sugars a. site of photosynthesis b. found in plants and algae_ author unknown address unknown accessed unknown Click

2. The mitochondria releases energy from sugar a. site of cellular respiration b. found in plant and animal cells c. called “the powerhouse”_ author unknown address unknown accessed unknown Click

3. The cytoskeleton is a network of fibers extending throughout the cytoplasm a. microtubules give shape, rigidity, & organization b. microfilaments enable movement & shape change author unknown address unknown accessed unknown Play

4. Cell walls are strong protective coverings found in plant cells a. made of cellulose microfibers which crisscross over one another author unknown address unknown accessed unknown

5. Some cells have projections that enable the cell to move a. cilia- short and numerous, move back-and-forth b. flagella- long thin whiplike, move with a “Sshaped” movement_ author unknown address unknown accessed unknown Play

Prokaryotic Cells D. Comparing Cells Eukaryotic Cells DNA in cytoplasm DNA associated with proteins 1. There are several differences prokaryotic DNA between enclosed in a nuclear and eukaryotic cells_ envelope no mitochondria 70 S ribosomes 80 S ribosomes no internal membranes that compartmentalize their functions naked DNA Charlotte Country Day School http: //www. ccds. charlotte. nc. us/biology/resources. htm accessed 29. 02. 08 Click

2. There are three distinct differences between plant and animal cells, plant cells have: a. cell wall b. chloroplasts c. large central vacuole author unknown address unknown accessed unknown Click Play

E. Extracellular Matrix 1. The plant cell wall maintains cell shape, prevents excessive water uptake, and holds the whole plant up against the force of gravity 2. Animal cells secrete glycoproteins that form the extracellular matrix a. this functions in support, adhesion and movement_ Science Daily http: //www. sciencedaily. com/releases/2007/12/071217092914. htm accessed. 29. 02. 08

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Membranes A. Membrane Structure B. Diffusion & Osmosis C. Types of Transport author unknown address unknown accessed unknown Click

A. Membrane Structure 1. The plasma membrane separates the interior of a cell from its surroundings a. the membrane acts like a layer of skin_ author unknown address unknown accessed unknown Play

2. Each membrane is composed of phospholipids, proteins, & cholesterol (carbohydrates may also be present) a. forms a phospholipid bilayer that is fluid-like b. proteins scattered throughout float like icebergs 1) glycoproteins 2) integral proteins (embeded) 3) peripheral proteins (surface)_ author unknown address unknown accessed unknown Think

3. Hydrophilic and hydrophobic properties of phospholipids help to maintain the structure of cell membranes a. phosphate groups (heads) are negatively charged and are attracted to the positively charged polar ends of water molecules b. fatty acids (tails) are nonpolar and are BROOKLYN COLLEGE http: //academic. brooklyn. cuny. edu/biology/bio 4 fv/page/phosphb. htm repelled by water, accessed 01. 10. 07 tucking to the inside to avoid water_ BROOKLYN COLLEGE http: //academic. brooklyn. cuny. edu/biology/bio 4 fv/page/phosphb. htm accessed 01. 10. 07 Click

4. Other functions include a. hormone binding sites b. immobilized enzymes c. cell adhesion d. cell-to-cell communication e. channels for passive transport f. pumps for active transport_ Eo. L author unknown address unknown accessed unknown

B. Diffusion & Osmosis 1. Diffusion is the passive movement of particles from a region of high concentration to a region of low concentration a. equilibrium is reached when particles are evenly spread out_ author unknown address unknown accessed unknown Click Play

3. Osmosis is the passive movement of water molecules, across a partially permeable membrane, from a region of lower solute concentration to a region of higher solute concentration_ author unknown address unknown accessed unknown Play

C. Types of Transport 1. Membranes are selectively permeable and control what passes across through: a. passive transport b. active transport c. bulk transport_ author unknown address unknown accessed unknown Play

2. Passive transport- diffusion across a membrane a. simple diffusion occurs between phospholipids 1) small/uncharged molecules (O 2, CO 2, H 2 O) b. facilitated diffusion through protein channels 1) large/charged molecules (proteins, sugars, and ions)_ author unknown address unknown accessed unknown

3. Active transport- the use of energy to move molecules across the membrane usually against the concentration gradient a. protein pumps change shape to transport solutes b. ATP is hydrolysed to ADP (provides the energy) c. terminal P-group attaches to the protein, causing it to change shape d. eg. sodium-potassium pump (nerve impulses)_ author unknown address unknown accessed unknown Play

4. Bulk transport- the use of membrane vesicles to move large particles across the membrane a. the fluidity of the membrane allows it to change shape, break, and re-form 1) exocytosis- spills contents outside of the cell 2) endocytosis- takes materials into the cell_ author unknown address unknown accessed unknown Play

5. Vesicles are used to transport materials within a cell a. proteins made at ribosomes on the rough endoplasmic reticulum and enclosed in a membranous vesicle buds from the rough ER and fuses with the membrane of the Golgi apparatus c. proteins are processed by the Golgi_ author unknown address unknown accessed unknown Play

d. vesicle buds from the Golgi and fuses with the plasma membrane e. products are expelled from the cell by exocytosis_ author unknown address unknown accessed unknown Play

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Cell Division A. The Cell Division Cycle B. Mitosis C. Stages of Mitosis D. Cytokinesis E. Cancer author unknown address unknown accessed unknown

A. The Cell Division Cycle 1. All cells come from other cells 2. The division (involving mitosis) of cells in living things allows for: a. growth b. embryonic development c. tissue repair c. asexual reproduction_ author unknown address unknown accessed unknown Play

3. The process of cell division involves: a. interphase (90%) b. mitosis c. cytokinesis_ author unknown address unknown accessed unknown Play

4. Interphase is an active period in the life of a cell when many metabolic reactions occur: a. G 1: growth, many biochemical reactions including protein synthesis b. S: synthesis, DNA replication occurs* c. G 2: growth, preparation for division (mitochondria and chloroplasts divide)_ Play

5. Mitotic phase: division of cell * a. mitosis- nucleus divides (PMAT) b. cytokinesis- cytoplasm divides_ author unknown address unknown accessed unknown

B. Mitosis 1. Mitosis is the process of splitting the nucleus during cell division 2. It produces two genetically identical nuclei 3. Four stages of mitosis: a. prophase b. metaphase c. anaphase d. telophase_ author unknown address unknown accessed unknown Play

C. Stages of Mitosis 1. Prophase- DNA condenses 2. Metaphase- DNA lines up in the middle 3. Anaphase- DNA separates 4. Telophase- DNA relaxes_ author unknown address unknown accessed unknown Click

C. Stages of Mitosis 1. Prophase- DNA condenses 2. Metaphase- DNA lines up in the middle 3. Anaphase- DNA separates 4. Telophase- DNA relaxes_ author unknown address unknown accessed unknown Click

C. Stages of Mitosis 1. Prophase- DNA condenses a. supercoiling of chromosome makes DNA visible, chromosomes are doubled (two identical chromatids) b. centrioles move to opposite poles, attachment of spindle microtubules (plant cells lack centrioles) c. breakage of nuclear membrane, nucleolus ‘dissappears’ 2. Metaphase- DNA lines up in the middle author unknown address unknown accessed unknown 3. Anaphase- DNA separates 4. Telophase- DNA relaxes_ author unknown address unknown accessed unknown Click

C. Stages of Mitosis 1. Prophase- DNA condenses a. supercoiling of chromosome makes DNA visible, chromosomes are doubled (two identical chromatids) b. centrioles move to opposite poles, attachment of spindle microtubules (plant cells lack centrioles) c. breakage of nuclear membrane, nucleolus ‘dissappears’ 2. Metaphase- DNA lines up in the middle 3. Anaphase- DNA separates 4. Telophase- DNA relaxes_ author unknown address unknown accessed unknown

C. Stages of Mitosis 1. Prophase- DNA condenses 2. Metaphase- DNA lines up in the middle a. chromosomes line up on the equator of the cell b. spindle fibers/microtubules connect centromere of each chromosome to poles c. some spindle fibers go from pole to pole 3. Anaphase- DNA separates 4. Telophase- DNA relaxes_ author unknown address unknown accessed unknown

C. Stages of Mitosis 1. Prophase- DNA condenses 2. Metaphase- DNA lines up in the middle 3. Anaphase- DNA separates a. splitting of centromeres b. movement of sister chromatids (now often called chromosomes) to opposite poles c. pulled by spindle fibers 4. Telophase- DNA relaxes_ author unknown address unknown accessed unknown

C. Stages of Mitosis 1. Prophase- DNA condenses 2. Metaphase- DNA lines up in the middle 3. Anaphase- DNA separates 4. Telophase- DNA relaxes a. chromosomes ‘disappear’ as the DNA uncoils (needed for normal transcription…) b. spindles disappear c. reformation of nuclear membranes, nucleolus reorganize/reappear_ author unknown address unknown accessed unknown

C. Stages of Mitosis 1. Prophase- DNA condenses 2. Metaphase- DNA lines up in the middle 3. Anaphase- DNA separates 4. Telophase- DNA relaxes a. chromosomes ‘disappear’ as the DNA uncoils (needed for normal transcription…) b. spindles disappear c. reformation of nuclear membranes, nucleolus reorganize/reappear_ author unknown address unknown accessed unknown Play

D. Cytokinesis 1. Mitosis (nuclear division) is almost always followed by cell division 2. Cytokinesis differs in plants and animals: a. animal cells pinch in the middle to separate cells b. plant cells form a cell plate in the middle on which a new cell wall is built_ author unknown address unknown accessed unknown Play

E. Cancer 1. Tumours (cancers) are the result of uncontrolled cell division and that these can occur in any organ or tissue 2. Benign tumour is a mass of normal cells 3. Malignant tumour is a mass of cancer cells author unknown address unknown accessed unknown a. when cancer spreads it is called metastasis b. cancer is treated by radiation and chemotherapy_ Click Play

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