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16 Cards in this Set
- Front
- Back
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Describe a technique used to understand more about the function and structure of organelles? |
Substances like amino acids can be labelled using radioactive chemicals. Then microscopy or a centrifuge can be used to trace the pathways of where they appear |
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What does the S in ribosomes mean? |
S - Svedburg It is the measure of the rate of sedimentation in a centrifuge - it depends of size and shape. |
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What is the ratios of RNA:protein in 80S and 70S ribosomes? |
80S - 1:1 70S -2:1 |
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What two subunits is the 70s ribosome made up of? |
50s and 30s And 80s is made of 40s and 60s |
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What is the function of the RER? |
It isolates, synthesises and transports the proteins made by the ribosomes. |
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What is the function of the SER? |
Synthesis and transports of lipids and steroids. So lots of SER is found in cells like liver cells(cholesterol) |
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The amount of endoplasmic reticulum allows scientists to... |
Determine the function of the cell. |
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What is the function of the Golgi Apparatus? |
- modifying proteins sent from the RER via vesicles that fuses with the Golgi membrane. - adds carbohydrates to proteins to make glycoproteins, lipids to make lipoproteins. |
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What is the connection between the Golgi and lysosomes? |
Digestive enzymes in the Golgi is pinched off surrounded by a membrane to make lysosomes. This can fuse with cell membrane to release digestive enzymes into extracellular environment. |
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Describe the structure of the Golgi Apparatus |
- stacks of parallel flattened sacs of membrane called Cisternae. - formed by vesicles of ER. - trans face and cis face |
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What technique did scientists use to understand the function of the Golgi? |
Radioactive Labelling |
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What are the 3 main function of the lysosomes? |
1.Can fuse with cell membrane and release digestive enzymes into extracellular environment. - normal digestion or fighting pathogens 2. Apoptosis 3. Can digest material in cell that is dangerous or unnecessary. |
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How do lysosomes perform apoptosis? |
Lysosomes release their digestive enzymes to digest the entire cell. |
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What are the reasons for a cell to go into apoptosis? |
1. Wearing out 2. Mutation 3. Under stress 4. Just removing areas that is no longer needed e.g. webbing during development of embryo |
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Give 2 examples in which too much apoptosis occurs and 1 when it is too little. |
Too much: heart tissue after heart attack Death of T killer cells in HIV/AIDS Too little: Cancer cells fail to die by apoptosis. |
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When looking through a microscope, how do the lysosomes look like? |
Dark spherical bodies in the cytoplasm |
