Term
| what are the two main steps of organelle isolation |
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Definition
1. homogenization 2. fractionation |
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|
Term
| what is the homogenization step of organelle isolation? |
|
Definition
disruption of cells so that intact organelles can be isolated |
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|
Term
| what is the fractionation step of organelle isolation |
|
Definition
| the actual isolation of the organelles, usually through centrifugation |
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|
Term
| what are the 3 steps of homogenization |
|
Definition
1. disrupt cell adhesion molecules 2. break cell-ECM bonds 3. disrupt cell membranes |
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Term
| what role does EDTA or other chelating agents play in homogenization |
|
Definition
binds up Calcium ions needed by many of the molecules involved in cell to cell bonds |
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Term
| what role does trypsin or other proteolytic enzymes play in homogenization? why |
|
Definition
| disrupts cell to ECM bonds b/c ECM consists mostly of proteins |
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Term
| what role do detergants play in the homogenization process |
|
Definition
| disrupts the cellular membranes |
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|
Term
| what are three methods of mechanical disruption homogenization |
|
Definition
1. blender 2. homogenizer/cell disrupter 3. sonicator |
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Term
| what are the 2 parts of fractionation |
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Definition
1. differential velocity centrifugation 2. density gradient centrifugation |
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|
Term
| what type of rotor used for differential velocity centrifugation |
|
Definition
|
|
Term
| what type of speed and time used in differential velocity for isolating large organelles (ex. nucleii) |
|
Definition
|
|
Term
| what type of rotor used for density gradient centrifugation? what type of fluid? |
|
Definition
swinging bucket rotor sucrose solution or Percoll |
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Term
| what is needed for in vitro protein synthesis |
|
Definition
1. transcription/translation system (contains all necessary components for these events) 2. gene encoding desired protein 3. tag (usually S35) |
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|
Term
| how are in vitro synthesized proteins used to study organelles |
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Definition
| proteins introduced to isolated organelles to see if they uptake them |
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|
Term
| what is a cell-free system? |
|
Definition
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|
Term
what is the diff between cytoplasm and cytosol? |
|
Definition
cytoplasm - intercellular space cytosol - intercellular fluid |
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|
Term
| what is another name for the nuclear membrane |
|
Definition
|
|
Term
| what are some molecules transported in to the nucleus? out? |
|
Definition
in: histones, nucleotides, replication enzymes, transcription enzymes out: mRNA, ribosomes |
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|
Term
| what does the nucleolus do? |
|
Definition
|
|
Term
| what are the two populations of ribosome? |
|
Definition
1. free ribosomes 2. ER ribosomes |
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|
Term
|
Definition
tight interaction of DNA and histones -form of DNA during interphase |
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|
Term
| where does protein synthesis occur in cell |
|
Definition
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|
Term
describe the path of mRNA from nucleus to ER |
|
Definition
1. leaves through nuclear pores into cytoplasm 2. ribosomes carry mRNA to ER 3. cross ER membrane |
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|
Term
| what type of proteins synthesized in the rough ER |
|
Definition
trans membrane proteins (span membranes) water-soluble proteins (cross membranes) |
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|
Term
| what are the 4 main functions of the smooth ER |
|
Definition
1. lipid synthesis (phospholipid, fatty acid, steroid) 2. carbohydrate metabolism 3. detoxification of cells - removal of harmful substances from body (liver high in smooth ER) 4. Calcium storage - used for rapid cell responses (ex. in muscle cells) |
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|
Term
| what is the sarcoplasmic reticulum |
|
Definition
| smooth ER in muscle cells |
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|
Term
| what 2 things happen in the golgi complex |
|
Definition
1. proteins modified, packaged, sent out 'post office' of the cell 2. site of some carbohydrate synthesis |
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|
Term
| what do clathrin coated vessicles do |
|
Definition
| recognize cytoplasmic side of membrane proteins for exocytosis |
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|
Term
| what carbohydrates are synthesized in the golgi complex |
|
Definition
1. carbs destined for ECM (animal) or cell wall (plant) 2. carbs attached as side chains to proteins or lipids |
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|
Term
| what is the glycoprotein that makes up most of the ECM |
|
Definition
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|
Term
| what are the 2 models of transport through the golgi complex |
|
Definition
1. vessicle transport 2. cisternal maturation model |
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|
Term
what happens in the outer membrane of mitochondria |
|
Definition
1. contains enzymes that aid in synthesizing lipids needed inside mitochondria |
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|
Term
| what happens in the inner membrane of mitochondria |
|
Definition
1. oxidation reactions/cell respiration 2. contains ATP synthase |
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|
Term
|
Definition
| inner projections of the inner mitochondrial membrane |
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|
Term
| what is the general reaction of glycolysis |
|
Definition
|
|
Term
| where does glycolysis occur |
|
Definition
|
|
Term
| where does the kreb's cycle occur |
|
Definition
|
|
Term
| what happens in kreb's cycle |
|
Definition
1. CO2 given off 2. high energy electrons generated 3. 2 ATP produced |
|
|
Term
| where does electron tranport system occur |
|
Definition
| inner mitochondrial membrane |
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|
Term
| what happens in electron transport system |
|
Definition
1. high energy electrons go through redox reactions 2. creates proton gradient 3. protons driven through ATP synthase |
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|
Term
| what are the steps of cellular respiration |
|
Definition
glycolysis kreb's cycle electron transport |
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|
Term
| what molecules carry the high energy electrons in the kreb's cycle |
|
Definition
|
|
Term
| how many membranes in chloroplasts |
|
Definition
|
|
Term
| where do the light dependant reactions occur? what are the products? |
|
Definition
thylakoid membrane 1. ATP 2. high energy electrons carried by NADPH 3. Oxygen |
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|
Term
| where does the citric acid cylce occur? what happens? |
|
Definition
stroma ATP and high energy electrons used to fix CO2 into carbohydrates |
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|
Term
| why is it hypothesized that endosymbiosis occurred? |
|
Definition
| early eukaryote cells were anaerobic so engulfed prokaryotes capable of carrying out cellular respiration |
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|
Term
| what is the evidence for the endosymbiont hypothesis |
|
Definition
1. chloroplasts and mitochondria have their own DNA, DNA machinery, ribosomes, amino acids, etc. 2. have double membranes 3. have RNA polymerases and ribosomes similar to prokaryotic types |
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|
Term
| what type of enzymes enclosed in lysosomes |
|
Definition
|
|
Term
| what are 2 major components of lysosome membrane |
|
Definition
1. transport proteins to import materials for digestion 2. proton pumps to maintain acidic lumen |
|
|
Term
| why aren't proteins in lysosome membrane digested by lysosome proteases? |
|
Definition
| membrane proteins are highly glycosylated - protects them from proteases |
|
|
Term
| how are digestive enzymes tranferred to lysosome |
|
Definition
| modified in golgi with sugar side chain (mannose 6-phosphate). this marks them for transport to lysosome |
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|
Term
| what are 2 methods for a cell to take in molecules to be digested |
|
Definition
1. endocytosis 2. phagocytosis |
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