Microanatomy – Flashcards
Unlock all answers in this set
Unlock answersquestion
| Name 3 functions of the cytoskeleton in the cell. |
answer
1. Cell structure 2. Organelle movement and vesicle movement 3. Cell motility |
question
| Function of microtubules. |
answer
| Organelle position & intracelluar transport are a function of which cytoskeleton structure? |
question
| Function of intermediate filaments |
answer
| Mechainical strength is a property of which cytoskeletal structure? |
question
| Function of microfilaments. |
answer
| Cell shape & movement are determined by which cytoskeleton structure? |
question
| Which cytoskeletal structure can survive cell death (very strong)? |
answer
| Intermediate filaments. |
question
| Which cytoskeletal structure makes up hair, nails, claws, fur, scales, and other out covering of skin? |
answer
| Intermediate filaments |
question
| Desmosomes link cells together by what means? |
answer
| Linking Intermediate filaments |
question
| How are cells held together? |
answer
| Intermediate filaments linking to desmosomes. |
question
| How can pathologists characterize the origin of a tumor cell that may have metastasized? |
answer
| Through the identification of intermediate filament type. |
question
| What does it mean if a cell is keratinized? |
answer
| The cell is dead and contains a tough protein called KERATIN. |
question
| You biopsy a tumor found in the lymph node under the armpit and find that tumor cells express neurofilaments. Where was the origin of the tumor? |
answer
| The brain or spinal cord. |
question
| Name the 6 types of intermediate filaments. If possible also affiliate cell types & examples. |
answer
| 1. Keratins 2. Vimentin 3. Desmin 4. Gilial fibrillary 5. Neurofilaments 6. Lamins |
question
| Where might you find cells with more than one nucleus? |
answer
| Skeletal muscle cells, they have fused together. |
question
| Describe how chromosomes are structurally made up. |
answer
| DNA wrapped around HISTONES making NUCLEOSOMES which collectively make up CHROMATIN. This makes up chromosomes. |
question
| What is the basic unit of DNA packing? |
answer
| Nucleosome |
question
| What makes up a nucleosome? |
answer
| DNA wrapped around HISTONES H2A, H2B, H3, & H4. |
question
| There are approximately __________ nuclear pores in a nucleus. |
answer
| 2000-4000 |
question
| What are the 3 types of RNA transcribed from DNA? |
answer
| rRNA, tRNA, mRNA |
question
| What is the name for a highly condensed, trascriptionally INACTIVE part of DNA? |
answer
| Heterochromatin |
question
| What is the name for an uncondensed, trascriptionally active part of DNA? |
answer
| Euchromatin |
question
| Where are rRNA, tRNA, and mRNA trascribed? |
answer
| tRNA and rRNA are transcribed from euchromatin scattered throughout the nucleus. mRNA is transcribed in the NUCLEOLUS. |
question
| Where are ribosomes synthesized? |
answer
| In the nucleolus. |
question
| Where are ribosomal proteins made? |
answer
| In the cytoplasm, they are imported to the nucelous during ribosomal synthesis. |
question
| True or false: The large and small subunit are synthesized in the nucleolus and remain associated from then on. |
answer
| False: The small and large subunits separate after being constructed together and leave separately from the nucleus. |
question
| Knobs on chromosomes indicate what? |
answer
| Knobs indicate the position of genes that code for RNA. |
question
| What indicates genes that code for RNA? |
answer
| Knobs; like on chromosomes 13, 14, 15, 21, and 22 |
question
| Explain NLS |
answer
| Nuclear Localization Sequence, signals for nuclear import and usually contains basics amino acids. |
question
| Explain NES |
answer
| Nuclear Export Sequence, singals for nuclear export and contains hydrophobic amino acids usually. |
question
| Name two nuclear carriers. |
answer
| Importin & Exportin |
question
| Name the enzyme that regulates nuclear carriers by binding and releasing thier cargo. |
answer
| Ran - Ras-related Nuclear protein |
question
| How many ribosomes are made per minute in a single cell? |
answer
| 7000 ribosomes |
question
| Name the process that is highly associated with mRNA export. |
answer
| Splicing |
question
| What does the Greek term -ome mean? |
answer
| mass |
question
| What does the Greek term -oma mean? |
answer
| body |
question
| Name two ways a cell can produce ATP. |
answer
| 1. Oxidative phosphorylation (in the mitochondria) 2. glycolysis in the cytoplasm |
question
| How many APTs come from the mitochondrial breakdown of a molecule of glucose? |
answer
| 36 ATP |
question
| What organelles can break down fatty acids to produce acetyl-Coa? |
answer
| Mitochondria & Peroxisomes |
question
| What organelles can use acetyl-CoA to produce ATP? |
answer
| Mitochondria |
question
| Human cells have how many mitochondria per cell? |
answer
| 1,000 (100-10,000) |
question
| True or False: Mitochondria are rigid structures. |
answer
| False, they are very plastic and change shape rapidly |
question
| Are mitochondria spherical, tubular, or none of the above? |
answer
| Tubular |
question
| What are the foldings in a mitochondria called? |
answer
| cristae |
question
| Where are the only ion pores in human cells found? |
answer
| Mitochondria, they are called porins |
question
| What compartment of the mitochondria has a similar contents as the cells cytosol? |
answer
| The intermembrane space |
question
| How many genes are on the mitochondrial DNA? |
answer
| 37 |
question
| How does the mitochondria make its proteins? |
answer
| Most are encoded by the nuclear genome, translated on cytoplasmic ribosomes, and imported post-translationally into mitochondria. |
question
| In which compartment of the mitochondria does the DNA reside? |
answer
| The matrix |
question
| How many copies of DNA are in the mitochondria? |
answer
| 2-10 copies |
question
| When does the mitochondria replicate for cell division? |
answer
| It dynamically divides by fission and fuses as needed. |
question
| All mitochondria comes from our mother, but if sperm are packed with mitochondria to work the flagellum why don't we get any from our father? |
answer
| 2 ways: (1) sperm mitochondria are tagged with ubiquitin which taggs them for destruction in the embryo. (2) dilution factor: many more mitochondria in the egg than the sperm. |
question
| Where is cytochrome C located? |
answer
| It is mobile in the intermembrane space. |
question
| What is the name of a "double" phopholipid? |
answer
| Cardiolipin, it has 4 fatty acid tails. |
question
| What is the key feature cardiolipin plays in the mitochondria? |
answer
| It packs tighter in the inner membrane making it stronger to withstand the extreme stress from the proton motive force. |
question
| How and where is cardiolipin converted? |
answer
| The mitochondria imports lipids and performs the conversion. |
question
| How is the signal for ubiquination identified? |
answer
| It is buried deep in the protein structure, when the structure degrades it is exposed. |
question
| Name 3 special properties of the lysosome membrane: |
answer
| 1. ATP drivin [H+] pump 2. glycoprotein coat to protect itself 3. transporter channels to move out broken down products. |
question
| Name the membrane bound organelle that digest proteins. |
answer
| Lysosome, proteosome also digest protein specifically but is not membrane bound. |
question
| Name the sources of vesicles that contain material bound for lysosomal degradation. |
answer
| 1. Endosomes containing EC molecules 2. Phagosomes, phagocytosed material 3. Autosomes containing expired organelles |
question
| Give an example of a lysosomal storage disease. |
answer
| Tay-Sachs |
question
| What is the main function of the peroxisome? |
answer
| To ride the body of toxins. (hydrogen peroxide, alcohol) |
question
| What two organelles are the highest oxygen consumers? |
answer
| Mitochondria & Peroxisome. |
question
| Name the peroxisomal matrix enzyme that uses H2O2 to oxidize other substrates. |
answer
| Catalase |
question
| Describe the B-oxidation reactants and products. |
answer
| The alkyl chains of fatty acids are shortened to for Acetyl CoA, this is then used in the mitochondria if completed in peroxisomes. |
question
| Which organelle is responsible for the synthesis of bile acids from cholesterol made in the smooth ER? |
answer
| Peroxisomes |
question
| What defects cause someone to have the genetic disease, Zellweger's syndrome? |
answer
| Defective PTS (Peroxisomal targeting signal) which makes 'empty' peroxisomes. Peroxisomes make precursors to myelin, so there are neuron complications as well. |
