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22 Cards in this Set
- Front
- Back
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How many cells does an adult human body have?
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10^13
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What is the 'Central Dogma' of molecular biology?
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The central dogma states that sequence information is transferred from DNA to mRNA to protein. The DNA is held in the nucleus & transcribed to mRNA. The mRNA is translated into protein in the cytoplasm, via the rough ER. This process is all held in place by cellular membranes & is provided with energy by the mitochondria.
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Approximately how many difference cell types do humans have?
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200
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Briefly describe the plasma membrane (PM) & its functions.
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Phospholipid bilayer. Encloses the cell, separating it from environment. Semi-permeable barrier. Cholesterol regulates membrane fluidity. Allows cell to be charged - used for energy & communication.
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How is the PM clinically relevant?
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The PM is important for drug efficacy: uptake of the drug & secretion of the drug (resistance)
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What are the general movements of sodium, potassium & chloride in/out of a cell?
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Higher [K+] inside cell.
Higher [Na+] & [Cl-] outside cell. |
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Briefly describe the nucleus & its functions
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Stores DNA & is the site of DNA replication & synthesis
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How might the nucleus be involved in the onset/treatment of disease?
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controls gene expression. Errors in DNA replication cause disease.
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How many nucleotides does human DNA have?
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3x10^9
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How many genes do humans have?
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24,000
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Briefly describe the function of the cytoplasm.
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Provides an environment for many biochemical processes (metabolic reactions).
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Briefly describe the role of mitochondria.
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Generate ATP via O2 utilisation, producing energy.
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Briefly describe lysosomes & their functions.
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Membrane-bound organelles containing powerful digestive enzymes. Destroy damaged cells & phagocytosed materials.
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Briefly describe peroxisomes & their functions.
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Contain oxidative enzymes involved in the detoxification of many substances. Contain catalase which breaks down hydrogen peroxide.
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Briefly describe ribosomes.
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Composed of RNA & protein & are the site of protein synthesis. Free ribosomes synthesise proteins in the cytoplasm & rough ER ribosomes translocate the newly synthesised proteins into the ER lumen for further processing & secretion.
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Briefly describe the endoplasmic reticulum (ER).
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Large intracellular membrane system. RER - associated with ribosomes, modifies proteins, synthesised phospholipids & cholesterol. SER - synthesises lipids & steroids, detoxifies drugs, stores calcium (muscles).
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Briefly describe the Golgi apparatus.
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Stack of smooth membrane sacks & vesicles close to nucleus. Sorts & organises protein transport for secretion - normally only 1/cell
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Describe the cytoskeleton.
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Dynamic & includes microfilaments, microtubules & intermediate filaments. Involved in muscle contraction, cell motility, intracellular movement, structural role, protein trafficking & centriole formation.
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What are the centrioles?
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Paired cylindrical structures composed of microtubuli (9 triplets). Organise the microtubule network for segregation of chromosomes during cell division.
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What are 2 key functions of the cell?
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gene expression & cell division (mitosis)
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What are the phases of mitosis?
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Interphase, Prophase, (Prometaphase), Metaphase, Anaphase, Telophase, Cytokinesis
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What is the clinical significance of mitosis?
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errors during cell division can cause disease
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