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42 Cards in this Set
- Front
- Back
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Plasma (cell) membrane |
A phospholipid bilayer that surrounds a cell, and is selectively permeable (i.e. only allows certain substances through) |
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Simple diffusion |
Transport of molecules from an area of high concentration to an area of low concentration (a concentration gradient) A passive process (does not require energy/ATP) |
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Osmosis |
Transport of water from an area of high concentration to an area of low concentration across a selectively permeable membrane. A passive process. |
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Facilitated diffusion |
Movement of certain molecules across the plasma membrane, from an area of high concentration to an area of low concentration, using specific protein channels. A passive process. |
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Active transport |
Movement of molecule from an area of low concentration to an area of high concentration (against the concentration gradient). Active processes require energy (usually ATP). |
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Primary active transport |
Specific transport molecules (proteins) move specific substances across the cell membrane |
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Secondary active transport |
The energy stored in a Na+ or H+ concentration gradient is used to drive other substances across the membrane against their own concentration gradients (when a substance follows a substance that is undergoing primary active transport across the cell membrane) |
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Symporter |
A transporter that moves two substances in the same direction |
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Antiporter |
A transporter that moves two substances in the opposite direction |
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Cytoplasm |
Region between the plasma membrane and the nuclear membrane |
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Cytosol |
The fluid portion of the cytoplasm (ex: If you squish the juice from an apple, you are taking out the cytosol) |
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Organelles |
Specific structures that perform specific functions in a cell |
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Cytoskeleton |
A network of protein filaments |
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Microfilaments |
The thinnest type of filament, mostly made of actin, provide support and movement in and around the cell |
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Intermediate filament |
Larger in diameter than microfilaments, help prevent mechanical stress to cells and anchor organelles |
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Microtubules |
Largest in diameter, help determine cell shape and aid in cellular transport |
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Ribosomes |
Sites of protein synthesis |
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Transcription |
Synthesis of RNA using DNA at the template - Occurs within the nucleus, at the nucleolus - Messenger RNA (mRNA) is synthesized from genes then transported to the cytoplasm |
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Exon |
The portion of mRNA that leaves the nucleus and is translated (i.e. converted into a protein) |
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Intron |
The portion of the mRNA that is removed from the original transcript (the mRNA that was not copied from the gene) and remains in the nucleus (it is not translated) |
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Translation |
Producing proteins using mRNA as a template - Occurs in the cytoplasm and at the ribosomes ( the main component of ribosomes is ribosomal RNA or rRNA) (The third type of RNA is transfer RNA (tRNA) which moves through the cytoplasm to obtain amino acids then transports amino acids to the ribosomes for protein synthesis) |
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Prophase |
- Nuclear envelope disappears - Chromatin condenses to form from chromosomes, which can now be seen under the microscope - Centrioles move to opposite poles |
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Metaphase |
Chromosomes line up along the metaphase (equatorial) plate |
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Anaphase |
Chromosomes separate then travel towards the centrioles |
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Telophase |
Chromosome reach their destination then un-condense - Nuclear envelopes form around each set of chromatin |
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Cytokinesis |
- Division of the cytoplasm - Results in the formation of two distinct daughter cells |
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Receptor mediated endocytosis |
movement of specific ligands into a cell by forming a vesicle around that material; the vesicle is formed from the cell membrane (- phagocytosis (when large substances like a virus or bacterium) is a type of endocytosis) |
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Exocytosis |
substances are removed from the cell after a secretory vesicle fuses with the cell membrane |
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Rough endoplasmic reticulum (RER) |
- a membrane that extends from the nuclear envelope - has ribosomes imbedded in it - helps modify proteins |
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Smooth endoplasmic reticulum |
- extends from the RER - does not have ribosomes - associated with fatty acid and steroid synthesis |
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Golgi complex |
- a stack of flattened membranous sacs - associated with protein modification and the transport of the final product |
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Lysosome |
- membrane bound sacs of digestive enzymes |
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Peroxisomes |
- membrane bound sacs, smaller than lysosomes - contains catalase (breaks down hydrogen peroxide) and other enzymes that oxidize (removes hydrogen to deactivate) various molecules |
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Mitochondria |
- structures designed to produce large quantities of ATP - are self-replicating |
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Nucleus |
- usually one per cell - surrounded by a double membrane known as the nuclear envelope - nuclear envelope contain passage ways allied nuclear pores which allow RNA to pass out of the nucleus |
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Nucleolus |
- site of ribosome synthesis inside the nucleus - contains 46 strands of DNA known as chromatin (these structures condense during mitosis to form chromosomes) |
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Cell cycle in somatic cells |
the orderly sequence of events in which a cell duplicates its contents and divides into two cells |
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Interphase |
- the longest portion of the cell cycle - the cell is metabolically active |
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G1 phase |
- when the cell has the highest metabolic activity - if this cell is going to reproduce, new organelles are produced |
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S phase |
DNA replication |
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G2 phase |
enzymes required for mitosis and the remaining cellular components are manufactured |
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Mitosis |
- nuclear division (not cellular division) - division of the contents of nucleus ( stages (PMAT) prophase, metaphase, anaphase, telophase) |
