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Cell Eukaryote создатель Mind Map: Cell Eukaryote

1. The energy-harvesting organelle of the cell. In addition to participating in the breakdown of glucose (and making ATP), is also involved in breaking down fats and amino acids. It consumes all the oxygen used by the cell.

1.1. In the Krebs cycle, the carbon skeletons are broken apart to make CO2, while the hydrogen atoms are removed on special nucleotide carriers.

1.1.1. For creating and modifying nucleotides, amino acids, and other building blocks.

1.2. In the electron transport chain, the hydrogens are stripped of their energy in a series of steps to make ATP, and in the end are reacted with oxygen to form water.

2. Metabolism

2.1. The entire set of reactions within the cell.   The energy transfer involves the interconversion of ATP and ADP. Energy is released when ATP loses a phosphate to become ADP, while energy is required to make ATP from ADP and phosphate. ATP can also be converted to AMP by the loss of two phosphates.

2.1.1. Anabolic use stored energy to build more complex molecules from simpler ones. (Protein synthesis)

2.1.2. Catabolic reactions break down complex molecules to simpler ones, releasing energy.(Glucose breakdown)

3. Signal Transduction/Relay

3.1. Hormone is a small molecule released by one cell in the body to influence the behavior of another. Exerts its influence by binding to a protein receptor in the target cell either on the membrane or within the cytoplasm.

3.1.1. Adrenaline binds to a membrane-spanning receptor. The binding changes the shape of the receptor, which produces a molecule called cyclic AMP. This "second messenger" binds to enzymes, activating them and leading to production of substances depending on the particular cell. The set of proteins in the cell is determined by the genes it has expressed.

3.1.2. Testosterone passes through the plasma membrane and binds to a receptor in the cytosol. Then is transported to the nucleus. It binds to DNA, altering the rate of gene expression for a wide variety. It stimulates the production of new, long-lasting proteins that alter the cell's function for much longer.

3.1.3. Cells continually respond to signals, and they influence other cells through the signals they release.

3.1.3.1. Control the rate of cell division,.

3.1.3.2. The development and differentiation of the cell

3.1.3.3. The secretion of proteins and other molecules

3.1.3.4. The response to injury

4. Proteins

4.1. Are long chains of amino acids. They have unique shapes and chemical properties that dictate their diverse functions.

4.2. Give each organelle, and the cell as a whole, its unique characters.

4.2.1. Molecules can also cross the membrane attached to protein pumps that are powered by ATP.

4.2.2. Neurons have gated sodium channels that open to allow an electrical impulse to pass and close to recharge the cell.

4.3. Govern the range of materials that enter and leave the cell, relay signals from the environment to the interior, and

4.4. Participate in many metabolic reactions, to transform raw materials into the molecules needed by the cell for growth, repair.

5. Membranes

5.1. Are bilayered structures, made of two layers of phospholipid molecules, built from phosphoric acids and fatty acids.

5.2. The exterior head is hydrophilic, and the interior tails are hydrophobic.

5.3. Water molecules can pass freely through the bilayer, as can oxygen and carbon dioxide. Water passes through special channels formed by a protein called aquaporin.

5.4. Ions (sodium or chloride) and larger molecules (sugars or amino acids) must pass through the membrane via specialized proteins subunits that together form a pore from one side of the membrane to the other. And can also be powered indirectly, by coupling their movement to the flow of another substance.

5.5. This selective permeability allows the membrane to control the flow of materials in and out of the cell and its organelles.

6. Mitochondrion

7. Physical Characteristics

7.1. Have a nucleus, which contains the cell's chromosomes. Are present in plants, animals, protists, and fungi

7.2. Are large and structurally and functionally complex. Contain organelles, which carry out specialized reactions within their boundaries.

7.3. May be an individual organism (amoeba)

7.3.1. or a highly specialized part of a multicellular organism (neuron).

7.4. A typical eukaryotic cell is about 25 micrometers in diameter

7.5. Shape

7.5.1. Red blood cells are flattened disks indented

7.5.2. Muscle cells are highly elongated

7.5.3. Neurons are long and thin with many branches on each end

7.5.4. White blood cells constantly change their shapes as they crawl through the body

8. Cytoskeleton

8.1. Dense network of structural proteins which is embedded a large collection of organelles

8.2. Cytoplasm: material within the cell except for the nucleus.

8.3. Cytosol: the nonorganelle portion of the cytoplasm

9. Nucleus

9.1. The nucleus contains the chromosomes. Chromosomes contain the genes, which are DNA sequences used to create RNA. Is bounded by the nuclear envelope.

9.1.1. Translation occurs in the cytoplasm at ribosomes, large complexes made of protein and RNA. Ribosomes are assembled in the nucleolus. RNA is synthesized by the enzyme RNA polymerase, which unwinds DNA and transcribes genes. These RNA molecules are processed further before being exported as messenger RNA, used for protein construction.

9.1.1.1. RNA used in ribosomes (ribosomal RNA),

9.1.1.2. RNA that carry amino acids to the ribosome (transfer RNA)

9.1.1.3. Host of small RNAs that mostly function in the nucleus to modify other RNAs.

10. Chloroplast

10.1. Present in plants and protists, whose green chlorophyll gives their color.

10.1.1. Chlorophyll absorbs sunlight and funnels it to a complex set of proteins nearby

10.1.2. Light energy is used to split water into oxygen (waste) and hydrogen, which is attached to nucleotide carriers.

10.1.3. The hydrogen is then reacted with CO2 to form sugars, the essential high-energy product.

11. Protein Synthesis, Modification and Export

11.1. Messenger RNA exported binds to a ribosome in the cytosol, which translate the genetic message into a protein. Those carry a sequence of amino acids at their end, (signal peptide) This sequence directs the growing protein with its ribosome to the surface of the ER. Here, the ribosome attaches and extrudes the growing protein into the interior of the ER, giving the ER a rough appearance. The ER also synthesizes lipids, and so appears smooth. 

11.2. Many of the proteins entering the ER lumen contain organelle-specific targeting sequences. They are first modified by the addition of sugar groups to make "glycoproteins.".

11.2.1. They may help the protein to fold correctly after synthesis.

11.2.2. Act in cell-cell recognition and adhesion

11.2.3. Promote appropriate interactions with other proteins.

11.3. Proteins are further modified and sorted in the Golgi apparatus. Here proteins and lipids are packaged in vesicles and travel along the cytoskeleton.

11.3.1. Fusion of the vesicle membrane with the target membrane delivers the contents to the target organelle.

11.3.2. Proteins and other materials that the cell exports travel to the plasma membrane via vesicles.

11.3.3. Fusion of the vesicle with the plasma membrane delivers the contents to the exterior.

12. Cycle

12.1. Cells must reproduce in order for the organism to grow or repair damage. Each get a set of chromosomes, which must be duplicated and divided to the two daughter cells.

12.2. The orderly series of events involving cell growth and division.

12.2.1. Immediately following a division, the cell grows by taking up and metabolizing nutrients, and by synthesizing the many proteins, lipids, nucleic acids, sugars

12.2.2. DNA replication occurs next, making duplicate chromosomes

12.2.3. The cell synthesizes the numerous proteins.

12.3. Cell division includes two linked processes: mitosis, or chromosome division, and cytokinesis, or cytoplasm division.

12.3.1. Triggered by specific protein changes, the chromosomes begin to coil up tightly.

12.3.2. Cytoskeleton fibers attach to them, and position the chromosomes in pairs along the cell's imaginary equator.

12.3.2.1. the nuclear envelope breaks down.

12.3.3. The spindle pull the chromosome duplicates apart, segregating one member of each pair to opposite sides of the cell.

12.3.4. Other cytoskeleton proteins pinch the membrane to separate the two cell halves, forming two daughter cells.

12.3.4.1. along the equator (in animal cells)

12.3.4.2. build a wall across it (in plant cells)

12.3.5. Finally, the nuclear envelope re-forms and the chromosomes uncoil.