click below
click below
Normal Size Small Size show me how
NURS1004 Week 5
Introduction to human cells pp. 91-157, 539-542
Question | Answer |
---|---|
What is cytology? | The study of cellular structure and function |
What 2 general classes of cells does the human body contain? | 1. Somatic cells 2. Sex cells |
What are sex cells in the human body? What is their purpose? What can they also be called sometimes? | They are either sperm of males or oocytes or "eggs" of females. The fusion of a sperm and an oocyte at fertilization is the first step in creating a new individual. They can otherwise be known as germ cells or reproductive cells. |
What are somatic cells? | They are 'body' cells and include all the other cells in the human body. |
What is the cytoplasm of a cell? | The inside of a cell that can be subdivided into the cytosol (fluid), and intracellular structures called organelles. |
What is the Plasma Membrane? | Phospholipid bilayer containing phospholipids, steroids, proteins and carbohydrates. The plasma membrane isolates protects and supports the structure of the cell as well as controlling the entry and exit of materials. |
What is the Cytoskeleton? | Proteins organised in fine filaments or slender tubes. They provide strength, support and movement of cellular structures and materials. ------ (slender) Microfilaments ======== (thicker) Microtubles |
What are the Centrosomes and Centrioles? How many are in the cytoplasm? How many microtubule triplets is composed in each centriole? | Essential for movement of chromosomes during cell division; organisation of microtubules in cytoskeleton. Cytoplasm contains 2 centrioles at right angles. 9 microtubule triplets in a 9 + 0 array. |
What is the Cilla? What are the different types? | Long extentions of the plasma membrane containing microtubules. There is 2 types; Primary and Motile. A primary cillium acts as a sensor and motile cillia move materials over cell surfaces. |
What are Proteasomes? | Hollow cylinders of proteolytic enzymes with regulatory proteins at their ends. They breakdown and recycle damaged or abnormal intracellular proteins. |
What are Ribosomes? What are the 2 types? What is their function? | RNA and proteins, 2 types fixed and free. Fixed are bound to rough endoplasmic reticulum and free are scattered in the cytoplasm. Their function is to synthesis protein. |
What are Peroxisomes? | Vessicles containing degradative enzymes. They catabolise fats and other organic compounds and neutralize toxic compounds generated in the process. |
What is Catabolism? | The breakdown of complex molecules in living organisms to form simpler ones, together with the release of energy; destructive metabolism. |
What are Lysosomes? | Vesicles containing digestive enzymes, their function is the intracellular removal of damaged organelles or pathogens. |
What is the Golgi apparatus? | Stacks of flattened membranes (cisternae) containing chambers. They store, alter and package secretory products and lysosomal enzymes. |
What is the Mitochondria? | Double membrane with inner membrane folds (cristae) enclosing important metabolic enzymes. The mitochondria portuces 95% of the ATP required by a cell (energy). |
What does the Rough Endoplasmic Reticulum do? | Modifies and packages newly synthesized proteins. |
What does the Smooth Endoplasmic Reticulum do? | Synthesises lipids and carbohydrates |
What is cyanosis? | Bluish dis-colouration due to excessive de-oxygenation |
What is the Nucleus? | Controls metabolism, stores and processes genetic information and controls protein synthesis. |
What are 4 functions of the plasma membrane? | 1. Physical isolation 2. Regulation of exchange with the environment 3. Sensitivity to the environment 4. Structural support |
What is another terminology for the plasma membrane of a cell and what is it made up of? | Phospholipid Bilayer, Lipids are the hydrophobic tail on the inside of the layer, Phosphates are the hydrophillic head. |
What is extracellular fluid? | Fluid outside of the cell |
What is intracellular fluid? | Fluid inside the cell (cytosol) |
What 4 other substances are in the cell membrane? | 1. Cholesterole and other seroids 2. Small quantites of other lipids 3. Proteins 4. Glycolipids. |
What is the cholesteroles purpose for the cell membrane? | Stiffens the plasma membrane making it less fluid and less permeable. |