The exterior surface of the plasma membrane can contain carbohydrates. How are the peripheral proteins attached to membrane? Peripheral (extrinsic) proteins are associated with the surface of the bilayer surface via ionic interactions (electrostatic) and H bonds. They do not extend into the hydrophobic interior and can be removed by agents that disrupt ionic interactions and H bonds, such as high salt concentrations, urea, or extremes of pH. How do proteins associate with cell membrane?
| | | A) | endoplastic reticulum | | | B) | microtubules | | | C) | cytoplasm | | | D) | mitochondria | | | | | | Feedback: The cell's chemical processes take place in a semifluid material called the cytoplasm. This material provides an ideal environment for organelles because of its fluidity. | | 7 CORRECT | | This shows an example of endoplasmic reticulum. What is the significance of its structure? | | | A) | provides a location for DNA production | | | B) | helps decrease surface area | | | C) | allows selective permeability of cell membrane | | | D) | facilitates breakdown of chemical bonds | | | | | | Feedback: The pleats and folds of the endoplasmic reticulum provides a large surface area where cellular functions, such as breaking chemical bonds, can take place.
Two main reasons the membrane of a cell is important is because first off, the chemical reactions that are necessary for life could occur efficiently in an enclosed area since reactants could collide more frequently (Freeman et al., 2011). Secondly, the membrane serves as a selective barrier where it keeps compounds that could damage the cell out and brings compounds that are needed by the cell in (Freeman et al., 2011). Cell membranes consist of two types of lipids. The ones that form membranes have a polar end and a non-polar end. Polar heads of the lipids are hydrophilic, meaning that they love interacting with water.
Passive transport processes: Diffusion Diffusion is the movement of ions or molecules from regions of high to low concentration; down a concentration gradient. Diffusion and the plasma membrane The plasma membrane is semipermeable which means it will allow certain substances to go in and out but not others. Moecules that pass through the phospholipid bilayer easily: Hydrophobic molecules: 02 and N2 Non-polar: Benzene Small uncharged polar molecules: H20, Urea, glycerol and CO2 Molecules that don’t pass through the phospholipid bilayer easily: Large uncharged molecules: Glucose Polar molecules: Sucrose Ions (charged): H+, Na+, HCO3, K+Ca2+, Cl- and Mg2+ Therefore the three characteristics of a molecule that determine their permeability through the membrane are: 1. Polarity- Hydrophobic vs Hydrophilic 2. Charge- Charged vs Uncharged 3.
The bilayer is selectively permeable which enables it to act as a barrier that keeps proteins, ions and other molecules where they are needed and prevents them from diffusing into areas where they are not (Wisegeek.com/bilayer. 2011). Small molecules can move through the layer automatically, this is diffusion from a high concentration to an area of low concentration, whereas water diffuses from highly concentrated areas to low concentrated areas. This process is known as osmosis and its purpose is to maintain equilibrium within the cell in order for it to function properly (Wisegeek.com/bilayer. 2011).
C.) Eukaryotic organelles are enclosed by lipid membranes. There are those that have double-membrane compartments such as chloroplast and mitochondria among others. Single-membrane compartment organelles include endoplasmic reticulum and Golgi apparatus. However, Ribosomes do not have a membrane. The breakdown of the membranes of these structures, affect the function of his heart cells because lysosomal enzymes which are normally bound safely inside vesicles will digest the plasma membranes and the membranes of the organelles.
It is located outside the cell membrane and provides these cells with structural support, protection and in addition is acting as a filtering mechanism. A major function of the cell wall is to act as a pressure vessel, preventing over-expansion when water enters the cell. ( Holes 2010 pg76.) B. Nuclear envelope What genetic material is found in this part of the cell more than anywhere else in the cell?
CHAPTER 5: MICROIAL METABOLISM PRE-TEST 1: Which of the following types of transport involves the expenditure of energy and special membrane proteins? ACTIVE TRANSPORT 2: Which of the following molecules serves as the short-term recyclable energy supply for a cell? ATP 3: Which of the following is a waxy lipid found predominantly in the cell walls of Mycobacterium? MYCOLIC ACID 4: Catabolic reactions are chemical reactions that BREAK LARGE MOLECULES APART 5: Denaturation is typically a problem with which of the following? PROTEINS 6: A difference in the concentration of a chemical on both sides of a membrane leads to which of the following phenomena?
Ghostbuster Slime Lab 10/4/2012 Abstract The purpose of this experiment was to observe the physical properties and changes of the creation of a polymer as a result from cross-linking. A borax solution was made and was combined with a polyvinyl alcohol solution. A polymer’s cross-links give them many properties, like bonding ability, elasticity, and viscosity. The amount of water added in the experiment directly affected the viscosity and elasticity of the slime polymer. Too much water added resulted in a high viscosity and low elasticity.
Conclusion It was determined by comparing the positive and negative controls that chick peas are negative for glucose. However, beano was positive for cellulose. So when beano is combined with the chick peas, it breaks down the fiber in the chick peas. Causing the fiber to break down into digestible glucose. B.