How do proteins associate with cell membrane? They associate as either peripheral or integral proteins. Associating as peripheral or integral depends on whether they are hydrophobic and can attach into the bilayer or hydrophilic and must stay on the outside of the bilayer via ionic interactions or H bonds. Integral proteins usually must be removed with detergents. How does the presence of cholesterol affect lipid
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.
* An electrogenic pump is a transport protein that generates voltage across a membrane * Animal- sodium/potassium * Plants- proton pump Understand how a co-transporter works. Where you likely find one? Understand how large molecules and particles are transported across membranes including the role of Vesicles. What is meant by endocytosis? There are several types – what are they and how do they differ?
| Goigi Apparatus | The main function of the Golgi apparatus is to be responsible for handling the macromolecules that are required for proper cell functioning | It packages and ships molecules made in the ER. | Lysosome | Lysosomes are spherical bag like structures that are bound by a single layer membrane, however, the lysosome shape and size may vary to some extent in different organisms. The lysosome size ranges between 0.1 to 1.2μm. | Lysosomes function as the digestive system of the cell, serving both to degrade material taken up from outside the cell and to digest obsolete components of the cell itself. | P1 tasks 2 Organs | Anatomy | Physiology
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?
D1; Analyse the role of the phospholipid bilayer in terms of the movement of materials into and out of cells The phospholipid bilayer is the structure which surrounds a cell, this plasma membrane is made up of two layers of phospholipids; these are the intracellular layer, which is at the bottom, and the extracellular layer which is at the top (Wisegeek.com/bilayer. 2011). The mosaic model shows that the phospholipids are arranged in shapes like heads and tails, the polar heads are made up of glycerol, phosphate and nitrogen and the non-polar tails are made up of fatty acid chains (Wisegeek.com/bilayer. 2011). The polar heads will interact with water as they are hydrophilic, though the tails/fatty acids are never exposed to water therefore they are hydrophobic (Wisegeek.com/bilayer.
| | | 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.
P1- Describe the microstructure of a typical animal cell and the functions of the main cell components. The microstructure of a typical animal cell consists of a plasma membrane which is made up of two phospholid molecules, proteins and cholesterol. They form a lipid bilayer which is semi-permeable allowing only certain molecules to diffuse across the membrance. Cholesterol helps ‘to stiffen plasma membranes and is not found in the membranes of plant cells.’ Bailey, About.com. The nucleus regulates all cell activity and is bounded by a double membrane called the nuclear envelope, this membrane separates the contents of the nucleus from the cytoplasm.
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?
Analyze the polarity of the different regions of a phospholipid molecule. Use the model of the phospholipid to describe the structure of the cell membrane. How do water, phospholipids, and proteins interact to produce the cell membrane? * Analyze the polarity and water-solubility of the different regions of the globular protein floating in the phospholipid bilayer membrane shown below. The protein molecule is able to float in the membrane – part of it is embedded in the membrane, part of it sticks into the cytoplasm, and part of it sticks out into the aqueous environment of the cell.