Unit 13 P2 Describe how materials of different states pass into and out of cells. The cells plasma membrane is not only used for structural purposes. Its functions to allow certain substances in and out of the cell. It can allow other substances into the cell against the concentration gradient or allow other substances (for example waste) out of the cell. There are two ways that the cell can transport substances; passive transport processes and active transport processes.
Nuclear envelope What genetic material is found in this part of the cell more than anywhere else in the cell? RNA C. Nucleolus D. Cytoplasm E. Mitochondria F. Lysosomes G. Endoplasmic Reticulum H. Golgi apparatus I. This part of the cell is reponsible for breaking down organic molecules. J. Ribosomes K. centrioles L. Chromatin What function do peroxisomes serve? Peroxisomes contain a variety of enzymes, which primarily function together to rid the cell of toxic substances, and in particular, hydrogen peroxide (a common byproduct of cellular metabolism).
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.
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?
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.
Aim: To find out the effect of the temperature on the permeability of the cell membrane. Research Question: Effect of temperature on amount of pigment Background: Cell membranes contain many different types of molecules/substances that help maintain the overall structure, fluidity and functioning of the membrane. It is mainly consisted of a phospholipid bilayer, with a hydrophilic phosphate head and a hydrophobic lipid tail. The phospholipid bilayer is effective in stopping molecules from exiting or entering the call. Since the membrane has a non-polar layer in its centre and two polar layers on either side, it is difficult for both polar and non-polar molecules to pass through both layers.
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. What do you suspect about its structure, including its amino acid sequence, to make it behave as it does? * Examine the diagram of the cell membrane below. Is the diagram a “good” illustration of the fluid mosaic model of the cell membrane? What aspects of cell membrane structure are accurately illustrated by it?
Carrier Mediated Transport Carrier Mediated Transport is the movement of substances across the plasma membrane by protein carrier molecules, this transport is used when molecules can’t cross membrane or cross very slowly. These are examples of important molecules that require carrier mediated transport, water, glucose, amino acids, vitamins, phosphate, multivalent cations. There are three mechanism of carrier mediated transport, one is facilitated diffusion, two is second is primary active transport and three is secondary active transport. Facilitated diffusion is also known as facilitated transport. This is a form of passive transport across a membrane in which a transporter protein facilitates the movement of an impermeable membrane or ion across the plasma membrane down its concentration gradient.
Electrophoresis – An Introduction • An analytical technique in which the motion of scattered particles run through a fluid under the influence of uniformly charged field is called electrophoresis. • This phenomenon was first observed by Ferdinand Frederic Reuss followed by Arne Tiselius who won the Nobel Prize in chemistry for his research on electrophoresis, adsorption analysis and his discoveries concerning the complex nature of serum protein. It is a technique used in laboratories in order to separate macromolecules based on molecular size and charge. • This technique applies a negative charge so proteins move towards a positive charge. This is used for both nucleic acids and proteins.
The Effect of Diffusion and Osmosis on Hypertonic and Hypotonic Solutions. Introduction: In order to maintain homeostasis, a cell must be able to transport materials back and forth across the membrane due to the fact that cell membranes are selectively permeable. Selectively permeable means that some substances can pass through the membrane while others cannot, like glucose, proteins and carbohydrates. Both solutes and solvents may cross the cell membrane. Solutes meaning: the substance that is being dissolved, while solvents meaning: substance being dissolved into, much like diffusion.