1d Single-membrane structure.
The thickness of structure C shows to be only a single membrane cell. Also the structure when compared to other similar looking cells on the diagram, such as structure D, looks less rigid and unstable. I believe structure D to be a double-membrane structure
2a Large molecular structure increases penetration rate
2b Small Number of Hydroxyl groups decrease the penetration rate
2c Low lipid solubility decreases penetration rate
2d The Hydrophilic nature increases penetration rate
3a
3b The cytoskeleton is a network of protein elements that extends through the cytoplasm in eucaryotic cells.
Microtubules
Microtubules are small cylindrical fibers that change in length by assembling and disassembling.
The fibers are lengthened and shortened as they assemble or disassemble from one or both ends.
The assembly of microtubules is controlled by an area near the nucleus called the centrosome.
The centrosome contains two barrel-shaped structures that are composed of microtubules. These structures, called centrioles, are oriented at right angles to each other.
The centrosome and centrioles are involved in the formation of the microtubules.
Microtubules play a role in moving things within the cell and also in moving the cillia and flagella.
For example, they are associated with movement of from the to the . During cell division, they move the chromosomes into the newly-forming cells.
http://faculty.clintoncc.suny.edu/faculty/Michael.Gregory/default.htm
4 Simple passive diffusion occurs when small molecules pass through the lipid bilayer of a cell membrane. Facilitated diffusion depends on carrier proteins imbedded in the membrane to allow specific substances to pass through that might not be able to diffuse through the cell membrane
Darnell, J., H. Lodish, and D. Baltimore. 1986. Molecular Cell Biology. Scientific American Books, Inc., New York
5a. A substance that increases the rate of a chemical reaction, without being consumed or produced by the reaction. Enzymes are catalysts for many biochemical reactions.
5b When the reactants collide, they may form an intermediate product whose chemical energy is higher than the combined chemical energy of the reactants. In order for this transition state in the reaction to be achieved, some energy must enter into the reaction other than the chemical energy of the reactants. This energy is the activation energy. Once the intermediate product, or activated complex, is formed, the final products are formed from it.
5c Enzymes carry out their function of lowering activation energy by temporarily combining with the chemicals involved in the reaction. These chemicals are called the substrate. Enzymes are specific for their substrate: A particular substrate molecule will combine temporarily with one enzyme type, and the active site of a particular enzyme will fit only one kind of substrate. For example, the enzyme sucrase will attach only to the substrate sucrose. The combination is called the enzyme- substrate complex. When the enzyme and substrate combine, the substrate is changed to a different chemical called the product. The enzyme is not consumed or altered by the reaction.
Biology Sixth Edition
Active learner
5d The most fundamental reactions in chemistry are the redox processes. The term redox process accounts for all processes in which atoms have their (oxidation state) changed.
This can be a simple redox process, such as the combustion of carbon by oxygen to yield carbon dioxide, it could be the reduction of carbon by hydrogen to yield methane, or it could be the oxidation of sugar in the human body, through a series of very complex electron transfer processes, to yield water and carbon dioxide.
The term redox comes from the two concepts of reduction and oxidation.
Reduction describes the uptake of an electron by a molecule or atom.
Oxidation describes the loss of an electron by a molecule or atom.
Redox reactions primarily involve the transfer of electrons between two chemical species. The compound that loses an electron is said to be oxidized, the one that gains an electron is said to be reduced. There are also specific terms that describe the specific chemical species. A compound that is oxidized is referred to as a reducing agent, while a compound that is reduced is referred to as the oxidizing agent.
http://www.chemistry.co.nz/redox_begin.htm
5e Protein-based metabolic enzymes
6(i) C
6(ii) C
6(iii) A
6(iv) A and C
6(v) B and C
