Tromaville Coalition Essays - Membrane Biology, Cell Biology

Tromaville Coalition Essays - Membrane Biology, Cell Biology Tromaville Coalition Member of the Tromaville Coalition Chemistry 1. a) Bulk movement is the overall movement of a fluid. The molecules all move in the same direction. Diffusion however is the random movement of molecules which usually results in a fairly even distribution. In other words the movement is not guaranteed to move in one direction but the probability that it will move in the lower gradient is greater. Osmosis is similar to diffusion but is differentiated by the membrane's behavior. The cell membrane does allow water to move from higher to lower concentrations but does not allow solutes do that. b) Water potential is the capacity of water to move to a from a region where there is high water potential to low water potential. This action happens without the affect of outside forces. When outside actions due occur and they give water a high potential energy than the water will move to the region where less potential energy is. Hydrostatic pressure is the pressure required to stop water the movement of water. This is a method of measurement. The osmotic potential is the measure of tendency of water to move through a membrane which contains a solution. This occurs when a cell does not allow a hypertonic solution to leave the cell membrane. The cell begins to increase with water but the cell membrane can not release the solution and thus the water potential within the cell increases. This causes the water to no longer enter the cell. c) Hypotonic is less solute to a certain amount of water. Hypertonic is more solute to a certain amount of water. Isotonic is the equal amount of solutes in two different solutions. d) Endocytosis is the inward bulge causes by incoming molecules. Exocytosis is the expelling of a material outside a cell. e) Phagocytosis is the process where the cell obtains solid matter. This is different from the pinocytosis where the cell obtains liquid matter. These both are endocytic processes. Receptor-mediated endocytosis is the process where there are interactions between a material and receptor sites on the cell. In this process the cell accepts the material if it matches with the receptor sites. f) Coated pits are areas which peripheral proteins indent the membrane. This is where the vesicles for certain materials are formed. The vesicle which is formed is called the coated vesicle. g) Plasmodesmata are the links which hold two adjacent cells together. Gap junctions are the channels which allow materials to flow between cells. 2. The concentration gradient is the difference in the density of a material from one region to another region. The concentration gradient affects diffusion by allowing the substance to flow from high concentration to low concentration. The concentration gradient affects osmosis by the same manner it does in diffusion. The cell does not allow the solution to exit the cell when water is entering. This keeps the solution in the cell making the concentration high and thus no further penetration of water. 4. Diffusion is more rapid in gases because they are less dense than liquids. They repel each other more resulting in faster diffusion. Diffusion is greater at higher temperatures because of the greater kinetic energy among the molecules. They push each other more making them less dense. 5. The concentration of the solute is 1%. This happens because a 1% sugar solution is isotonic with that of the 1% sugar solution in the tubes. The 2% sugar solution was increased because the substance was hypertonic. The membrane did not allow the hypertonic solution to exit because the pressure from the hypotonic solution was forcing water in. This later reached an equilibrium when the hypertonic solution was gaining water potential and the water stopped rising. The vice versa happened in the distilled water solution.

Verbs + Gerund or Infinitive That Change in Meaning

Verbs + Gerund or Infinitive That Change in Meaning Many verbs in English can be combined with verbs  in the gerund (doing) or infinitive (to do) form.   Verb Gerund Some verbs are followed by the gerund (or  ing) form of the verb: consider doing - I havent considered looking for a new job.appreciate doing - I appreciate listening to music on a daily basis. Verb Infinitive Some verbs are followed by the infinitive form of the verb: hope to do - I hope to see you next week at the party.decide to do - Ive decided to find a new job next week. Most verbs take either the gerund or the infinitive, but not both forms. In this case, its important to learn which verbs take which form. However, there are a number of verbs which can take both forms. Most of these keep the meaning the same:   She started to play the piano. She started playing the piano.I like to go to the beach at least once a year. I like going to the beach at least once a year. Some verbs which can take both forms have a change in meaning depending on whether the verb is followed by the gerund  or the infinitive. Here is an explanation of these verbs with examples to help provide context. Forget to Do Use  forget to do  to indicate that someone did not do something: She often forgets to lock the door when she leaves the house.I forgot to get the groceries at the supermarket. Forget Doing Use  forget doing  to say that someone doesnt remember something that they have done in the past: Mary forgets meeting Tim in Italy.Annette forgot locking the door before she left her home. Remember to Do Use  remember to do  when speaking about something someone should do: Make sure you remember to pick up some eggs at the supermarket.Im sure Ill remember to invite Peter to the party. Dont worry about it! Remember Doing Use  remember doing  to speak about a memory that someone has: I remember buying him a present.Jeff remembers living in Italy like it was yesterday. Regret to Do Use  regret to do  in the case that someone must do something that is unpleasant: I regret to tell you the bad newsThey regret to inform us that weve lost all our money! Regret Doing Use  regret doing  to express that someone doesnt like what they did at some time in the past: Peter regrets moving to Chicago.Allison regrets falling in love with Tim. Stop to Do Use  stop to do  in order to say that someone stops one action in order to do another action: Jason stopped to speak with his boss about the convention.My friend stopped to smoke a cigarette before he continued with the conversation. Stop Doing Use  stop doing  to show that someone has completely quit some action. This form is often used when speaking about bad habits: I stopped smoking cigarettes.You should stop complaining about money all the time. Try to Do Use try to do  to encourage someone to do something: He should try to learn a new language.I think you should try to save some money this month. Try Doing Use  try doing  when speaking about an experiment or something that is new: He tried going to a fitness club, but it didnt work out for him.Have you ever tried cooking fish in olive oil? Infinitive or Gerund Quiz Test your understanding of these differences in meaning by deciding whether the verb should be used in the infinitive or gerund form based on the clues provided: Jack remembers _____ (buy) eggs at the supermarket because he always takes a list.Jason stopped _____  (play)  the piano at six because it was time for dinner.I certainly didnt forget ___________ (ask) him the question because hes already given me his answer.Janice stopped _____ (make) a telephone call before she continued with her shopping.  Whats the worst thing you regret _____ (do) in your life?Have you ever forgotten _____ (get) a present for your wife on your anniversary?Alan stopped _____ (drink) years ago because of a serious liver problem.I regret _____ (tell) you that we are going out of business next month.I remember ______ (play) football when I was in high school. Unfortunately, I didnt play much during the games.I dont think Ill ever regret _____ (fall) in love with my wife. Weve been married for over thirty years! Answers: to buyplayingto askto makedoingto getdrinkingto tellplayingfalling