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Active and passive transport quizlet
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Question 1: Briefly describe and list fives characteristics of living organisms. Give examples of each.
1. Organization is one characteristic of life. An example of this is the levels of biological organization. The complex organization of life begins with atoms, the basic unit of matter. The atoms then combine to form small molecules and then begin to form larger molecules within a cell. Eventually the organism grow to form new populations. Each level progresses into something bigger.
2. The second characteristic of life is, life requires materials and energy. All living organisms require a source of energy. For plants, they require sunlight or solar energy. Animals require food for nutrients and energy. example of this is plants requiring
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A buffer is important to the pH of living system because, the buffer helps keep our body fluids within normal limits. In all living organism the pH of bodily fluids has to stay within normal limits for any organism to maintain life. If a living organism has hydrogen ion concentration level is too high, it will be too acidic or too low on the pH scale. Likewise, if the organism’s hydroxide ion concentration is too high, it will be too basic or too high on the pH scale. If this occurs, it can affect the living organism’s life. An example of this is human blood on the pH scale. The pH level of our blood, when we are healthy is 7.4; which is slightly basic (alkaline). If blood increases on the pH scale it can be life threatening; likewise, if blood decreases on the pH scale below 7.0, it can be life threatening. In order to keep blood at 7.4 it has to have stability that our body has; and a buffer is an essential mechanism to keep blood at a safe level.
Question 3: Describe how DNA and RNA are both different from and similar to each
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The plasma membrane of the cell is selectively permeable. This means that the plasma membrane only allows certain substances to enter and exit the cell by certain methods, and keeps other things that are not needed, out. It is important that that the cell filters certain things because, the cell must maintain its normal composition under changing environment conditions. If the plasma membrane was not selective of what enters and exits the cell, the cell could be harmed by things that are not supposed to be in the cell. Molecules that are allowed to enter the cell membrane, generally requires little to no energy. Substances that are hydrophobic is similar to the phospholipid center of the membrane. This allows substances to diffuse across across the membrane with zero energy. Molecules like, carbon dioxide, oxygen, alcohol, and glycerol; can freely move across the cell because they are none charged molecules that require no energy. The molecules are a Substances can cross the plasma membrane through passive transport or facilitated transport. If a substance enters the cell through passive transport, the plasma membrane is completely permeable to that substance, meaning that the substance is following its concentration gradient. This means it is moving from a high concentration to a low concentration. During facilitated transport, a
In life, it is critical to understand what substances can permeate the cell membrane. This is important because the substances that are able to permeate the cell membrane can be necessary for the cell to function. Likewise, it is important to have a semi-permeable membrane in the cell due to the fact that it can help guard against harmful items that want to enter the cell. In addition, it is critical to understand how water moves through the cell through osmosis because if solute concentration is unregulated, net osmosis can occur outside or inside the cell, causing issues such as plasmolysis and cytolysis. The plasma membrane of a cell can be modeled various ways, but dialysis tubing is especially helpful to model what substances will diffuse or be transported out of a cell membrane. The experiment seeks to expose what substances would be permeable to the cell membrane through the use of dialysis tubing, starch, glucose, salt, and various solute indicators. However, before analyzing which of the solutes (starch, glucose, and salt) is likely to pass through the membrane, it is critical to understand how the dialysis tubing compares to the cell membrane.
Miller, Kenneth R. and Joseph S. Levine. “Chapter 12: DNA and RNA.” Biology. Upper Saddle River: Pearson Education, Inc., 2002. Print.
Show your understanding of the structure of nucleic acids by describing the similarities and differences between DNA, mRNA and tRNA. Your descriptions should include drawings with labels of the nucleotide structures and the overall structures of each where applicable.
This cell membrane plays an important part in Diffusion. Cell membrane and Diffusion Diffusion is the movement of the molecules of gas or liquids from a higher concentrated region to a lower concentration through the partially permeable cell membrane along a concentraion gradient. This explanation is in the diagram shown below: [IMAGE] Turgor When a plant cell is placed in a dilute solution or a less concentrated solution then the water particles pass through the partially permeable membrane and fill the cell up with water. The cell then becomes Turgor or hard. An example of this is a strong well-watered plant.
All of these substances cross the membrane in a variety of ways. From diffusion and osmosis, to active transport the traffic through the cell membrane is regulated. Diffusion is the movement of molecules form one area of higher concentration to an area of lower concentration. Concentration gradient causes the molecules to move from higher concentration to a lower concentration.
The highest level of organization is the organism. An organism is a living being that has a cellular structure and that can independently perform all physiologic functions necessary for life. In multicellular organisms, including humans, all cells, tissues, organs, and organ systems of the body work together to form the organism.
When a cell membrane is said to be selectively permeable, it means that the cell membrane controls what substances pass in and out through the membrane. This characteristic of cell membranes plays a great role in passive transport. Passive transport is the movement of substances across the cell membrane without any input of energy by the cell. The energy for passive transport comes entirely from kinetic energy that the molecules have. The simplest type of passive transport is diffusion, which is the movement of molecules from an area of high concentration to an area of lower concentration. Diffusion
For homeostasis to work the transport, respiratory, gastrointestinal, renal and cardiovascular system have to function together.
The purpose of this lab was to see firsthand the diffusion of a substance across a selectively permeable membrane. Diffusion is the movement of molecules from an area of high concentration to an area of lower concentration until both concentrations are equal, or as you could more professionally call it, equilibrium. This concept is one that we have been studying in depth currently in Biology class.
The body has a buffer system that mixes of a weak acid and a weak base to resist changes in pH, it is the least efficient but it is quick. It includes buffers such as bicarbonate, phosphate, and a few proteins that help too. The respiratory system place a part too, it is a bit slower but it is more effective than the buffer system. The kidney secretion of hydrogen ions, is the most effective but is the slowest. It lowers the pH of the blood and raises pH of the urine.
4. Human function is not growth and nutrition because these aspects of life are shared with plants. It is sensible to make this exclusion if one accepts the third premise.
Most cell membranes are like that, being permeable to water and some solutes only. Osmosis is therefore the diffusion of water through a partially permeable membrane. The basic principles of diffusion apply here.
Bases or alkalis have low hydrogen ion concentration and accept hydrogen ions in solution. Acidity or alkalinity of a solution is measured by pH. Acids are constantly produced during metabolism. Several body systems are actively involved in maintaining the narrow pH range necessary for optimal function. Buffers help maintain acid bases balance by neutralizing excess acids and bases. The lungs and the kidneys help maintain a normal pH by either excreting or retaining acids or bases.
Life according to scientists is “the condition that distinguishes animals and plants from inorganic matter, including the capacity for growth, reproduction, functional activity, and continual change preceding death, also the way of life of a human being or animal.”("Life,”) In order for one to have life, one must have the nine characteristics to be considered a living thing. These nine characteristics are; all living things are made up of cells, living things are able to reproduce, living thing use energy, maintain homeostasis, respond and adapt to the environment, grow and develop, have a life span, evolve over time, and are interdependence. All of the nine characteristics have one thing in common, something that is needed for all living things to use, even if they do not know it. This beautiful thing that all living things should value is photosynthesis. Without photosynthesis there wouldn’t consist humans, animals, insects, and most importantly life!