1. Draw a cell with both plant and animal characteristics. Label and explain the function of all organelles. Cross reference the functions and the drawing.

I am sorry, the picture for this assignment is not available because I was not able to put it on the compter.

1.Nucleus-The nucleus is the site where the nucleic acids are synthesized and it therefore directs the activities of the cell. It holds the DNA in the cell. It is surrounded by the nuclear envelope which is a membrane that prevents particles from coming into the nucleus. The particles the nucleus needs enter the nucleus thought holes in this membrane called pores. Inside the nuclear envelope is a dense, protein rich substance called nucleoplasm. The nucleoplasm contains 5 strands of chromatin, a combination of DNA and proteins. When the cell is dividing, a strand of chromatin coils up and condenses and can be seen under the microscope as chromosome. Chromosomes are the genetic info of the cell.

2. Cytoplasm-The cytoplasm is the jelly like material found inside the cell membrane. It surrounds organelles and contains water, salts, and organic molecules. The cytoplasm is in continuous motion as particles and organelles move around.

3. Protoplasm-is the cytoplasm inside the nuclear envelope (membrane).

4. Mitochondria-are large organelles that can grow, divide or fuse with each another. The mitochondrion’s are the respiration centers of the cell. They transfer the nutrients in the cell to energy and then use it when required The mitochondrion has two membranes, one is to divide it from the cytoplasm and the other (inner) has many long folds called cristae that enlarge the internal surface area, providing more space for the reaction of cell respiration to take place there.

The mitochondrion is also he place where adenosine triphosphate (ATP) is formed. ATP provides the chemical energy that drives the chemical reaction in the cell.

The mitochondria are the power houses in our community..

5 and 6. Endoplasmic reticulum-a membrane system of folded sacs and tunnels. The relative amounts of smooth and rough ER will vary in different kinds of cells. Cells that make a lot of protein will have a lot of rough ER. Smooth ER primarily functions as a intercellular highway, a path along which molecules move from one part of the cell to another. Smooth ER can also serve as a storage area for the proteins that will be exported later from the cell. An example as said earlier is an intercellular highway.

7. Ribosome-are the factories that make the polypeptide chains. Each ribosome is a spherical structure of about 15-20 nm in diameter. It is composed of three nucleic acids molecules and over 50 proteins. The ribosome is the sight of protein synthesis. The distribution of ribosome’s within a cell depend on how the proteins they produce will be used. Proteins within the cell are produced by ribosome’s that float freely in the cytoplasm. Proteins that will be exported for use outside the cell are produced by ribosome’s attached to a system of membranes called the endoplasmic reticulum.

8. Lysosomes- Are organelles within the cell that contain digestive enzymes. These small spherical organelles are surrounded by a single membrane. They exist primarily in animal and fungal cells and contain some 40 digestive enzymes. These enzymes digest sugars, dead bacteria and broken parts of the cell. Enzymes also play giant role in development, in embryo they destroy the cells creating a stump to create your finger instead of it. The lysosomes are always close to the place where the food is created.

9. Golgi Aparatus- packaging, processing ad secreting organelle of the cell. It consists of a stack of membranes or sacs filled with fluid and dissolved or suspended substances. The Golgi apparatus works like the production line in a factory the product is assembled at one end and packaged at the other. After the protein is synthesized on a ribosome, the protein passes into the interior of the ER membrane. Then it moves throughout the interior of the membrane to an area of smooth ER. There the protein is enclosed in a vesicle, or membranous pouch, that buds off from smooth ER. The vesicle migrates and fuses with a golgi sac. The contents of the vesicle are then modified as they pass from sac to sac. Finally a new vesicle is formed from the last golgi sac, which moves the cell membrane and discharges its contents outside the cell.

10. Cell Membrane-is the outer boundary of the cell and separates the cell from its surroundings and other cells.

11. Nuclear Envelope(Membrane)-A double membrane surrounding the nucleus. Substances enter and leave the nucleus thought holes in this envelope called nuclear pores. The pores form channels that allow large molecules, such as nucleic acids, to pass back and forth from the interior of the nucleus to the cytoplasm. It is made of phospholipids. It has carrier molecules in it to let the "big" substances enter it.

12. Cilia-hair like extensions on the outside of the cell , they move in unison to move the cell.

13. Flagella-a hair-like extension to make a cell move, many bacteria use this.

14. Food Vacuole- A membrane bound sack which has digestive enzymes from the lysosomes which break down the food inside of the food vacuole

15.Water Vacuoles- A vacuole which stores water for plants. The water vacuole takes up 1/3 of a plant is the water vacuole. Animal cells don’t need this because they have an aqueous environment.

16. Contractile Vacuole- It is found in paramecium. Paramecium has a problem with having too much water. This vacuole forces water out of it because it’s aqueous and has too much water.

17. Cell Wall-the rigid covering of a plant cell. It is made primarily of long chains of cellulose. The pores in the cell wall allow ions and molecules to pass to and from the cell membrane.

18.Cytoskeleton-The cytoplasm of eukaryotic cells is crisscrossed by a network of several kinds of protein fibers that supports the shape of the cell.

19. Peroxisome- Almost every eukaryotic cell contains small vesicles called peroxisomes, which are derived from the smooth ER. Peroxisomes contain several kinds of enzymes. Some peroxisomes enzymes covert fats to carbohydrates. Others alter potentially harmful molecules within the cell by forming hydrogen peroxide, H₂O₂, which is converted to water.

20. Nucleolus-A spherical body contained within the nucleus which contains all the nucleic acids and their building blocks. Animal cells usually have bigger Nucleolus that plant cells.

21. Plasmid- is a circular DNA molecule, usually found in bacteria, that can replicate independently from the main chromosome.

22. Chloroplast-contains a green pigment called phorophil that absorbs sunlight as the first step in the conversion process. Chromoplasts are same as chloroplast except they store the beta-carrotene orange color instead of the green pigment.

23. Centrioles - Organelles within the cell used for cell division. Centrioles are positioned at right angles to each other And are composed of nine evenly spaced microtubules with 3 microtubules in each bundle.

24. Microtubules- are long slander protein tubes and fine protein threads called microfiliments that help shape and support cells. Collectively they form the cytoskeleton, the frame work of the cell. They are assembled as needed and are then broken down and reassembled to form new structures. They have the ability to constrict and move materials. All animal cells capable of cell division have centrosomes located on one side of the side of the nucleus. The centrosome is a small amorphous mass which serves as a factory for the production of microtubules, which are major component for spindle fibers.

25. Macrotubules- is an assembly of microtubules in the cell.

26. Spindle fiber- As centrioles move apart, a network of protein cabels, called the spindle, forms between them. The spindle will help move chromosomes apart. Each cable is called a spindle fiber and is made of microtubules, long hollow tubes of proteins.

27. Vesicle-Membrane line storage containers. The example in our community is tanks to store natural gas, petroleum, oil.

2. Compare the organelle functions with similar functions in our community. Explain why your examples are a good choice.

1.Nucleus- An example of this would be the hard disk of a computer. This is a good example because the hard disk also holds information like DNA which runs the computer.

2. Cytoplasm- An example would be some Jell-O with fruit inside of it. The Jell-O is like the cytoplasm and the fruit would be like the organelles within the cytoplasm

3. Protoplasm- An example of this would be one of the bottles which has the lemon shapes suspended in the liquid. This is a good example because the liquid would be the protoplasm and the lemon shapes would be like the stuff within the nuclear membrane.

4.Mitochondria- An example would be the coal power plant which gives power to one-third of Salt Lake City. This is a good example because the mitochondria also gives power to the cell.

5. Rough ER- An example of this would be a highway with pathways. This is a good examples because molecules move along the Rough ER to get to other parts of the cell but there are ribosome’s in the way which serve as pathways.

6.Smooth ER- An example of this would be just a highway. This is a good example because the smooth ER allows molecules to travel to parts of cells.

7. Ribosome’s- An example in the community would be a factory. This is a good example because Ribosome’s are the factories in cells that make polypeptide chains.

8. Lysosomes- An example in the human society would be the food processing plant. This is a good example because the Lysosomes within the cell also process food, etc.

9. Golgi Apparatus- An example in the community is a packaging and shipping plant. The Golgi Apparatus also packages organelles into vesicles and ships them to places.

10. Cell Membrane- An example would be the borders between states. The borders also serve as boundaries for each state. You can also exit or enter the states by means of roads like the different methods of the cell membrane.

11. Nuclear Membrane- An example would also be an border of a city. The city lies within the state just like the nuclear membrane within the cell and the city also has boundaries to enter and exit through like the Nuclear Membrane.

12. Cilia- An example of this would be a series of rows on a rowboat. The rows also move in unison to move the boat around.

13. Flagella- An example of this would be the propeller of an engine. The propeller is an extension to the boat by which it moves just like the flagella.

14. Food Vacuole- An example of this would be your stomach. Your stomach also stores food and breaks it up by digestive enzymes like the food vacuole.

15. Water Vacuole- An example of this would be the water supply to a city or town. This water supply holds the water for the city or town just like the water vacuole holds the water for the cell.

16. Contractile Vacuole- An example of this would be the bladder. The bladder also forces water out just like the contractile vacuole.

17. Cell Wall- An example of this would be the wall of a building. This wall also surrounds the building and what is within it.

18. Cytoskeleton- An example of this would be the sides of a pool. The sides of a pool also help keep the water inside the pool and support it.

19. Peroxisome- An example of this would be gasoline engine. This is a good example because the engine also converts gasoline into energy just like the peroxisomes convert fats or hydrogen peroxide.

20. Nucleolus- Nucleolus’s example in the community would be the building of congressman. This could also be considered the center which controls the community just like inside the cell.

21. Plasmid- An example of this would be a animal. An animal can also replicate itself.

22. Chloroplasts- An example of this would be a solar power plant. A solar power plant also absorbs sunlight and then converts it into energy.

23. Centrioles- Centrioles could be considered two different political parties in the community. This is a good example because the political parties also stand apart from each other like the centrioles.

24. Microtubules- An example of this would be tent pole that support a tent. This is a good example because the frame also supports the outside wall and the tent poles are also flexible like the microtubules.

25.Macrotubules- An example would be a street gang since they are also a bunch of people who have united.

26. Spindle Fiber- An example of this would be when you pull apart some toilet paper. Fibers also seem to pull apart just like the spindle fibers on the chromosomes.

27. Vesicles- An example of this would be a shopping bag. The shopping bag is also used to carry materials to your house or some place, the material is packaged inside the shopping bag like whatever organelle inside the cell.

3. Discuss in detail all parts of a cell membrane. Explain the role of each structure and how it accomplishes this task.

To understand cell activities one must know about membranes and their functions. A cell is surrounded by a continuous membrane. It walls the cell's interior from the outer environment. The life processes go on inside the cytoplasm, or cell interior. The cell interior contains tiny organelles with membranes. These organelles include the mitochondrion (plural, mitochondria), the chloroplast (in plants only), the endoplasmic reticulum, and the nucleus. All the membranes of a cell are so thin that their width can be seen only under the extremely high magnification of the electron microscope. A membrane is constructed from two types of molecules proteins and phospholipids. They nest together to form the membrane. Both types of molecules have two surfaces. One surface, the hydrophilic one, "loves" water. The other surface, the hydrophobic one, "hates" water but likes oil. Membrane proteins and phospholipids are arranged in paired tiers, with protein tiers alternating with phospholipids tiers. Since water is a major component of the cytoplasm and also of the outside environment, the fashion in which protein and phospholipid surfaces react to water forms the unique basis of membranes. Arranged in paired tiers, the membrane molecules expose their water-loving surfaces to the water both inside and outside the cell. By contrast, their water-hating, oil-loving surfaces avoid the water by lining up opposite each other at the middle of the membrane. This tightly organized molecular arrangement is so stable that it tenaciously resists disruption. Even when disrupted by strong forces, it tries to reseal any momentary holes to keep a continuous surface. Only membrane proteins, however, are designed for membrane service. Ordinary proteins having only water-loving surfaces cannot be used in membranes. Each of the cell's organelles has its own distinctive membrane containing specific types of proteins and phospholipids. The specificity of membranes is possible because they can contain an endless variety of water-loving and oil-loving components as long as their bimodal character is kept. What does a membrane do? One of its functions is to serve as a container. Another is to act as a barrier for preventing molecules from moving into and out of a cell at random. A membrane does this by providing molecular "turnstiles" that regulate which molecules can enter and which cannot. Still another function is fulfilled by a membrane: it houses some of the cell's enzymes as well as its energy-converting "machines." The membrane enzymes, which are special proteins themselves, carry out respiration needed for energy production, active transport of materials across membranes, metabolic cycles essential for life, and many molecule-building activities. Enzymes can be easily assembled on membranes. This feature pays enormous dividends to a cell because its vital biochemical reactions are facilitated by these important proteins. The manner in which protein molecules pair together in the double-tier arrangement of membranes is akin to the way in which complementary strands of deoxyribonucleic acid (DNA) pair. Since DNA, the important molecule of heredity, directs the assembly of enzymes and other proteins by complementarily matching certain chemical groups, it is clear why complementarity plays such a major role in cellular activities. Biophysical analyses of cells, tissues, and organs rely on the electron microscope and the techniques of surface chemistry and birefringence, or double refraction. These techniques are helpful in the study of the membranes that enclose cells. Surface chemistry explores the forces at work on membrane edges. Birefringence can pinpoint the presence of certain chemicals in both the membrane and the cell by the way in which light is doubly refracted through them. Cell membranes are essential for the life of a cell. They determine what gets in and out of it. Cell membranes are only about one hundred angstroms thick. (An angstrom is one ten millionth of a millimeter.) They consist of lipids and proteins organized as tiny leaflets, two molecules thick, or as tightly packed globules. They have great selective permeability that is, they give some molecules easy access to the cell while making it very hard for others to enter. Cells receive some substances by osmosis. Simple sugars usually pass through the pore-studded membrane when the concentration of sugar molecules outside a cell is greater than that within it. Molecules and ions generally enter a cell when they are small enough to fit through the pores of its membrane, when their concentration gradient permits more of them to diffuse into the cell than out of it, and, in the case of ions, when similarly charged ions already in the cells do not repel them. In some instances, active transport helps molecules and ions to penetrate the cell membrane despite the resistance of electrochemical forces. Cell membranes seem to contain "pumps" that are energized from within the cell. These pumps may be chemical compounds that react with substances outside the cell and carry them across the cell membrane when their concentration gradients are not otherwise great enough to permit their entry. At the inner edge of the membrane, next to the cytoplasm, the carrier pump probably dissociates from the transported substance, which is then absorbed by the cytoplasm for metabolic use. Active transport processes in the membrane permit cells to regulate food absorption, hormone and enzyme secretion, and the transfer of genetic material from the cell nucleus to the ribosome’s, where protein synthesis occurs. Bioelectrical events also take place in cell membranes. Nerve impulses, for example, are generated by means of changes in the polarity of nerve-cell membranes that are electrically neutral when at rest positively charged on the outside and negatively charged on the inside. An inflow of sodium ions positively charges the interior of the nerve cell. As the impulse passes along the nerve fiber, positively charged potassium ions are "pumped" out of the cell, restoring the nerve-cell membrane to its normal, neutral state.

4. Contrast with examples osmosis and diffusion. Show how these processes work in humans. Use examples!

Particles move in or out of a cell by passing through the cell’s plasma membrane. Passive transport is the movement of a substance through a cell’s membrane without the expenditure of cellular energy. Substances pass into or out of your cells by way of several different passive transport processes.

If you were submerged within a drop of water, with your body no bigger than a protein, what would you see? Water molecules as big as basketballs would be zipping around, many of them bashing into you! Molecules do not stand still; they are in constant motion. Water molecules and particles dissolved in water more randomly. Their path is not predictable.

This random movement of individual dissolved particles within water has an important consequence that is predictable, however. Since the movement is random, a particle them (an area of high concentration) to an area where there are fewer of them(an area of lower concentration). This net movement of particles from an area of high concentration to an area of lower concentration is called diffusion. In your lungs, oxygen diffuses into the bloodstream because there is a higher concentration of oxygen molecules in the lung’s air sacs than there is in the blood. Eventually, dissolved particles diffuse within a liquid until they fill the volume uniformly, as if you drop a lump of sugar into a beaker of water, the sugar particles will diffuse and become evenly distributed throughout the water. At this point the system can be described as being in equilibrium, the situation that exists when the concentration of a substance is the same throughout a space. A substance that dissolves in another is called a solute. Sugars, amino acids, and ions are all solutes in cells. The more plentiful substance that dissolved the solute is called the solvent. In cells, the solvent is water. The mixture of solutes and solvent is called a solution.

Solute and solvent particles tend to diffuse from areas where their concentration is high to areas where their concentration is lower. Now imagine that a membrane separates two region of a liquid. As long as solute particles and solvent(water) molecule can pass freely through the membrane, diffusion will soon equalized the amount of solute and solvent on the two sides. Equilibrium will be reached. But what if a polar solute is added to one side and it cannot pass through the membrane? This situation arises in cells all the time. An amino acid cannot cross a lipid bilayer, and neither can an ion or a sugar molecule. What happens? Unable to cross the membrane, the polar solute particles from hydrogen bonds with the water molecules surrounding them ,as the addition of solutes to one side of a membrane reduces the number of water molecules that can move freely on that side. This is because the water molecules become bound to solute molecules. Water then moves by osmosis from the side where water molecules concentration is higher to the side where their concentration is lower. These "bound" water molecules are no longer free to diffuse through the membrane. In effect, the polar solute has reduced the number of free water molecules than the side with the polar solute. As a result, water molecules move by diffusion from the opposite side toward the side with the polar solute. Eventually, the concentration of free water molecules will equalize on both sides of the membrane. At this point, however, there are more water molecule (bound and unbound) on the side of the membrane with the polar solute. Net water movement through a membrane in response to the concentration of a solute is called osmosis. Stated another way, osmosis is the diffusion of water molecules through a membrane in the direction of higher solute concentration. As a result of osmosis, extra water molecules accumulate inside the cell, they will exert a pressure that can become very great – great enough to burst the cell! Osmotic pressure is the increased water pressure that results from osmosis. Cells with strong cell walls (like plants and fungi cells) can withstand high interval osmotic pressures.

5. Explain the terminology used to describe varying concentrations of solute when describing osmosis.

A cell immersed in pure water is said to be hypertonic with respect to the surrounding solution because the call has a greater concentration of solutes. The surrounding solution, which has a lower concentration of solutes than the cell , is said to be hypotonic. Most of your body cells and the tissue fluid that circulates around them are said to be isotonic because the concentration of solutes in the cell and fluid is the same.

The effect of osmosis on animal cells is shown below:

6. Explain active transport. Use examples to explain the situations when active transport is needed.

If facilitated diffusion were the only tool cells had to harvest particles from the environment, they would have serious problems. Many amino acids and sugars are even more scarce outside cells than inside. Facilitated diffusion of these particles would result in their pouring out of cells, an event that could affect cellular protein synthesis and energy production. Recall that amino acids are the building blocks of proteins, and sugars are a major energy source for cells. Cells must have a way to beat the diffusion game so that they can maintain their concentration of these important food molecules at a level different from the concentration level outside the cell. Interplay between several important transport mechanisms in cell membranes enables cells to maintain a high interval level of amino acids and sugars. Proton pumps cause the production of ATP molecules, the energy currency of the cell. Coupled channels carry the sodium ions, along with food molecules, back inside the cell. Proton pumps and sodium-potassium pumps are highly specialized protein channels. As you will see, both use energy to transport ions (charged particles) against a concentration gradient (toward the side of higher particle concentration). Using energy to transport a particle through a membrane against a concentration grading is called active transport.

A proton pump is one type of active transport channel. Proton pumps actively transport protons through the internal plasma membranes of mitochondria and chloroplasts. A proton is a hydrogen atom that is missing its electron. Proton pump channels are used to make ATP from ADP. ATP is the cell’s key energy-storing molecule. This active transport of protons to make ATP is called chemiosmosis. All the energy harvested by plants in photosynthesis and practically all the energy you get from the food you eat is derived from chemiosmosis.

A second kind of active transport channel is called a sodium-potassium pumps. A sodium potassium pump uses energy stored in the form of ATP to power active transport of sodium ions (Na⁺) out through a cell’s membrane. The action of the sodium-potassium pump is the most important energy using process in your body. More than one-third of all the energy expanded by a human cell that is not actively dividing is used to transport sodium ions in this way!

Why do cells use so much of their energy pumping sodium and potassium ions? For one thing, nerve cells use the differences in sodium and potassium ion concentrations produced by sodium-potassium pumps to send signals throughout the body, like electrical signals passing over wires. Sodium-potassium pumps also help to transport food particles into cells.

The transport of many food particles and a variety of other particles into your cells involves two different kinds of channels. One of the channels is the sodium-potassium pump. The other channels are coupled channels. In the first step, the active transport of sodium ions out of the cell by the sodium-potassium pump increases the sodium ion concentration outside the cell. Each channel is capable of transporting as many as 300 sodium ions per second when working full tilt. The fact that there are so many sodium ions outside the cell due to the action of the sodium-potassium pump leads to the second step: sodium ions move back into the cell by means of coupled channels that also carry sugar molecules. The coupled channel has two passageways through the membrane, both of which must be used for the channel to work. Imagine the two passageways a s two turnstiles attached to the same gear. One passageway fits a particular molecule, such as a sugar molecule. The other fits sodium ions. Because there are so many sodium ions outside the cell due to the action of the sodium-potassium pump, sodium ions will diffuse back into the cell. The force of their entry is so great that it pulls sugar molecules into the cell too, even though the cell interior already has a generous supply of sugar. Just as it takes two hands to clap, so it takes two membrane channels to actively transport many food particles into the cells of your body. This two-step transport process is one of the most fundamental and important activities of the cell.