Unit 1 Cell Biology: Properties & Roles of Water Questions

1. Explain how ions of otherwise neutral compounds are formed.
"Ion" refers to an excess or deficiency of electronic charge. Ions are formed when an atom gains or loses an electron, meaning the atom will no longer be neutral. Atoms with more protons are positive, and atoms with more electrons are negative.
Example: dissolve salt in water and it will dissociate into sodium and chlorine ions.

2. Discuss the nature of covalent bonding using water as an example.
Water is a covalent bond because the two hydrogen's in H2O share the outer electrons with oxygen.

3. Describe the difference between polar and non-polar covalent bonds.
Polar bonds in my memory trick are "greedy" bonds that have one atom that is electronegative and the electrons are shared unequally. Non-polar bonds (not greedy bonds) are symmetrical and  share electrons equally.

4. Illustrate what is meant by a hydrogen bond.
(already posted on blog)

5. Distinguish between organic molecules and inorganic ones.
Organic compounds must have carbon and hydrogen. Example:  carbohydrates, proteins and lipids.
Inorganic compounds have either one or none of carbon and hydrogen. Water is inorganic as it only has hydrogen and carbon dioxide is also inorganic

6. Discuss how water dissolves substances like table salt and sugar.
Water is a polar solvent, that when introduced to salt rips apart the molecule by  connecting its negative charges to the positive ones in salt (and positive charges with salts negative charges) ultimately seperating the salt pieces and dissolving it in the water.

7. Describe the difference between hydrophobic and hydrophobic substances. Explain the reasons for the difference in their chemical behavior.
A hydrophilic material is a friend of water. Friends like to come closer, so a water droplet would spread on a hydrophilic surface.  A material that is hydrophobic would be afraid of water, it would stay away from water as if it had a "phobia" (phobic) of water.

8. Explain the process of hydrophobic interaction.
Hydrophobic, nonpolar substances have a tendency to repel water molecules. The name, literally meaning "water-fearing," this explains the segregation between water and nonpolar substances. This interaction explains the separation of a mixture of oil and water.

9. Identify the role that water plays in many cellular chemical reactions.
Acids: Sour tasting, pH lower than 7, create H ions

Water plays a very important role in cellular chemical reactions, that for example support plant life. Water is very important to cellular respiration and photosynthesis in plant leaves. Without those reactions and water, plants would not be able to survive. 

10. Define acid, base and relate them to the pH scale.
Acids: Sour tasting, pH lower than 7, create H ions
Bases: (alkaline) feel slipper, pH higher than 7, create OH ions



 11. Discuss the theory of "buffering" and explain why the process is important to maintenance of cells.
Buffers and "buffering" are very important to cells because without them, a cell could easily become too acidic or to basic. Either way, it is harmful to the cell, as it should be at a pH of 7.4. Buffers balance out the pH to a reasonable limit within a substance including cells.

12. Identify the 3 unique properties of water in terms of temperature change and relate theses characteristics to the presercation of cells.
-Water has a high specific heat, which is the amount of energy required to change the temperature of a substance. Because water has a high specific heat, it can absorb large amounts of heat energy before it begins to get hot. It also means that water releases heat energy slowly when situations cause it to cool. Water's high specific heat allows for the moderation of the Earth's climate and helps organisms regulate their body temperature more effectively.
-Water conducts heat very easily, cuasing large bodies of liquid (lakes, oceans) uniform temperature profile. Meaning that organisms won't boil or freeze rapidly.
-Water is a solvent that is able to dissolve a large number of different chemical compounds. This feature also enables water to carry solvent nutrients to plants and living organisms.

13. Discuss the importance of the unusual nature of water as a solid, to the living things.


14. outline the importance of the cohesiveness of water to animals and plants.
Waters cohesiveness is extremely important to animals and plants because humans for example are made of 60% water, and plants move water around their stems to survive. Water is able to stick together with hydrogen bonds and move in a continuous stream which is beneficial to a living organisms survival. 

Ph Buffers

Hydrogen Bonds in water

Cell questions Part 2

11. Describe the different structures and techniques that cells employ to move themselves from place to place OR to move material over their surfaces
-Previously explained

12. Review the stages of mitotic cell division
Mitotic cell division is a process in which a eukaryotic cell separates the chromosomes in its nucleus into two identical sets in two separate nuclei. Then cytokinesis divides the nuclei,  cytoplasm, organelles and cell membrane into two roughly equal cells. (The division of the mother cell into two daughter cells)

13. Explain the differences between animal and plant cells

14. Describe the difference between light microscopes and elctron microscopes
Both electron and light microscopes are technical devices which are used for visualizing structures that are too small to see with the naked eye. Electron microscopes have higher resolutions and are therefore are also capable of a higher magnification (up to 2 million times), but it is nearly impossible to observe living organisms. Light microscopes on the other hand are able to view living organisms. 

15. Identify some of the advantages and disadvantages of electron microscopy.
-Advantages: Depending on the type of microscope, it is possible to view the three dimensional external shape of an object
-Electron microscopes have a greater depth of field compared to light microscopes
-Disadvantages: Sample preparations are much more complex
-Difficult identification of objects
-Can not view in color, and microscopes are expensive.

Unit 1 Cell Biology, Cellular Structure and Function Questions

1. Identify the 3 principles of modern cell theory
-All organisms consist of one or more cells.
-The cell is the basic unit of structure for all organisms.- All organisms are composed of cells.
-All cells arise only from preixisting cells.

2. Explain the factors that limit the size of a cell
The ration of volume to cell surface is the biggest factor. If the cell gets too big, it will take too long to transport necessary molecules form the cytoplasmic mebrane or nucleus out to the environmment or vica versa. The size is usually per-determined by genes encoded in the DNA.

3. Explain the differences between eukaryotic and prokaryotic cells.
Eukaryotic cells are more complex with specialized organelles, while Prokaryotic cells are more simple that lack a nucleus, and any other membrane bound organelles. For example bacteria are prokaryotic organisms animals and plants are eukaryotic.

4. Relate the structure to the function of the nucleus in eukaryotic cells.
- The nucleus contains the DNA. It is the site for replication and transcription; the most important processes of a cell.

-Attached to the nucleus's outside membrane, there are the ribosomes (found free in Cytoplasm and on the Rough endoplasmic reticulum, creating the rough texture)

-The nuclear envelope encloses the genetic material

5. Describe the differences and similarities in membrane structure in various organelles
The ultimate purpose of a membrane is the same in all organelles, like the whole cell membrane seperates the interior of the cell from the outside environment in the organism. The cell membrane is selectively permeable to organic molecules, ions and controls the flow of substances in and out of the cell. Compared to the endoplasmic reticulum is an extensive membrane network of lace like cisternae ( flattened membrane disks that make up the golgi apparatus). The endoplasmic reticulum is an extensive membrane network of  cisternae held together by the cytoskeleton.

6. Explain the relationship between the endoplasmic reticulum and the golgi apparatus
Rough ER has ribosomes attached to it and is an extensive network of folded membranes with interconnected tubes and sacs. After ribosomes synthesis proteins, the proteins are transported through the rough ER. The proteins are enclosed in a vesicle and then transported to the Golgi apparatus where the processing, packaging and transport of protein is done. After the protein is processed, it will bud off from the Golgi apparatus as vesicles and be transported to the place where it is needed.

7. Trace the path of food particles from the outside of the cell would take to the mitochondrion where it is metabolized
Particles will enter the cell through the cell membrane, floats around in the cytoplasm where it is then brought to the mitochondria. Inside, the whole purpose is to break down the particles into ATP (cell food/energy) so the cell has enough energy needed to live.

8. Explain the origins of mitochondria and chlorplast using the endosymbiotic hypothesis
The endosymbiotic theory involves the mitochondria, chloroplast, and possibly other organelles of eukaryotic cells. According to this theory, certain organelles originated as free-living bacteria that were taken inside other cell as endosymbionts (any organism that lives within the body or cells of another organism.) Mitochondria developed from proteobacteria (major phylum of bacteria) and chloroplasts from cyanobacteria (phylum of bacteria that obtain energy from photosynthesis- algae)

9. Discuss the various ways that cells support themselves and maintain a recognizable shape and form
Cells support themselves in different ways that ultimately create the shape of the entire cell. For example plant cells have rigid green cell walls that support the whole rectangular shape of each cell. In animal cells, the cytoskeleton serves as the skeleton for the "body" of the cell.

10. outline the various ways in which cells conduct the internal movement of materials and structure from one place to another
A flagellum (tail-like structure that protrudes from the cells body) occurs in certain prokaryotic and  eukaryotic cells, and allows cells to move.