Biology Lab 4

Tamica Mingo

Professor Dr. Carder

UMUC

· BIOL 103 6980 Introduction to Biology (2175)

June 25, 2017

1. Similarities between prokaryotic and eukaryotic cells.

Both cells have a lipid bilayer that is phospholipids and the proteins arrangement which acts as a barrier selectively between the external and the internal cell environment. Because of this, it’s essential for both selective export and import of compounds. Prokaryotic and the eukaryotic cells have the DNA (deoxyribonucleic acid) which is the base of genes. The DNA is essential for the regulation of the cell functions and therefore encodes information passed on progeny. Both the cells contain ribosomes that usually gives proteins to the cells. The main component of cytoplasm is cytosol found both in the eukaryotes and the prokaryotes cells. The cytosol solution normally contains various ions and organelles therefore becomes a site for numerous metabolic reactions like the synthesis of proteins.

The differences between prokaryotic and the eukaryotic cells.

The eukaryotic cells are generally considered larger as compared to the prokaryotic cells. The eukaryotic cells having 10-100um while the prokaryotic cells are 1-10um. The eukaryotic cells are usually multicellular while the prokaryotic cells are unicellular. The eukaryotic cells has nucleus that is bound by the double membrane. It usually has the DNA related roles of a large cell in smaller insertion to make sure that there is close materials proximity and improved efficiency for the cellular functions and the communication. Contrary to this, the small prokaryotic cells do not contain nucleus. The materials already are enclosed to each other and only nucleoid has the central opening for the cell in which the DNA is situated. The DNA of the eukaryotic cells is linear and is complex with the packaging proteins known as the histones before they are organized into chromosomes. On contrary to the prokaryotic cells, the DNA is circular therefore it’s not linked with the histones and is not organized to chromosomes. The prokaryotic cells are normally simpler and needs fewer genes in order to function as compared to the eukaryotic cells and therefore has one DNA that is circular and several smaller DNA known as the plasmids.

2. In the DNA in the prokaryotes is housed in the nucleus while in the prokaryotes lacking the nucleus, the DNA is housed within the cytoplasm. In the eukaryotic cells, it is seen as the genomic DNA that makes most of the cell’s DNA to be originated from the nucleus.

3. Three structures that providing protection and support in the eukaryotic cell include;

Microfilaments

Cell wall

Microtubule

Onion Root Tip: 1000X

A

B

C

D

4.

A- Chromosomes

B- Nucleus

C- Cell wall

D- Cytoplasm.

Post-lab

1. Rough and smooth endoplasmic reticulum differences

Rough endoplasmic reticulum refers to the organelle that is found in the eukaryotic cells, contains a chain of membranes which a highly folded. The organelle if usually found within the cytoplasm and functions as a site for chemical reactions. It also contains ribosomes. While the smooth endoplasmic reticulum a eukaryotic cell organelle which has a chain of membranes which are also highly folded and are usually located in the cytoplasm and it functions as a site for cellular reactions.

2. An animal cell cannot survive without a mitochondria because the mitochondria breaks down the glucose into ATP that provides energy. It also produces heat to the cell hence making it active. If the animal cell lacks mitochondria it therefore dies.

3. If the slide image shows a specimen having a cell wall with no nucleus and the mitochondria then the cell could either be an Achaea cell or a bacteria cell. These are examples of the prokaryotic cells that lacks nucleus and the mitochondria.

4. The green parts of a plant for instance the leaves usually contains chlorophyll which useful in absorbing light and utilizes this light energy to synthesize carbohydrates from carbon dioxide and water. Therefore the absorption of light only occurs on leaves of the plant but not the roots hence making the leaves green.

Molecules move from a higher concentrated to a lower concentrated areas where it diffuses evenly in the solutions when a similar concentration occurs all over the area. Osmosis involves movement of water through a semi permeable membrane. The molecules spread evenly in a similar way.

Post lab

1. In the yellow tube, the solution was hypotonic (lowly concentrated)

In the red tube, the solution was hypotonic too

In the blue tube, the solution was isotonic (same osmotic pressure)

In the green tube, the solution was hypertonic (highly concentrated)

2. The tubing that increased the most volume was the yellow tube this is because the tube carried 30% of sucrose and as put in a beaker of 3% sucrose only.

3. This experiment gave me approve that the diffusion particles moves from a highly concentrated area to a lowly concentrated area to distribute the molecules out on hand.

4. If the tube with a yellow band is put in a beaker containing distilled water, it (water) will therefore be absorbed and then be mixed with the entire solution.

5. The excess salts that gather in the cells are usually transferred to the bloodstream through diffusion process. They are then released through the skin pores inform of sweat.

6. The solution concentration in the beaker could be more than 50% for the concentration to diffuse evenly. This is because diffusion only moves molecules from a highly concentrated solution to a lowly concentrated one.

7. Both the tube membrane and the cell membrane were semi permeable thus the membranes were capable of moving across the water. The tube was synthetic and worked very well in the experiment like what the natural cell membrane could actually do.

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