Biology Lab need done

Your third lab deals with cellular biology.  Remember that "the cell is the basic unit of life" and, therefore, you must become very familiar with cellular structure and function.  Eukaryotic cells contain a number of smaller units – organelles – each one of which has very specific jobs to do. You may think of a cell as a factory: 

The nucleus is the “administrative office” from which directions go out for production. The nucleus contains the genetic material. Then, there is the ribosomal, or rough, endoplasmic reticulum, the site of polypeptide production.  The smooth endoplasmic reticulum puts lipids together. The Golgi bodies are the packaging and storage sites, where polypeptides are put together into functioning proteins. Lysosomes are in charge of removing waste products. All of this work requires energy, which is produced by the mitochondria. You will find additional structures that also have specific functions.

Before you begin with any lab work, please read the Introduction section of your Lab Manual very carefully. The first cells to develop were the very small and quite simple prokaryotes. Fossils of such early cells have been found and they have been dated to over 3.8 billion years ago! This is almost a billion years after the earth first formed from solar dust. About two billion years later, the first eukaryotes appeared. Compare the two cell types very carefully in terms of their structure and function. On pages 40 and 43 (of your lab Manual), you will find a useful list of structural comparisons. You should be able to interpret the functional differences from this information!

Looking at eukaryotes, you will discover that there are significant differences between plant and animal cells, which are based on different functions. Plants photosynthesize, that is, they make the basic chemical energy – glucose – required for all metabolic functions from two inorganic substances: carbon dioxide (CO2) and water (H2O). Carefully look at all the physical differences between these two cell types and then interpret these differences in terms of ‘function’. In other words, there are good reasons for these differences, because plants and animals have different lifestyles with different needs.

Experiment 1: Identifying Cell Structure

After you have thoroughly familiarized yourself with the structure and function of cells, try to answer carefully and in detail the nine questions. (No materials required.)

Experiment 2: Direction and Concentration Gradients

In this experiment, you will test how the concentration of a solute will affect osmosis. A semi-permeable membrane is necessary for osmosis to occur, and cells have such membranes. Water is the actor in this scenario.

You will need the following items from your lab kit: 30% sucrose solution, 3 250ml Beakers, 4 15cm long each of dialysis tubing (it is flat!), 4 colored beads, and 8 small rubber bands. You will find the dialysis tubing, beads and rubber bands in a small plastic bag, labeled Cell Structure & Function – Osmosis. You will have to supply the water and a reliable watch. The plastic dialysis tubing is flat, and before you begin your work with the four pieces of tubing, you will have to soak them first in water, in order to open them. Simply follow the instructions and don’t hurry through this exercise – give yourself plenty of time!

Have fun with this lab and be sure to involve your family or friends!