Growth Afrocentric Program

What are some of the differences and similarities between cells?

Below you will find some of the topics we learned more about:

• single-celled organisms compared to multicellular organisms
  • paramecium is an example of a single-celled organism; plants, mushrooms and humans are multicellular
• cells structures and organelles
  • including cell walls, cell membranes, mitochondria, vacuoles, the nucleus, cytoplasm, chloroplasts. We looked at many of these structures under the cool microscopes at Delta College.

• specialized cells
  • muscle cells, neurons (brain cells), osteblasts (bone cells), cardiac cells (heart cells), blood cells (WBC's, RBC's)
• tissues
  • are composed of many cells like the smooth muscle tissue found in the gut, organs are composed of several kinds of tissues that perform a specific task like the small intestine where food is absorbed, systems are composed of many organs that work together to get a job done - like the digestive system.

• how autotrophs make food
  • self-feeders like plants, seaweed and algae make food by a process called photosynthesis
• how molecules enter and leave the cell
  • via the cell membrane that is semi-permeable. Semi-permeable membranes allow small molecules like water and oxygen to past through and exclude large molecules like the protein in the hamburgers we eat.

• how cells use food for energy
  • the mitochondria found in all cells burn sugars by a process called cellular respiration. Simple sugars like glucose are the bodies main fuel. Large sugars like starchs and fats like butter must be digested into smaller subunits first.
• how molecules get in and out of cells
  • one way is via passive transport which includes osmosis the movement of water from a high concentration to a low concentration & diffusion the random movement of small molecules from where there are more to where there are less.

How to do scientific research?

The biological topic we studied was: osmosis

The process we engaged in is called the: scientific method

How to design an experiment?

Ask a Question: How do molecules get into and out of cells? What is osmosis?

Come up with a Problem: How can we observe osmosis?

State a Hypothesis: If there are more water molecules in the environment surrounding a cell than inside the cell, the cell will take up water molecules by a process called osmosis.

Design an Experiement to test the hypothesis:

These are the steps that we followed:

• Gathered all our materials

• Made sure we had plenty of paper towels handy

• Measured 250 ml of water and poured this amount into three different beakers

• Put three strips of dialysis tubing in a beaker to soak and soften

• Once the tubing was soft we tied one end of each bag with string

• Measured three different amounts of corn syrup and water to make solutions of 100% water, 100% syrup and 50% syrup/water

• Used a funnel to pour solutions into each bag

• Tied bags up at other end to create a simulated cell

• Cut off excess string and weighed each bag using a balance

• Put all the bags into the water in the 3 separate beakers and recorded the time

• We weighed the bags every 5 minutes to see if they increased or decreased in weight

• Recorded the information (data) in a table

• Analyzed the data using some of the math skills we have learned

• Drew a graph of our results to demonstrate more clearly what had happened

• Used the results of our experiment to support or reject our hypothesis

How to analyze the results?

Dependent Variable: the dependent variable is the factor that will change; in this case the gain or loss of weight for each bag

Independent Variable: the factor that we manipulated; in this case we decided how much sugar to put in each bag and how long to wait between each reading

Control Group: in a scientific experiment the control group serves as a basis of comparison or standard, in this case the bag that contained 100% water was our control

Title: We decided to call our experiment - The Effect of Sugar Concentration on Osmosis

Results: most groups found that the bag with the highest sugar concentration (100% sugar) gained the most water. This indicates that more water molecules moved from outside the bag (100% H2O) into the bag since it gained the most weight. Our experiment demonstrated osmosis (the movement of water molecules from a high concentration to a low concentration) across a semi-permeable membrane. Cells follow these same rules.

What did we learn?

I learned that there are billions of cells in your body. H2O represents water. I also learned that if you put bags of sugar syrup and H2O it will not weigh the same. I looked at the cells in a microscope and some of them were moving slow and some were moving fast. Vanessa Blunt

I learned that on Earthday, people really do care about animals because when they brought out the animals they were caring for them and I like to see people taking care of animals. Charclia Jackson

I learned that osmosis is the passage of water from a region of high water concentration through a semi-permeable membrane to a region of low water concentration. I also learned that the goals of this program are to develop student's critical thinking skills through product development, inventions, and basic research methodology which will lead to career development. Darneisha

We learned tht the scientific method is a method scientists use to find the correct results to their experiment, but it doesn't always work. Artisha Longuemire

I learned that we have billions of cells in our body. We need every cell in our body because if we didn't have cells we couldn't see, hear, listen, or move. I also learned that it is good to stay healthy. Angelica Castaneda

I learned that osmosis is a movement of H2O from high concentration to a low concentration through semi-permeable cell until H2O reaches equilibrium.DeHayward Oliver

I learned that osmosis is H2O moving from a high concentration to a low concentration. In conclusion - to that an example of osmosis is say that you left something in the refrigerator with some kind of sauce on it, it would have changed into osmosis. I also learned about the scientific method and the purpose for it. Whitney Davis

I learned a lot about osmosis. I learned that it moves from a high concentration to a low concentration. The definition for osmosis is the passage of water from a region of high water concentration through a semi-permeable membrane. We used sugar and water. But like osmosis, if too much, it will not work and if not enough, it won't work. Jasmine Brewer

I learned that osmosis has a high conentration and a low concentration. Another thing I learned is when we did that experiment and used sugar and water. Tiffany M

I know a semi-permeable membrane is a very thin layer of material which allows water to pass through. Ricky Ball

How does your Delta experience apply to every day life?

Osmosis is the process associated with making your fingers wrinkle when soaked in water for a long time, making lettuce soggy over time once salad dressing has been added, and making vegetables slowly lose their crispness after salt has been added Dr. Charis

It applys to my life because I ate salad last night and I was going to put my salad in the refrigerator and eat it in the morning. I didn't, so I ate it all that night. I learned that if I would have put it in the refrigerator it would have gotten mushy. Tyisa Murphy

This applys to my life because maybe one day I will be making animal fur into clothes in a career as a fashion designer. Ernestine Lester

If you don't put food in the refrigerator, then bacteria will grow. Vanessa Blunt

This applys to my everyday life because I see people abusing animals and I think that is wrong because animals have feelings too. That is why I am so concerned about animals. Charclia Jackson

The scientific method applys to my everyday life because when you are trying to answer a very difficult math problem, you have to try different methods to find the answer. But the key thing is to keep a "backup method", so if one method doesn't work you can use the backup method. That is how the scientific method applys to my every life.

If somone ask me about osmosis, I will remember I did it in the 6th grade. Alious Griffin

It applys to my life because I have to stay healthy and some cells are bad. Some people aren't healthy and some people die from sickness. Angelica Castaneda

This applys to my everyday life because when I go out in the real world and a question pops up about osmosis, I can tell someone what osmosis is exactly. Courtney Dunn

I know how osmosis moves to a high concentration to a low concentration and how water molecules and sugar molecules work. Elashia Works

This applys to my life if I was to do an experiment on an dead animal that I found on the way home or if I want to become a scientist and do research on animals. I want to become a veternarian and study animal sickness. Joe Crockett