independent, dependent, and controlled variables for report? help

[carefulcare]

I have a lab report due over anatomy physiology II and I am confused. Digestion of protein:

we used pepsin (Acidic) as the enzyme and the substrate albumin. Biuret was the reagent. Please help. Temperature also played a role with the digestion. what are the variables? when I went to the science tutors for lab they told me

"people make it more complicated than it really is. just put it in plain words."

That was all the assistance I got from the tutors. HELP

[lilgop]

Did you vary any of the factors? Like in one case was the temp. higher than in another case?

[carefulcare]

YES, one test tube at room temp. one test tube with pepsin and albumin at body temp with no hcl. one test tube at body temp with hcl, pepsin, and albumin. and one test tube on ice with hcl, pepsin, and albumin

[carefulcare]

Did you vary any of the factors? Like in one case was the temp. higher than in another case?

Yes, one test tube at room temp. one test tube with pepsin and albumin at body temp with no hcl. one test tube at body temp with hcl, pepsin, and albumin.

and one test tube on ice with hcl, pepsin, and albumin

[carefulcare]

i still need help

[DidiRN]

Moved to Nursing Student Assistance for best response.

[Esme12, ASN, BSN, RN]

I am so far removed from this.....I'll try to help when my kids get home.....they'll know the answer.

In the meantime.....look here. this may help..

Scientists use an experiment to search for cause and effect relationships in nature. In other words, they design an experiment so that changes to one item cause something else to vary in a predictable way.

These changing quantities are called variables. A variable is any factor, trait, or condition that can exist in differing amounts or types. An experiment usually has three kinds of variables: independent, dependent, and controlled.

The independent variable is the one that is changed by the scientist. To insure a fair test, a good experiment has only one independent variable. As the scientist changes the independent variable, he or she observes what happens.

The scientist focuses his or her observations on the dependent variable to see how it responds to the change made to the independent variable. The new value of the dependent variable is caused by and depends on the value of the independent variable.

For example, if you open a faucet (the independent variable), the quantity of water flowing (dependent variable) changes in response--you observe that the water flow increases. The number of dependent variables in an experiment varies, but there is often more than one.

Experiments also have controlled variables. Controlled variables are quantities that a scientist wants to remain constant, and he must observe them as carefully as the dependent variables. For example, if we want to measure how much water flow increases when we open a faucet, it is important to make sure that the water pressure (the controlled variable) is held constant. That's because both the water pressure and the opening of a faucet have an impact on how much water flows. If we change both of them at the same time, we can't be sure how much of the change in water flow is because of the faucet opening and how much because of the water pressure. In other words, it would not be a fair test. Most experiments have more than one controlled variable. Some people refer to controlled variables as "constant variables."

..http://www.sciencebuddies.org/science-fair-projects/project_variables.shtml

[nurseprnRN, BSN, RN]

Plain words also means, "Describe it in ordinary English."

First we did this.

Next we did this.

When we changed this, this happened differently in this way.

[Esme12, ASN, BSN, RN]

brain fog.....thanks grntea

[tokebi]

Independent variables are factors (or conditions) that you control in your experiment.

Dependent variables are the the outcome you see as a result of the independent variables you introduced to the experiment.

In other words, "dependent variables" depend on the "independent variables."

Now in your experiment, the substrate, the enzyme and reagent used were all identical in each test tube. But there are couple of things you identified that you did differently. Can you see them as "variables?" And what kind of variable would they be? If you saw any different results in the test tubes, what kind of variables would that be?

[tokebi]

Oops, basically what Esme said above. Nice website!