BIO 151L exam 1 study guide

Both cellular respiration and fermentation begin with what molecule?

glucose

What gas do organisms give off when they carry out cellular respiration?

CO2

Both aerobic respiration and anaerobic fermentation provide what molecule needed by cells?

atp?

Products of aerobic respiration

carbon dioxide, water, and ATP

products of anaerobic fermentation

2 atp, lactic acid

List the seven steps, in order, that you would take to conduct an experiment begining with "Make an observation".

1. make an observation

2. form a hypothesis

3. experimental design

4. collect data

5. analyze/ present data

6. make conclusions

7. repeat

What is the difference between a null and an alternate hypothesis? Give an example of each.

A null hypothesis tells that there is no relationship between the independent and dependent variables. An example of a null hypothesis is that the age of an individual does not affect their ability to do the math. An alternate hypothesis tells that the independent variable does affect the dependent variable (the two variables have a correlation). An example of this would be that the age of an individual does affect their ability to do the math.

...what is the independent variable?

The independent variable is the condition that is varied by the investigator during the experiment.

...what is the dependent variable?

The dependent variable is the response you are measuring

...what are the constant variables?

The constant variables are all of the other variables within the experiment, that are not changed.

...what is the experimental treatment?

The experimental treatments are the groups subjected to change in the independent variable.

...what is the control treatment?

The control treatment is the group that is given "normal" or "standard" conditions, not being subjected to changes in the independent variable.

Identify the dependent and independent variables in the following experiments:

observing the number of nests built by birds in trees that have different densities of limbs.

The independent variable is the different densities of tree limbs. The dependent variable is the number of nests built.

Identify the dependent and independent variables in the following experiments:

Length of a regenerating limb of a starfish measured for 4 weeks

The independent variable is the 4 weeks the starfish is being measured for (time).The dependent variable is the length of regenerating limb of a starfish.

Identify the dependent and independent variables in the following experiments:

Amount of weight loss for patients taking three different doses of a new medication.

The independent variable is the three different doses of a new medication. The dependent variable is the amount of weight loss for the patients.

Suggest a control treatment for each of the following experiments:

Plants are exposed to different intensities of light and the amount of oxygen produced during photosynthesis is recorded.

The control treatment for this experiment could be plants exposed to regular daylight.

Suggest a control treatment for each of the following experiments:

Frogs are captured from polluted ponds. The investigator records the number of limb deformities.

the control treatments for this experiment could be the same species of frogs captured from non-polluted lakes.

Suggest a control treatment for each of the following experiments:

Patients taking different doses of a new medication were monitored for weight loss.

The control treatment for this experiment could be patients taking no dose of new medication and/or a placebo of the medication.

A scientist wants to study mating behavior of deer. She observes deer during mating season to obtain data. For each male, she counts the number of male male fights that he wins and then the number of females that the male mates with. She expects that males who win the most fights will mate with the most females.

Design a null and alternate hypothesis for this study.

The null hypothesis would be the number of fights a male deer wins will have no effect on the number of females that deer mates with.

The alternate hypothesis would be the number of fights a male deer wins will have an effect on the number of females that deer mates with.

A scientist wants to study mating behavior of deer. She observes deer during mating season to obtain data. For each male, she counts the number of malemale fights that he wins and then the number of females that the male mates with. She expects that males who win the most fights will mate with the most females.

What is the independent variable?

The independent variable is the different numbers of fights the male deer won

A scientist wants to study mating behavior of deer. She observes deer during mating season to obtain data. For each male, she counts the number of malemale fights that he wins and then the number of females that the male mates with. She expects that males who win the most fights will mate with the most females.

What is the dependent variable?

The dependent variable is the number of female deer the male deer mates with

Which of the following statements is/are true?

A. Hypotheses and predictions can be proven or disproven.

B. Hypotheses are usually more general statements, while predictions are more specific.

C.Experiments are always designed after the hypotheses have been created.

D.Predictions are usually more general statements, while hypotheses are more specific.

BC

Now, using the information you just learned, apply it to the following 5 questions to make sure you fully understand it. Which of the following is not an accurate description of a null hypothesis?

A. It is presumed to be true until it is refuted by results supporting the working hypothesis.

B. It states that no relationship exists between the dependent and independent variables.

C. It serves as a baseline hypothesis against which the working hypothesis can be compared.

D. It is generally considered less likely to be true than the working hypothesis.

D

Which of the following statements best describes a prediction as it relates to a hypothesis?

A. A prediction is used to develop a working hypothesis.

B. A prediction is a specific description of a subject's behavior based on a hypothesis.

C. A prediction is a looser, less-developed version of a working hypothesis.

D. A prediction is untestable, whereas a hypothesis is testable.

B

Which of the following choices shows the correct order of development for a scientific prediction?

A. experimental purpose, scientific hypothesis, prediction

B. prediction, experimental purpose, scientific hypothesis

C. scientific hypothesis, prediction, experimental purpose

D. experimental purpose, prediction, scientific hypothesis

A

suppose you are studying the effect of sunlight on tomato plants and have developed the hypothesis, "Sunlight has an effect on the growth of tomato plants." Which of the following statements would be an appropriate null hypothesis?

A. Sunlight will decrease the rate of growth of tomato plants.

B. Tomato plants are affected by factors other than sunlight.

C. The effect of sunlight on tomato plants cannot be tested.

D. Sunlight has no effect on the growth of tomato plants.

D

Suppose you are studying the effect of sunlight on tomato plants and have developed the hypothesis, "Sunlight has an effect on the growth of tomato plants." Which of the following statements could not be used as an experimental prediction?

A. If tomato plants are exposed to increased amounts of sunlight, then the growth rate of the tomato plants will decrease.

B. If tomato plants are exposed to decreased amounts of sunlight, then the growth rate of the tomato plants will decrease.

C. If tomato plants are exposed to increased amounts of sunlight, then the growth rate of the tomato plants will increase.

D. If tomato plants are given increased amounts of fertilizer, then the growth rate of the tomato plants will increase.

D

List two things you should never do when using a serological pipette.

1. You should never contaminate the tip of the pipette by placing it on the table or touching the tip.2. You should never let the fluid enter the cotton plug/suctioning bulb.

List two things you should never do when using a micropipette.

When using a micropipette you should never measure the liquid without a tip and you should never touch/contaminate the tip.

After setting the volume on your adjustable micropipette to 20 μL, explain the proper method of using the pipette to be sure you are actually transferring 20 μL of liquid.

First, you tightly secure a tip to the pipette without using your hands, to prevent cross-contamination. Then you push down the pipette syringe to the first gage. Next place the tip of the pipette into the liquid, making sure not to touch anything else on the way. Once the pipette is inserted into the liquid, slowly release your grip on the syringe all the way, slowly watching the liquid enter the tip. Once your grip is completely loose, remove the tip from the liquid, and tap off any drips from the tip into the beaker. Compare the liquid measured to the image provided to ensure the appropriate amount was collected. Then transport the micropipette to the designated location. To release the liquid, push down on the syringe to the first gauge until all the liquid is out. Once all the visible liquid is out, press the syringe all the way down in order to make sure every last bit of liquid was removed from the micropipette. Once you are finished with the tip, you can click the dispensing button which releases the tip in a hand-free manner.

What does a spectrophotometer actually measure? Be specific.

A spectrophotometer actually measures the amount of light, of a specific wavelength, that passes through a solution

The graph below is a standard curve showing absorbance vs. protein concentration using a Bradford assay. You are given a solution with an unknown amount of protein in it. You read the absorbance of that solution in a spectrophotometer and find it to be 0.8. Based on the standard curve below, what is the estimated concentration of the protein solution?

If the absorbance is 0.8, then the estimated concentration of the protein solution would be 1.5 mg/ml.

The two types of microscopes you will learn about in this lab are called _________ and ____________ light microscopes.

simple compound

The difference between these two types of microscopes is the number of _________ they possess.

lenses

When focusing your microscope, you must NEVER use the _________ focus knob when using the ____________ lens.

coarse high power

What amount of volume does the symbol "µl" designate?

microliters

0.345 milliliters is equal to _____ microliters.

345

When a solution is placed in a path of light, three things may occur to the light when it hits the solution. The light may be ____________ , ___________ , or ______________.

transmitted scattered absorbed

The instrument that is used to measure the amount of light absorbed by a substance in solution is called a

spectrophotometer

The previous question was just a convoluted mathematical way of saying "the more stuff there is dissolved in a solution, the less light will be able pass through it".

true

If we were to replace the solution in the rectangular cuvette in the image from question 8 with a solution of higher concentration, would you expect the detector to return a higher or lower absorbance reading than the solution currently shown?

Higher absorbance reading returned for a more highly concentrated solution

Solutions, by definition, are made up of two components:

solvent solute

The cellular structure involved in controlling the concentration of solutes within the cell is the

plasma membrane

The main molecule that makes up a cell's plasma membrane is the

phospholipid

The major difference between active and passive transport is the requirement of

energy

The terms of tonicity are relative terms, which means you cannot simply say "This solution is hypertonic", you must say "This solution is hypertonic when compared to that solution".

true

Graphing data often helps you understand experimental results in a way that staring at a column of numbers never could. Trends, outliers, and gaps in the data are all easier to detect graphically. In addition, variables that cannot be measured directly in the lab may also be determined from a graph of the measured variables. When presenting data in a lab report or research article, you never present ______________ , but rather an analyzed, summarized form that is more easily understood.

raw data

As you learned in week one, most experiments focus on two variables at a time, the independent variable (the cause) and the dependent variable (the effect). The dependent variable is the one the researcher is interested in, and the independent variable is often one that the researcher controls. For example, suppose that a researcher feeds several mice different meals. Each meal is identical, except for the amount of sugar present. Then, the researcher measures the blood sugar levels of the mice one hour later. In this case, the ________ in the meals is the independent variable and the ________________________ is the dependent variable.

sugar blood sugar levels

Sometimes, experiments are performed where the independent variable is not directly controlled by the researcher. You performed one of the most common experiments like this in the last lab (and will perform another like it in your next lab) in which time served as the independent variable. To use the example from above, suppose that rather than taking one blood sugar measurement after one hour, the researcher takes one of the mice and tracks its blood sugar level over time by taking measurements every five minutes. The researcher does not control time, of course, but the blood sugar level of the mouse is thought to depend on the time between the feeding and the measurement. In this experiment, there are two independent variables, ________ and ________ .

sugar time

List the four major groups of organic molecules that construct all living things (the four main building blocks of a cell).

carbohydrates lipids proteins nucleic acids

This lab will focus on one specific group of these organic molecules, the proteins. Specifically, a subset within the proteins called enzymes. With regard to enzymes, determine whether the following statement is true or false.All enzymes are proteins, but not all proteins are enzymes.

true

All chemical reactions, by their most basic definition, are just the breaking apart or putting together of molecules and atoms. All living organisms, by their most basic definition, are just an organized, compartmentalized set of chemical reactions. If left to occur on their own, most chemical reactions occur at rates so slow, life-sustaining processes would not be possible. Bringing enzymes into the picture changes everything. Enzymes speed up chemical reactions by bringing together the correct reactants and forcing them into the correct products. This can mean the reactants are broken down into two or more smaller products or combined into one bigger one. Either way, without enzymes performing this function, life would not be possible. Scientifically, we say that enzymes are in the business of lowering the amount of ____________ required to start a chemical reaction.

energy

The position on the enzyme where the chemical reaction takes place (highlighted in the image above) is called the ______________.

active site

In lab this week, you will be studying various environmental effects on the performance of peroxidase, an enzyme that breaks hydrogen peroxide into two separate molecules: _________ and __________.

oxygen water

Organisms that manufacture their own "food" (i.e. energy packed organic molecules) from inorganic molecules are called

autotroph

Organisms that must collect their "food" (energy packed organic molecules) from an outside source are called

heterotroph

One way that autotrophs power the manufacture of their own "food" is by using the energy found in light waves. This, as you know, is called photosynthesis. What organelle must exist in autotrophs for them to conduct photosynthesis?

chloroplast

What organelle must be present in an organism for it to conduct respiration to create ATP?

mitochondria

Photosynthesizing organisms have cells that contain

both mitochondria and chloroplasts

The layer of cells within a leaf that houses most of the chloroplasts is called the

mesophyll

Photosynthetic reactions in plants occur in two separate reactions, the ______________ reactions and the _______________________ reactions.

light dependent light independent

Match the wavelength of light with its corresponding color.

A. 510

B. 475

C. 650

A green

B blue

C red

The main goal of respiration is the production of _________ , which is most often stored in the chemical bonds of the molecule __________ .

energy atp

The three main steps of aerobic respiration, in their order of use, are __________ , the ________________ , and the _____________________________ .

glycolysis citric acid cycle electron transport chain

Which is more efficient (i.e. creates more energy for the cell), respiration or fermentation?

respiration

Order of scientific process

observation, hypothesis, design experiment, collect data, analyze data, conclusion, repeat

step one of the scientific process

make an observation (my plants are dying)

step two of the scientific process

form a hypothesis (null and alternative)

null hypothesis

the independent does not affect the dependent

alternative hypothesis

the independent does effect the dependent

hypothesis

the general statement about how you expect your experiment to go

step three of the scientific process

experimental design (independent, dependent, constants, treatments)

independent variable

The experimental factor that is manipulated (color of light)

dependent variable

The measurable effect, outcome, or response in which the research is interested (plant growth)

constants

Conditions that stay the same in the experiment

experimental treatments

Alternative manipulations of the independent variable being investigated

control groups

groups whose members do not obtain the treatment, while other conditions are held constant

step four of the scientific process

data collection

step five of the scientific process

analyze/ present data

never present...

raw data, this includes numbers and math

simplest statistical analysis is...

averages and standard deviation

step six of the scientific process

make conclusions

step seven of the scientific process

repeat (if you get the same results over multiple attempts, then your data is more reliable)

what are pipettes used for

The transfer of a small volume of liquid from one container to another.

what is the difference between a serological pipette and a micropipette?

serological pipette: Used to measure medium-small volumes of liquids

micropipette: A laboratory instrument used to measure, dispense, and transfer very small amounts of liquid.

how should you go about choosing the correct pipette for the amount of liquid you need to measure

micropipettes measure between 1 and 1000µl

serological pipette measures from 1ml to 50 ml

what are some common dos and donts for pipette use

do:

-keep the pipette in the plastic until needed

-look for the blown out marks

-do check the numbers on the side to get the correct number

-place the tip onto the correct pipette

-do set micropipette only within the range specified for that specific instrument

-do keep the micropipette in a vertical position when there is fluid in the tip

dont:

-touch the tip of the pipette with your hand or on the table

-dont let the submission enter the cotton plug

-dont use a micropipette without first applying a plastic, dispenable tip

What is a spectrophotometer?

an instrument used to measure the amount of light that passes through a solution.

What does a spectrophotometer measure

-measurement of photo, which is light, and photo on a spectrum, so the full spectrum of light

-measures the absorbance or % transmittance of those waves and photons through a solution

(light absorbance)

What is the lambert beer law

The pattern of light absorption of a substance varies predictably with the amount present (linear relationship between concentration and absorption)

- under certain conditions absorbance is directly related to the concentration of a solution.

what are the three assumptions required for the law to apply

-monochromatic light is used (one wavelength/color at a time)

-the absorbance is measured at the wavelength of maximum absorbance

-the absorbance is less than 3.0

formula when calculating the proper volumes to make a specific dilution of a solution

C1V1 = C2V2

What do you need for each chemical in a lab

- commonly used names

- physical properties

- hazards to health

- reactivity

- flammability

- safety procedures if accidents occur

- special protection required

HMIS

1- health

2- flammability

3-chemical stability

4-special qualities

what does the red on the HMIS mean

flammability

what does the blue on the HMIS mean

health risk

health risk numbers

0 normal material

4 potentially deadly

flammability numbers

0 will not burn

1 above 200

2 100-200

3 below 100

4 below 73 (room temp)

what does the yellow on the HMIS mean

chemical stability

chemical stability numbers

0 stable

4 may detonate