BIO 101 Lab Midterm Study Guide

Lab 1 - Scientific Method

Multiple Choice

What is the definition of scientific methods?

• A process that involves the formation and testing of hypotheses

• A conclusion drawn from data and observations

• A step-by-step process to follow

Multiple Choice

Put the steps of the scientific method in order:

• Observation, Question, Hypothesis, Experiment, Conclusion

• Observation, Hypothesis, Experiment, Analyze, Conclusion

• Observation, Question, Hypothesis, Experiment, Analyze, Conclusion

Multiple Choice

A controlled experiment...

• introduces bias

• tests only one variable and is free of bias

• changes no variables

• tests several variables at once.

A controlled experiment allows scientists to test hypotheses and to draw conclusions based on reproducible results.

A controlled experiment allows comparison between a control group and a test (experimental) group that has been exposed to an experimental factor (the variable).

Multiple Choice

What is the control group?

• the group that changes

• the group that is used as a comparison

• the group results

Multiple Choice

Which group in an experiment receives the treatment?

• Control Group

• Experimental Group

They feed on live or decaying plant material, fungi and dead animals

​​Pillbugs are omnivores

​Positive response- the pillbug will move toward certain substances like cornstarch

Pillbugs detect food using a sense similar to smell

​When a pillbug is repelled from a substance, it will move away from it - a negative response

​​Negative response

​Cornstarch - contains nutrients and has similar texture to sand
Sand - pillbugs are not repelled from sand

​​Two ingredients in our experiment

1. Top Chamber: you put sand on one side and cornstarch on the other.

2. Bottom Chamber: you put sand on both sides.

3. You added 5 pillbugs to each side of both chambers.

4. The experimental group was the top chamber with cornstarch and sand.
   

​Pillbug Experiment

Multiple Choice

What did you learn about the behavior of the pillbugs in the experiment?

• The pillbugs moved away from the cornstarch

• the pillbugs tend to move toward the cornstarch, and the control groups shows they don't change behavior regarding sand

• The pillbugs tend to move toward the sand, and the control group show they don't change behavior regarding cornstarch

Lab 2 - Test for Proteins

Multiple Choice

What are the monomers of proteins?

• amino acids

• monosaccharides

• nucleotides

• fatty acids and glycerol

Multiple Choice

Biuret reagent test for...

• lipids

• starch

• proteins

• sugars

​Biuret Test Results

Multiple Choice

When we performed the protein test, what was the negative control?

• albumin

• starch

• pepsin

• water

Lab 2 - Test for Starch

Multiple Choice

Which biomolecule has simple forms, like glucose, and complex forms like starch?

• carbohydrate

• lipid

• protein

• nucleic acid

• The building blocks of sugars are monosaccharides.

• Simple sugars can be monosaccharide - 1 sugar or disaccharide - 2 sugars

• Starches contain many monosaccharides - they are called polysaccharides

Multiple Choice

What color does iodine solution turned into in the presence of starch?

• blue/black

• purple

• orange

• it forms two layers

Multiple Select

Which test tubes tested for highest starch concentration? Select more than one answer!

• 1

• 2

• 3

• 4

• 5

Multiple Select

Which test tubes tested negative for the presence of starch? Select more than one answer!

• 1

• 2

• 3

• 4

• 5

Glucose and starch are both carbohydrates.

Why does glucose produce a negative result when using iodine?

Iodine only tests for polysaccharides and glucose is a monosaccharide

• Lab 2 - Test for Simple Sugars

Multiple Choice

A term that describes simple sugars is

• glycogen

• complex carbohydrate

• polysaccharide

• monosaccharide

Multiple Select

What are some examples of simple sugars?

• sucrose

• glucose

• starch

• cellulose

• glycogen

Multiple Choice

Which food group does Benedict's reagent test for?

• proteins

• starch

• lipids

• glucose

Multiple Select

What is a positive result for simple sugars using Benedict's solution?

• Brick red

• Orange

• Green

• Blue

Multiple Choice

What is a negative result for simple sugars using Benedict's solution?

• Brick red

• Orange

• Green

• Blue

Lab 2 - Test for Lipids

Multiple Select

What are the building blocks of triglycerides?

• fatty acids

• glycerol

• amino acids

• monosaccharides

What is a fatty acid?

• A straight chain of an even number of carbon atoms, with hydrogen atoms along the length of the chain

• One end has a carboxyl group (-COOH) - this makes it an acid

Multiple Choice

Which fatty acids do NOT have double bonds?

• saturated

• unsaturated

Multiple Choice

What kind of test did we perform for lipids?

• Brown paper test

• Benedict's test

• Biuret test

• Iodine test

Lab 3 - Cells

Multiple Choice

What is a cell?

• a holding room

• a place where criminals are kept

• The basic unit of structure and function in living things

Multiple Select

All cells have several features in common, what are they?

• cell membrane

• cytoplasm

• ribosomes

• nucleus

Multiple Choice

Which type of cell has no nucleus or membrane bound organelles?

• prokaryotes

• eukaryotes

Multiple Select

What is the difference between the Cell Wall and Cell Membrane?

• The cell wall protects and supports

• The cell membrane controls what goes in/out of the cell

• Both have similar functions but different structures

• Cell walls help animal cells keep their shape

Multiple Choice

        What structure found in plant cells is an organelle for storing water and metabolites?

• central vacuole

• chloroplast

• golgi apparatus

• plasmodesmata

Multiple Choice

        What is the name of all the cell contents between the nucleus and the cell membrane?

• nucleoplasm

• cytoplasm

• interstitial fluid

• matrix

Lab 3 - Diffusion

Multiple Choice

Define diffusion...The net movement of particles...

• ...from a low to a high concentration

• ...from a high to a low concentration

• From a high to a low concentration of water

• You put glucose and starch in the dialysis tubing.

• You put water and iodine in the beaker and submerged the dialysis tubing.

• A glucose test strip was placed into the beaker, the test was negative which shows there was no glucose in the beaker in the beginning of the experiment

​Dialysis Tubing Experiment

• At the end of the experiment, the fluid in the bag turned blue black which indicated the presence of starch. This indicated that the molecules of starch did not diffuse through the bag.

• The iodine diffused into the bag. Iodine turns blue/black in the presence of starch
  
  

​Dialysis Tubing Experiment

• The glucose test strip was place in the beaker. It gave a positive test result.

• This showed that the glucose was small enough to pass through the tubing.

• The glucose went through the tubing into the solution outside of the bag.
  
  

​Dialysis Tubing Experiment

Lab 3 - Osmosis

Multiple Select

Selectively Permeable Membrane...

• allows some substances to pass but not others based on size and charge

  
  

• substances flow from high to low concentration

  
  

• Follow concentration gradient

  
  

• Large and charged molecules don't cross without help

  
  

Multiple Choice

What is a solution with a higher concentration of nonpermeable solutes in comparison to another solution?

• hypertonic

• hypotonic

• isotonic

Multiple Choice

What is a solution with a lower concentration of nonpermeable solutes in comparison to another solution?

• hypertonic

• hypotonic

• isotonic

Fill in the Blank

What is a long tube of glassware with an open round reservoir at one end?

Multiple Choice

What effect did corn syrup concentration have on the movement of water in the stimulation?

• more water is drawn up into the thistle tube with higher concentrations of corn syrup.

• less water is drawn up into the thistle tube with higher concentrations of corn syrup

• more water is drawn into the thistle tube with lower concentrations of corn syrup

Fill in the Blank

        An ____________ environment is balanced so water enters and leaves cells at the same rate.

Lab 3 - Tonicity

Fill in the Blank

        A ______________ environment tends to cause a cell to shrivel or collapse as water exits the cell.

Fill in the Blank

A ______________ environment tends to cause a cell to swell or burst as water enters the cell.

Multiple Choice

In the blood and 0.9% NaCl solution, what happened to the since there seems to be no change?

• The water went to where there was more solutes (the solution) - result: the water left the cells and went into the solution

• The water went to where there was more solutes (the cell) - result: the water left the solution and went into the cells

• The amount of solutes was equal in the cell and the solution, the water went equal into and out of the cell

Multiple Choice

In the blood and 10% NaCl solution, what happened to the cells to cause them to shrink?

• The water went to where there was more solutes (the solution) - result: the water left the cells and went into the solution

• The water went to where there was more solutes (the cell) - result: the water left the solution and went into the cells

• The amount of solutes was equal in the cell and the solution, the water went equal into and out of the cell

Multiple Choice

In the blood and distilled water solution, what happened to the cells to cause them to swell and burst?

• The water went to where there was more solutes (the solution) - result: the water left the cells and went into the solution

• The water went to where there was more solutes (the cell) - result: the water left the solution and went into the cells

• The amount of solutes was equal in the cell and the solution, the water went equal into and out of the cell

Lab 4 - Enzyme Activity

1. Amount of substrate consumed

2. Amount of product produced

​Enzymatic activity can be measure in two ways

Fill in the Blank

        What is an enzyme that converts the substrate hydrogen peroxide (H₂O₂) into the products water (H₂O) and oxygen (O₂)?

Multiple Choice

When you performed the catalase experiment, how could you tell if the reaction took place?

• You produced bubbles that you measured

• You produced heat that you could feel

• You changed the color of the solution in the tube

• Your solution had particulates which solidified and fell to the bottom of the tube

Multiple Choice

        Did the catalase and hydrogen peroxide react together?

• Yes, you produced bubbles - the products produced were water and oxygen

• No, you did not produce any products because you did not have a reaction

Multiple Choice

        Did the catalase and water react together?

• Yes, you produced bubbles - the products produced were water and oxygen

• No, you did not produce any products because you did not have a reaction

Multiple Choice

        Did the hydrogen peroxide and water react together?

• Yes, you produced bubbles - the products produced were water and oxygen

• No, you did not produce any products because you did not have a reaction

Multiple Select

Which of the following enzyme substrate combinations are necessary for a reaction to take place? Pick two answers!

• water

• hydrogen peroxide

• catalase

Lab 4 - Effect of Temperature on Enzymes

Multiple Choice

Molecules move ____________ (faster or slower) at higher temperatures.

• faster

• slower

Multiple Choice

What is the relationship between temperature and enzyme activity?

• as temperature increases, enzyme activity decreases

• as temperature increases, enzyme activity increases until denaturation

• as temperature increases, enzyme activity increases indefinitely

• as temperature decreases, enzyme activity increases

  
  

Lab 4 - Effect of pH on Enzymes

Multiple Choice

        The influence of pH on enzyme activity reflects the fact that pH can affect ___________-___________ binding.

• enzyme-substrate

• enzyme-product

• substrate-product

Multiple Choice

        Enzymes are active within a certain pH range, and their activity is _____________ (increased or decreased) below and above that range.

• increased

• decreased

Multiple Select

pH and enzymes: (choose more than one answer!)

• pH is a factor for enzyme stability

  
  

• too acidic/basic pH denatures enzyme

  
  

• outside of optimum pH, enzyme active site is altered

  
  

Lab 4 - Effect of Concentration on Enzymes

Effect of Enzyme Concentration

• The influence of enzyme concentration reflects the fact that without the enzyme, the reaction will not occur.

• A greater enzyme concentration increases the reaction rate because the chance of both collision and binding between substrate and enzyme is increased.

Fill in the Blank

What was the enzyme that we used in all parts of lab 4?

Multiple Choice

What was the substrate that we used in all of the lab 4 activities?

• water

• catalase

• hydrogen peroxide

Multiple Choice

By changing the catalase from 5% to 10% to 20%, what is being tested?

• the enzyme concentration

• the pH of the enzyme

• the temperature of the enzyme

• the substrate concentration

Multiple Choice

If enzyme concentration ____, enzyme activity ____.

• Increases, increases

  
  

• Increases, decreases

  
  

• Decreases, increases

  
  

• Increases, does not change