WEEK 1: INTRODUCTION, SOLUTIONS PH
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WEEK 1:
Null Hypothesis
The hypothesis being tested. It says there is no difference between the treatment and control groups.
Hypothesis
Tentative explanation for some phenomenon that can be testable.
Mean
arithmetic average
Scientific method
process of research/learning; the process of establishing new facts and understanding mechanisms.
Standard Error
Describe how much variation is associated with the mean. It is the standard deviation divided by the square root of n.
Standard Deviation
Square root of variance. Most commonly used method of experimental variation.
Student's T Table
Provides tabular values that enable you to determine if there is a significant difference due to treatment. The table provides significant values based on sample size.
Statistical Analysis
Performed on experimental data to ascertain how much variation is due to random fluctuation, and how much is due to an actual difference between treatment and control groups. The purpose of your statistical analysis is to give you a basis to either support your null hypothesis or your alternative hypothesis. If your null hypothesis is correct, your treatment group was not different from your control group. Your data will show there is no difference between the two groups. If your alternative hypothesis is correct the variable had an effect on the outcome of the experiment.
Buffer
A solution (usually a weak acid or a weak base) that can serve as a proton acceptor or proton donor, and through those activities, maintains the pH of a solution under a variety of conditions.
Varience
Measure of distribution
Acid
An acid is a proton donor. Any substance with a hydrogen ion concentration of greater than 10^-7
Alternative Hypothesis
If the null hypothesis is rejected, the alternative is proposed. There is a difference between the treatment and control groups that can be attributed to the variable being tested.
Experimental Error
The deviation of individual data points from the experimental mean or from an established norm.
Student's T Table
A type of statistical analysis used to compare two sample means
Solvent
A substance in which other substances are dissolved. Water is a well-known solvent. Ionic and polar covalently bonded molecules are soluble in water. Water is the solvent inside cells, and in the circulatory system.
Molarity
Molar concentration (molarity) is the moles of solute dissolved in one liter of solvent.
Control
Experimental group that serves as the standard of comparison. If you were testing the effect of a medication that was given in pill form, the control group would receive a placebo.
Theory
Supported by evidence, provides a stronger explanation than a hypothesis.
Solution
Solutes are dissolved in solvents, creating a solution
Normal Distribution
A data plot of measurements of a given parameter among a population typically follows a normal distribution, or bell-shaped curve. The mean would be in the center of the curve, with a symmetrical distribution above and below the mean.
Variable
Substance being tested. The only difference between the control and treatment group is the variable.
Law
Explanation that is virtually irrefutable. (Biogenetic Law that states all cells arise from other cells)
Week 1: The lower the pH the the hydrogen ion concentration
higher
Percent concentration
Percent of solute with respect to solvent
Significant difference
The mean of the treatment group is statistically different from that of the control group.
P value
The probability that there is no difference between control and treatment groups
Life and water
water is essential to support life. Scientists looking for extraterrestrial life are looking for planets/moons that have some evidence of the presence of water on their surfaces. Water covers about 70% of Earth. Life originated in water.
Base
Associated with a low hydrogen ion concentration. pH greater than 7. Hydrogen ion concentration less than 10^-7. A base is considered to be a proton acceptor.
Solute
substance that is dissolved in a solvent
pH
A measure of hydrogen ion concentration. pH is the negative logarithm of hydrogen ion concentration.
Concentration
The concentration of a solution refers to the amount of solute per unit volume of that solution.
Placebo
insert substance which can be used for control group
repetition
repeated observations are necessary to determine if there is a real difference between treatment and control groups. You must have replicates to complete statistical analysis.
A pH of 2 has a hydrogen ion concentration
high
How does litmus paper work?
If it turns blue its a base, if it turns red its an acid
What's a buffer and what does it do?
A solution (usually a weak acid or a weak base)
Which substances tested to be acids? Which was the strongest acid? Weakest Acid?
Tomato Juice, Cola, Lime Juice, Vinegar, Salicylic Acid, Milk, distilled water
-Strongest Acid: lime juice, vinegar
-Weakest Acid: distilled water and milk
Which substances tested to be bases? Which was the strongest base? Weakest base?
Ammonia, Baking Soda
- Strongest Base: Ammonia
- Weakest Base: Baking Soda
Which substances tested to be neutral?
NaCl, Urea
WEEK 2: MACROMOLECULES
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Week 2: What are the four macromolecules?
Carbohydrates
Lipids
Nucleic Acids
Proteins
What is the function of carbohydrates?
They serve as a primary energy source for most organisms. They are also important in cell-cell recognition in animals.
What is the most abundant carbohydrate in nature?
Cellulose (major constituent of cell walls)
What are some functions of proteins?
Enzymes, Immune Function, Transport, Support, Movement, Regulation, Storage
What is the monomeric subunit of protein?
Amino Acid
How many amino acids are found in proteins?
20
What is largely responsible for the integrity of cell membranes?
Phospholipids
Function of lipids?
they act as lipids hormones, and as bile to aid in lipid digestion
what is the classification of lipids based on?
Their solubility; whether they are hydrophobic or hydrophilic
What solution tests for reducing sugars?
Benedict's Test/ Solution
What test and solution are used to test for starches?
- Polysaccharide Test
- Iodine Solution
What test is used to identify proteins?
- Biuret Test
What solution is used to test for lipids?
Sudan IV
What color would a solution turn if it tested positive for the Benedict's test? (reducing sugar)
RED
What color would a solution turn if it tested positive for the Polysaccharide test? (starches/iodine solution)
BLACK
What color would a solution turn if it tested positive for proteins with a Biuret test?
PURPLE
What color would a solution turn if it tested positive for Lipids with a Sudan IV
RED
What equipment was used during the week 2 lab?
- mechanical pipet
- test tubes
- hot bath
Which solution tested positive in the Benedict's test that tests for reducing sugars?
POSITIVE: glucose, fructose, lactose, galactose, milk
NEGATIVE: sucrose, rice, water
Which solutions tested positive in the polysaccharide test that identifies starches?
POSITIVE: potato extract, corn starch, rice, wheat flower
NEGATIVE: sucrose, glucose, water
Which solutions tested positive in the Biruet test that identifies protein?
POSITIVE: milk, casein, albumin, whey
NEGATIVE: urea, glucose, water
Which solutions test positive for the lipid test (sudan IV)?
POSITIVE: vegetable oil, whole milk
NEGATIVE: alcohol, glucose, water
True or False. Albumin can be classified as a protein.
True
What protein makes up the white of a chicken egg?
Albumin
True or False. Corn tested positive for starch/polysaccharides.
True
True or False. Fructose is a Reducing Sugar.
True
True or False. Galactose is a reducing sugar.
True
True or False. Glucose can be classified as a protein.
False
Lactose is a reducing sugar.
True
Milk contains reducing sugars.
True
Potato tested positive for starch/polysaccharide test
True
Rice tested positive for reducing sugars
False
Rice tested positive for starch/polysaccharides
True
Sucrose is a reducing sugar
False
Sucrose tested positive for starch/polysaccharides
False
Urea is a protein
false
Wheat tested positive for starch/polysaccharide
True
Whey can be classified as a protein
true
What is the major protein found in dairy products
casein
What is the most common inorganic molecule found in the human body?
Water
Which bonds form the primary structure of the protein?
Peptide Bonds
When you added NaOH to your substrate during the Biuret test you
?
Increased pH
What feature of phospholipids makes them amphiphatic?
- one end is hydrophilic and one end is hydrophobic
WEEK 3: CELLS, MICROSCOPES, ORGANISMS
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Week 3: What are the full names of the species viewed under the microscope
- Paramecium Caudatum
- Amoeba Proteus
- Euglena
- Bacteria
- Onion Cell
-Cheek Swab
What are the different parts of Paramecium Caudatum?
- Contractile Vacuole, food vacuole, cilia, micronucleus, macronucleus, oral groove, anal pore, cytoplasm
How does Paramecium move?
Using Cilia
How do Paramecium obtain energy?
- Paramecium are heterotrophs and obtain energy through their oral groove. Bacteria are their prey.
What are the different parts of Amoeba Proteus?
- contractile vacuole, cell membrane, cytoplasm, pseudopods, nucleus and food vacuole
How do Amoeba move?
- Pseudopods (false feet)
How do Amoeba obtain energy?
Food Vacuole?
What is the name of the condition that can cause permanent visual impairment and/or blindness and that is common in people who are not hygienic with their contact lenses?
Acanthameoba Keratitis
What causes amoebic meningoencephalitis?
Naegleri Fowleri
What causes amebiasis which leads to diarrhea?
Entamoeba Histolytica
What are the different parts of Euglena?
cytoplasm, nucleus, photoreceptor, stigma, contractile vacuole, membrane, nucleolus, flagellum, chloroplast
How do Euglena move?
flagella
How do Euglena obtain energy?
All euglena have chloroplasts and can make their own food by photosynthesis.
What dye did you use during this lab?
Methylene Blue
What are the different parts of the microscope?
- fine adjustment knob, course adjustment knob, stage, objective lens: scanning lens, low power objective, high power objective, oil emulsion, Ocular lens, tungsten lamp aka light source
How do you calculate magnification and total magnification?
- Total magnification is the ocular lens (10x) multiplied by the objective lens (4, 10, 45, or 100x)
- Magnification is just of the objective lens
As the degree of magnification increases what happens to the barrel length of the objective lens? To the aperture that allows light in?
- increases
- decreases
What should you never use when you switch from low power to the high power lens
The coarse adjustment knob
WEEK 4: TRANSPORT
WEEK 4: Transport
WEEK 4: What Materials did we use in this lab?
- petri dish
- agar plate
- cork borer
-dialysis tubing (tape thing)
What is the effect of molecular weight on the rate of diffusion?
They are inversely proportional. The higher the molecular weight the slower the rate of diffusion.
What is the effect of temperature on the rate of diffusion?
The higher the temperature the faster the rate of diffusion. We tested 23, 40, and 55, degrees celsius. 55 degrees diffused the fastest.
What 3 anions did we test? What are their molecular weights?
- ferricyanide: 212 (slowest)
- bromide: 80 (yeah)
- chloride: 35 (fastest)
How do you calculate molecular weight?
- first go to your periodic table and find the mass of each element (big number with decimals)
- Second multiply each element depending on the subscripts or number of that specific element
- Third add all the elements together
What substances are soluble in the lipid bilayer?
- Oxygen
- Carbon Dioxide
- Water
What are the 3 passive transport processes?
- simple diffusion
- osmosis
- facilitated diffusion
What are the 3 active transport processes?
-transport pumps
- exocytosis
- endocytosis
What is the molecular weight cut off of dialysis tubing?
10,000 daltons
WEEK 5: ENZYMES EFFECT OF CONCENTRATION
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What enzyme was used during this lab?
Peroxidase
What is the function of Peroxidase in this lab?
- catalyzes (speeds up) a chemical reaction
- causes the reaction to occur
What substrates were used during this lab?
- Guaiacol
- Peroxide (H2O2)
What is the function of Guaiacol and Peroxide in this lab?
They bind to the active site of the enzyme and then are altered by the enzyme
How does enzyme concentration affect reaction rate?
If substrate concentration is not limiting, then adding more enzyme should increase reaction rate.
How does substrate concentration affect reaction rate?
Adding substrate will often increase rate of a chemical reaction as long as there are enzyme molecules available to accommodate the additional substrate. When the enzyme molecules are all taken up, the solution is saturated. After it is saturated, adding more substrate will not increase the rate of reaction.
What instruments/materials were used in lab?
- Spectrophotometer
- Micro-pipette
- Micro-pipette tip
- cuvette
What does the micro pipette measure in and how much does it contain?
microliters; 100 microliters
0.1 milliliters is how many microliters
100 microliters
What happened to the color when more enzyme was added?
It got darker brown each time
What happened to the color when more substrate was added?
It stayed the same and the numbers rose but only to a certain extent
How were we able to measure reaction rate and how to do we calculate it?
- Reaction rate is the slope of the line you are plotting
- By quantifying the oxidized guaiacol spectrophotometrically, the product formation, or rate of reaction is calculated.
What is saturation?
Saturation means that all of the enzyme active sites are occupied by substrate
What is the difference between guaiacol in its reduced from and in its oxidized form?
- Reduced: gain electrons, colorless
- Oxidized: lost electrons, brown
What test is used to detect blood in the stool?
The Guaiac Test
What is the Beer-Lambert Law
- states that the concentration of a light absorbing solute is directly proportional to its absorbance
WEEK 5: In an exergonic reaction:
The energy level of the reactants is higher than the energy level of the products
What is the mechanism by which an enzyme functions to increase reaction rate?
An enzyme decreases activation energy required to initiate a reaction
The location on an enzyme that binds substrate is known as the:
Active Site
A spectrophotometer measures?
Absorbance
What indicator molecule is used to track the reaction rate of peroxidase
Gualacol
The reactant that is recognized by a specific enzyme is its:
substrate
In which animal cells would you expect to find peroxidase-containing peroxisomes?
Erythrocytes
In tracking product formation of peroxidase, the guanacos is:
Oxidized
When you graph absorbance in an attempt to measure your reaction rate, which variable going on the x-axis (horizontal axis)?
Time
Which parameter on your graph is directly proportional to the reaction rate of the enzyme?
Slope
The experimental setup for your lab involved the extraction of an enzyme from turnip, and observing its reaction rate under a variety of conditions. What is the enzyme?
Peroxidase
What does the slope of the line you are plotting give you?
Reaction rate
What is the point of this lab and of next weeks?
To see how reaction rate changes
What are the substrates
Guaiacol + H202
Would reaction occur without an enzyme?
NO
What color does Guaiacol become when it reacts?
Brown
What equipment did we use in lab?
- Spectrophotometer
- micro pipette
- micro pipette tip
- cuvette
What does the micro pipette measure in?
- Microliters (100 microliters in 0.1 milliliters)
How many nm should the spectrophotometer be at?
470nm
What happened to the enzyme as the concentration got higher?
It got darker and the reaction rate got higher
What happened to the substrate as the concentration got higher?
The color stayed the same and the numbers rose to a certain extent and then stayed constant
Names of enzymes typically end with
-ase
What happens to an enzyme when it denatures?
Loss of 3D shape of the molecule
How does an enzyme catalyze a reaction?
by decreasing the energy of activation for a chemical reaction
Vitamins are essential to the survival of organisms because vitamins usually function as:
Coenzymes
Substrates are held in the active site of an enzyme by
hydrogen and ionic bonds
If the substrate concentration is limiting, how does increasing enzyme concentration affect reaction rate?
Increasing enzyme concentration has no effect on reaction rate.
When guaiacol reacts with peroxide and peroxidase, it is ______________ to tetraguaiacol, resulting in the formation of a color compound that can be detected spectrophotometrically.
Oxidized
What does it mean when all of the active sites of the enzyme are occupied
It is SATURATED
What enzyme is important in fat digestion?
lipase
The organic nonprotein portion of an enzyme that is required for proper function is a(n):
coenzyme
The location of an enzyme that binds substrate is its?
Active Site
The inactive form of an enzyme is a:
Zymogen
True or False. Enzymes increase the rate of reaction.
True
WEEK 6: ENZYMES-- EFFECTS OF TEMPERATURE/INHIBITORS
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In this lab what was the name of the inhibitor?
Hydroxylamine
How did the inhibitor, Hydroxylamine, affect the reaction?
Hydroxylamine slowed down the reaction because it blocks the iron atom that is present at the active site of peroxidase
What is the wavelength at which the spectrophotometer was used to measure absorbance?
470 nm
What is the name of the plant used in lab?
Turnip
What is the difference between a competitor and a non competitor inhibitor?
- A competitive inhibitor binds to the active site of an enzyme, and competes with the substrate for the active site.
- An allosteric inhibitor is noncompetitive because the inhibitor and substrate do NOT compete for the same binding site.
WEEK 6: An example of a competitive inhibitor is one that?
Binds to the active site of the enzyme
What is the competitive inhibitor of the enzyme peroxidase?
Hydroxylamine
What conditions can denature an enzyme?
A drop in pH
An increase in pH
An increase in temperature above optimum
As temperature increases:
Rate of random molecular motion increases
True of False. Biological reactions that take place in cells are inhibited.
True
When an enzyme denatures which bonds are destroyed?
Hydrogen bonds
When an enzyme denatures, which level(s) of protein structure are affected?
Secondary structure
Tertiary structure
Quaternary structure
From what organism was the peroxidase used in lab isolated?
Turnip
Identify the structure of hydroxylamine.
HO OH
N
H
EXTRA QUESTIONS
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What is the most common inorganic molecule found in the human body?
water
Triglycerides are classified as blank and are composed of blank
lipids; fatty acids and glycerol
Bioluminescence is the conversion of a chemical compound into light energy and heat. Fireflies and sea creatures use bioluminescence to "light up". The reaction below demonstrates the process of bioluminescence. What is the substrate?
Luciferin
Which molecules move across the cell membrane by simple diffusion?
- water
- oxygen
- carbon dioxide
Ideally, control and experimental groups differ in how many variables?
1