# Biology Lab Mid Term Review Flashcards

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Review over material covered in class during weeks 1-6 of the semester.
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1

WEEK 1: INTRODUCTION, SOLUTIONS PH

...

2

WEEK 1:

Null Hypothesis

The hypothesis being tested. It says there is no difference between the treatment and control groups.

3

Hypothesis

Tentative explanation for some phenomenon that can be testable.

4

Mean

arithmetic average

5

Scientific method

process of research/learning; the process of establishing new facts and understanding mechanisms.

6

Standard Error

Describe how much variation is associated with the mean. It is the standard deviation divided by the square root of n.

7

Standard Deviation

Square root of variance. Most commonly used method of experimental variation.

8

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.

9

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.

10

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.

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Varience

Measure of distribution

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Acid

An acid is a proton donor. Any substance with a hydrogen ion concentration of greater than 10^-7

13

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.

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Experimental Error

The deviation of individual data points from the experimental mean or from an established norm.

15

Student's T Table

A type of statistical analysis used to compare two sample means

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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.

17

Molarity

Molar concentration (molarity) is the moles of solute dissolved in one liter of solvent.

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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.

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Theory

Supported by evidence, provides a stronger explanation than a hypothesis.

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Solution

Solutes are dissolved in solvents, creating a solution

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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.

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Variable

Substance being tested. The only difference between the control and treatment group is the variable.

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Law

Explanation that is virtually irrefutable. (Biogenetic Law that states all cells arise from other cells)

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Week 1: The lower the pH the the hydrogen ion concentration

higher

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Percent concentration

Percent of solute with respect to solvent

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Significant difference

The mean of the treatment group is statistically different from that of the control group.

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P value

The probability that there is no difference between control and treatment groups

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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.

29

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.

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Solute

substance that is dissolved in a solvent

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pH

A measure of hydrogen ion concentration. pH is the negative logarithm of hydrogen ion concentration.

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Concentration

The concentration of a solution refers to the amount of solute per unit volume of that solution.

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Placebo

insert substance which can be used for control group

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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.

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A pH of 2 has a hydrogen ion concentration

high

36

How does litmus paper work?

If it turns blue its a base, if it turns red its an acid

37

What's a buffer and what does it do?

A solution (usually a weak acid or a weak base)

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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

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Which substances tested to be bases? Which was the strongest base? Weakest base?

Ammonia, Baking Soda

- Strongest Base: Ammonia

- Weakest Base: Baking Soda

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Which substances tested to be neutral?

NaCl, Urea

41

WEEK 2: MACROMOLECULES

...

42

Week 2: What are the four macromolecules?

Carbohydrates

Lipids

Nucleic Acids

Proteins

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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.

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What is the most abundant carbohydrate in nature?

Cellulose (major constituent of cell walls)

45

What are some functions of proteins?

Enzymes, Immune Function, Transport, Support, Movement, Regulation, Storage

46

What is the monomeric subunit of protein?

Amino Acid

47

How many amino acids are found in proteins?

20

48

What is largely responsible for the integrity of cell membranes?

Phospholipids

49

Function of lipids?

they act as lipids hormones, and as bile to aid in lipid digestion

50

what is the classification of lipids based on?

Their solubility; whether they are hydrophobic or hydrophilic

51

What solution tests for reducing sugars?

Benedict's Test/ Solution

52

What test and solution are used to test for starches?

- Polysaccharide Test

- Iodine Solution

53

What test is used to identify proteins?

- Biuret Test

54

What solution is used to test for lipids?

Sudan IV

55

What color would a solution turn if it tested positive for the Benedict's test? (reducing sugar)

RED

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What color would a solution turn if it tested positive for the Polysaccharide test? (starches/iodine solution)

BLACK

57

What color would a solution turn if it tested positive for proteins with a Biuret test?

PURPLE

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What color would a solution turn if it tested positive for Lipids with a Sudan IV

RED

59

What equipment was used during the week 2 lab?

- mechanical pipet

- test tubes

- hot bath

60

Which solution tested positive in the Benedict's test that tests for reducing sugars?

POSITIVE: glucose, fructose, lactose, galactose, milk

NEGATIVE: sucrose, rice, water

61

Which solutions tested positive in the polysaccharide test that identifies starches?

POSITIVE: potato extract, corn starch, rice, wheat flower

NEGATIVE: sucrose, glucose, water

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Which solutions tested positive in the Biruet test that identifies protein?

POSITIVE: milk, casein, albumin, whey

NEGATIVE: urea, glucose, water

63

Which solutions test positive for the lipid test (sudan IV)?

POSITIVE: vegetable oil, whole milk

NEGATIVE: alcohol, glucose, water

64

True or False. Albumin can be classified as a protein.

True

65

What protein makes up the white of a chicken egg?

Albumin

66

True or False. Corn tested positive for starch/polysaccharides.

True

67

True or False. Fructose is a Reducing Sugar.

True

68

True or False. Galactose is a reducing sugar.

True

69

True or False. Glucose can be classified as a protein.

False

70

Lactose is a reducing sugar.

True

71

Milk contains reducing sugars.

True

72

Potato tested positive for starch/polysaccharide test

True

73

Rice tested positive for reducing sugars

False

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Rice tested positive for starch/polysaccharides

True

75

Sucrose is a reducing sugar

False

76

Sucrose tested positive for starch/polysaccharides

False

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Urea is a protein

false

78

Wheat tested positive for starch/polysaccharide

True

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Whey can be classified as a protein

true

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What is the major protein found in dairy products

casein

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What is the most common inorganic molecule found in the human body?

Water

82

Which bonds form the primary structure of the protein?

Peptide Bonds

83

When you added NaOH to your substrate during the Biuret test you

?

Increased pH

84

What feature of phospholipids makes them amphiphatic?

- one end is hydrophilic and one end is hydrophobic

85

WEEK 3: CELLS, MICROSCOPES, ORGANISMS

...

86

Week 3: What are the full names of the species viewed under the microscope

- Paramecium Caudatum

- Amoeba Proteus

- Euglena

- Bacteria

- Onion Cell

-Cheek Swab

87

What are the different parts of Paramecium Caudatum?

- Contractile Vacuole, food vacuole, cilia, micronucleus, macronucleus, oral groove, anal pore, cytoplasm

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How does Paramecium move?

Using Cilia

89

How do Paramecium obtain energy?

- Paramecium are heterotrophs and obtain energy through their oral groove. Bacteria are their prey.

90

What are the different parts of Amoeba Proteus?

- contractile vacuole, cell membrane, cytoplasm, pseudopods, nucleus and food vacuole

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How do Amoeba move?

- Pseudopods (false feet)

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How do Amoeba obtain energy?

Food Vacuole?

93

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

94

What causes amoebic meningoencephalitis?

Naegleri Fowleri

95

What causes amebiasis which leads to diarrhea?

Entamoeba Histolytica

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What are the different parts of Euglena?

cytoplasm, nucleus, photoreceptor, stigma, contractile vacuole, membrane, nucleolus, flagellum, chloroplast

97

How do Euglena move?

flagella

98

How do Euglena obtain energy?

All euglena have chloroplasts and can make their own food by photosynthesis.

99

What dye did you use during this lab?

Methylene Blue

100

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

101

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

102

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

103

What should you never use when you switch from low power to the high power lens

The coarse adjustment knob

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WEEK 4: TRANSPORT

WEEK 4: Transport

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WEEK 4: What Materials did we use in this lab?

- petri dish

- agar plate

- cork borer

-dialysis tubing (tape thing)

106

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.

107

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.

108

What 3 anions did we test? What are their molecular weights?

- ferricyanide: 212 (slowest)

- bromide: 80 (yeah)

- chloride: 35 (fastest)

109

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

110

What substances are soluble in the lipid bilayer?

- Oxygen

- Carbon Dioxide

- Water

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What are the 3 passive transport processes?

- simple diffusion

- osmosis

- facilitated diffusion

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What are the 3 active transport processes?

-transport pumps

- exocytosis

- endocytosis

113

What is the molecular weight cut off of dialysis tubing?

10,000 daltons

114

WEEK 5: ENZYMES EFFECT OF CONCENTRATION

...

115

What enzyme was used during this lab?

Peroxidase

116

What is the function of Peroxidase in this lab?

- catalyzes (speeds up) a chemical reaction

- causes the reaction to occur

117

What substrates were used during this lab?

- Guaiacol

- Peroxide (H2O2)

118

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

119

How does enzyme concentration affect reaction rate?

If substrate concentration is not limiting, then adding more enzyme should increase reaction rate.

120

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.

121

What instruments/materials were used in lab?

- Spectrophotometer

- Micro-pipette

- Micro-pipette tip

- cuvette

122

What does the micro pipette measure in and how much does it contain?

microliters; 100 microliters

123

0.1 milliliters is how many microliters

100 microliters

124

What happened to the color when more enzyme was added?

It got darker brown each time

125

What happened to the color when more substrate was added?

It stayed the same and the numbers rose but only to a certain extent

126

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.

127

What is saturation?

Saturation means that all of the enzyme active sites are occupied by substrate

128

What is the difference between guaiacol in its reduced from and in its oxidized form?

- Reduced: gain electrons, colorless

- Oxidized: lost electrons, brown

129

What test is used to detect blood in the stool?

The Guaiac Test

130

What is the Beer-Lambert Law

- states that the concentration of a light absorbing solute is directly proportional to its absorbance

131

WEEK 5: In an exergonic reaction:

The energy level of the reactants is higher than the energy level of the products

132

What is the mechanism by which an enzyme functions to increase reaction rate?

An enzyme decreases activation energy required to initiate a reaction

133

The location on an enzyme that binds substrate is known as the:

Active Site

134

A spectrophotometer measures?

Absorbance

135

What indicator molecule is used to track the reaction rate of peroxidase

Gualacol

136

The reactant that is recognized by a specific enzyme is its:

substrate

137

In which animal cells would you expect to find peroxidase-containing peroxisomes?

Erythrocytes

138

In tracking product formation of peroxidase, the guanacos is:

Oxidized

139

When you graph absorbance in an attempt to measure your reaction rate, which variable going on the x-axis (horizontal axis)?

Time

140

Which parameter on your graph is directly proportional to the reaction rate of the enzyme?

Slope

141

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

142

What does the slope of the line you are plotting give you?

Reaction rate

143

What is the point of this lab and of next weeks?

To see how reaction rate changes

144

What are the substrates

Guaiacol + H202

145

Would reaction occur without an enzyme?

NO

146

What color does Guaiacol become when it reacts?

Brown

147

What equipment did we use in lab?

- Spectrophotometer

- micro pipette

- micro pipette tip

- cuvette

148

What does the micro pipette measure in?

- Microliters (100 microliters in 0.1 milliliters)

149

How many nm should the spectrophotometer be at?

470nm

150

What happened to the enzyme as the concentration got higher?

It got darker and the reaction rate got higher

151

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

152

Names of enzymes typically end with

-ase

153

What happens to an enzyme when it denatures?

Loss of 3D shape of the molecule

154

How does an enzyme catalyze a reaction?

by decreasing the energy of activation for a chemical reaction

155

Vitamins are essential to the survival of organisms because vitamins usually function as:

Coenzymes

156

Substrates are held in the active site of an enzyme by

hydrogen and ionic bonds

157

If the substrate concentration is limiting, how does increasing enzyme concentration affect reaction rate?

Increasing enzyme concentration has no effect on reaction rate.

158

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

159

What does it mean when all of the active sites of the enzyme are occupied

It is SATURATED

160

What enzyme is important in fat digestion?

lipase

161

The organic nonprotein portion of an enzyme that is required for proper function is a(n):

coenzyme

162

The location of an enzyme that binds substrate is its?

Active Site

163

The inactive form of an enzyme is a:

Zymogen

164

True or False. Enzymes increase the rate of reaction.

True

165

WEEK 6: ENZYMES-- EFFECTS OF TEMPERATURE/INHIBITORS

...

166

In this lab what was the name of the inhibitor?

Hydroxylamine

167

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

168

What is the wavelength at which the spectrophotometer was used to measure absorbance?

470 nm

169

What is the name of the plant used in lab?

Turnip

170

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.

171

WEEK 6: An example of a competitive inhibitor is one that?

Binds to the active site of the enzyme

172

What is the competitive inhibitor of the enzyme peroxidase?

Hydroxylamine

173

What conditions can denature an enzyme?

A drop in pH

An increase in pH

An increase in temperature above optimum

174

As temperature increases:

Rate of random molecular motion increases

175

True of False. Biological reactions that take place in cells are inhibited.

True

176

When an enzyme denatures which bonds are destroyed?

Hydrogen bonds

177

When an enzyme denatures, which level(s) of protein structure are affected?

Secondary structure

Tertiary structure

Quaternary structure

178

From what organism was the peroxidase used in lab isolated?

Turnip

179

Identify the structure of hydroxylamine.

HO OH

N

H

180

EXTRA QUESTIONS

...

181

What is the most common inorganic molecule found in the human body?

water

182

Triglycerides are classified as blank and are composed of blank

lipids; fatty acids and glycerol

183

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

184

Which molecules move across the cell membrane by simple diffusion?

- water

- oxygen

- carbon dioxide

185

Ideally, control and experimental groups differ in how many variables?

1