Bio Lab Flashcards
1
Q
All science is ….
A
provisional
arranged or existing for the present, possibly to be changed later.
2
Q
Null hypothesis
A
Just by chance
3
Q
Theory stands the test of time it becomes
A
a law
4
Q
Analysis
A
Reject or accept the hypothesis
5
Q
Negative control group
A
Do not receive the manipulation of the experimental variable
6
Q
Positive control group
A
Do not receive the manipulation either, but they do receive a different kind of manipulation one whose effects are known.
7
Q
Confounding variables
A
Any variables that make the experimental and control groups dissimilar
8
Q
Blind experiment
A
When patients do not know whether they are in the experimental or control group
9
Q
Double blind experiment
A
When the person who administers the treatment doesn’t know which one contains actual medicine and which are placebo’s. It is a standard procedure for testing the efficacy of new drugs.
10
Q
A graph which is used when the experiment of variable is a continuous range of numbers with no discreet lumping of the numbers into categories.
A
Line graph
11
Q
A graph that is used when the experimental variable is composed of categories rather than a continuous range of number numbers.
A
Bar graph
12
Q
The range of the pH scale
A
0 - 14
13
Q
Equation of water dissociating
A
H20 ⇌ H+ +OH-
14
Q
What is dissociating
A
when a molecule breaks apart into smaller components, like atoms or ions, usually happening when a substance dissolves in water; essentially, it’s the process of a compound splitting into its individual parts
15
Q
What does it mean for an acid to be strong?
A
pH between 0 and 2
More Hydrogen Ions
16
Q
What does it mean for an acid to be weak?
A
pH between 3 and 6.
Fewer Hydrogen Ions: Partially ionizes, resulting in a lower concentration of H+
17
Q
What does it mean for a base to be strong?
A
Higher pH between 12 and 14
More OH- ions
18
Q
Complete ionization, produces high concentration of hydroxide ions in water it is a
A
Strong Base
19
Q
Strong Dissociation example
A
NaOH –> Na+ +OH-
20
Q
What does it mean for a base to be weak?
A
pH around 8 to 11
Produces fewer OH−OH− ions compared to a strong base at the same concentration.
21
Q
How does a buffer work?
A
any substance that picks up or releases hydrogen ions
Buffers rely on substances that can accept or donate hydrogen ions (H+) to maintain a stable pH.
22
Q
A neutral substance of 50% H+ and 50% OH-
A
Water
23
Q
Weak acids
A
dissociate slightly, most molecules stay together
23
Q
Strong acids
A
have more dissociation of hydrogen ions
24
All acids, bases, salts are
ionic
25
When a strong acid reacts with a strong base, they
neutralize each other to form a salt and water:
Strong Acid+Strong Base→Salt+Water
26
If blood becomes too basic (alkaline), the body will
work to lower the pH back to normal (around 7.4) by releasing hydrogen ions (H+H+) to restore the balance.
27
if blood becomes too acidic (a condition called acidosis) the body will
works to raise the pH by removing excess hydrogen ions (H⁺) to restore the balance.
28
Blood contains chemical systems that resist changes in pH. Called
Buffers
29
How is pure water always neutral?
It is 50-50 hydrogen and hydroxide not favoring acidity or basicity
30
How does a solution become acidic
When there is an increase in H+
31
Explain how a solution can become basic
When there is an increase in hydroxide ions
33
The body always strives to maintain pH around-/——- to keep biological processes stable.
7.35–7.45
34
Reagent for lipids is
Sudan III
35
Sudan III tests for
Presence of lipids.
It is a fat-soluble dye that stains fat cells.
If fat cells are present the paper will turn dark orange
36
If Fat are present, the Sudan III will turn
Dark Orange. Orange colored spots
37
The color red in Sundan III indicates that
triglycerides or fats are not present
38
Benedicts solution tests for
the presence of reducing sugars such as monosaccharides, and dissaccahires
39
Why will polysacchirides not react to Benedict's solution?
because they are not reducing sugars.
They have few free aldehyde or ketone groups to react with the reagent
“Benedict’s test detects reducing sugars, which have free aldehyde or ketone groups that can donate electrons to the reagent, causing a color change. Polysaccharides have few free groups available, so they do not react.”
40
Reducing sugars such as monosachharides or disacchirides will have a ______ that can be oxidized. Therefor, Benedict's solution is used.
aldehyde group (-CHO)
41
If no reducing sugars are present Benedict's solution stays
Blue
42
In the presence of reducing sugars, the Benedicts solution turns
Red-orange, orange, yellow, or green.
From Blue.
43
Lugol's iodine test for
the presence of starch in carbohydrates
44
If starch is present, Lugol's solution will turn from
yellow-orange to deep blue-black
45
The test for the presence of proteins and short peptides is
Biuret
46
In the presence of proteins the Biuret will turn from
blue to violet
47
A blue biuret indicates
negative results. No presence of proteins
48
Smallest molecule for each macromolecule:
Fats:
Carbohydrates:
Proteins:
Nucleic Acid:
Fats: fatty acids
Carbohydrates: monosacchires
Proteins: amino acids
Nucleic Acid: nucleotide
49
Proteins are considered polar molecules because they contain both polar and nonpolar regions within their structure, with the polar regions generally facing outward and the nonpolar regions usually tucked inside the protein's core when folded in an aqueous environment; this is due to the different polarities of the amino acid side chains that make up the protein.
Proteins are considered polar molecules because they contain both polar and nonpolar regions within their structure, with the polar regions generally facing outward and the nonpolar regions usually tucked inside the protein's core when folded in an aqueous environment; this is due to the different polarities of the amino acid side chains that make up the protein.
50
Are call carbohydrates polar?
Yes
51
Are all lipids are non-polar?
Yes. All lipids are non-polar
52
A molecule that has a nitrogenous base, a pentose sugar, and a phosphate would be?
A nucleotide
-Base Unit for DNA and RNA
53
Protein identifying features
Amino (NH3),Carboxyl (C=00), R Group, Hydrogen (H)
54
Carbohydrate identifying features:
Carbon, Oxygen, Hydrogen. Straight or Ringed.
55
Lipid features:
Hydrocarbon chain, Carboxyl group, Alcohol
56
How does Lugol's iodine test for polysaccharides but not monosacahrides?
iodine binds to the helical structure of polysaccharides, not individual sugar molecules.
An easy test answer:
“Lugol’s iodine binds to the coiled structure of polysaccharides like starch, causing a color change. Monosaccharides lack this structure, so no reaction occurs.”
57
Why will polysaccharides not react wirh Sundan III?
Sudan III is specifically designed to detect lipids, which are nonpolar.
polysaccharides are polar carbohydrates.
58
Why is water often use as a control in scientific experiments
It provides a neutral baseline with minimal potential for interfering reactions, allowing for accurate comparison.
59
What happens to the field of view when switching from the scanning lens (4x) to the low-power lens(10x)?
A: The field of view shrinks (gets smaller).
60
Keep both eyes open when using an ocular lens microscope (10x)?
It reduces eye strain and helps with depth perception.
61
What is the magnification of the red scanning lens?
A: 4x
62
What is the function of the rheostat on a microscope?
It controls the light intensity.
63
Why should the coarse adjustment knob never be used with low, high, or oil immersion lenses?
It can damage the slide or objective lens due to large, sudden movements.
64
How do you calculate total magnification?
A: Multiply the ocular lens (usually 10x) by the objective lens
65
What is the total magnification for the scanning lens (4x)?
A: 40x (4x * 10x)
66
What is the total magnification for the low-power lens (10x)?
A: 100x (10x * 10x)
67
What is the total magnification for the high-power lens (40x)?
A: 400x (40x * 10x)
68
What do all cells have in common?
A: Plasma membrane, cytoplasm, ribosomes, and DNA.
69
What is the difference between animal and plant cells?
Animal cells have lysosomes and centrioles.
Plant cells have chloroplasts, a cell wall, and a central vacuole.
70
What is an organelle?
A specialized structure inside a cell that performs a specific function.
71
What are the three domains of life?
A: Bacteria, Archaea, and Eukarya.
72
What are the six kingdoms of life?
Bacteria, Archaea, Protista, Fungi, Plantae, and Animalia.
73
Which kingdom contains unicellular organisms?
A: Bacteria, Archaea, and Protista.
74
Which kingdoms contain multicellular organisms?
Fungi, Plantae, and Animalia.
Part of the domain Eukarya
75
Which domains do prokaryotes belong to?
A: Bacteria and Archaea.
76
Which domain do eukaryotic organisms belong to?
A: Eukarya.
77
Why do humans belong to the domain Eukarya?
Because our cells have a nucleus and membrane-bound organelles.
78
What is the difference between a scanning electron microscope (SEM) and a transmission electron microscope (TEM)?
SEM creates a 3D surface image by scanning with electrons.
TEM provides detailed internal structures by passing electrons through the sample.
79
When would you use a compound microscope?
When viewing small, thin, transparent specimens like cells and tissues.
80
When would you use a dissecting microscope?
A: When viewing larger, 3D objects such as insects, plants, or small dissections.
81
What is the difference between a microscope’s magnification and field of view?
Magnification enlarges the image.
Field of view is the area visible through the lens and decreases as magnification increases.
82
Why is staining necessary when making a slide?
A: To increase contrast and make cell structures more visible.
83
Why is the iris diaphragm important on a microscope?
A: It controls how much light passes through the specimen, affecting contrast.
84
Why do scientists use microscopes?
A: To study structures too small to see with the naked eye.
85
Why is it important to understand depth of field in microscopy?
A: It allows you to focus on different layers of a specimen, especially when it is thick.
86
How are cells similar to bricks in a building?
A: Cells build up tissues and organisms just like bricks form a structure.
87
What is a cell?
A: The basic unit of life in all living organisms.
88
What influences the rate of diffusion?
Size, temperature, concentration gradient
89
iso:
hyper:
hypo:
equal
high
low
90
hypotonic solution: A solution with a ____ solute concentration compared to the inside of the cell, causing water to move___ the cell.
A solution with a lower solute concentration compared to the inside of the cell, causing water to move into the cell.
91
An animal cell in a hypotonic solution: The cell will ____ as water enters, and it may ___(burst) due to the lack of a cell wall.
The cell will swell as water enters, and it may lyse (burst) due to the lack of a cell wall.
92
Why doesn't a plant cell burst in a hypotonic solution?
Plant cells have a rigid cell wall that prevents them from bursting. Instead, they become turgid (firm).
93
Plant cells have a rigid cell wall that prevents them from bursting. Instead, they become_____ (firm).
turgid
94
What is lysis?
The breaking or bursting of an animal cell membrane when too much water enters in a hypotonic solution.
95
What is turgidity?
The state of being swollen and firm due to water entering a plant cell, supported by the cell wall.
96
Best environment for plant cells is a ______ solution
hypotonic solution. The cell wall prevents it from bursting
97
An an isotonic solution an animal cell ______, a plant cell ______
normal
flacid
98
_______ occurs when a plant cell is placed in a ______ solution. Water leaves the cell, causing the cell membrane to pull away from the cell wall.
Plasmolysis occurs when a plant cell is placed in a hypertonic solution. Water leaves the cell, causing the cell membrane to pull away from the cell wall.
99
plasmolysis: happens in a ______ solution because water moves out of the cell by osmosis, leading to the shrinking of the cytoplasm and membrane.
hypertonic
100
Do animal cells experience plasmolysis?
No, animal cells do lack a cell wall. Instead, they undergo crenation in a hypertonic solution.
101
_____ is the shrinking of red blood cells when placed in a hypertonic solution as water moves out of the cell.
Crenation is the shrinking of red blood cells when placed in a hypertonic solution as water moves out of the cell.
102
______: Happens in plant cells due to water loss, causing the membrane to shrink away from the wall.
______: Happens in animal cells like red blood cells, causing them to shrivel without a cell wall.
Plasmolysis: Happens in plant cells due to water loss, causing the membrane to shrink away from the wall.
Crenation: Happens in animal cells like red blood cells, causing them to shrivel without a cell wall.
103
What does selectively permeable mean?
A membrane that allows certain molecules to pass while blocking others.
104
What are phospholipids?
Molecules with a polar (hydrophilic) head and nonpolar (hydrophobic) tails that make up the plasma membrane.
105
What is an integral protein?
: A protein embedded within the plasma membrane, involved in transport and signaling.
106
What three factors affect diffusion rate?
1. Concentration gradient
2. Molecular weight
3. Temperature
107
How does temperature affect diffusion?
Higher temperature increases kinetic energy, leading to a faster diffusion rate.
108
How does molecular weight affect diffusion?
Heavier molecules diffuse more slowly than lighter ones.
109
How does concentration gradient affect diffusion?
A higher concentration gradient results in a faster diffusion rate.
110
What happens to a cell in a hypertonic solution?
It shrinks (crenation in animal cells, plasmolysis in plant cells) due to water loss.
111
What happens to a cell in a hypotonic solution?
It swells; animal cells may burst (lysis), while plant cells become turgid.
112
What is an isotonic solution?
A solution with equal solute concentration inside and outside the cell, causing no net water movement.
113
What is the best environment for a plant cell?
A hypotonic solution, as the cell wall prevents it from bursting while maintaining turgor pressure.
114
What is osmosis?
The diffusion of water across a selectively permeable membrane.
115
What are the expected results of diffusion experiments regarding molecular weight?
Smaller molecules diffuse faster than larger ones.
116
What happens when the concentration of a solute increases?
The rate of diffusion increases.
the solution becomes more hypertonic relative to the cell’s interior. This causes water to move out of the cell via osmosis, as water flows from an area of lower solute concentration (inside the cell) to higher solute concentration (outside the cell)
Animal cells: crenation (water loss)
Plant cells: plasmolysis (losing tugor-shrink away from cell wall )
117
Osmosis is diffusion of water across membranes through ____
aquaporin channel protein (transmembrane-intergral proteins)
118
An _____ _____ is where the enzyme binds to the _____
An active site is where the enzyme binds to the substrate
119
In the lab 8 experiment,
What was the substrate?
What was the enzyme?
What was the product?
Substrate: starch
Enzyme: Amylayse
Product: Glucose
120
A solution containing starch and an enzyme (such as amylase) gets lighter in color because the enzyme breaks down the starch into
simpler sugars.
121
What happens with the enzyme concentration?
Enzymes do not get used up in the reaction, but they can become less effective over time due to:
Denaturation (due to unfavorable conditions like heat or pH changes).
Degradation (natural breakdown of the enzyme molecules over time).
If the solution is stored for a long time, the enzyme’s activity might gradually decline.
122
What happens with temperature?
Optimal Temperature (Usually 35–40°C): Enzyme activity is highest.
Too Low Temperature (<10°C): The reaction slows down significantly, but the enzyme remains intact.
Too High Temperature (>50°C): The enzyme denatures, losing its shape and function, stopping the reaction permanently.
123
What happens with pH?
If the enzyme produces acidic byproducts, the pH might decrease slightly.
If buffering agents are present, the pH may stay relatively stable.
Extreme pH shifts (too acidic or too basic) can denature the enzyme, stopping the reaction.
124
What happens over time?
The enzyme continues breaking down starch into simpler sugars (maltose, glucose).
The solution becomes clearer and lighter as starch disappears.
Once all the starch is broken down, the reaction slows down and eventually stops because there is no more substrate (starch) left.
If left for an extended time, microbial activity could start affecting the solution, possibly leading to contamination.
125
An enzyme serves as a ____ providing activation energy by _____ the activation energy needed for a chemical reaction to occur.
An enzyme serves as a catalyst providing activation energy by lowering the activation energy needed for a chemical reaction to occur.
126
What affects enzymes?
Concentration, Temperature, pH, Time
127
Adding an enzyme to Reactants(substrate)- creates ____
Reactants(substrate)---enzyme----->
Products
128
Enzyme reaction process:
Substrate+Enzyme→Product+Enzyme
Starch+Amylase→Maltose (Product)
129
A substrate binds to an enzyme, which helps convert it into _____ through a chemical reaction. The enzyme itself is not consumed and can be reused.
A substrate binds to an enzyme, which helps convert it into products through a chemical reaction. The enzyme itself is not consumed and can be reused.
130
The starting materials of a reaction. The molecule that undergoes change (e.g., starch).
Reactants, Substrate (e.g., starch).
131
The biological catalyst that speeds up the reaction
Enzyme (e.g., amylase).
132
The end result after the reaction
Product (e.g., maltose, glucose).
133
What is the purpose of heat-fixing the smear?
What cells can you not apply heat?
Make them fix to the slide
Animal cells should not apply heat because they can lyse.
134
Why might fungal colonies be found growing on the Petri dish with the bacteria colonies?
Spores are all over, you can find it on damp surfaces.
135
How can Bacteria gain resistance to antibiotics?
Through mutation, and horizontal gene transfer
136
What is the name for spherical bacterial cells?
coccus
cocci
137
What is the name for rod-shaped bacterial cells?
bacillus
bacilli
138
What is the name for spiral-shaped bacterial cells?
pirillum
spirilla
spirochete
spirochetes
139
The prefix strepto means 'occur in
chains
chain
140
The prefix staphylo means 'occur in
bunches
bunch
clusters
cluster
groups
group
141
_____ happens when a bacterial cell takes in new DNA from the environment.
Transformation
142
_____ happens when DNA is transferred from a donor bacterial cell to a recipient bacterial cell.
Conjugation; donor, recipient
143
_____ happens when a bacterial cell receives new DNA from another organism or from the environment
Horizontal Gene Transfer
144
Bacteria reproduce via _____, which is a form of _____.
binary fission, vertical gene transfer
145
Bacterial cell walls are composed of
peptidoglycan
146
Bacteria are
unicellular, have a cell wall, are prokaryotes
147
The transfer of genetic material from parent to offspring during reproduction.
Vertical Gene transfer
Happens when bacteria replicate by binary fission.
148
The transfer of genes that happens when bacteria replicate by binary fission.
vertical gene transfer
149
The transfer of genetic material between organisms that are not parent and offspring. It often happens between different bacteria—even different species!
Horizontal gene Transfer
Occurs among living bacteria
150
Main ways _____ Gene Transfer happens:
*______ – DNA is transferred through direct contact (via a pilus).
*______ – Bacteria absorb DNA from the environment (usually from dead bacteria).
Main ways Horizontal Gene Transfer happens:
Conjugation – gDNA is transferred through direct contact (via a pilus).
Transformation – Bacteria absorb DNA from the environment (usually from dead bacteria).
151
What is the difference between cellular respiration and breathing?
The production 4 ATP's, the cell uses 2 ATP
152
DNA is transferred through direct contact (via a pilus).
Conjugation
153
What is the chemical reaction for aerobic cellular respiration?
C6H12O6 + 6O2 → 6CO2 + 6H2O + Energy (ATP).
154
For every molecule of glucose, a total of __ATP's are produced
36
155
Why did the BTB change color?
It is an acid base indicator
156
In fermentation, ____ is produced, _____ is a waste
alcohol is produced, CO2 is a waste
157
What goes into cellular respiration?
Glucose and oxygen
158
What is waste and what is produced in cellular respiration?
CO2 and water is waste, ATP is produced
159
Glycolysis:
Inputs: Glucose, 2 ADP, 2 Pi, 2 NAD+.
Outputs: 2 Pyruvate, 2 ATP, 2 NADH
Glycolysis:
Inputs: Glucose, 2 ADP, 2 Pi, 2 NAD+.
Outputs: 2 Pyruvate, 2 ATP, 2 NADH
160
