Bio Exam 1 Flashcards
(313 cards)
1
Q
What is biology?
A
The study of living organisms and life, and their interactions with each other and their environments.
2
Q
What is natural science?
A
The branch of science that deals with the physical world.
3
Q
What is basic science?
A
Science done simply to gain knowledge, regardless of application. No product or service is developed.
4
Q
What is applied science?
A
Science applied to real-world problems, with the problems defined by the researchers.
5
Q
What is inductive reasoning?
A
From a number of observations, a general conclusion is drawn.
6
Q
What is deductive reasoning?
A
From a general premise, specific results are predicted.
7
Q
What is a theory?
A
A hypothesis that has been thoroughly tested and has not yet been falsified.
8
Q
What is a hypothesis?
A
A prediction based on prior knowledge that can be tested and falsified.
9
Q
Serendipity
A
fortunate accidents or lucky surprises (like how penicillin was discovered)
10
Q
What is a cell?
A
The smallest structural and functional unit of life.
11
Q
What is Gene Theory?
A
Genes are the basic units of inheritance and are comprised of DNA. .
12
Q
What is the Theory of Heredity?
A
How traits are passed from parents to their offspring.: Genes are located on chromosomes, which come in pairs called diploids. The mom gives one chromosome of each pair and the dad gives the other. Variations in traits happen because genes can have different versions, called alleles.
13
Q
What is the Theory of Evolution?
A
If an organism changes during life to adapt to its environment, those changes are passed on to its offspring.
14
Q
Chemotaxis
A
The movement of an organism response to a chemical stimulus. Can be positive chemotaxis (moving toward the stimulus) or negative chemotaxis (moving away from the stimulus)
15
Q
Phototaxis
A
The movement of an organism in response to light. Can be positive phototaxis (moving toward the stimulus) or negative phototaxis (movement away from the stimulus)
16
Q
Evolutionary adaptation in Archaea
A
Archaea are a type of microorganism that can survive in extreme environments. This is because some Archaea live in boiling hot springs, and they have adapted to survive at extremely high temperatures.
17
Q
Homeostasis in organisms
A
The conditions a cell needs to function properly (such as temperature and pH) can change at any time. Homeostasis helps organisms keep their internal conditions stable and within a safe range, even when the environment around them changes.
18
Q
What is taxonomy?
A
The branch of biology that names and classifies species.
19
Q
What is phylogeny?
A
The evolutionary history of a kind of organism
20
Q
What is a phylogenetic tree?
A
Shows which species an organism evolved from and which species the organism is most closely related to.
21
Q
What does a node represent on a phylogenetic tree?
A
A common ancestor from which two species have descended from
22
Q
What is a eukaryote?
A
An organism containing a nucleus and other membrane-bound organelles. Most are multicellular. The DNA/chromosome structure is linear.
23
Q
What is a prokaryote?
A
A microscopic single-celled organism that has neither a distinct nucleus with a membrane nor other specialized organelles. It does have ribosomes though. The DNA/chromosome structure is circular.
24
Q
Similarities between animal cells, plant cells, and bacterial cells
A
The only things all three of them share are a plasma membrane and ribosomes. Animal and plant cells are eukaryotic and bacterial cells are prokaryotic, and we know the differences between those. Plant cells are unique bc they have cell walls, chloroplasts, and vacuoles. Animal cells are unique bc they have centrioles. Bacterial cells are unique bc they are prokaryotic.
25
What are the 4 Tenets of Cell Theory?
- All living organisms are made of one or more cells
- Chemical reactions necessary for life take place in cells
- All cells arise only from pre-existing cells
- Cells contain hereditary information in the form of DNA.
26
What is the scientific method?
1. Make an observation
2. Ask a question
3. Form a hypothesis that answers the question
4. Make a prediction based on the hypothesis
5. Do an experiment to test the prediction
6. Analyze the results
7. Report results
8. Conduct a new experiment if hypothesis is not supported.
27
What are the 8 Fundamental Traits of Life?
1. Order
2. Sensing and responding to stimuli
3. Growth
4. Reproduction
5. Evolutionary adaptation
6. Evolution
7. Regulation/Homeostasis
8. Energy Processing.
28
What are the Taxonomic Ranks?
- Domain
- Kingdom
- Phylum
- Class
- Order
- Family
- Genus
- Species.
29
Inductive reasoning is ________ based
Discovery based.
30
Deductive reasoning is _______ based
Hypothesis based.
31
True or false: all eukaryotes are multicellular
False. Protists, for example, are single-celled eukaryotes.
32
Who created the phylogenetic tree?
Microbiologist Carl Woese.
33
What did Woese use to create the phylogenetic tree?
Data that he obtained from sequencing ribosomal RNA genes.
34
What does data derived from 'controls' in a control experiment do?
Does not eliminate variables, but it cancels their effects.
35
What are the 12 Levels of Organization Among Living Things?
1. Atom
2. Molecule
3. Organelle
4. Cell
5. Tissue
6. Organ
7. Organ System
8. Organism
9. Population
10. Community
11. Ecosystem
12. Biosphere
36
Which of the 12 levels of organization do prokaryotes (single-celled organisms) have?
The first four (atom to cell). Anything that goes past that is multicellular (by definition, this is common sense).
37
What is a population?
All of the individuals of a species that live in a specific area.
38
What is a community?
The sum of populations inhabiting a particular area.
## Footnote
Example: the forest's community includes the population of pine trees, spiders, etc.
39
What is an ecosystem?
All the living things in a particular area and their abiotic (physical) environment.
40
What is a biosphere?
The sum of all ecosystems on earth.
41
What is evolution?
The overall process of changes over time.
42
What is natural selection?
A mechanism of evolution where organisms better adapted to their environment tend to survive and produce more offspring.
43
What is Darwin's Theory of Evolution Inference #1?
Offspring with the 'best' traits leave more offspring than others because their traits help them survive and reproduce more in their environment
44
What is Darwin's Theory of Evolution Inference #2?
Heritable, favorable traits, called adaptations, accumulate over time, matching the species to its current environment.
45
What is relative fitness?
A measure of how good a specific trait is at helping organisms survive and reproduce compared to other traits in the same population.
46
What is the relative fitness ratio?
Absolute fitness/average fitness (you don't need to know the definitions of these)
47
What is matter?
Anything that takes up space and has mass.
48
What are elements?
A fundemental substances that cannot be broken down further by chemical reactions.
49
What is a compound?
A substance consisting of two or more elements combined in a fixed ratio, with properties different from the individual elements.
50
What is nitrogen's role in plants?
An essential macro for plant function and a key component of amino acids (important for plant proteins).
51
What is nitrogen deficiency?
Symptoms include yellowing plant leaves and stunted growth, indicating an unhealthy plant.
52
What is iodine essential for?
The production of thyroid hormones, found primarily in seawater and soil in coastal areas.
53
What is hypothyroidism?
Iodine deficiency that can cause a goiter (enlarged thyroid). Cats are commonly affected by this.
54
What is hyperthyroidism?
Iodine excess that causes overproduction of thyroid hormones.
55
What is iron essential for?
The role of hemoglobin, a protein that transports oxygen in the blood.
56
What is Heme β?
a component of hemoglobin
57
What is anemia?
Iron deficiency that occurs when the blood doesn't have enough red blood cells (where hemoglobin is found, leading to oxygen deprivation.
58
What is iron excess?
Polycythemia vera. Blood cancer that causes overproduction of red blood cells. Leads to thick, slow-flowing blood. Can be genetic or caused by blood transfusions. Usually treated by removing blood
59
What is an atom?
the smallest unit of matter that retains the properties of an element
60
What is 1 Dalton?
A unit used to express atomic weight, AKA the atomic mass unit. 1 dalton/1 amu = 1.67 x 10^-24 g
61
What is the mass number?
The sum of the number of protons and neutrons in an atom.
62
What is atomic number?
The number of protons in an atom. In an uncharged atom, this is the number of electrons as well
63
What are isotopes?
Different forms of the same element with the same number of protons but different numbers of neutrons.
64
What is radioactive decay?
When an unstable atomic nucleus emits particles (alpha, beta, or gamma particles) and energy, transforming it into an atom of a different element.
65
What is beta decay? Give the example of Carbon-14.
The type of radioactive decay where the nucleus emits a beta particle.
Carbon-14 beta decay: beta particle is emitted and Carbon-14 becomes Nitrogen-14
66
What is radiometric dating?
Determining the age of an object containing organic matter by using radioactive isotopes. (Ex: carbon dating uses radioactive carbon)
67
What is half-life?
The time it takes for half the atoms in a radioactive substance to decay.
68
What is valence/valency?
Usually equal to the number of UNPAIRED electrons in the outermost shell. (the chem definition is the total number electrons in the outer shell, not just the number of unpaired ones
69
What are electron orbitals?
The three-dimensional space where an electron is found 90% of the time.
70
What are chemical bonds?
The sharing or transferring of electrons
71
What is a covalent bond?
The sharing of a pair of valence electrons, forming a very strong bond.
72
What is a double bond?
When two pairs of electrons are shared.
73
What is a molecular compound?
Consists of two or more different elements.
74
What is a molecule?
two or more atoms held together by covalent bonds
75
What is an unreactive atom?
An atom with a full valence shell.
76
What is a reactive atom?
An atom with an incomplete valence shell that reacts with other atoms to complete it.
77
What do all life forms share? (5 things)
1. The same genetic material (DNA, mRNA, tRNA)
2. The same genetic code (A, C, G, T)
3. The same gene expression process (transcription and translation)
4. The same molecular building blocks (proteins made of 20 amino acids)
5. The presence of ribosomes.
78
What are the 4 most common elements of living organisms?
1. Carbon (valence 4)
2. Oxygen (valence 2)
3. Hydrogen (valence 1)
4. Nitrogen (valence 3)
Together they make up 96% of living matter.
79
Molar masses of H, O, C, and N
Hydrogen = 1
Oxygen = 16
Carbon = 12
Nitrogen = 14
80
What are the three carbon isotopes?
1. 12C (common, stable)
2. 13C (common, stable)
3. 14C (rare, highly unstable, radioactive)
81
What are the 11 essential elements (vital and needed in larger amounts)?
1. Hydrogen (H)
2. Oxygen (O)
3. Nitrogen (N)
4. Carbon (C)
5. Calcium (Ca)
6. Potassium (K)
7. Magnesium (Mg)
8. Sulfur (S)
9. Sodium (Na)
10. Chlorine (Cl)
11. Phosphorus (P)
82
What are the 14 trace elements (vital but only needed in tiny amounts?)
1. Zinc (Zn)
2. Tin (Sn)
3. Iron (Fe)
4. Fluorine (F)
5. Cobalt (Co)
6. Boron (B)
7. Copper (Cu)
8. Iodine (I)
9. Chromium (Cr)
10. Manganese (Mn)
11. Silicon (Si)
12. Vanadium (V)
13. Selenium (Se)
14. Molybdenum (Mo)
83
Who are the two Darwins of evolution?
Erasmus Darwin and his grandson Charles Darwin.
84
Are the theory of evolution and the theory of natural selection the same?
No, they are not the same.
85
What laid the groundwork for Darwin's studies on evolution?
Darwin's travels as a naturalist from 1831-1836.
86
What happened in 1858 regarding evolution?
Alfred Wallace and Darwin connected with the same ideas and publicly presented their work together.
87
What is 'On The Origin of Species'?
Darwin's book that came out in 1859, arguing that evolution was an old idea and natural selection was the new, more accurate idea.
88
Which two atomic particles have essentially the same mass?
Proton and neutron.
89
In which part of the periodic table do elements have very similar chemical properties?
In the same vertical column.
90
Where are most biologically important elements located on the periodic table?
In the top three rows.
91
How many electrons fill the first shell of an atom?
2 electrons.
92
How many electrons fill subsequent shells of an atom?
8 electrons.
93
How many bonds does H2 form?
1 (a single bond).
94
How many bonds does O2 form?
2 (a double bond).
95
How many bonds does N2 form?
3 (a triple bond).
96
What is electronegativity?
A measure of how strongly an atom pulls electrons toward itself in a bond/how attracted an atom is to the electrons in the bond
97
What is a polar covalent bond?
Electrons are shared unequally and the atoms have different electronegativities.
98
What is a nonpolar covalent bond?
Electrons are shared equally and the atoms have similar electronegativities.
99
What are strong bonds?
Covalent and ionic bonds.
100
What is an ionic bond?
When electrons are transferred from one atom to another, making one atom a cation and one atom an anion. The opposite charges create the bond that holds the ions together.
101
What are ions?
Atoms with more or fewer electrons than the number of protons, making them charged.
102
What are weak bonds?
Hydrogen bonds and Van der Waals interactions.
103
What is a hydrogen bond?
Forms when a hydrogen atom covalently bonded to an electronegative atom (either N, O, or F) is attracted to and bonds with another electronegative atom.
104
What are Van der Waals interactions?
Occur when transiently (lasting only a short amount of time) positive and negative regions of molecules attract to each other.
105
What is chemical equilibrium?
When the rate of the forward reaction reaches that of the reverse reaction.
106
What does hydrophilic mean?
Water loving; has an affinity with water.
107
What does hydrophobic mean?
Water-fearing; has no affinity with water.
108
What is cohesion?
The attraction of one water molecule to another due to hydrogen bonding.
109
What is surface tension?
A measure of how hard it is to break the surface of a liquid when placed under stress.
110
What is adhesion?
Attraction between water molecules and other molecules.
111
What is specific heat?
The amount of heat that must be absorbed or lost for 1 gram of a substance to change temperature by 1ºC.
112
What is a calorie?
The amount of heat energy necessary to raise the temperature of 1 gram of water by 1ºC. (specific heat, but specifically for water)
113
What is a kilocalorie (kcal)?
1000 calories (food Calories = 1 kcal).
114
What is evaporation?
The transformation of a substance from a liquid to a gas.
115
What is heat of vaporization?
The quantity of heat that must be absorbed for 1 gram of a liquid to be converted to a gas.
116
What is evaporative cooling?
As bonds must be broken for evaporation, energy is taken from the environment, cooling it.
117
What is a solute?
The substance that is dissolved.
118
What is a solvent?
The liquid that dissolves the solute.
119
What is a solution?
The mixture of a solute and solvent.
120
What is the sphere of hydration?
The shell of water molecules surrounding an ion or polar molecule in a solution. This is what makes water such a great solvent.
121
What is dissociation?
When molecules or ionic compounds dissociate/break down into smaller components such as ions or atoms.
122
What is a mole?
Represents an exact number, 6.02214 x 10^23 units, called Avogadro's number.
123
What is 1 molar (M)?
A solution has a concentration of 1 molar when it has 1 mole of a solute in 1 liter.
124
What is an acid?
Any substance that increases the hydrogen ion concentration of a solution.
125
What is a base?
Any substance that reduces the hydrogen ion concentration of a solution.
126
What is the pH scale?
A measure of the H+ concentration of a solution.
127
What is the pOH scale?
A measure of the OH- concentration of a solution.
128
What are buffers?
Substances that minimize changes in the concentrations of hydrogen and hydroxide ions in a solution. Consist of a weak acid-base pair. They can accept or donate H+ ions when necessary.
129
What is carbon's role in macromolecules?
The backbone/key component.
130
What are hydrocarbons?
Molecules consisting only of carbon and hydrogen.
131
What is an aliphatic hydrocarbon?
A linear chain of carbon atoms.
132
What is an aromatic hydrocarbon?
A closed ring of carbon atoms.
133
What is benzene?
A 6-carbon ring with alternating double bonds.
134
What is beta-carotene?
A hydrocarbon with both an aliphatic and aromatic portion, responsible for the orange color in fruits and vegetables.
135
What is unique about the bonds/polarity of carbon dioxide?
The bonds are polar but the molecule is nonpolar because it has a linear structure.
136
Classic example of a nonpolar molecule
methane (CH4)
137
What are oxygen and nitrogen in terms of electronegativity?
They are strongly electronegative.
138
What do chemical reactions do?
They break bonds in the reactants to form new bonds in the products.
139
What percentage of our body is water?
70%.
140
What are evaporation of sweat in humans and panting in dogs examples of?
Homeostasis; it helps with the regulation of internal body temperature.
141
What type of bonds are water molecules made with?
Polar covalent bonds.
142
What does the polarity of water result in?
Hydrogen bonding.
143
How many hydrogen bonds can water molecules form?
Up to 4 hydrogen bonds.
144
Partial charges on a water molecule
Delta - on the oxygen and delta + on the hydrogens
145
What is water considered?
The universal solvent.
146
What does water dissociate into?
A hydrogen ion (H+) and a hydroxide ion (OH-).
147
What does a lower pH indicate?
The solution is more acidic.
148
What does a higher pH indicate?
The solution is more basic.
149
On a pH scale, what is the most acidic, neutral, and most basic?
1 is the most acidic, 7 is neutral, and 14 is the most basic.
150
What is the relationship between pH and pOH?
pH + pOH = 14.
151
What is the relationship between pH and [H+]?
pH = -log [H+]. The reverse is [H+] = 10^-pH
152
What is the relationship between pOH and [OH-]?
pOH = -log [OH-]. The reverse is [OH-] = 10^-pOH
153
In pure water, what are the concentrations of [H+] and [OH-]?
[H+] = 10^-7 and [OH-] = 10^-7. Therefore, [H+] x [OH-] = 10^-14
154
What is the pH of pure water?
7.
155
What are the three states of water?
1. Solid - not enough energy to break hydrogen bonds, crystalline structure is maintained.
156
In pure water, what are the concentrations of [H+] and [OH-]?
[H+] = 10^-7 and [OH-] = 10^-7 Therefore, [H+] x [OH-] = 10^-14
## Footnote
Therefore, [H+] x [OH-] = 10^-14
157
What is the pH of pure water?
7
158
What are the three states of water?
1. Solid - not enough energy to break hydrogen bonds, crystalline structure is maintained.
2. Liquid - hydrogen bonds constantly breaking and reforming.
3. Gas - hydrogen bonds are completely broken.
159
What is unique about solid water?
It is less dense than liquid water (ice floats in water). This is not seen in other substances!
160
What are isomers?
Compounds that have the same number and types of atoms in an element, but they are arranged differently.
161
What are structural isomers?
Isomers that differ in covalent arrangement, same molecular formula, varying functions based on shape.
162
What are geometric isomers?
Isomers that have a similar placement of covalent bonds but differ in how these bonds are made to the surrounding atoms, especially in C=C bonds.
163
What are enantiomers?
Molecules that share the same chemical structure and chemical bonds but differ in the three-dimensional placement of atoms so that they are NON-SUPERIMPOSABLE MIRROR IMAGES.
164
What are functional/chemical groups?
Groups added to hydrocarbons to replace a hydrogen to form vastly more complex organic molecules.
## Footnote
Example: an OH group replacing a hydrogen.
165
What is an aldehyde sugar/aldose?
A sugar that contains a terminal carbonyl group (on the terminal end, on the tail).
166
What is a ketone sugar?
A sugar that contains an internal carbonyl group.
167
What is a hydroxyl group?
O-H (single bond).
168
What is a carbonyl group?
C=O (double bond).
169
What is a sulfhydryl group?
S-H (single bond).
170
What is an amino group?
NH2.
171
What is a carboxyl group?
COOH.
172
What is a phosphate group?
PO43-.
173
What is a methyl group?
CH3.
174
What are organic molecules?
Molecules that all contain carbon and may also contain hydrogen, oxygen, nitrogen, and some other minor elements.
175
What are dehydration reactions?
Reactions in which large macromolecules form by joining monomers in condensation reactions. WATER IS LOST IN THIS PROCESS.
176
What are hydrolysis reactions?
Processes of breaking down polymers into individual monomers.
177
What is a monosaccharide?
The simplest form of sugar/one monomer of sugar.
178
What is maltose?
A disaccharide made of two glucose monomers.
179
What is sucrose?
A disaccharide made of the monomers glucose and fructose.
180
What is lactose?
A disaccharide made of the monomers glucose and galactose.
181
What are glycosidic linkages?
Bonds that link two monosaccharides, creating a disaccharide.
182
What are polysaccharides?
Long chains of monosaccharides joined by glycosidic linkages.
183
What is starch?
A polysaccharide consisting entirely of glucose monomers/monosaccharides.
184
What is amylose?
A linear (unbranched) chain of glucose monomers in ALPHA 1-4 glycosidic bonds.
185
What is amylopectin?
A branched chain of glucose monomers in ALPHA 1-4 and ALPHA 1-6 glycosidic bonds
186
What is glycogen?
The storage form of glucose, a branched chain of glucose monomers in ALPHA 1-4 and ALPHA 1-6 glycosidic bonds.
187
What is cellulose?
The only polysaccharide with BETA 1,4 glycosidic bonds.
188
What is chitin?
The only polysaccharide with a modified sugar (the sugar contains nitrogen).
189
What are enzymes?
Protein catalysts in chemical reactions and are very susceptible to denaturation.
190
What are amino acids?
The monomers that make up proteins.
191
What is a peptide bond?
The bonds that link amino acids to form polypeptides.
192
What is a polypeptide?
A chain of amino acids/peptide bonds together.
193
What is a protein?
Made of one or more polypeptides.
194
What is primary structure in proteins?
The unique sequence of amino acids in a polypeptide.
195
What is secondary structure in proteins?
Local folding of the polypeptide into a repeating configuration via hydrogen bonding, can be an alpha helix or a beta pleated sheet.
196
What is an α-helix?
Formed by a hydrogen bond between oxygen in a carbonyl group and an amino acid 4 positions down the chain.
197
What is a β-pleated sheet?
Hydrogen bonding between atoms on the backbone of the polypeptide chain creates pleats.
198
What is tertiary structure in proteins?
The three-dimensional shape of a polypeptide resulting from interactions between amino acids, especially their R groups and H-bonding.
199
What is quaternary structure in proteins?
The overall protein structure that results from the aggregation of two or more polypeptide chains; it is optional.
200
What causes sickle cell disease?
A single amino acid substitution in the protein hemoglobin.
201
What is denaturation?
Occurs when a protein unravels and loses its native conformation.
202
What is protein conformation?
The arrangement of the atoms in a protein molecule, which determines how the protein functions.
203
What are lipids?
Hydrophobic and nonpolar molecules that are not true polymers.
204
What are fats?
A specific type of lipid composed of a glycerol (a 3-carbon molecule) and three fatty acids.
205
What are ester bonds?
The bonds that link fatty acids and glycerol to form fats.
206
What are saturated fatty acids (SFAs)?
Fatty acids that increase the amount of LDL (low-density lipoprotein) in the blood.
207
What are unsaturated fatty acids (UFAs)?
Fatty acids that increase the amount of HDL (high-density lipoprotein, good cholesterol) and decrease LDL (bad cholesterol) in the blood.
208
What are omega-3 and omega-6 fatty acids?
The only two essential unsaturated fatty acids that must be obtained from the diet.
209
What is the cis configuration in fatty acids?
The configuration where the hydrogens are on the same side of the carbon backbone chain, creating a bend.
210
What is the trans configuration in fatty acids?
The configuration where the hydrogens are on opposite sides of the carbon backbone chain, keeping the chain linear.
211
Why are cis-fatty acids liquid at room temperature?
Because of the bend in the carbon backbone, the fatty acids cannot be packed as tightly.
212
Why are trans-fatty acids solid at room temperature?
Because there is no bend in the carbon backbone, the fatty acids can be packed more tightly together.
213
Which forms of ibuprofen and albuterol are the effective enantiomer forms?
The s-form of ibuprofen and the r-form of albuterol.
214
What makes methyl unique from other functional groups?
It is nonpolar, hydrophobic, and non-reactive.
215
What suffix do most names for sugars end with?
-ose.
216
In what form are monosaccharides mostly found in aqueous solutions?
As rings.
217
When glucose forms a ring, where can the OH at carbon #1 end up?
In the down position (alpha) or in the up position (beta).
218
What are the 2 structural polysaccharides and what do they provide structure for?
Cellulose - structure for plants
Chitin - structure for fungi/arthropods.
219
How many common amino acids make up proteins, and how many of those are essential?
20 common amino acids, 9 essential.
220
Which protein structures are optional?
Only quaternary structure; every protein has the other three.
221
Does hemoglobin have quaternary structure?
Yes.
222
What type of reaction do glycosidic, peptide, and ester bonds perform when they form?
Dehydration reactions because they all lose H2O when they form bonds.
223
What two factors play a huge role in the conformation and denaturation of proteins?
pH and temperature.
224
What are the three main subtypes of carbohydrates?
Monosaccharides, disaccharides, polysaccharides.
225
What are the four main classes of macromolecules?
Carbohydrates, proteins, lipids, and nucleic acids.
226
Which of the four main classes of macromolecules is unique and why?
Lipids are unique because they are not polymers like the other three.
227
What are the six functions of proteins?
1. Regulatory
2. Structural
3. Protective
4. Transport
5. Enzymes
6. Toxins.
228
What are the three types of enzymes?
1. Catabolic - break down substrates
2. Anabolic - build more complex molecules
3. Catalytic - affect the rate of reactions.
229
What are the five parts of an amino acid?
1. Central carbon
2. Hydrogen
3. Amino group
4. Carboxyl group
5. R-group (side chain).
230
What are the three aromatic (ring structure) amino acids?
Phenylalanine, tryptophan, tyrosine.
231
What are the four functions of lipids?
1. Long-term energy storage
2. Insulation from environment
3. Component of cell membranes
4. Building blocks for some hormones.
232
What property of water molecules can capillary action be attributed to?
Adhesion.
233
When the pH of a solution changes from 6 to 5, what is the increase in the concentration of H+ ions?
10-fold increase.
234
How many covalent bonds can a carbon atom form?
4.
235
Explain Jedwa's table that relates pH, pOH, [H+], and [OH-] using a pH of 6.
[H+] = 10^-6, pH = 6, pOH = 8, [OH-] = 10^-8.
236
Which biomolecule is NOT considered a true polymer?
lipids
237
Which nucleotide is present in RNA but not DNA?
uracil
238
DNA's pentose sugar vs RNA's pentose sugar
DNA's pentose sugar is deoxyribose. It has an H on the C-2 of the pentose sugar.
RNA's pentose sugar is ribose. It has an OH on the C-2 of the pentose sugar.
239
The unique sequence of AAs in a protein determines which structure?
It's primary structure
240
What are the characteristics of a compound with a methyl group as its predominant functional group?
It will be hydrophobic and not form hydrogen bonds with water (bc it will also be nonpolar).
241
List the three main characteristics of glycogen as a storage polysaccharide.
1. Highly branched, allowing for rapid mobilization of sugar units during metabolic need
2. Stored primarily in liver and muscle cells
3. Glycogen stores are mainly replenished through food consumption
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Hydrolysis is involved with which 3 main processes?
Hydrolysis is the process of breaking down molecules by adding water. It is involved in breaking down polymers into monomers, such as:
1. Converting glycogen to glucose
2. Converting triacylglycerol to a mixture of fatty acids + glycerol
3. Converting DNA to a mixture of four deoxynucleotides
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Amphipathic
having both hydrophilic and hydrophobic parts
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Phospholipids
Same as triglycerides except one of the three fatty acids is replaced with a phosphate group. The phosphate “head” is hydrophilic and the fatty acid “tails” are hydrophobic (making phospholipids amphipathic)
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Steroids/sterols
lipids with a carbon skeleton made of four fused rings: three honeycombs and a house
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Nucleic acids
DNA and RNA. Constitute the genetic material of living organisms. They store and transmit hereditary information. They are polymers called polynucleotides.
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Nucleotides
Combine to form the polynucleotides DNA and RNA. Composed of a nitrogenous base, of a pentose (5-carbon) sugar, and a phosphate group.
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Nucleosides
Incomplete nucleotides. Composed of a nitrogenous base and a pentose sugar. (Remember: nucleoSide Stops at Sugar)
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Pyrimidines
Single-ring nitrogenous bases. Cytosine, Thymine, and Uracil.
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Purines
double-ring nitrogenous bases. Adenine and Guanine.
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Uracil
The substitute/replacement for Thymine in RNA.
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Phosphodiester bonds
the bonds that link nucleotides together on A SINGLE DNA STRAND
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Lipid bilayer
the main building block of the plasma membrane, made of phospholipids because of their amphipathic nature. It has two layers of phospholipids. The inner layer/core is hydrophobic because the tails of the phospholipids (the hydrophobic parts) face each other so they’re turned away from the fluid on both sides of the membrane
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The nature of DNA strands
Complementary to each other; the 3' end of one strand faces the 5' end of the other. They spiral around each other to form a double helix
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The role of hydrogen bonds in DNA
Hydrogen bonds bind the nitrogenous bases/nucleotides together BETWEEN THE 2 DNA STRANDS. (Remember, the pairs are A+T and G+C (or A+U in RNA)
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How many hydrogen bonds do A+T and G+C form?
A+T = 2 bonds
G+C = 3 bonds
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The 4 locations of nucleic acids
Mitochondria
Chloroplasts
Nucleus of eukaryotic cells
Prokaryotic cells (no nucleus, but still)
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Plasma membrane
A semipermeable membrane that separates the living cell from its surroundings. Made of two layers of phospholipids (the bilayer), proteins, cholesterol, and carbohydrates.
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Fluid mosaic model
Describes the structure of cell membranes.
"Fluid" refers to the membranes' flexibility, dynamics, and ever-changing nature. "Mosaic" refers to the collage of different molecules scattered throughout the membrane.
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Integral proteins
Embedded through BOTH layers of the bilayer so they can transport molecules in or out.
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Peripheral proteins
Embedded through only ONE layer of the bilayer (can be the exterior or interior layer). They typically serve as enzymes or provide the membrane with structural support.
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Transmembrane proteins
The main type of integral protein. Two types: channel proteins and carrier proteins.
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Carrier proteins
They are specific to a single substance. They bind to it and change shape to carry the substance across the membrane. Can move in either direction, as concentration gradients change.
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Protein pumps
carrier proteins used in primary and secondary active transport
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GLUTS
Glucose transport proteins. A classic example of carrier proteins.
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Channel proteins
Composed of hydrophilic amino acids. The proteins' beta-pleated sheets form pores/channels in the membrane that allow specific substances to pass through. The channels can be gated (opening and closing in response to signals) or ungated (constantly open).
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Examples of channel proteins
insulin receptors, aquaporins (allow water through), gated ion channels in muscle and nerve cells that allow muscle contractions when opened (allow sodium, potassium, and calcium through). Kidneys also have cells with channel proteins.
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Insulin receptor (IR)
A gated channel protein. It is activated/signaled to "open the gate" when it binds to insulin.
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Glycoproteins
Sugar + protein --> carbohydrates bound to proteins on the plasma membrane
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Glycolipids
Sugar + lipids. Carbs bound to lipids on the plasma membrane
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Endomembrane system
The group of membranes and membrane-bound organelles that work together to synthesize, modify, package, and transport proteins and lipids
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Passive transport
Diffusion of a substance across a membrane with no energy investment. Solute moves from areas of high concentration to areas of low concentration.
Three types: diffusion, osmosis, and facilitated diffusion.
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Active transport
Transport of a substance across a membrane with a required energy investment.
Three types: primary active transport, secondary active transport, and bulk transport.
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Diffusion
The tendency for molecules/a solute to spread out evenly into available space
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Osmosis
The movement of water across a SEMIPERMEABLE MEMBRANE. Unique because water moves from areas of low solute concentration to areas of high solute concentration. Osmosis occurs when a solute cannot pass through the membrane to even things out so the water moves to even things out instead. (This is the difference between diffusion and osmosis.)
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Water potential
The tendency of water to move from one place to another (generally, from areas of low concentration to areas of high concentration). Three types: hypertonic, hypotonic, and isotonic
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Plasma membranes are asymmetric. What two things does this affect?
It powers the endomembrane system and causes selective permeability, which allows some substances to pass through more easily than others.
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Where are carbs found in the plasma membrane?
On the exterior surface, attached to either proteins or lipids (to make glycoproteins or glycolipids).
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Why is the plasma membrane flexible?
Phospholipids can move within the bilayer, making it impossible to form a completely impenetrable barrier and making it flexible
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Role of cholesterol in the plasma membrane
It acts as a buffer, increasing fluidity at low temps and decreasing fluidity at high temps
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How do substances generally diffuse?
Down their concentration gradient (from high to low concentration)
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The Permeability of the Lipid Bilayer
- Small, nonpolar molecules pass through easily and quickly. Don’t require help from proteins.
- Small, polar molecules take longer to pass through and can only do it with the help of proteins
- Large, nonpolar molecules can pass through but slowly.
- Large polar molecules and ions cannot pass through without help
TO HELP REMEMBER: The bilayer's interior layer is hydrophobic and nonpolar. So nonpolar molecules will get through easier since they'll match the polarity of the cell's interior. And ofc the smaller the molecule the easier it'll get through
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Tonicity
The ability of a solution to cause a cell to gain or lose water. REFERS TO EXTRACELLULAR FLUID.
Three types: hypertonic, hypotonic, and isotonic.
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Isotonic
the concentration of solutes as the same as it is inside the cell, it is at equilibrium. There will be no net movement of water (the water will flow equally in both directions)
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Hypertonic
the concentration of solutes outside is greater than it is inside the cell, so the cell will lose water. Hypertonic = shriveled
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Hypotonic
the concentration of solutes outside is less than it is inside the cell and the cell will gain water. Hypotonic = swollen
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Cell lysis
cell rupture from being too hypotonic
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Electrochemical gradient
the energy source used for secondary active transport. Results from the combined effects of concentration and electrical gradients.
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Uniporters
A type of carrier protein pump that actively transports molecules through the plasma membrane. This type carries 1 molecule or ion in or out.
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Symporters
carries two molecules or ions in or out, but both in the same direction.
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Antiporters
carry two molecules or ions in or out, but in different directions.
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Primary active transport
moves an ion or molecule against its concentration gradient (from low to high). Uses energy from ATP hydrolysis.
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Classic example of primary active transport
the sodium potassium pump. Moves 3 NA+ out and 2K+ in using 1 ATP
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Electrogenic pumps
Transport proteins, generated voltage across a membrane
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Vesicle
A small, membrane-bound sac that forms around substances during endocytosis. It helps transport materials into the cell.
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Bulk transport
when cells need to import or export molecules/particles that are too large to pass through a transport protein.
Two types: endocytosis and exocytosis
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Exocytosis
one type of bulk transport. Transport vesicles migrate to the plasma membrane, fuse with it, and release their contents into the extracellular membrane space.
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Endocytosis
one type of bulk transport. the cell takes in molecules by forming new vesicles from the plasma membrane.
Three types: phagocytosis, pinocytosis, and receptor-mediated cytosis.
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Phagocytosis
"Cell eating". A type of endocytosis where a cell engulfs large particles, by extending its membrane around them to form a vesicle.
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Pinocytosis
"Cell drinking". A type of endocytosis where the cell takes in extracellular fluid and dissolved solutes by forming small vesicles.
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Receptor-mediated endocytosis
A type of endocytosis where the cell uses receptor proteins to recognize specific molecules, then it folds its membrane around those molecules to form a vesicle and transport the molecules into the cell.
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Animals and other organisms without rigid cell walls live in _______ or _________ conditions, but they have to adapt to survive that way. ______ conditions are most preferable but uncommon.
Hypertonic or hypotonic, isotonic
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Animal cells have ________ pressure while plant cells have ______ pressure
osmotic, turgor
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The cytoplasm in plants is always slightly _______to the cellular environment
hypertonic
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Plant cells are healthiest in a _______ environment. these plant cells are called ______ plant cells.
Hypotonic, turgid
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Osmoregulation
The regulation of an organisms' osmotic pressure/water balance.
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Osmoregulation in freshwater protists
The protists use contractile vacuoles to pump water out of the cell to keep it from bursting.
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Osmoregulation with osmoreceptors
Osmoreceptors are specialized cells in the brain that monitor solute concentration in the blood. If the solute levels increase too much, a hormone activates and slows water loss through the kidney and dilutes the blood to a safer level.
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Are polar molecules and ions hydrophilic or hydrophobic?
Hydrophilic
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Are nonpolar molecules hydrophobic or hydrophilic?
hydrophobic
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Active transport requirements
- Must move AGAINST its concentration gradient
- needs ATP energy
- needs a protein pump for transport
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Role of ATP in active transport
the ATP is responsible for shifting a phosphate group from ATP to the transport protein, which is what induces the protein to change shape and transport the substance across the membrane (see carrier protein)
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Alternative form of energy for secondary active transport
electrochemical gradient
