Bio 111 Exam 1 Flashcards
1
Q
Evolution
A
The process of change that has transformed life on Earth from today. An organism’s adaptations to its environment are a result of this
2
Q
Biology
A
The scientific study of life
3
Q
What are the central activities of Biology?
A
Posing questions about the living world and seeking science-based answers- scientific inquiry
4
Q
What are 7 properties of life?
A
Order, response to environment, evolutionary adaptation, reproduction, regulation, energy processing, growth and development
5
Q
8 Unifying themes of biology
A
New properties emerge at each level in the biological hierarchy, organisms interact with other organisms and the physical environment, life requires energy transfer and transformation, structure and function are correlated at all levels of biological organization, the cell is an organism’s basic unit of structure and function, the continuity of life is based on heritable information in the form of DNA, feedback mechanisms regulate biological systems, evolution
6
Q
Emergent properties
A
Properties that emerge at each step, properties that are not present at the preceding level. Due to the arrangement and interactions of parts as complexity increases. Our thoughts and memories are emergent properties of a complex network of nerve cells
7
Q
Reductionism
A
the approach of reducing complex systems to simpler components that are more manageable to study
8
Q
System
A
a combination of components that function together
9
Q
Systems biology
A
An approach that attempts to model the dynamic behavior of whole biological systems based on a study of the interactions among the system’s parts
10
Q
Levels of biological organization
A
biosphere, ecosystems, communities, populations, organisms, organs and organ systems, tissues, cells, organelles, molecules
11
Q
Interactions between organisms ultimately result in…
A
the cycling of nutrients in ecosystems
12
Q
Organisms often transform one form of energy to another
A
.
13
Q
Energy flows through an ecosystem, usually entering as ____ and exiting as ____
A
energy flows through an ecosystem, usually entering as light and exiting as heat
14
Q
Why is it important that a leaf is thin and flat?
A
Its thin, flat shape maximizes the amount of sunlight that can be captured
14
Q
What is the lowest level of organization that can perform all activities required for life?
A
The cell
15
Q
What are the two main forms of cells?
A
Prokaryotic cells and eukaryotic cells
16
Q
What two groups of microorganisms are prokaryotic?
A
Bacteria (bacterium) and archaea (archaean)
17
Q
Eukaryotic cell
A
Subdivided by internal membranes into various membrane-enclosed organelles. In most eukaryotic cells, the largest organelle is the nucleus, which contains the cell’s DNA. Other organelles are located in the cytoplasm (the entire region between the nucleus and outer membrane of the cell.
18
Q
What is the largest organelle in most eukaryotic cells?
A
The nucleus, which contains the cell’s DNA
19
Q
Cytoplasm
A
The entire region between the nucleus and outer membrane of the cell in eukaryotic cells
20
Q
Chloroplast
A
An organelle found in eukaryotic cells that carry out photosynthesis
21
Q
Prokaryotic cell
A
The DNA is not separated from the rest of the cell by enclosure in a membrane-bounded nucleus
22
Q
DNA
A
The cells genetic material contained in the chromosomes. Short for deoxyribonucleic acid. Made up of two long chains, called strands, arranged in a double helix. Each chain is made up of four kinds of chemical building blocks called nucleotides (A, T, C, G). Provides the blueprints for making proteins, and proteins are the main players in building and maintaining the cell and carrying out its activities.
23
Q
Genes
A
The units of inheritance that transmit information from parents to offspring. DNA is the substance of genes
24
Enzymes
Catalyze (speed up) specific chemical reactions
25
RNA
Used by DNA as an intermediary to control protein production. The sequence of nucleotides along a gene is transcribed into RNA, which is then translated into specific protein with a unique shape and function. Not all RNA molecules in the cell are translated into protein
26
Gene expression
Information in a gene directs the production of a cellular product. Nucleotides transcribed into RNA, which is then translated into a specific protein with a unique shape and function. Differences between organisms reflect differences between their nucleotide sequences rather than between their genetic codes
27
Differences between organisms reflect differences between their _____ rather than between their _________
Differences between organisms reflect differences between their nucleotide sequences rather than between their genetic codes
28
Genome
"Library" of genetic instructions that an organism inherits
29
Genomics and examples that make this possible
Studying whole sets of genes of a species as well as comparing genomes between species. Important research developments have made this possible.
1) "High-throughput" technology, tools that can analyze biological materials very rapidly and produce enormous amounts of data. Automatic DNA-squencing machines
2) Bioinformatics
3) Formation of interdisciplinary research teams
30
Bioinformatics
Use of computational tools to store, organize, and analyze the huge volume of data that result from high-throughput methods.
31
Negative feedback
Most common form of regulation in living systems. Accumulation of an end product of a process slows that process. Example: cell's breakdown of sugar generates ATP
32
Feedback regulation
The output, or product, of a process regulates that very process
33
Positive feedback
An end product speeds up its own product. Example: clotting of your blood- chemicals released by platelets attract more platelets
34
Evolution
The idea that the organisms living on Earth today are the modified descendants of common ancestors
35
Core theme of biology
Evolution
36
Taxonomy
The branch of biology that names and classifies species
37
Three domains of life
Bacteria, Archaea, Eukarya
38
Bacteria
prokaryotic
39
Archaea
prokaryotic. At least as closely related to eukaryotic organisms as they are to bacteria.
40
Eukarya
All the eukaryotes (organisms with eukaryotic cells). Includes three kingdoms of multicellular eukaryotes: Plantae, Fungi, Animalia.
41
Three kingdoms of Eukarya and facts about each
Plantae- produce their own sugars and other food molecules by photosynthesis
Fungi- absorb dissolved nutirents from their surroundings; decompose dead organisms and organic wastes
Animalia- obtain food by ingestion
Neither animals, plants, nor fungi are as numerous or diverse as the single-celled eukaryotes we call protists
42
Protists
Single-celled eukaryotes. Plants, animals, or fungi are not as numerous or diverse. Was in their own kingdom, but not anymore because do nor form a single natural group of species
43
On the Origin of Species
One of mos important and influential books ever written. Published by Darwin.
1) Contemporary species areos from a succession of ancestors
2) "Natural selection" - descent with modification, individuals in a population vary in their traits, a population can produce far more offspring than can survive to produce offspring of their own, species generally suit their environments (aka they are adapted)
44
Natural Selection
Darwin. Mechanism of evolutionary adaptation. Called this because the natural environment "selects" for the propagation of certain traits.
Three observations:
1) Individuals in a population vary in their traits
2) Population can produce far more offspring than can survive to produce offspring of their own
3) Species generally suit their environment (are adapted)
45
Science
a way of knowing- an approach to understanding the natural world
46
Inquiry
The heart of science, a search for information and explanation. Scientists attempt to understand how natural phenomena work using a process of inquire that includes making observations, forming logical hypotheses, and testing them. Process is necessarily repetitive
47
Observation
Use of the senses to gather information. Recorded observations are called data
48
Data
Recorded observations.
Qualitative- recorded descriptions
Quantitative- measurements
49
Inductive reasoning
*Reasoning from a set of specific observations to reach a general conclusion.* A type of logic involving collecting and analyzing observations that can lead to important conclusions. We derive generalizations from a large number of specific observations
50
Hypothesis
A tentative answer to a well-framed question. Leads to predictions that can be tested. No amount of experimental testing can prove a hypothesis beyond a shadow of a doubt. Must be testable and falsifiable**
51
Deductive reasoning
Generally used after the hypothesis has been developed and involves logic that flows in the opposite direction, from the general to the specific. Takes the form of "If... then" logic
52
Scientific method
Observation > question > hypothesis > prediction > test > confirm or reject hypothesis. Must be repeatable
53
Warning coloration
Signals "dangerous species" to potential predators. Snake experiment
54
Controlled experiment
One designed to compare an experimental group with a control group. Researchers usually "control" unwanted variables not by eliminating them through environmental regulation, but by canceling out their effects by using control groups.
55
Theory
Much broader in scope than a hypothesis. General enough to spin off many new, specific hypotheses that can be tested. Compared to any one hypothesis, a theory is generally supported by a much greater body of evidence. Must sometimes modify or even reject theories
56
Model organism
A species that is easy to grow in the lab and lends itself particularly well to the questions being investigated. Fruit fly (drosophilia melanogaster), mustard plant (arabidopsis thaliana), soil worm (caenorhabditis elegans), zebrafish ( dania rerio), mouse (mus musculus), bacterium (escherichia coli)
57
Technology
Generally applies scientific knowledge for some specific purpose. Science and technology are interdependent
58
Goal of science?
To understand natural phenomena.
59
Matter
Organisms are composed of this. Anything that takes up space and has mass
60
Element
Makes up matter. Is a substance that cannot be broken down to other substances by chemical reactions
61
Compound
Substance consisting of two or more different elements combined in a fixed ratio
62
Essential elements
About 20-25% of natural elements. Organism needs these to live a healthy life and reproduce
63
What four elements make up 96% of living matter?
Oxygen, carbon, hydrogen, nitrogen
64
Trace elements
required by an organism in only minute quantities. Iodine is essential in vertebrates
65
Atom
smallest unit of matter that still retains the properties of an element. Mostly empty space
66
Atomic nucleus
the center of an atom; protons (positive charge) and neutrons (neutral)
67
Atomic number
Number of protons. Written as subscript
68
Dalton
same as the atomic mass unit (amu). Neutrons and protons have masses close to 1 dalton. Electrons are ignored when computing the total mass. There are 6.02 x 10^23 daltons in 1 g (because of Avogadro's number)
69
Mass number
Sum of protons and neutrons. Written as superscript. Neutrons = mass number(top) - atomic number(bottom)
70
Atomic mass
The total mass of an atom (the mass number is an approximation of this)
71
Isotopes
Different atomic forms of the same element. Slightly different masses. Behave identically in chemical reactions. An average of the atomic masses of all the element's naturally occurring isotopes is the atomic mass
72
Radioactive isotope
Isotope which the nucleus decays spontaneously, giving off particles and energy. Useful as tracers to follow atoms through metabolism
73
Energy
Capacity to cause change- for instance, by doing work
74
Potential energy
Energy that matter possesses because of its location or structure. Matter has a natural tendency to move to the lowest possible state of potential energy
75
Electron shells
Where electrons are found. Represented as circles. When an electron absorbs energy, it moves to a shell farther out from the nucleus
76
Periods
Rows of the periodic table
77
Valence electrons/ valence shell
Outermost shell. Chemical behavior depends mostly on the number of electrons here.
78
Inert
Chemically unreactive
79
Orbital
Space in which electron spends most of its time (since we can never know the exact location of an electron
80
Chemical bonds
Attractions that hold atoms together. Strongest are covalent and ionic
81
Covalent bond
Sharing of a pair of valence electrons by two atoms
82
Molecular Formula
Lewis dot structure
Structural formula
H2
H:H
H-H
83
Single bond
| Double bond
A pair of shared electrons
| Sharing two pairs of electrons
84
Atom's valence
The bonding capacity, usually equals the number of unpaired electrons required to complete the atom's outermost (valence) shell
85
Pure elements vs. Compound
H2 and O2 are pure elements. Compound is a combination of two or more different elements
86
Electronegativity
Attraction of a particular atom for the electrons of a covalent bond. More electronegative, more strongly it pulls
87
Nonpolar covalent
Two atoms have same electronegativity
88
Ion (cation and anion)
Ion is a charged atom (or molecule)
Cation- positive charge
Anion- negative charge
89
Polar covalent
One atom is bonded to a more electronegative atom. Unequal sharing of electrons
90
Ionic bond
Transfer of electron is not the formation of a bond; rather, it allows a bond to form because it results in two ions of opposite charge
91
Ionic compounds
Salts. Compounds formed by ionic bonds. Does not consist of molecules. Formula only indicates the ratio
92
Hydrogen bond
Noncovalent attraction between a hydrogen and an electronegative atom
93
Van der Waals interactions
Individually weak and occur only when atoms and molecules are very close together. Ever-changing regions of positive and negative charge that enable all atoms and molecules to stick to one another
94
Tetrahedron
A pyramid with a triangular base
95
Opiates have a shape similar to endorphins and mimic them by binding to endorphin receptors in the brain
.
96
Chemical reactions
Making and breakin of chemical bonds, leading to changes in the composition of matter
97
Reactants and products
Starting material- reactants, what is produced- products
98
Raw materials of photosynthesis? What powers the conversion? What it produces?
Raw materials- CO2 and H20
Sunlight powers the conversion
Converted into glucose and oxygen
6 CO2 + 6 H2O --> C6H12O6 + 6 O2
99
The greater the concentration of reactant molecules, the (more/less) frequently they collide with one another and have an opportunity to react and form products
more
100
Chemical equilibrium
Point at which the reactions offset one another exactly. Reactions are still going on, but with no net effect on the concentrations of reactants and products
101
Water
The biological medium here on Earth. Only common substance to exist in the natural environment in all three physical states of matter. All living organisms require this more than any other substance. Solid less dense than liquid. Water reaches its greatest density at 4C. Floating ice insulates the liquid water below, preventing it from freezing and allowing life to exist under the frozen surface. Most of the chemical reactions in organisms involve solutes dissolved in water.
102
Polar molecule
Overall charge is unevenly distributed
103
In water, which atom has the negative charge? The positive charge?
Oxygen is negative, hydrogen is positive
104
What holds water molecules together?
Hydrogen bonds. These linkages also make water more structured than most other liquids
105
Cohesion
Collection of hydrogen bonds that hold the substance (water) together. Cohesion due to hydrogen bonding contributes to the transport of water and dissolved nutrients agains gravity in plants
106
Adhesion
The clinging of one substance to another. Adhesion of water to cell walls
107
Surface tension
A measure of how difficult it is to stretch or break the surface of a liquid. Water has a greater surface tension than most other liquids
108
Kinetic energy
Energy of motion
109
Heat
A form of energy. The amount of heat is a measure of the matter's total kinetic energy due to motion of its molecules. Depends in part on the matter's volume
110
Temperature
A measure of heat intensity that represents the average kinetic energy of the molecules
111
How does an ice cube cool a drink?
Not by adding coldness to the liquid, but by absorbing heat from the liquid as the ice itself melts
112
Average human body temperature?
37 degrees C
113
Calorie
Amount of heat it takes to raise the temperature of 1 g of water by 1 degree C
114
Kilocalotie
Amount of heat required to raise the temperature of 1 kg of water by 1 degree C
115
Joule (J)
equal to 0.239 cal. 1 cal = 4.184 J
116
Specific heat
Amount of heat that must be absorbed or lost for 1 g of that substance to change its temperature by 1 degree C. Water usually has a high specific heat.
117
Does water have a high or low specific heat? How does this help Earth?
Water has a high specific heat. The water that covers most of Earth keeps temperature fluctuations on land and in water within limits that permit life
118
Evaporation
Vaporization. Liquid to gas
119
Heat of vaporization
Quantity of heat a liquid must absorb for 1 g of it to be converted from the liquid to the gaseous state. Water has a high heat of vaporization.
120
Evaporative cooling
As a liquid evaporates, the surface of the liquid that remains behind cools down. Occurs because the "hottest" molecules are the most likely to leave as a gas.
121
Solution
A liquid that is a completely homogeneous mixture of two or more substances
122
Solvent
The dissolving agent of a solution (typically water)
123
Solute
Substance that is dissolved
124
Aqueous solution
Solution where water is the solvent
125
Hydration shell
The sphere of water molecules around each dissolved ion
126
Hydrophilic
Affinity for water
127
Colloid
*A stable suspension of fine particles in a liquid.* Molecules that are so large they do not dissolve and instead remain suspended in the aqueous liquid of the cell.
128
Hydrophobic
Water fearing, seems to repel water
129
Molecular mass
The sum of the masses of all the atoms in a molecule
130
Mole (mol)
Represents an exact number of objects (6.02 x 10^23)
131
Avogadro's number
6.02 x 10^23
132
Molar mass
weight that is one mole of molecules
133
Molarity
M/L
| Number of moles of solute per liter of solution
134
Hydrogen ion
H+
| Does not exist on its own in an aqueous solution
135
Hydroxide ion
OH-
136
Hydronium ion
H3O+
137
Acid
Substance that increases the hydrogen ion concentration of a solution. Also removes hydroxide ions. HCl is a strong acid
138
Base
Substance that reduces they hydrogen ion concentration of a solution. NaCl is a strong base. Ammonia is a weak base
139
pH
= -log[H+]
Declines as H+ increases. The lower the number, the more acidic the solution. Most biological fluids are within the range pH 6-8
140
Buffer
Allows biological fluids to maintain a relatively constant pH despite the addition of acids or bases. A substance that minimizes changes in the concentrations of H+ and OH- in a solution. Does so by accepting hydrogen ions from the solution when they are in excess and donating hydrogen ions to the solution when they have been depleted. Most buffer solutions contain a weak acid and its corresponding base
141
Ocean acidification
When CO2 dissolves in seawater, it reacts with water to form carbonic acid, which lowers ocean pH
142
Acid precipitation
Refers to rain, snow, or fog with a pH lower than 5.2
143
Organic chemistry
Branch of chemistry that specializes in the study of carbon compounds
144
Organic compounds/ inorganic compounds (Berzelius)
Those thought to arise only in living organisms. Those found only in the nonliving world
145
Vitalism
The belief in a life force outside the jurisdiction of physical and chemical laws
146
Mechanism
The view that physical and chemical laws govern all natural phenomena
147
Is CO2 normally considered organic or inorganic?
Inorganic even though it contains carbon, because it lacks hydrogen
148
What form the skeletons of most organic molecules?
Carbon chains. Hydrophobic. Can undergo reactions that release a relatively large amount of energy. Fats have long hydrocarbon tails attached to nonhydrocarbon component
149
Hydrocarbons
Organic molecules consisting of only carbon and hydrogen.
150
Isomers
Compounds that have the same numbers of atoms of the same elements but different structures and hence different properties. Number of possible isomers increases tremendously as carbon skeletons increase in size
151
Structural isomers
Differ in the covalent arrangements of their atoms.
152
Cis-trans isomers
Formerly called geometric isomers. Carbons have covalent bonds to the same atoms, but these atoms differ in their spatial arrangements due to the inflexibility of double bonds. Cis- arrangement with Xs on same side. Trans- arrangement with Xs on opposite sides
153
Enantiomers
Isomers that are mirror images of each other and that differ in shape due to the presence of an asymmetric carbon. In a way, they are left-handed and right-handed versions of the molecule
154
Functional groups
Chemical groups that affect molecular function by being directly involved in chemical reactions
155
Adenosine triphosphate
ATP. Consists of an organic molecule called adenosine attached to a string of three phosphate groups.
156
Adenosine diphosphate
ADP. After ATP loses a phosphate
157
4 main classes of important large molecules
carbohydrates, lipids, proteins, nucleic acids
158
Macromolecules
huge molecules. carbohydrates, proteins, nucleic acids
159
polymers
chain-like molecules. Long molecule consisting of many similar or identical building blocks linked by covalent bonds
160
Monomers
repeating units that serve as the building blocks of a polymer
161
Enzymes
specialized macromolecules that speed up chemical reactions
162
dehydration reaction
two molecules are covalently bonded to each other, with the loss of a water molecule
163
Hydrolysis
Reverse of dehydration. Break using water
164
How many amino acids build proteins
20
165
Carbohydrates
sugars and polymers of sugars. Monosaccharides, disaccharides, polysaccharides
166
Monosaccharides
Simple sugars. Monomers from which more complex carbohydrates are constructed. CH2O. Glucose is the most common
167
Disaccharides
Double sugars. Two monosaccharides joined by a covalent bond (glycosidic linkage). Sucrose most prevalent (glucose + fructose)
168
Polysaccharides
Macromolecules. Polymers composed of many sugar building blocks (a few hundred or thousand joined by glycosidic linkages)
169
A sugar is either an ____ or a ____
aldose (aldehyde sugar) or a ketose (ketone sugar)
170
Glycosidic linkage
Covalent bond formed between two monosaccharides by a dehydration reaction
171
Starch
A polymer of glucose monomers. Plants store as granules within cellular structures known as plastides, which include chloroplasts
172
Amylose
Simplest form of starch. Unbranched
173
Amylopectin
More complex starch. Branched polymer with 1-6 linkages at the branch
174
Glycogen
Polymer of glucose that is like amylopectin but more extensively branched. Animals store. Mainly in liver and muscle cells
175
Cellulose
Polysaccharide that is a major component of the tough walls that enclose plant cells. Plants produce almost 100 billion tons per year. Most abundant organic compound on earth. Polymer of glucose, but the glycosidic linkages in these two polymers differ (two slightly different ring structures for glucose). Cellulose molecule is straight and never branched. Major constituent of paper and only component of cotton. Few organisms posses enzymes that can digest this.
176
Chitin
Carbohydrate used by arthropods to build their exoskeletons. Leathery and flexible when pure, becomes hardened when encrusted with calcium carbonate (a salt)
177
Lipids
Does not include true polymers, generally not big enough to be considered macromolecules. Mix poorly, if at all, with water. Consist mostly of hydrocarbon regions. Fats, phospholipids, steroids
178
Fat
Constructed from two kinds of smaller molecules: glycerol and fatty acids. Glycerol is an alcohol. A gram of fat stores more than twice as much energy as a gram of a polysaccharide such as starch.
179
Fatty acid
Long carbon skeleton, usually 16 or 18 carbon atoms in length. One end is part of a carboxyl group
180
Triacylglycerol
Triglyceride. Three fatty acid molecules each joind to glycerol by an ester linkage
181
Ester linkage
Bond between a hydroxyl group and a carboxyl group
182
Saturated
No double bonds between carbon atoms. Saturated with hydrogen. Saturated animal fats solid at room temp. Diet rich in saturated fat one of several factors that may contribute to the cardiovascular disease known as atherosclerosis (plaques develop, inward bulges impede blood flow and reduse resilience of the vessels
183
Unsaturated
One or more double bonds. Nearly all double bonds in naturally occurring fatty acids are cis double bonds which cause a kink. Fats of plants and fish generally unsaturated and usually liquid at room temp. Cis bonds prevent molecules from packing together closely enough to solidify
184
Trans fats
May contribute more than saturated fats to atherosclerosis. USDA requires nutritional labels to include information on trans fat content
185
Adipose cells
Where humans and other mammals stock their long-term food reserves. Swell and shrink as fat is deposited and withdrawn from storage. Cushions vial organs and insulates body
186
Phospholipids
Make up cell membranes. Similar to a fat molecule but has only two fatty acids attached to glycerol rather than three. Joined to a phosphate group which has a negative electrical charge in the cell, hydrophilic. Hydrocarbon tails are hydrophobic.
187
Bilayers
When phospholipids self assemble into double-layered structures shielding their hydrophobic portions from water
188
Steroids
Lipids characterized by a carbon skeleton consisting of four fused rings
189
Cholesterol
Crucial molecule in animals. Precursor from which other steroids are synthesized. In vertebrates, synthesized in liver and obtained from diet. May contribute to atherosclerosis
190
Proteins
Biologically functional molecule that consists of one or more polypeptides, each folded and coiled into a specific 3-D structure. Account for more than 50% of they dry mass of most cells. Speed up chemical reactions, play a role in defense, storage, transport, cellular communication, movement, or structural support. Most structurally sophisticated molecules known. Not JUST a polypeptide chain, but one or more polypeptides precisely twisted, folded, and coiled into a molecule of unique shape
191
Catalyst
Chemical agents that selectively speed up chemical reactions without being consumed by the reaction. How enzymatic proteins regulate metabolism
192
Polypeptides
Polymers of amino acids
193
Amino acid
Organic molecule possessing both amino group and a carboxyl group. All share a common structure. At center- asymmetric carbon atom (called alpha carbon)
194
Acidic vs. Basic amino acids
Acidic- side chains generally negative owing to the presence of a carboxyl group
Basic- have amino groups in their side chains that are generally positive in charge
Acidic and Basic refer only to groups on the side chains
195
Peptide bond
Carboxyl group joins by dehydration reaction to the amino group of the other
196
Polypeptide
Polymer of many amino acids linked by peptide bonds. One end has a free amino group while the other has a free carboxyl group. Not synonymous with protein.
197
N-terminus and C-terminus
N- single amino end of a polypeptide
| C- single carboxyl end of a polypeptide
198
Globular proteins
Roughly spherical
199
Fibrous proteins
shaped like long fibers
200
Antibody
A protein in the body
201
Primary structure
A linked series of amino acids with a unique sequence
202
Secondary structure
Coils and folds. Result of hydrogen bonds between the repeating constituents of the polypeptide bonds. Alpha helix and Beta pleated sheet
203
Alpha helix
| Beta pleated sheet
Delicate coil held together by hydrogen bonding between every fourth amino acid
Two or more strands of the polypeptide chain lying side by side. Silk protein of a spider's web
204
Tertiary structure
Overall shape of a polypeptide resulting from interactions between the side chains (R groups) of the various amino acids. One type of interaction is a hydrophobic interaction. Disulfide bridges may further reinforce the shape of a protein
205
Hydrophobic interaction
Amino acids with hydrophobic side chains usually end up in clusters at the core of the protein, out of contact with water. Actually caused by the exclusion of nonpolar substances by water molecules
206
Disulfide bridge
Form where two cysteine monomers, which have sulfhydryl groups (-SH) on side chains are brought close together by the folding of protein. Further reinforce the shape of a protein
207
Quaternary structure
Overall protein structure that results from the aggregation of these polypeptide subunits. Multiple polypeptides forming a functional protein
208
Sickle-ell disease
An inherited blood disorder. Caused by substitution of one amino acid (valine) for the normal one (glutamic acid) at a particular position in the primary structure of hemoglobin. Abnormal hemoglobin molecules tend to crystalilize, deforming some of the cells into a sickle shape
209
Denaturation
Destruction of protein by unraveling and losing its native shape. Caused by extreme salt concentration, pH, temperature change. Most proteins become denatured if they are transferred from an aqueous environment to a nonpolar solvent. White of egg becomes opaque because the denatured proteins are insoluble and solidify
210
Chaperonins
Chaperone proteins. Protein molecules that assist in the proper folding of other proteins
211
Diseases associated with accumulation of misfolded proteins
Alzheimer's, Parkinson's, mad cow
212
X-ray crystallography
Used to determine the 3-D structure of many other proteins.
213
Nuclear magnetic resonance (NMR) spectroscopy
Method used for analyzing protein structure. Does not require protein crystallization
214
Gene
Discrete unit of inheritance. Consist of DNA
215
Nucleic acids
Polymers made of monomers called nucleotides. DNA belongs to this class of compounds
216
Deoxyribonucleic acid (DNA)
Enable living organisms to reproduce their complex components from one generation to the next. Provides directions for its own replication. Directs RNA synthesis. Not directly involved in running the operations of the cell (like computer software). Almost always exists as a double helix
217
Ribonucleic acid (RNA)
Enable living organisms to reproduce their complex components from one generation to the next. More variable in shape (unlike DNA)
218
Flow of genetic information from DNA to proteins
Each gene along a DNA molecule directs synthesis of a type of RNA called messenger RNA (mRNA). mRNA interacts with the cell's protein-synthesizing machinery to direct production of a polypeptide, which folds into all or part of a protein. DNA > RNA > protein.
219
Ribosomes
Sits of protein synthesis
220
Polynucleotides
Nucleic acids that exist as polymers. Consists of nucleotides. Each monomer has only one phosphate group
221
Nucleotides
Monomers. In general, composed of a nitrogen containing (nitrogenous) base, a five-carbon sugar (a pentose), and or one or more phosphate groups.
222
Nucleoside
Portion of nucleotide without any phosphate group
223
Pyrimidine
Has one six-membered ring of carbon and nitrogen atoms. Members of pyrimidine family are cytosine (C), thymine (T), and uracil (U). Thymine only found in DNA, uracil only found in RNA
224
Purines
Larger than pyrimidines. Six-membered ring fused to a five-membered ring. Adenine (A) and guanine (G).
225
Deoxyribose
Ribose
The sugar in DNA. Lacks an oxygen atom on second carbon in the ring
The sugar in RNA
226
Phosphodiester linkage
Adjacent nucleotides joined by this. Consists of a phosphate group that links the sugars of two nucleotides. Phosphate attached to a 5' carbon and the other end has a hydroxyl group on a 3' carbon
227
Double helix
Shape of DNA. Run in opposite 5' > 3' directions from each other (antiparallel). Sugar phosphate backbones are on the outside of the helix, and the nitrogenous bases are paired in the interior of the helix. Two strands are complimentary
228
A, T, C, G, U
Adenine, Thymine, Cytosine, Guanine, Uracil
A-T (DNA)
G-C
A-U (RNA)
229
tRNA
Transfer RNA. Brings amino acids to the ribosome during synthesis of a polypeptide. Its functional shape results from base pairing btween nucleotides where complementary stretches of the moleule run antiparallel to eachother
