Test 1 Study Guide Flashcards
1
Q
What did Carl Sagan mean when he said we are all made of star stuff?
A
Living things are composed of the same chemical elements as nonliving things. They also obey the same physical and chemical laws that govern everything in the universe.
2
Q
Define Biology.
A
The scientific study of life.
3
Q
What are the characteristics of living things?
A
- Organized from the atom to the biosphere.
- Use materials and energy from the environment (sun)
- Maintain a relatively constant internal environment (homeostasis)
- Respond to internal and external stimuli
- Reproduce and grow
- Have the ability to change over time
4
Q
What are the stages of the hierarchy of complexity?
A
- Atom
- Molecule
- Cell
- Tissue
- Organ
- Organ System
- Organism
- Population
- Community
- Ecosystem
- Biosphere
5
Q
What is the basic unit of structure and function of all living things?
A
The cell
6
Q
What are emergent properties?
A
Properties that become apparent and result from various interacting components within a system but are properties that do not belong to the individual components themselves.
7
Q
What is metabolism?
A
All the chemical reactions that occur in a cell.
8
Q
What is the ultimate source of energy for nearly all life on Earth?
A
The sun
9
Q
Who is capable of conducting photosynthesis?
A
Eukaryotic cells with chloroplasts; ie. plants
10
Q
Who is capable of conducting cellular respiration?
A
All eukaryotic cells; ie plants and animals
11
Q
What is homeostasis?
A
The maintenance of internal conditions within certain boundaries.
12
Q
What does Eukarya mean?
A
“True Nucleus”, meaning the cell contains a membrane-bound nucleus
13
Q
What are the three domains of life?
A
Domain Archaea, Domain Bacteria, Domain Eukarya
14
Q
What domain are prokaryotes located in?
A
Domain Archaea, Domain Bacteria
15
Q
What is the difference between Domain Archaea and Domain Bacteria?
A
Archaea live in extreme environments similar to the primative earth, whereas, Bacteria live in all environments.
16
Q
What are the kingdoms of Domain Eukarya?
A
Protista, Animalia, Plantae, Fungi
17
Q
What is the least inclusive category for organizing life?
A
species
18
Q
What is the most inclusive category for organizing life?
A
domain
19
Q
What are the categories for organizing life from most inclusive to least inclusive?
A
domain, kingdom, phylum, class, order, family, genus, species
20
Q
How does adaptations relate to “Survival of the fittest”?
A
Adaptation is a process where, over a LONG time, characteristics that lead to better reproductive success become more prevalent in the population. The means that only the “fittest” survive.
21
Q
How does natural selection apply to “Survival of the fittest”?
A
Natural selection are traits that enhance survival and reproduction. They are fueled by mutations and if positive, lead to adaptations in the entire population over time.
22
Q
What are the steps of the scientific method?
A
- Observation
- Question
- Hypothesis
- Predictions
- Test with Data Collection and Statistical Analysis
- Results/Conclusion
23
Q
What is a hypothesis?
A
A statement that tries to explain the question.
24
Q
What are predictions?
A
Specific statements that can directly be tested (if/then statements)
25
What is the purpose of Peer Review?
It helps guard against faulty research. Any paper that is not up to par must be revised before being published.
26
What is the difference between a scientific theory and a scientific law?
A theory joins together two or more hypothesis that are supported by a broad range of observations, experiments, and data. A law is a widely accepted set of theories, with no challenges to validity.
27
How are species names set up? Ex. Homo sapien.
The first name is the genius and the second name is the species.
28
What is the difference between an experimental and control group?
An experiment manipulates a variable to produce a result. The control group does not get the variable, whereas an experimental group does.
29
What is a gene?
The code for making a single individual protein.
30
What do genes determine?
The characteristics of an organism.
31
What are genes composed of?
DNA (deoxyribonucleic acid)
32
What is matter?
Anything that occupies space and has mass.
33
What is energy?
The capacity to do work (put matter into motion).
34
What is kinetic energy?
The movement of particles or objects (active energy).
35
What is potential energy?
stored energy (has the potential to do work).
36
What is chemical energy?
Energy locked up in chemical bonds (when bonds break = kinetic)
37
What is electrical energy?
Energy from the movement of charged particles (ex. nervous impulses).
38
What is mechanical energy?
Energy directly involved in moving matter (ex. riding bike).
39
What is radiant energy?
(Electromagnetic energy) Energy that travels in waves (ex. light, UV, X-ray).
40
What energy does your cells use?
ATP (adenosine triphosphate)
41
Can energy be created or destroyed?
No, the law of conservation of energy states that the total amount of energy in an isolated system remains constant. Energy can only be converted between different forms.
42
What are the subatomic particles?
protons, neutrons, electrons
43
Where are the subatomic particles located?
Nucleus: protons and neutrons
Orbiting clouds around nucleus (electron shells): electrons
44
What is the mass of the subatomic particles?
1 amu: protons and neutrons
0 amu: electrons
45
What is the charge of the subatomic particles?
+: protons
0: neutrons
-: electrons
46
What is a valence shell?
The outermost energy shell, where electrons that participate in chemical bonding occur.
47
How many electrons are needed for stability in an atom?
8 electrons are needed in an atom's valence shell.
48
How do isotopes differ from each other?
Isotopes have the same number of protons, but they differ in the number of neutrons they contain.
49
How many atoms of each element is in C_6H_12O_6?
C: 6
H: 12
O: 6
50
What is an ionic bond?
A bond where atoms donate or take on electrons. These occur between particles that are charged.
51
What is a non-polar covalent bond?
A bond where electrons are shared equally between atoms.
52
What is a polar covalent bond?
A bond where electrons are shared unequally between atoms. Different atoms have different abilities to attract electrons, therefore, they attract the electron closer to them than to the other atom. This creates partial charges on the atoms involved in the bond.
53
What is a hydrogen bond?
A weak attraction between the "poles" of water molecules due to the partial charges created by the polar covalent bond between oxygen and hydrogen.
54
Why do hydrogen bonds matter to humans?
Gives water its unique properties and plays an enormous role in the stabilization of biological molecules (such as DNA and proteins).
55
What properties arise in water due to hydrogen bonding?
1. high heat capacity
2. high heat of evaporation
3. good solvent
4. cohesion
5. adhesion
6. ice is less dense than water
56
Why is a high heat capacity important for water?
The many hydrogen bonds allow water to absorb a large amount of thermal energy without great change in temperature.
57
Why is high heat of evaporation important for water?
Hydrogen bonds must be broken to evaporate water, this cools organisms
58
Why is cohesion important for water?
Cohesion is the ability of water molecules to cling to each other due to hydrogen bonding. This creates surface tension and allows water to flow freely.
59
Why is adhesion important for water?
Adhesion is the ability of water molecules to cling to other polar surfaces due to its own polarity. This leads to capillary action.
60
Why is water being a good solvent important?
Water is a good solvent due to its polarity. It can readily dissolve other polar substances.
61
Why is ice being less dense than water important?
Without this property, ice would sink and oceans would freeze solid, ice acts as an insulator on top of a frozen body of water.
62
What does hydrophilic mean?
"Water Loving", meaning it will dissolve in water.
63
What does hydrophobic mean?
"Water Fearing", meaning it will not dissolve in water.
64
What are inorganic molecules?
Typically those molecules that do not contain carbon (exceptions, ex. CO_2); salts, acids, bases, WATER
65
What are organic molecules?
Those molecules that contain carbon and are covalently bonded; proteins, carbohydrates, lipids, nucleic acids
66
What are the monomers of the organic macromolecules?
Carbohydrates: Monosaccharides
Lipids: Glycerol + 3 Fatty Acids
Protein: Amino Acids
Nucleic Acids: Nucleotides
67
Does your body utilize some acids and bases?
Yes, acid in the stomach and bases in the blood.
68
What is the pH of blood?
7.4
69
Explain the pH scale.
The pH scale is a logarithmic scale (meaning each pH unit is an increase of 10x less acidic). The scale runs from 0 to 14, with <7 being acidic and >7 being basic.
70
What do acids do?
They are proton donors and release [H+] into solution
71
What do bases do?
They are proton acceptors and release [OH-] into solution
72
What is a buffer?
A chemical or combination of chemicals that keeps pH within normal limits (homeostasis).
73
What is dehydration synthesis?
Combining two monomers to form a polymer, releases H_2O.
74
What is hydrolysis?
Adding H_2O to a polymer to break into monomers.
75
Why is glycogen important?
It is the only polysaccharide found in human tissues. Produced by the liver as a storage of energy. Broken down between meals.
76
Where is glycogen found? starch? cellulose?
glycogen: human tissues
starch: plants (potatoes)
cellulose: plant cell walls
77
What is the difference between saturated and unsaturated fats?
Saturated fats have only single bonds, can be packed into solids and are from animal origin. Unsaturated fats have one or more double bonds, found as liquids/oils, and come from plants.
78
What is a trans fat?
A manufactured fat that converts the bent (cis) form to a straightened (trans) form. Trans fats are able to be packed tightly as solids. They often resist enzymatic breakdown in the body, which raises the risk of heart disease.
79
Describe a phospholipid.
Phosphate (polar) containing head, glycerol backbone, 2 fatty acid chains (nonpolar)
80
Why are phospholipids important?
The polar and nonpolar ends allow for the formation of the lipid bilayer than forms the cell membrane in all cells. The phosphate group head is polar and is attracted to water, whereas, the fatty acids are nonpolar in shy away from water.
81
Why is cholesterol important?
It is the precursor to all steroid hormones (ex. testosterone, estrogen, vitamin D).
82
How are steroids structured?
4 interlocking carbon rings
83
How are amino acids linked together?
peptide bond (covalent bond)
84
Where can you find protein in the body?
Almost anywhere, 50% of the dry weight of most cells consists of proteins.
85
What are peptides and polypeptides?
Peptides are two or most amino acids linked together, whereas a polypeptide is a long chain of amino acids.
86
When does a polypeptide get the name protein?
When it has folded into a particular shape, which is essential for its proper functioning.
87
What are the different protein structures?
1. primary: polypeptide strand
2. secondary: alpha-helix, beta-pleated sheet
3. Tertiary: disulfide bridge
4. Quaternary: many different proteins together
88
What is a denatured protein?
A protein that is unfolded. Can happen in extreme heat or in the presence of strong acids or bases.
89
What are the differences between purines and pyrimidines?
Purines are large, have 2-rings, and consist of adenine and guanine.
Pyrimidines are small, have 1-ring and consist of cytosine, thymine, and uracil
90
What is the difference between DNA and RNA?
DNA is large, double helix, inside the nucleus, contains (AGTC), deoxyribose sugar
RNA is small, single stranded, outside the nucleus, contains (AGUC), ribose sugar
91
What molecule does ATP look like?
Nucleic acid, adenine + ribose + 3 phosphates
92
What are the proposals of cell theory?
1. All organisms are composed of cells and cell products.
2. Cells are the basic structural and functional unit of life.
3. The activity of cells is manifested as organism activity.
4. Cellular activity reflects their structural components (organelle type).
5. Life is propagated through cellular activity (reproduction from pre-existing cells, no spontaneous generation).
93
What is magnification?
The ratio between the size of an image and its actual size.
94
What is resolution?
The minimum distance between two objects that allows them to be seen as two separate objects.
95
What is contrast?
The difference in shading of an object compared to its background.
96
How does a compound light microscope work?
Light is passed through a specimen. Then it is focused by a series of glass lenses, which form an image on the human retina.
97
What is the maximum magnification of a compound light microscope?
1000x
98
What is the resolution of a compound light microscope?
Resolves objects separated by 0.2 millimeters.
99
What is the resolving power of the human eye?
1.0
100
What is the magnification of a transmission electron microscope?
10 million x
101
How does a transmission electron microscope work?
Electrons are passed through a specimen and then they are focused by a set of magnetic lenses. A 2D image is formed on a fluorescent screen similar to a TV screen.
102
What is the resolution of a transmission electron microscope?
Resolves objects separated by 0.0002 millimeters.
103
How does a scanning electron microscope work?
The specimen is sprayed with a thin coat of metal. Then an electron beam is scanned across the surface of the specimen. The surface metal emits secondary electrons. The emitted electrons are detected and focused by magnetic lenses. A 3D image is formed on a fluorescent screen similar to a TV screen.
104
What is the magnification of a scanning electron microscope?
30 thousand x
105
Compare and contrast bacteria and viruses.
Viruses are non-living as they are only genetic material with a protein coating; whereas, bacteria are prokaryotic cells. Viruses are also much smaller than bacteria.
106
What is the difference between bacteria and eukaryotic cells?
Bacteria are prokaryotic cells and are often much smaller than eukaryotic cells. Prokaryotic cells also have no nucleus or internal membranes.
107
Why do cells need a large surface area to volume ratio?
Cells need a large surface area of plasma membrane to adequately exchange materials. If a cell is too large, it decreases the efficiency of transporting materials in and out of the cell.
108
What are the 3 basic shapes of prokaryotic cells?
1. coccus: spherical
2. bacillus: rod-shaped
3. spirillum (spirochete): spiral
109
Explain the endosymbiotic theory.
Energy organelles, mitochondria and chloroplasts, may have originated when eukaryotic cells engulfed smaller prokaryotic cells. Eukaryotic cells would have benefitted from the ability to utilize oxygen or synthesize organic food.
110
How was the nucleus formed?
Cells gain a nucleus by the plasma membrane invaginating and surrounding the DNA with a double membrane.
111
What are the main differences between Animal and Plant cells?
Plant cells have chloroplasts, a cell wall, and a central vacuole. Plant cells are also generally larger than animal cells.
112
What are chloroplasts?
Chloroplasts are membrane-bound organelles in plants where photosynthesis occurs.
113
Who has chloroplasts?
Plant cells
114
Why are chloroplasts green?
The chlorophyll in thylakoid membranes.
115
Distinguish between thylakoids and grana.
Thylakoids are the disc-like membranes where photosynthesis occurs in the chloroplast. Grana are simply stacks of thylakoid discs.
116
What is the formula for photosynthesis?
6CO_2 + 6H_2O + Sun Energy -> C_6H_12O_6 + 6O_2
117
What is a mitochondria?
A membrane-bound organelle present in both plants and animals where cellular respiration occurs. It is the organelle that provides energy for the cell in the form of ATP. The number of mitochondria varies with metabolic activities and energy requirements of cells.
118
Who has mitochondria?
All eukaryotic cells, both plants and animals.
119
What are cristae?
The inner membrane folds within mitochondria where cellular respiration occurs.
120
What is the formula for cellular respiration?
C_6H_12O_6 + 6O_2 -> 6CO_2 + 6H_2O + Energy
121
What is special about the nuclear pores?
They permit exchange between nucleoplasm and cytoplasm. These pores are small enough to keep DNA within the nucleus, but large enough to allow RNA to escape.
122
What is chromatin?
Chromatin is a combination of nucleic acids and proteins that condense to form chromosomes during cell division. Located in the nucleoplasm.
123
Describe the endomembrane system.
1. DNA is translated to RNA within the nucleus.
2. RNA escapes the nucleus through the nuclear pores.
3. RNA arrives at the ribosomes on the Rough Endoplasmic Reticulum (proteins) or Smooth ER (lipids).
4. The rough ER synthesizes the proteins and packages them in vesicles to move onto the Golgi apparatus.
5. The Golgi modifies lipids and proteins from the ER and then sorts and packages them in vesicles.
6. Sends packaged proteins out of the cell, to areas of the cell, or into lysosomes that attach to vesicles coming into the cell to break down materials or other cellular parts.
124
What is the difference between RNA and DNA?
RNA is much smaller than DNA and it is single-stranded; whereas, DNA is double-stranded.
125
What is the point of a vacuole?
A vacuole is a membranous sac that stores water and materials that occur in excess. The central vacuole is almost 90% of the volume of some cells. It can also be useful in the development of turgor pressure that keeps the structure of plants.
126
What is the cytoskeleton?
A network of rods located in the cytosol. It is a support system for cellular structures and provides means for cell movement.
127
What are the parts of the cell's cytoskeleton?
1. Microfilaments
2. Intermediate Filaments
3. Microtubules
128
What are microfilaments?
These are the thinnest cytoskeletal elements that are composed of strands of actin. It is involved in cell motility and cell shape.
129
What are intermediate filaments?
This is the most stable of the 3 cytoskeletal elements and have high tensile strength. They associate with desmosomes to resist tension and serve no transport or contractile purposes.
130
What are microtubules?
They have the largest diameter made of tubulin subunits and they radiate from centrosomes. They determine the cell shape and serve as docking stations for organelles. The organelles move along these by motor proteins.
131
Where are centrosomes found?
They are found in animal cells only.
132
What is a centrosome?
They are short, hollow cylinders composed of 27 microtubules arranged into 9 overlapping triplets. Only one pair per cell and they are arranged at right angles to each other.
133
What are the differences between cilia and flagella?
Cilia come in two varieties: nonmotile and motile. Nonmotile cilia are used primarily for sensory and motile cilia beat in waves with a power stroke followed by a recovery stroke. Flagella move with a whiplike motion and are much longer than cilia.
