Levels of Organization Flashcards
(170 cards)
1
Q
level consisting of atoms, ions, and small molecules
A
chemical level
2
Q
level consisting of large molecules
A
molecular level
3
Q
level consisting of individual cells
A
cellular level
4
Q
level consisting of related cells cooperating for functionality
A
tissue level
5
Q
level consisting of related tissues cooperating for functionality
A
organ level
6
Q
level consisting of related organs cooperating for a vital function
A
organ system level
7
Q
level consisting of a whole person
A
organism or body level
8
Q
level involving the interactions of the person with his/her environment
A
population or environment level
9
Q
An ion is…
A
an atom with an altered number of electrons, creating a positive (cation) or negative (anion) charge
10
Q
What are the key biologically relevant elements?
A
Hydrogen (H) Carbon (C) Nitrogen (N) Oxygen (O) Phosphorous (P) Sulfur (S)
11
Q
What are valence electrons?
A
the electrons in the outermost orbit around the nucleus of an atom.
12
Q
What is atomic mass?
A
the sum of protons and neutrons. amu or atomic mass unit.
13
Q
what is electronegativity?
A
the degree to which an atom will attract electrons in a chemical bond. highly electronegative atoms will pull electrons away from less electronegative atoms.
14
Q
A molecule is…
A
a stable bond between 2+ atoms of the same or different types.
15
Q
Gaining an electron turns an atom into a…
A
negative ion or anion
16
Q
Losing an electron turns an atom into a…
A
positive ion or cation
17
Q
what sort of bond might form between a cation and anion?
A
an ionic bond, caused by the electrostatic interaction of ions with different charges.
18
Q
Which bond is created when atoms share an electron?
A
covalent bond
19
Q
which is stronger? ionic or covalent bonds?
A
covalent.
20
Q
what determines the number of covalent bonds an atom can support?
A
the number of valence electrons. There is a maximum number of electrons per orbit. 2, or 8. An atom can only form as many bonds as it takes to fill the valence orbit.
21
Q
what sort of bond usually forms between a metal and nonmetal?
A
ionic bond
22
Q
what sort of bond usually forms between two nonmetals?
A
a nonpolar covalent bond.
23
Q
Are electrons in covalent bonds shared equally?
A
they are shared equally in non-polar bonds. They are NOT shared equally in polar covalent bonds, causing the molecule to have polarity (not the same as charge).
24
Q
How is “charge” different from “polarity”?
A
An atom can be charged - the entire structure has a positive or negative electromagnetism.
A molecule is NOT charged, as the entire molecule has a neutral electromagnetism, but if the electrons are shared unequally, then parts of the molecule will be positive or negative.
25
What creates a hydrogen bond?
water is a polar molecule. the partially positive hydrogen ends attract the partial negative free electrons of other water molecules. it is a weak, but critically important bond.
26
how many hydrogen bonds does a water molecule have?
four. two hydrogens and two sets of free electrons.
27
hydrophilic
water-loving. water soluble. polar molecules are generally water soluble and dissolve in water.
28
hydrophobic
water-fearing. non-polar molecules that do not dissolve in water and tend to clump together in water, like oil.
29
amphipathic
molecules with distinctly polar and nonpolar regions. they do not form true solutions, but end up in clumps with nonpolar ends together and polar ends facing the water.
30
how much energy is required to break a covalent bond?
100 kcal/mol
31
how much energy is required to break an ionic bond?
5 kcal/mol
32
how much energy is required to break a hydrogen bond or hydrophobic interaction?
5 kcal/mol
33
will a salt crystal dissolve in a nonpolar solvent?
No.
34
will a protein unfold in a sea of lipids?
Yes. without water or a polar solution to keep the non-polar residue folded in the core of the protein, it will unfold or solvate.
35
what is an electrolyte?
any fluid that contains free ions.
36
What are important ions in physiology?
```
Sodium (Na)
Potassium (K)
Calcium (Ca)
Chloride (Cl)
Phosphate (P)
```
37
what does pH measure?
the hydrogen ion (H+) concentration of a solution.
38
What is the hydrogen ion concentration in a solution with a pH of 7?
0, or as many hydrogen ions as there would be in distilled water
39
What is the hydrogen ion concentration in a solution with a pH of 10?
1/1,000. it's basic. There are fewer hydrogen ions than there would be in distilled water.
40
What is the hydrogen ion concentration in a solution with a pH of 4?
1000 to 1. Acidic. there are many more hydrogen ions than there would be in distilled water.
41
The lower the pH, the ____ the number of free protons
higher.
42
what is the Bronsted definition of an acid?
a proton donor.
43
what is the Bronsted definition of a base?
a proton acceptor
44
What are the four major macromolecules?
nucleic acids, proteins, lipids, carbohydrates.
45
nucleotide subunits linked by phosphate backbone
nucleic acid
46
amino acid subunits link between carbon and nitrogen
protein
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large molecules with nonpolar bonds. hydrophobic... but some have covalently attached polar groups.
lipids
48
covalently linked sugar groups
carbohydrates
49
large molecules made of smaller units joined by covalent bonds
polymer.
50
which macromolecule type is NOT a polymer?
lipids.
51
Which macromolecule has the general formula: (C(H2O))n ?
Carbohydrates / saccharides
52
Describe monosaccharides
most basic carbs. simple sugars. 3-7 carbon atoms, sweet tasting, used for energy.
53
Describe polysaccharides
long polymers of monosaccharides with covalent bonds. Used to store monosaccharide energy. plants may use them for structural support (cellulose).
54
what is a glycoprotein?
a complex carb (polysaccharide) linked to a protein.
55
what is a glycolipid?
a complex carb linked to a lipid.
56
what is the primary function of carbs?
source of energy.
57
why are carbs good sources of energy?
They are formed with covalent bonds, which can be broken to release more energy than other bonds. With an enzyme, carbs can be digested with minimal processing compared to lipids or proteins.
58
How much energy is in 1 g of glucose?
3.7 kcal/g. usually rounded to 4 kcal/g for food package labels.
59
What are the secondary functions of carbs?
structure;
| cell recognition and signaling
60
What is a protein's primary structure?
the sequence of amino acids. there are 20 to choose from, which may be combined in any order in any number.
61
What is a protein's secondary structure?
the size, shape, and reactive properties of the protein. the hydrogen bonding of amino acid side chains often causes the protein to curl up in a specific shape.
62
what is a protein's tertiary structure?
the shape of the protein once the secondary structures are integrated into a 3D protein. the functional form.
63
what is a protein's quaternary structure?
a protein complex formed by the combination of several different proteins.
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what are the functions of proteins?
Enzyme activity.
cell signaling and cell recognition.
composition of connective tissues.
mechanical support for cell.
65
what are essential amino acids?
amino acids that the body cannot synthesize. we must ingest them from the environment.
66
A person with low-functioning kidneys should eat what sort of diet?
low protein. less protein to be metabolized into ammonia and urea gives kidneys a break.
67
If a protein has quaternary structure, that means it...
is likely coded for by multiple genes. each amino acid chain is coded by a different gene, so a combination of proteins is likely the result of many different genes.
68
an amino acid is generally composed of...
an amino group (the alpha amino group);
a carboxyl group;
an alpha hydrogen;
a variety of functional groups attached to the alpha-carbon (the "R" group),
69
What are the 20 common amino acids?
```
glycine
alanine
valine
leucine
isoleucine
histidine
tyrosine
tryptophan
phenylalanine
serine
asparagine
glutamine
threonine
methionine
aspartic acid
glutamic acid
lysine
arginine
cysteine
proline
```
70
what is a peptide?
a polymer of amino acids, joined by a dehydration synthesis. amino acids are joined by attaching the nitrogen of one's animo group to the carbonyl carbon (C=O) of the other's carboxyl group. yields a covalent peptide bond and a molecule of water.
71
when does a peptide become a polypeptide?
when it has over 50 amino acids.
72
what are the four bases of nucleic acids?
adenine, cytosine, guanine, and thymine (uracil in RNA)
73
what is the functional unit of DNA?
a nucleotide.
74
what composes a nucleotide?
a phosphate group, a nitrogenous base, and a furanose sugar group.
75
how many sides does a furanose sugar group have?
five
76
what is the difference between DNA and RNA's polymer backbones?
DNA has a hydrogen on the 2' position of the furanose sugar.
RNA has a hydroxyl group (OH) instead.
77
how are nucleotides linked?
one phosphate molecule bridges between two hydroxyl groups, one on each furanose ring, from the 3' to 5' positions. phosphodiester covalent bonds.
78
how are the nucleotide bases linked?
hydrogen bonding of purines (A, G) to pyrimidines (C, T, U).
79
which base binds to Adenine?
Thymine.
80
which base binds to Thymine?
Adenine
81
Which base binds to Guanine?
Cytosine
82
Which base binds to Cytosine?
Guanine
83
Define transcription
When DNA is transcribed into a single-stranded RNA
84
Define translation
RNA is translated from nucleic code to an amino acid sequence for protein synthesis
85
What is the most important role of lipids?
forming membranes of cells and organelles
86
what are the secondary functions of lipids?
energy storage
cell signaling
dissolving certain lipid soluble vitamins
87
what is homeostasis?
relatively constant internal state, necessary to support life.
88
What is cell theory?
1) All living things are composed of 1+ cells
2) all new cells are created by pre-existing cells
3) the cell is the most basic unit of structure and function in all living organisms.
89
What are the three basic components of a cell?
membrane
cytoplasm
organelles
90
what does a ribosome do?
synthesizes proteins
91
what do centrioles do?
move chromosomes to opposing ends of the cell during mitosis.
92
do neurons have centrioles?
neurons do not have centrioles and do not replicate.
93
what does smooth ER do?
lipid synthesis and toxin break down
94
what does rough ER do?
supports ribosomes
95
what does the golgi apparatus do?
processes/distributes newly synthesized proteins in vesicles. also makes lysosomes.
96
what do lysosomes do?
collect cell debris and destroys it. contains powerful hydrolytic enzymes.
97
what does the mitochondria do?
generates ATP (energy).
98
can mitochondria replicate?
Yes. mitochondria have their own DNA (mDNA) and can replicate independently.
99
what does a nucleus do?
contains the DNA and nucleolus.
100
what does the nucleolus do?
produces ribosomes
101
do all cells have one nucleus?
No. Some cells have no nucleus. others are multinucleate.
102
what does amphiphathic or amphiphilic mean?
containing both a nonpolar and a polar region. like a phospholipid with a polar head (a charged phosphate group) and nonpolar tails (hydrophobic fatty acids)
103
can hydrophobic molecules and gases cross a phospholipid bilayer?
yes. small molecules can dissolve in the membrane's core and cross the membrane.
104
can phospholipid bilayers maintain oxygen gradients?
no. gases pass through the membranes freely.
105
what is fluidity?
the ease of movement of molecules in the membrane
106
what increases fluidity?
higher temperature and unsaturated fatty acids
107
what decreases fluidity?
lower temperatures and higher concentrations of saturated fatty acids.
108
what is the rate of lateral phospholipid movement in the membrane?
22 um per second
109
What are some of the most important functions of membrane proteins?
transport
communication
metabolism
adhesion
110
what are the three major categories of membrane proteins?
1) integral proteins
2) Transmembrane proteins
3) peripheral proteins
111
what is an integral membrane protein?
(embedded in lipid bilayer and characterized by solubility in non-polar, hydrophobic solvents.
112
what is a transmembrane protein?
completely spanning the membrane. they have hydrophilic and hydrophobic sections.
113
what is a peripheral protein?
existing only on one side of the membrane, often attached to integral or transmembrane proteins
114
what are important molecules for cell identification and distinction?
oligosaccharides: glycolipids and glycoproteins.
115
which side of the membrane has more sugars on it?
the extracellular side.
116
What provides the driving force for passive transport since they can't used ATP?
concentration gradients
117
what are the two main types of passive transport?
1) diffusion and facilitated diffusion
| 2) osmosis and tonicity
118
What drives diffusion?
kinetic energy and concentration gradient
119
what is diffusion
movement of molecules from an area of high concentration to an area of low concentration
120
what is the difference between simple and facilitated diffusion?
facilitated diffusion requires a channel or carrier protein. cannot pass through membrane freely.
121
what sort of molecules can use simple diffusion
very small
lipid soluble
Examples: O2, CO2, and lipids.
122
when does diffusion stop?
when equilibrium is reached. molecules may still move, but the movements will be balanced and no more changes in concentration will occur.
123
what increases the rate of diffusion?
higher heat
more kinetic energy
smaller particles
less viscous medium
124
can small polar molecules diffuse simply?
occasionally. their small size lets them pass through temporary membrane holes.
125
can nonpolar molecules diffuse simply?
yes, they diffuse freely through the nonpolar lipid bilayer. some large nonpolar molecules can accumulate in the membrane.
126
can large polar molecules diffuse simple?
No, they need facilitation.
127
can ionic compounds diffuse simply?
NO.
128
what is osmosis?
net movement of water across a semipermeable membrane in the direction of the higer concentration of solutes.
129
hypertonic
with a higher concentration of solutes.
130
hypotonic
with a lower concentration of solutes.
131
isotonic
with an equal concentration of solutes
132
does water move in or out of a cell in a hypertonic solution?
out of the cell.
133
does water move in or out of a cell in a hypotonic solution?
into the cell.
134
does water move in or out of a cell in an isotonic solution?
water molecules may move in and out of the cell freely, but the concentration of water in and out of the cell will not change.
135
what is the internal solute concentration of a human cell?
1%. includes all molecules dissolved in the cytoplasm.
136
edema is an increase in water in interstitial fluid. what sort of IV would you put in the blood to correct it? isotonic, hypertonic, or hypotonic?
hypertonic.
| it would pull water from the interstitial fluid into the blood stream to clear the edema.
137
what drives filtration?
a hydrostatic pressure gradient. molecules will move from an area of high pressure to an area of low pressure.
138
hydrostatic pressure is countered by...
osmotic pressure.
139
Is hydrostatic pressure affected by solute concentration?
no.
140
can large molecules cross a membrane due to filtration?
No. only small molecules can be forced through membranes by filtration.
141
What are the three kinds of active transport?
1) primary active transport / solute pumps
2) endocytosis
3) exocytosis
142
Why does a sodium/potassium transport exchange pump require ATP?
the sodium/potassium exchange pump is used to maintain a concentration gradient of low sodium, high potassium inside the cell. It requires ATP in order to move the ions through the membrane against the concentration gradient.
143
What is secondary active transport?
active transport that uses energy from electrochemical gradients instead of using ATP directly. the action of primary active transport creates electrochemical gradients that support secondary active transport.
144
cotransport or symport
when the molecules moving in primary AND secondary active transport are moving in the same direction.
145
countertransport or antiport
when the molecules moving in primary AND secondary active transport are moving in the opposite directions.
146
endocytosis
material is engulfed in a fold of plasma membrane and brought into the cell in a cytoplasm vesicle.
147
phagocytosis
endocytosis involving large solid particles
148
pinocytosis
endocytosis involving uptake of fluid and any small molecules dissolved in that fluid.
149
exocytosis
fusing of an internal vesicle with the membrane, causing the release of the vesicle's contents into the interstitial fluid.
150
how many cells die every minute in the human body?
about 300 million.
151
mitosis
the process of cell division, producing two daughter cells identical to the parent cell.
152
what are the major stages of mitosis?
prophase, metaphase, anaphase, telophase
153
in what stage does a cell perform most day-to-day functions?
interphase
154
what happens during prophase?
1) nucleus disappears
2) chromatin condenses into chromosomes, splits into double-strand chromatids
3) separation of centrosomes to opposite poles of cell
4) formation of mitotic spindle from microtubules
155
What happens during Prometaphase?
1) nuclear envelope disappears
2) chromosomes form two kinetochores at the centromere
3) microtubules attach to chromosomes.
156
what happens in metaphase?
1) chromosomes align in the metaphase plate.
157
what happens in anaphase?
1) chromatids separate towards opposite poles.
2) kinetochore proteins break the microtubules and connections between each copy of the chromosome.
3) the cell elongates.
158
what are kinetochore microtubules?
microtubules attached to chromosomes during mitosis
159
what are non-kinetochore microtubules?
microtubules not attached to chromosomes during mitosis.
160
what happens in telophase?
1) new nuclear envelope forms
2) chromosomes unfold into chromatin
3) nucleoli reappear
4) cell continues to elongate
161
can the cell produce new proteins when the DNA is condensed into chromosomes?
no. the cell must produce all necessary proteins prior to mitosis.
162
what happens in cytokinesis?
the daughter cells divide. proteins pinch a cleavage furrow into the middle until the cell is divided into two parts.
163
apoptosis
programmed cell death.
164
what are the four kinds of tissues?
muscle tissue
nerve tissue
connective tissue
epithelial tissue
165
what kind of tissue is the skin on your hand?
epithelial
166
what kind of tissue is the bones in your fingers?
connective
167
what kind of tissue is the abductor pollicus brevis muscle?
muscle
168
what kind of tissue is the cartilage in your joints?
connective
169
what kind of tissue conveys the sense of touch?
nervous
170
what kind of tissue is blood?
connective
