Biology Flashcards
1
Q
______ signaling is a way of cellular specialization where one group of cells can influence another group of cells to differentiate
A
Inductive
2
Q
The three basic tenets of cell theory are that all living things are composed of cells, the cell is the basic functional unit of life and _____
A
Cells arise only from pre-existing cells
3
Q
The fourth tenet added to the cell theory later on is that
A
Cells carry genetic information in the form of DNA and is passed on from parent to daughter cell
4
Q
Eukaryotic are single celled or multi celled organisms?
A
They can be both single or Multi-cellular
5
Q
Prokaryotic organisms are aways _____ cellular
A
single
6
Q
________ cellular organisms do not contain a nucleus
A
prokaryotic
7
Q
The nucleus is surrounded immediately by the ______
A
nuclear membrane/envelope
8
Q
________ __________ allow for selective two-way exchange of material the cytoplasm and nucleus
A
nuclear pores
9
Q
What are the proteins called that DNA is wound around?
A
Histones
10
Q
This section of the nucleus is where RNA is synthesized
A
The nucleolus
11
Q
Which membrane of the Mitochondria contain the cristae?
A
The Inner Membrane (this contains the molecules and enzymes of the ETC)
12
Q
The space inside of the inter Mitochondrial membrane is known as
A
Mitochondrial Matrix
13
Q
Lysosomes often function in collaboration with _______ to help transport, ________, and sort cell material
A
Endosomes, package
14
Q
Which ER has ribosomes
A
Rough ER
15
Q
Ribosomes, on the rough ER, permit the ________ of proteins destined for secretion directly into its lumen
A
translation
16
Q
Primary function of the smooth ER
A
lipid synthesis
17
Q
T or F, a function of the rough ER is to detox certain drugs and poisons
A
F, smooth ER does this
18
Q
Materials from the ER are transferred to the ______ in vesicles
A
Golgi
19
Q
What is a primary function of perioxosomes?
A
breakdown of very long chain fatty acids via beta oxidation
20
Q
Microfilaments are made of _____
A
solid actin
21
Q
Microtubules are made of ______
A
hollow tubulin
22
Q
Actin can use ____ to generate force for movement by interacting with _____ during muscle contraction
A
ATP, myosin
23
Q
_____ plays a role in cytokinesis
A
Microfilaments
24
Q
During Mitosis, the ____ ______ is formed by Microfilaments
A
cleavage furrow
25
Motor proteins Kinesin and _____ carry vesicles on a pathways made of _______
Dynein, Microtubules
26
T or F, cilia are used for the movement of the cell itsef
F, that is flagella
27
Cilia are used for the movement of ___
materials along the surface of a cell
28
Cilia and Flagella share a common structure known as the_____
9+2 structure (9microtubules in a ring, with 2 in the center)
29
During mitosis, _______ migrate to the opposite poles of the dividing cell and form the mitotic spindle
Centrioles
30
Centrioles are made up of ________
microtubules
31
Epithelial cells are often polarized (T or F)
True, one sides faces a lumen or the outside world, and the other faces blood vessels/structural cells
32
Simple epithelia have ____ layer(s) of cells
1
33
Stratified epithelia have _____ layer(s) of cells
Multiple
34
Pseudostratified epithelia have _____ layer(s) of cells
1, though appear to have many d/t differences in cell height
35
Cuboidal vs. Squamos cell Type
cuboidal are cubed, squamos are flat
36
Bacteria are prokaryotes or eukaryotes?
prokaryotes
37
All bacteria contain ______ and _______
cell membrane and cyotplasm
38
Rod-Shaped Bacteria
bacilli
39
Sprial-Shaped Bacteria
spirilii
40
Spherical shaped bacteria
cocci
41
A Gram negative cell wall is
pink/red
42
A Gram Positive cell wall is
purple
43
A Gram (+/-) cell wall has a thick layer of peptidoglycan
gram positive
44
In addition to a singular circular chromosome, many bacteria also contain
plasmids, which often carry genes that may provide antibiotic resistance
45
_______ are a subset of plasmids capable of integrating into the genome of the bacteria
episomes
46
What are the three bacterial genetic recombination processes?
Transformation, conjugation, and transduction
47
This process of recombination results from the integration of foreign genetic material into the host genome
transformation
48
This process of recombination is when a bridge is formed that facilitates the transfer of genetic material
Conjugation
49
This process of recombination requires a vector
Transduction (duct/duck=vector)
50
A ________ is a virus that specifically targets bacteria
bacteriophage
51
T or F, viral genomes can be made of either single or double stranded DNA or RNA
True
52
Single Stranded DNA can be either ____ sense or _______ sense
positive, negative
53
_____ sense implies that the genome may be directly translated to functional proteins (like mRNA)
positive
54
_____ sense RNA acts as a template for synthesis of a complementary strand, which is then used as a template of protein synthesis
negative
55
_______ are infectious proteins that trigger misfolding of other proteins
prions
56
Where does fertilization typically occur
in the ampulla of the fallopian tube
57
________ _______ is when the first sperm penetrates , it causes a release of calcium ions (preventing more sperm from fertilizing) and increases the metabolic rate
the cortical reaction
58
These type of twins results from the fertilization of two eggs by two sperm
Fraternal (Dizygotic)
59
Before the placenta is established, the embryo is supported by the
yolk sac
60
This germ layer becomes much of the musculoskeletal, circulatory, and excretory systems, including gonads.
Mesoderm
61
This germ layer becomes epidermis, hair, nails, and anal canal
Ectoderm
62
This germ layer becomes epithelial linings of respiratory and digestive tracts
Endoderm
63
The development of the Nervous System is known as
Neurulation
64
The neural tube turns into _____
Central Nervous System
65
These type of stem cells are ablet o differentiate into all cell types, including the three germ layers and placental structures
Totipotent (think Total cells)
66
These stem cells are able to differentiate into the three germ layers and derivatives
Pluripotent
67
These stem cells are able only to differentiate into a specific subset of cell type
Multipotent
68
Uterine contractions are coordinated by
oxytocin and prostaglandins
69
Like all other cells (besides RBC), neurons have _____
a nucleus (found in the cell body)
70
The cell body of a neuron is also known as a _____
soma
71
appendages emanating from the soma are known as ______
dendrites
72
Dendrites receive incoming messages, and information is transmitted through the cell body before it reaches the _______
axon hillock
73
The axon hillock ______ incoming signals
integrates
74
Most nerve fibers are insulated by ______
myelin
75
Myelin is produced by _____ in the CNS and by _______ in the PNS
oligodendrocytes, Schwann cells
76
At the end of an axon is the _____
nerve terminal
77
These are found along the axon membrane (small breaks in the myelin sheath)
nodes of Ranvier
78
In the CNS, axons may be bundled together to form a
tract
79
Multiple neurons can be bundled together to form a ____ in the PNS
nerve
80
These cells ingest and break down waste products in the CNS
microglia
81
For neurons, a cells resting membrane potential is
-70 mV
82
The concentration of Na+ is ______ outside the cell
higher, therefore there is a driving force pushing it into the cell
83
The concentration of K+ is ______ outside the cell
lower, therefore there is a driving force to move K+ out of the cell
84
If an axon hillock receives enough excitatory input to be depolarized to the threshold value, what will happen?
an action potential will be triggered
85
When no amount of stimulation can cause another action potential to occur, this is known as
absolute refractory period
86
When there must be greater than normal stimulation to cause an action potential, this is known as
relative refractory period
87
_____ neurons ascend in the spinal cord towards the brain
afferent
88
_______ neurons exit the spinal cord on their way to the rest of the body
efferent
89
Is the (grey/white) matter of the brain myelinated?
white
90
what are the four sections of the spinal cord
cervical, thoracic, lumbar, sacral
91
_____ summation refers to the integration of multiple signals near each other in time
temporal
92
______ summation refers to the addition of multiple signals near each other in space
spatial
93
The refractory period occurs when the axon is ______
hyperpolarized
94
What typically passes through our cell membrane?
Small, nonpolar molecules (i.e. gases, O2 or CO2) via passive diffusion
95
This small, polar molecule passes through the cell membrane very slowly because it is _____
Water (H2O), polar
96
Large, nonpolar molecules (CAN/CANNOT) pass through our cell membrane?
CAN, but slowly (think: benzene)
97
Large, polar molecules (CAN/CANNOT) pass through our cell membrane?
CANNOT
98
Charged particles (CAN/CANNOT) pass through our cell membrane?
CANNOT
99
Phospholipids are made up of
-2 Fatty Acids
-Glycerol
-Phosphate group (polar head group)
100
What are the components found in our cell membrane?
-Phospholipids
-Cholesterol (inserts itself between phospholipids, maintains fluidity of cell membrane)
-Proteins (integral/transmembrane and peripheral)
101
These membrane proteins span the entire cell membrane
Integral
102
Channel proteins generally (DO/ DO NOT) require energy for ions to cross
DO NOT(think; they are just a tunnel, not a carrier protein that changes shape)
103
T or F, Carrier proteins can help ions go against the concentration gradient
T
104
A chain of sugars attached to any membrane proteins
a Glycoprotein
105
The purpose of glycoproteins are
for signaling
106
The three main factors that affect membrane fluidity
1. temperature
2. cholesterol
3. unsaturation
107
phospholipids at a low temperature do not have alot of energy, and huddle close together, and therefore have (high/low) fluidity
low fluidity
108
As temperature increases, phospholipids are more spread out, and have (decreased/increased) fluidity
increased
109
The presence of cholesterol in a membrane at low temps (increases/decreases) distance between phospholipids, and therefore the fluidity is (increased/decreased)
increases, increased
110
the presence of cholesterol in a membrane at high temps causes (increased/decreased) fluidity and why
decreased fluidity, since the phospholipids were already spread out due to high temp, the cholesterol actually draws them closer together, decreasing fluidity
111
If we have an unsaturated fatty acid, double bonds (ARE/ ARE NOT) present
ARE, causing kinks/bends, therefore causing increased distance between phospholipids, thus, increasing fluidity
112
the process of moving a phospholipid from the outside of the membrane to inner cell membrane is known as
transmembrane diffusion, or "flip flop". this is uncatalyzed movement, and is slow
113
the process of a phospholipid moving in any direction around it
lateral diffusion, an uncatalyzed movement, and it is fast
114
A flip of phospholipids from the outside to inside with the use of a catalyst is called
Flipase (fast process)
115
A flop of phospholipids from the inside to the outside with the use of a catalyst is called
Flopase (fast process)
116
What is the name of the enzyme that brings a phospholipid from the outer to inner membrane, and then another from inner to outer is known as ____
scramblase (fast process)
117
T or F, facilitated diffusion requires the input of energy
false, but it is able to transport polar molecules and larger ions (as there are a membrane transport channel: glycoproteins)
118
Transport that directly uses ATP for energy is considered ...
primary active transport
119
.... moves multiple molecules across the membrane, powering uphill movement of molecules, with the downhill movement of others
secondary active transport
120
A Potassium leak channel allows K+ out via what sort of transport
passive (facilitated diffusion, no energy required, as K+ flows from high to low concentration gradient_
121
The different types (4) of passive transport are:
-diffusion
-osmosis
-filtration
-facilitated diffusion
122
An example of secondary active transport is
a Na+, and Glucose Symport (using a gradient set up using energy, so indirectly using ATP)
123
In antiport, the two molecules move in the same direction (T or F)
False, they move in opposite directions
124
A chloride channel is an example of
facilitated diffusion, and the protein goes through a conformational change to bring the Cl- from the outside to the inside of the cell
125
Whatever there is more of in a solution / what does the dissolving is referred to as
the solvent
126
______ is the movement of particles from high concentration to the low concentration
Diffusion
127
A solution with a high concentration of solute is also known as
hypertonic
128
Osmolarity is the flow of water or solute
water
129
A solvent will flow from an area of (hyper/hypo) tonic solution to a (hyper/hypo) tonic solution
Hypotonic (less solute= more water) to hypertonic (more solute= less water)
130
The Equilibrium Potential of K+ is -92mV, and occurs when...
the net movement of K+ is equal
131
The ion that has a membrane potential of +67 mV is
Na+
132
The ion that has a membrane potential of -86mV is
Cl-
133
The ion that has a membrane potential of +123mV is
Ca2+
134
Cardiac muscle contains what type of cell junctions
Gap Junctions (common in cells that require propagation of electrical signal)
135
What is the name of the transmembrane ion channel that open/closes in response to the binding of a ligand
Ligand-Gated Ion Channels
136
These channels rely on the difference in membrane potential
voltage gated channels
137
Receptor Tyrosine Kinases (RTKs) are an example of what kind of receptor
Enzyme-linked receptor
138
T or F, receptor Tyrosine kinases occur in pairs
True, they come together and form a "cross-linked" dimer, and phosphorylate each other
139
Enzyme linked receptors function how,
by turning an extracellular chemical signal into enzyme activity inside the cell
140
Lipid Destruction is a function of what organelle
Perioxisome
141
where in the cell does glycolysis occur?
cytoplasm
142
where do post - translational modifications of proteins occur?
rough endoplasmic reticulum
143
What is the stack of Golgi referred to as that is closest to the ER
The Cis Golgi
144
The secretory pathway includes which organelles
ER, golgi, lysosomes and cell membrane
145
Crinophagy is when lysosomes...
digest excess secretory products
146
The alveoli are lined with (simple/stratified) epithelium and why?
simple, so that carbon dioxide and oxygen are able to diffuse easier across one layer of cells
147
epithelial cells are attached to the
basement membrane
148
how do epithelial cells get nutrients, since they are avascular?
from the basement membrane beneath epithelial cells
149
A map of your body in your brain is known as
the somatosensory homunculus
150
Our ability to sense pain is known as
nociception
151
A chemical signal that is released by one member of a species, and is sensed by another member of hte species and it triggers an innate response
Pheromones
152
T or F, each taste bud contains all of the cells with abilities to detect each of the five tastes
True
153
Sweet, umami, and bitter rely on
G Protein Coupled receptors
154
Sour and Salty taste cells rely on
Ion Channels
155
Which waves have a lower frequency, alpha or beta?
alpha
156
Who said that dreams represent our unconscious wishes, urges, and feelings
Freud
157
Four main groups of psychoactive drugs
-depressants
-stimulants
-hallucinogens
-opiates
158
Depressants and stimulants (CAN/CAN'T) cancel each other out
Cannot
159
Drugs that lower your bodies basic functions and neural activity
Depressants
160
Benzodiazepines (enhance/inhibit) your brains response to GABA (inhibitory neurotransmitter)
enhances
161
Which method of drug entry is the fastest?
Intravenous (few seconds), whereas inhalation is (approx 10 seconds)
162
This biological molecule accompanies oxidation reactions
NADP+ (an electron acceptor)
163
Coimmunoprecipitation is a common technique used to
identify interactions between two proteins
164
Thin Layer Chromatography is often used in organic chemistry for
testing the progress of a reaction
165
a decarboxylation reaction is the removal of
CO2 ( a carboxyl group)
166
Binding between the enzyme and substrate is strongest at what point
during the transition state
167
a (n) _____ site is any binding site outside of the active site
allosteric site
168
what is the first immune cell present at the site of infection
neutrophils, as they are the primary rapid innate host defense
169
T or F; neutrophils display MHCII on their surface?
False
170
Because B cell receptors and T cell receptors are created at random, this puts us at higher risk for
autoimmune diseases
171
Catalysts (do/do not) impact the end product of a reaction
do not
172
Increased levels of T3 and T4 would lead to
increased levels of basal metabolic rate (they are metabolism hormones)
173
The FLATPEG mnemonic for hormones from the Anterior Pituitary are:
F: FSH (follicle stimulating)
L: LH (luteinizing)
A: ACTH (adreocorticotropic)
T: TSH (thyroid stimulating)
P: PRL (prolactin)
E: endorphins
G: GH (growth)
174
epinephrine is secreted from the adrenal ______
medulla
175
when a naive B cell encounters an antigen that fits into its membrane-bound antibody, it quickly divides to become __ or ___
a memory B cell Or an effector B cell(plasma cell)
176
What has to be guranteed to happen in order to set off B cell differentiation
The antigen must effectively bind to the naive B cell's membrane bound antibody
177
A effector B cell is also known as a
plasma cell
178
Plasma B cells are capable of
secreting antibodies
179
B cells also express a specialized receptor known as ______ that plays an important role in signaling pathwasy
B Cell Receptor (BCR)
180
T cells are formed in the ____ and then migrate to the _____ to become mature T cells
bone marrow; thymus
181
In the thymus, T-cells begin forming these receptors
T-Cell Receptors (TCR)
CD4
CD8
(all T-cells express TCR, and either CD4 or CD8, not both)
182
T cell receptors can only recognize antigens bound to certain receptor molecules known as
MHCI and MHCII
183
When a T cell undergoes positive selection, what is happening?
The T cell is testing MHCI and MHCIIs ability to distinguish between self and non-self proteins
184
When a T cell undergoes negative selection, what is happening?
The T cell is testing binding capabilities of CD4 and CD8
185
After a T cell undergoes selection processes, what are the three possible outcomes?
-Helper T Cells (CD4)
-Cytotoxic T Cells (CD8)
-T Regulatory Cells (CD4 and CD25)
186
What are the two types of immunity that the adaptive immune system provides?
-Humoral
-Cell-Mediated
187
This type of immunity is from antibodies produced by plasma cells (effector B cells)
humoral immunity
188
This type of immunity is acquired through T cells from someone who is immune to the disease or infection
cell-mediated immunity. it is carried out by cytotoxic cells
189
T cells and B cells are part of which type of immunity (adaptive/innate)
Adaptive
190
what are they phagocytic cells ?
neutrophils, macrophages, dendritic cells
191
Phagocytes are all (what type of cell)
white blood cells/leukocytes
192
Phagocytes are specific or non-specific responses to the immune system?
non-specific
193
Gel filtration separates proteins based off
size
194
Ion exchange chromatography separates proteins based off
charge
195
SDS-Page is a technique used to separate proteins based off of
size
196
A reaction that has a Keq > 1 is _____
exergonic (releases energy)
197
The process by which nucleic acids are transferred from viruses to cells is known as
Transduction
198
________ is the exchange of nucleic acids between bacteria.
Conjugation
199
__________ is the process that transfers genetic material from the environment into bacteria.
Transformation
200
contraction of the diaphragm results in (inhalation/exhalation)
inhalation
201
Inhalation results in increased/decrease intrathoracic pressure
decreased
202
____ is the initial velocity of an enzymatic reaction
V0
203
_____ is the maximum velocity of a reaction
VMax
204
The cells that display MHCI and II are
macrophages, part of the innate immune system
205
neutrophils, eosinophils, and basophils are part of
the innate immune system
206
These cells produce antibodies
B cells ( part of the humoral immunity)
207
( B or T) cells mature in the bone marrow and then spleen
B cells
208
(B or T) cells mature in the thymus
T cells
209
These specific T cells are known as CD 4, and attach to which MHC
Helper T Cells. and MHC II
210
These specific T cells are known as CD8 and attach to which MHC
Cytotoxic, and MHC I
211
An antigen-presenting cell capable of phagocytosis + this cell secretes cytokines, signaling both innate and adaptive immune responses
dendritic cell
212
Proteolytic Cleavage is what type of chemical reaction?
Hydrolysis
213
Cartilage is vascular or avascular
ALL cartilage is Avascular (which means no blood vessels or lymphatic vessels, and it is not innervated)
214
fibrous connective tissue that binds muslce to bone
a tendon
215
pieces of fibrous tissue that binds bone to bone
a ligament
216
Tor F; both prokaryotes and eukaryotes contain mitochondria
F; mitochondria are only found in eukaryotes
217
T or F; both prokayotes and eukaryotes contain cell walls
T; they both can have cell walls, but not all do
218
This form of reproduction _______ is the sexual reproduction form in prokaryotes
conjugation (think- sex pilus, F-factor)
219
This is one of the key differences between mitosis and meiosis, and it occurs during anaphase
the splitting of centromeres (when sister chromatids separate); this occurs during mitosis, and during meisois 2 anaphase 2
220
This ______ is released by the posterior pituitary, and increases collecting duct permeability
ADH
221
This _____ stimulaties resorption of Na+ and Water, goal being for BP to increase
Aldosterone
222
The antagonist of Aldosterone
ANP
223
This ______ stimulates excretion of Na+ and Water
ANP
224
This model used in the field of psychology integrates the influence of biological predispositions and the environment, and attempts to explain a disorder, or its trajectory
the diathesis-stress model
225
Langerhans cells are _____ cells
dendritic (specialized immune cells in the skin and mucous membranes)
226
The role an individual takes in society during a period of illness can be described as :
The sick role (the societal role a sick individual takes, think: Sick; Societal)
227
The subjective experience of a sick individual can be described as:
The Illness Experience (think: Illness; Individual)
228
The speed of sounds is most fast in a what form of material?
solid (due to the strong bonds and close proximity of molecules)
229
what are the two main autonomic (subset of peripheral ns) neurotransmitters?
acetylcholine and norepinephrine
230
Transformation (bacterial replication) is done via what process
incorporation of genetic fragments
231
Thick, myelinated fibers (increase/decrease) conduction velocity
increase
232
macrophages are filled with ______ and this fulfills their primary purpose of phagocytosis
lysosomes
233
MH2 are found EXCLUSIVELY on ______
antigen presenting cells
234
What kind of inhibitors bind to the active site
competitive
235
Which region of a sarcomere will not change in size during a muscle contraction?
The A Band
236
This type of hormone is known to diffuse through the cell membrane of their target cell
steroid hormone
237
This type of hormone is known to rely on secondary messenger systems
peptide hormone
238
The descending limb of henle is ______ permeable to water and ________ permeable to ions
highly; barely
239
The ascending limb of henle is _______ permeable to water, and _______ permeable to ions
barely; highly
240
The ventral roots are composed of _____ neurons
motor
241
The dorsal roots are composed of ______ neurons
sensory
242
The idea of taking a long time to decipher the word"blue"written in red writing is an example of
The Stroop Effect
243
The idea that performance increases with emotional arousal (up to a point) is an example of
Yerkes-Dodson Law
244
operant condition is reward based (T or F)
true (rewards or punishments)
245
This is how well a study measures what it intends to do
internal validity
246
This is how well a study could be applied to other populations or societies
external validity
247
when a door opens and changes shape from a rectangle to a line, this is known as
perceptual constancy
248
electrons always frow from the ___ode to the ____ode
from the anode to the cathode (think alphabetical; A to C)
249
for electrolytic cells, the cell potential is ____
negative, meaning a potential input greater than the magnitude of the cell potential must be present for electrolysis to occur
250
galvanic/voltaic cells have a _____ cell potential
positive, thus, no input is required for these cells
251
The _____ has the highest reduction potential (and lowest oxidation potential )
the cathode
252
The ______ has the highest oxidation potential, and the lowest reduction potential
the anode
253
The ability of our brain to sort through a lot of stimuli to discern what is important information is known as
feature detection
254
What is the basic tenet of the theory of general intelligence?
Intelligence relies on a single 'g factor', which underlies performace in all cognitive domains.
255
What are the three tenets of the Triarchic Theory of Intelligence?
Analytical Intelligence (problem solving), practical intelligence (adapting to everyday life) , and creative intelligence (fostering insight)
256
_______ theory argues that behavior is primarily extrinsically motivated (people are more likely to act in a certain way if they know they are getting a reward)
Incentive Theory
257
_____ theory is the idea that people are motivated by their unfulfilled needs
needs based theory
258
Bandura created the social learning theory, that is most associated with which phrase of thought
"reciprocal determinism" which is cognition, behavior and context are all influencing each other
259
The idea that people perform simple tasks better when in the presence of other people is known as
social facilitation
260
The Elaboration Likelihood Model proposes ____ major routes to persuasion
2 (central and peripheral route to persuasion)
261
The _____-route of the elaboration likelihood model is one that is logic driven and uses facts as as means fo persuasion
central route
262
The _____ route of the elaboration likelihood model is one that uses peripheral cues to suggest positivity towards the message (think celebrity endorsement or positive emotions)
peripheral route
263
The idea that we tend to cut ourselves a break, while holding others 100% to their actions is known as
fundamental attribution error
264
_____ ______ are properties of compounds that are altered by the amount of substance present
colligative properties
265
________ are a group of genes that cause normal cells to become cancerous when they are mutated
proto-oncogenes (these play a crucial role in cell proliferation, and the cell cycle- so when mutated, it will be increasing cell proliferation of tumor cells)
266
The altered version of a protooncogene is known as
an oncogene
267
p53 is an example of a
tumor suppressor gene (keep the cell cycle in check- cancerous cells try to suppress these)
268
In order for an ______ ________ reaction to proceed spontaneously, the cell potential Ecell° for the net reaction must be positive
oxidation–reduction
269
Does a lighter or heavier molecule of gas diffuse faster?
a LIGHTER one
270
D-Glucose and D-Galactose are examples of
epimers
271
porphyrin is composed of
four pyrroles (fyi- heme contains a porphyrin ring)
