Exam 1 Flashcards
Internal Environment, The Cell, Transport of substances through Cell Membranes
1
Q
Where are Lipids synthesized in the cell?
A
The Smooth Endoplasmic Reticulum
2
Q
Where are Proteins synthesized in the cell?
A
The Ribosomes attached to the Rough Endoplasmic Reticulum
3
Q
What happens at the Golgi Apparatus
A
Proteins are modified and sent out in vesicles
4
Q
Who coined the phrase Homeostasis?
A
Walter Cannon
5
Q
What is the “Internal Environment”
A
Extracellular Fluid
6
Q
What is Negative Feedback?
A
Changes are “sensed” & the body responds to oppose/counter change.
Change is Negative to stimuli
7
Q
What is Positive Feedback
A
Change is seen and is amplified
Can be known as “vicious cycle”
8
Q
A healthy body can handle how much blood loss?
A
1 Liter (20%)
9
Q
What is the suffix “-“ used to identify enzymes?
A
“-ase”
10
Q
Fluid inside of the cell?
A
Intracellular fluid
11
Q
Fluid outside of the cell?
A
Extracellular fluid
12
Q
Ions typically found inside of the cell?
A
Potassium, Magnesium, Phosphate
13
Q
Ions typically found outside of the cell?
A
Sodium, Chloride, Bicarbonate
14
Q
How do Peroxisomes rid of toxins?
A
Oxidation Reactions
15
Q
What is the “Checkpoint” for oxytocin-induced uterine contraction?
A
Birth
16
Q
What is the “Checkpoint” for the blood clotting cascade?
A
Bleeding Stopped
17
Q
How many RBCs are typically found in the body?
A
25 Trillion RBCs
18
Q
What is the percentage of water in the cell? (Cytoplasm)
A
75-85%
19
Q
In what way do lysosomes rid of unwanted substances?
A
The use of highly acidic conditions
20
Q
What is the Cell membrane composed of?
A
Proteins and Lipids (mostly lipids)
21
Q
The tail end of the lipid bilayer is?
A
Hydrophobic
22
Q
The head of the lipid bilayer is?
A
Hydrophilic
23
Q
What is something that is allowed in the nucleus?
A
Steroids
24
Q
Where can Peroxisomes by found?
A
Liver
25
What is a common toxin peroxisomes rid of?
Ethanol (alcohol)
26
What can be stored in the Endoplasmic Reticulum?
Calcium
27
What is Homeostasis?
the maintenance of nearly constant conditions in the internal environment
28
How many cell are in the body?
About 35 Trillion
29
What is output energy?
Work, heat, potential energy
30
Relationship between PNS and SNS?
Inverse relationship, help maintain homeostasis
31
What is the Negative Feedback change for a decreased MAP with SNS?
An increase in SNS outflow
32
What is the Negative Feedback change for a decreased MAP with PNS?
A decrease in PNS outflow
33
What is the Negative Feedback change for a decreased MAP with AVP/ADH?
Arginine Vasopressin (AVP) & Antidiuretic hormone (ADH) increase
34
What is the Negative Feedback change for a decreased MAP with ANP?
Atrial Natriuretic Peptide (ANP) decrease
35
What are checkpoints in Positive Feedback?
Safety valves, point where positive feedback stops
36
Pathology of Positive Feedback in Severe Acidosis: CNS effects
CNS is depressed which decreases respiratory drive, worsens acidosis (pH decreases)
37
Pathology of Positive Feedback in Severe Hemorrhage
Loss of blood causes drop in MAP, leads to coronary blood flow; which leads to decrease in cardiac output; causes further decrease in MAP
38
Pathology of Positive Feedback in Sepsis/Necrosis
Systemic infection causes cellular death; cells die & release by products into ECF affecting neighboring cells
39
Pathology of Positive Feedback in Diabetic Renal Inflammation/Hyperfiltration
Decreased nephron regeneration, leads to increased workload of remaining nephrons, shortened nephron lifespan, worsened renal conditions
40
Pathology of Positive Feedback in Atherosclerotic Plaque Clotting
Overactive clotting cascade leads to clot formation in arteries, can lead to MI/Stroke
41
Pathology of Positive Feedback in Peripheral Acidotic conditions
Cellular dysfunction, impaired blood flow, and reliance on anaerobic metabolism worsens acidosis
42
How many liters blood in the Human body?
5 Liters
43
What is the smallest living unit?
A cell
44
What cells have difficulty Replicating?
Neuron and Cardiac
45
Can RBCs replicate?
No (no nucleus), RBCs are produced by bone marrow progenitor cells
46
How long do RBCs live
90-120 days
47
What causes cells being unable to replicate
Lack of Nucleus
48
What is the function of Nucleus?
To protect the DNA
49
Describe the Nuclear membrane
"Nuclear wall or envelope", a double phospholipid bilayer.
very selective
50
What is the Endoplasmic Reticulum?
Extension of the nuclear wall; produces lipids, proteins
51
What percentage of proteins are synthesized on the ribosomes attached to the Rough ER?
95%
52
What is an Enzyme
A protein that catalyzes chemical reactions
53
What is produced by the Mitochondria?
Adenosine Triphosphate (ATP)
54
List 5 examples of organelles in the cell
Mitochondria, Peroxisomes, Lysosomes, Golgi Apparatus, Endoplasmic Reticulum
55
ATP production starts in?
In the cytosol with anaerobic metabolism (glycolysis)
56
Glycolysis produces __ ATP
2
57
Sugars on the cell surface can have ___ charge
Negative
58
Due to __ charge; Sugars on cell surface ___ proteins
Negative; Repel
59
Sugars on cell surface can be ""
Sticky
60
Prefixes for sugars (3)
Glyco-
Carboxy-
Carb-
61
Flagella
Motility structure; assist with cell movement, one long thread-like structure
62
Cilia
Small projections that come out of cell
63
Mitochondria DNA is..?
inherited by our mother
64
How many "sets" of mitochondrial DNA do we carry
about 12-20 (gives variability in body's ability to inherit energy producing organelles)
65
Hydrophilic
like water; charged; Ions are found here
66
Hydrophobic
Oils (fats) found here, uncharged; lipid soluble
67
List common soluble substances
Ion; proteins; carbohydrates; CO2
68
List common insoluble substances
Cholesterol; Steroid Hormones; Lipids; Nitrous gas
69
What helps maintain pH?
Buffers
70
Insoluble drugs need a __ to travel in the body
a Carrier Protein/Lipid
71
Popular example of an insoluble drug utilizing lipid based carrier is?
Propofol
72
Total Body Water (TBW) is?
60% of body weight (Kg)
73
Intracellular fluid makes up
2/3 of TBW
74
Extracellular fluid makes up
1/3 of TBW
75
Extracellular fluid is divided into
Plasma and Interstitial fluid
76
Plasma fluid makes up
1/4 or 1/5 of ECF
77
Interstitial fluid makes up
3/4 or 4/5 of ECF
78
Without a mediator the cell wall will not let __ permeate
Charged Ions/molecules
79
Capillary membrane typically prevents __ from leaking out to interstitial fluid
Plasma (cardiovascular) Proteins
80
Capillaries found within the brain are
very tight
81
Steady State vs. Equilibrium
Steady state - tightly regulated differences that help maintain homeostasis.
Equilibrium - attempt to keep all concentrations the same (no bueno for us)
82
Notable difference between Plasma & Interstitial is?
Protein Concentration; higher in Plasma
(Plasma - 1.2) (ISF - 0.2)
83
Why is the protein concentration difference needed in Plasma and ISF?
Must be higher in Plasma to keep blood in the vascular system
84
Normal Sodium (Na+) range in ECF
140 -142 mOsm/L
85
ICF sodium concentration?
1/10th of ECF (10:1 ratio)
86
ECF Osmolarity can be estimated by:
Doubling ECF sodium
87
Normal ECF Osmolarity is:
280 - 283
88
Potassium (K+) ECF normal range
4 mEq/Ls
89
Potassium (K+) ICF normal range
30 times ECF (140) (neurons 120)
90
ICF Calcium concentration
zero or near it
91
ECF to ICF calcium ratio
10,000:1
92
Magnesium is used as
a cofactor for ICF chemical reactions
93
Magnesium has a higher concentration in
ICF
93
Primary Anion in ECF
Chloride (Cl-)
94
Chloride follows which cation
Sodium (Na+)
95
Secondary Anion in ECF
Bicarbonate (HCO3-)
96
Primary buffer of ECF
Bicarbonate (HCO3-)
97
What organ manages bicarb levels?
Kidneys
98
Important ICF buffer
Phosphate (HPO)
99
Phosphorylation is?
the attachment of a phosphate to a protein
100
Dephosphorylation is?
the detachment of a phosphate from a protein (Release of energy)
101
Phosphate in the cell can be used as?
Energy storage system (store ATP) or be used as a form of energy
102
Phosphates are more abundant in?
ICF
103
ATP
Adenosine + 3 phosphates; main source of energy for cells
104
Majority of Plasma is?
Albumin
105
Amino acid concentration is greater in the?
ICF; proteins are synthesized in ICF
106
Creatine is found in the?
Skeletal muscle
107
Phosphocreatine is
Creatine with a phosphate stuck to it;
High energy storage compound;
Phosphate when pulled of creatine releases energy (used before ATP consumption)
108
Lactate is Higher in the
ICF (Byproduct of metabolism)
109
Adenosine can leak out of cell if
the cell is highly metabolically active or in a low energy state
110
Adenosine in the ECF
increases (opens vessels) blood flow in area that is highly metabolically active
111
Cells are reliant on an external source of
Glucose
112
Protein concentration Plasma : ISF
5 : 1
113
Total sum mOsm/L (osmolarity)
about 300 mOsm/L
114
Corrected mOsm/L (osmolarity)
280 - 283 mOsm/L
115
Why do we correct for osmolarity
Ionic compounds can be formed in the ECF due to different charges (ex. Na+ & Cl-)
116
___ moves freely between ICF & ECF (Plasma & ISF)
Water; helps keep consistent osmolarity between all three
117
Glycolipids
carbohydrates (sugar) covalently bonded to lipids
118
Glycoproteins
sugar stuck to a protein; found on cell membrane
119
Glycocalyx
combination of glycoproteins & glycolipids
120
Glycocalyx
sum of all external sugar structures; used in cell adhesion & recognition / immunity
121
Cholesterol is
a fatty, uncharged compound
122
Cholesterol can be thought of as __ & __
planar and rigid (it reduces cell fluidity)
123
Cholesterol is a long chain of carbon and hydrogen with an __
OH group (polar)
124
Body temperature and rigidity of cholesterol are
Directly proportional (normal temp rigid/low temp more fluid)
125
Sex hormones produced by cholesterol
- Estradiol
- Testosterone
- Progesterone
- Androstenedione (precursor to testosterone - used by baseball players)
126
Atherosclerosis
condition in which fatty deposits (cholesterol) build up on the inner wall of arteries
127
The term "glycocalyx" refers to what?
The negatively charged carbohydrate layer on the outer cell surface
128
Which of the following best describes the osmolarity of a solution containing 150 millimolar NaCl, assuming a temperature of 37 C & dissociation constant of 0.93 (inmilliosmoles)
279 (150 x 2 x 0.93)
129
Cholesterol in the body comes from
80% endogenous
20% diet (exogenous)
130
Cholesterol makes blood vessels more
Rigid (not good for CV)
131
- statin
HMG-CoA reductase inhibitors
- reduce amount of endogenous cholesterol created
132
Cholesterol is a precursor for (6)
- Estradiol
- Progesterone
- Testosterone
- Androstenedione
- Cortisol
- Aldosterone
133
Stress hormones produced by Cholesterol
- Cortisol
- Aldosterone
134
There is cross-reactivity between cholesterol derivatives and their receptors because
Their molecular shape is very similar
135
Phosphatidyl
means phospholipid
136
Surfactant
produced in lungs to reduce surface tension of alveoli & keep lungs from collapsing
137
Phosphatidylinositol (PI) can be used in
Smooth muscle; regulates contraction (precursor to IP3)
138
Phosphatidylcholine (PCh) can be used to
stash choline for production of acetylcholine
139
Phosphatidylserine (cytosolic)
immune marker
140
In order to not elicit immune response Phosphatidylserine should be ___ the cell wall
facing inside
141
All four phosphatidyl compounds play a role in surfactant production which are:
- Phosphatidylinositol (PI)
- Phosphatidylethanolamine (PE)
- Phosphatidylserine (cytosolic)
- Phosphatidylcholine (PCh)
142
Flippase
Enzyme responsible for "flipping" phosphatidylserine back toward facing inward
143
Flippase is dependent on
ATP (flipping PE requires energy)
144
In a low energy state describe the effects of Phosphatidylserine on the cell.
Phosphatidyl will orient outward on cell wall. In low energy state (no ATP) flippase will not be able to reorient it. An immune response will result and destroy the cell.
145
Sphingomyelin is a precursor of ___ used in the ___
Myelin; Nervous system (constructs myelin)
146
Thromboxane A2 (TXa2) helps control bleeding by
Vasospasms; facilitates clotting/healing of injured vessel
147
COX1 & COX2 are
Enzymes that catalyzes two reactions which results in Prostaglandins & TXA2
148
Prostaglandins are perceived as
ramping up pain signals
149
Inhibition of COX 1 results in
Bleeding; Cox1 found all over body
150
Inhibition of COX2 results in
reduced pain
151
In the event of pain the COX2 gets
turned on
152
Strongest OTC pain medication
Naproxen (more COX2 specific)
152
Drugs more selective for COX1 more likely to
Cause bleeding (decreased TXA2 production) Ex. aspirin
153
Leukotrienes (LT) are responsible for
immune mediated inflammation
154
Example of leukotriene receptor antagonist
Singular
155
Lipoxygenase (LO)
enzymes responsible for converting Arachidonic Acid to leukotrienes
156
3rd "arm" of Arachidonic pathway produces
HETEs & EETs compounds resulting in acute inflammatory responses (like acute renal failure)
157
The main pathways of Arachidonic Acid
- Prostaglandin-thromboxane pathway
- Leukotriene-lipoxygenase pathways
- HETE & EET pathways
158
Arachidonic Acid &HETE/EET are __ while Leukotrienes & Prostaglandins are __
Hydrophobic;
Hydrophilic
159
Enzymes are
Proteins that function as catalyst
160
Simple diffusion is
the crossing of the membrane with out aid (does not require energy)
161
Gases cross the membrane via
simple diffusion
161
Channel proteins
provide conduit that allows specific molecules or ions to cross membrane via simple diffusion
162
Utilizing a channel protein does not require
Binding, conformational change, or energy (considered simple diffusion)
163
A cell at rest is __ charged
negatively
164
An active cell is __ charged
positively
165
Substances tend to move from ___ concentration to ___ concentration
Higher ; Lower
166
Facilitated Diffusion
utilizes aid from a protein but does not require energy
167
Active transport
movement across the membrane that requires energy
168
Water moves across the cell membrane via
Aquaporin channels (AQR) or sneak in with ions via ion channels
169
Ion channels
Transmembrane protein that allows specific ions to diffuse across membrane down its electrochemical gradient
170
Movement against the electrochemical gradient requires
Energy (active transport)
171
Sodium-Potassium ATPase pump
Utilizes ATP to actively transport
- 3 Sodium (Na+) ions out of cell
- 2 Potassium (K+) ions into cell
172
One cycle of the Na-K pump requires __ and moves __ out & __ in
1 ATP to dephosphorylate;
3 Na out
2 K in
173
The single most energy requiring process is
The ATPase pump
174
Na/K pump uses up
60-70% of cell energy
175
First degree active transport
Primary active transport process that directly uses ATP by the pump itself
176
Calcium pump moves Ca ion outside of cell & requires ATP & is considered
Primary active transport (1st degree)
177
Proton pumps of the stomach use ATP directly to
Move Hydrogen ions (protons) outside the cell making outside environment acidic (1st degree active transport)
178
Sodium Calcium Exchanger (NCX Transporter)
Exchanges 1 Ca ion out of cell; & swaps it for 3 Na ions inside of cell (Relies on electrochemical gradient of sodium)
179
Sodium Calcium Exchanger is an example of
Second degree active transport; process does not directly use ATP
180
Sodium Glucose Transporter (SGLT)
Moves glucose into cell while simultaneously carrying sodium down its gradient (does not utilize ATP itself; 2nd degree active transport)
181
Where can SGLT be found?
Kidneys
182
Steps in facilitated diffusion
1. Bind to something outside cell wall
2. Undergo conformation change
3. Release compound inside cell
183
GLUT transporter
Carrier proteins that move glucose across membrane
184
GLUT-4 transporters are
Insulin activated;
Insulin increases transporters to membrane which increases glucose entering cell
185
GLUT-1 transporters are
found on RBCs; non-insulin dependent glucose transporters
186
The speed of facilitated diffusion depends on (2)
Number of transporter receptors & concentration gradient
187
Ubiquitous
found everywhere; widely spread
188
The Total Osmotic Pressure is calculated by
Multiplying the corrected osmolar activity by 19.3 mmHg
189
Osmolality is
Qty mOsm / 1 kg H20
190
Osmolarity is
Qty mOsm / 1L of solution (used in class)
190
The molecular weight of Na & Cl is
58.4 g/mol
191
Difference between osmolality & osmolarity
the difference is the size of the solution (about 1%)
192
Top part of osmolarity equation is
how much (quantity)
193
Bottom part of osmolarity equation is
volume measurement
194
Water likes to move from areas of __ water concentration to __ water concentration
High; Low
194
Semipermeable membrane restricts
movement of solutes; allows water to cross
195
Equilibrium potential of Na
61mV
196
Equilibrium potential of K
-90mV
197
1mOsm moves how many mmHg?
19.3mmHg
198
Proteins have a net __ charge making the resting cell more ___
Negative ; Negative
199
GLUT-4 can be found in
Muscle/fat
200
Vmax is the
maximum speed at which conformational change can occur during facilitated diffusion
201
There is no Vmax in
Simple diffusion
202
What are the 2 things that affect speed of facilitated diffusion
Concentration & Conformational change
203
What can affect rate of diffusion?
- Concentration gradient
- Lipid solubility
- Size of particle / size of pore
- Number of pores
- Kinetic movement (temperature - higher temp)
- Physical pressure
- Electrical Charge
204
As Na is being pumped out of cell what follows?
water (this keeps intracellular volume in check)
205
Intracellular osmolarity is regulated by (kept down)
The difference in 2K & 3Na during ATPase pump; the extra Na being pumped out keeps intracellular osmolarity down
206
During an action potential what floods the cell?
Na
207
Resting membrane potential of a cell is
-80mV
208
At rest a cell is
negatively charged
209
During an action potential a cell is
Positively charged
210
A voltage refers to a
potential difference between two places
211
Nernst Potential is also known as
Equilibrium potential
212
What is the Equilibrium Potential formula
+/- 61 x log (concentration inside/concentration outside)
213
Equilibrium potential for Na?
- 61 x log(14/140) = 61mV (when Na enters cell; makes it more positive)
214
Equilibrium potential for K?
- 61 x log(120/4) = -90mV (when K leaves cell; makes it more negative)
215
The Nernst Potential tell us
what the membrane potential would be for one specific ion
216
The permeability of K is ___ times greater than that of Na at rest
10
217
The resting charge on a resting cell is much more dependent on __ than it is on ___
Potassium ; Sodium
218
The Goldman equation combines
combines all individual equilibrium potentials for each ion of interest, used to determine overall membrane potential
219
Increasing sodium permeability makes the membrane potential more
Positive
220
Increasing potassium permeability makes the cell more
Negative
221
Activity of the Na+ -K+ pump is reduced in
Hypokalemia
222
An increase in extracellular K+ makes the membrane potential more
Positive
223
Glucose is higher on the __ than the __ of a cell
outside; inside
224
Drugs that end in -caine affect
"fast" sodium gated channels
ex. Lidocaine, Bivocaine
225
Polarization
difference in electrical charge between inside & outside of cell (resting cell negative)
226
Depolarized
become less polar; become more POSITIVE (action potential)
227
Hyperpolarized
become more polar; MORE NEGATIVE than at rest (overshoot)
228
Repolarization
To return to Vrm or resting activity, negative (-80mV)
229
Neurons have a lot of __ permeability which affects membrane potential
Chloride (Cl-)
230
Leaky channels are
always open
231
At rest we have __ sodium leak channels open & __ of potassium leak channels open
few; lots
232
Fast sodium channels give us an
Action potential
233
In the heart, a plateau during an action potential allows for
myocardial muscle contraction, the longer the plateau the longer the contraction (more squeeze)
234
Conductance is
how much ion flow or potential current i have (inverse of resistance); describes relative ease at which ion can cross membrane
235
Hyperpolarization (overshoot) is caused by
Extra potassium channels being open & trying to return to Vrm quickly & channels closing slowly
236
What types of channels are involved in actions potentials?
Voltage-Gated channels (Na+ & K+)
237
Driving force refers to
speed at which ions will want to cross into cell membrane
238
Driving force depends on 3 thing:
- What is the charge of the ion
- What is the concentration gradient for the ion
- What is the charge of the inside of the cell
239
Which ion typically has the greatest driving force?
Calcium (10,000 (out):1 gradient (in), & double the positive charge)
240
Which ion typically has the least driving force?
Potassium (30:1 gradient in vs out)
241
Equilibrium potential describes
the charge that is required on the inside of the cell to prevent an electrolyte (ion) from moving down its concentration gradient
242
Under resting conditions, K is hindered from leaving cell by
cell negative charge; despite there being several K leaky channels
243
Under resting conditions, Na is hindered from entering cell by
there being fewer Na leaky channels compared to K
244
Membrane potential is
the "potential" to have current, only need the potential to have current, do not actually need a current
245
The activation gate is also known as
The M-gate (outermost)
246
The inactivation gate is also known as
The H-gate (innermost)
247
What are the Na+ gates doing in resting conditions?
- M-gate is closed
- H-gate is open
248
When activated both Na gates are
open (Na floods in for short period of time)
249
When inactivated, the Na gates are
- M-gate is open
- H-gate closed
250
To reset Na+ channel what must happen
- M-gate must close (1st) then
- H-gate must reopen (2nd)
- M-gate then reopens (3rd)
251
Voltage-Gated Potassium channels aid in
Repolarizing cell after action potential (slow)
252
Potassium channel gate is located
on inside of cell
253
When do Potassium channels begin to close?
at Vrm (-90mV)
254
Potassium channels are __ to open & __ to close
Slower & slower
255
Hyperkalemia will __ membrane potential
Increase (cell will not be able to fully reset, slowing down action potentials)
256
What is a negative affect of cell membrane potential being increased
Cell will not be able to fully rest (Vrm), hindering future action potentials (fewer Na sodium channels will open)
257
Membrane potential of a cell will favor that to which has the greatest ___
Permeability
258
When do K+ channels open?
During Repolarization
259
What enzymes do peroxisomes use?
Catalase
260
What are waste products of metabolism
CO2, H+, solid waste, H2O, urea, & heat
261
How many nephrons do the kidneys have?
1 million each; 2 million total
262
Peptides are
two or more amino acids; short chains
263
What enzymes do lysosomes use?
Hydrolase
264
What drug was VERY specific for cox2; which lead to heart/kidneys issues
Vioxx
265
Oxytocin is produced where?
Hypothalamus
266
Acetyl-CoA is used to
- produce ATP from Glucose & O2
- produce cholesterol
267
Every single lung issue is a product of
a surfactant issue
268
Which edema is more difficult to deal with ICF or ECF?
ICF
269
Calcium does what to cells?
Turns them on
270
What Hyperkalemic value will always lead to v-fib?
12
271
If a cell is not able to return to Vrm, what can it lead to?
Increased Vrm; less action potentials or slowing down of action potentials
272
Where is AVP/ADH produced?
Posterior Pituitary
273
mmHg calculations are done at?
Sea level
274
Cortisol has an __ group that aldosterone does not
OH
275
Primary role of phosphodiesterase?
Enzyme that converts cAMP to AMP
276
Primary role of guanylate cyclase?
Enzyme that converts GTP to cGMP
277
Primary role of phospholipase A2?
Enzyme that breaks down phospholipids to release arachidonic acids
278
Primary function of adenylate cyclase?
Enzyme that converts ATP to cAMP
