BECOM Final (High Yield) Flashcards
(270 cards)
1
Q
Saturated hydrocarbons
A
No double bonds
2
Q
Unsaturated
A
One or more double (or triple) bonds
3
Q
Oxidation
A
Addition of O, N, S or removal of electrons (us. attached to hydrogen as H●)
4
Q
Reduction
A
Addition of hydrogen (electrons) or removal of O, N, S
5
Q
Complete oxidation yields
A
CO2 and H2O
6
Q
Amino acid + Amin acid form
A
amide (peptide) bond
7
Q
Zwitterion
A
molecule having separated positively and negatively charged group
ex. @ pH 7.4 carb acid ionized and amino group pronated
8
Q
Dextrose =
A
glucose
9
Q
sucrose =
A
glucose + fructose
10
Q
pyranose =
A
6 carbon ring
11
Q
furanose =
A
5 carbon ring
12
Q
M (molarity) =
A
mol / L
13
Q
m (molality) =
A
mol / Kg
14
Q
Activation energy
A
amount of energy need to reach a transition state making a reaction occur
15
Q
Four Major Biochemical Macromolecules
A
Proteins (amino acid polymer)
TAGs (lipid polymer)
DNA, RNA (nucleic acid polymer)
Polysaccharide (carbohydrate polymer)
16
Q
anabolism and catabolism occur by
A
condensation and hydrolysis
17
Q
ATP’s phosphate bonds are
A
Phosphoanhydride bonds
18
Q
Substrate level phosphorylation
A
direct transfer of a phosphoryl group from one compound to ADP (or GDP)
ex. glycolysis
19
Q
Oxidative phosphorylation (OXPHOS)
A
a process in which oxidation of carbon substrate provides reduced coenzymes. These reduced coenzymes are used to establish a proton gradient. The natural dissipation of this gradient is coupled to the production of ATP from ADP.
ex. ETC
20
Q
Major cofactors involved in central metabolic pathway
A
NADH
NADPH
FADH2
FMNH2
21
Q
Metabolic need for oxygen
A
Oxygen takes up H+ making a gradient for the ETC.
Final e- acceptor
22
Q
Kwashiorkor
A
Adequate total calories with deficiency in protein content
23
Q
Marasmus
A
Inadequate calories with respect to protein and carbohydrate
24
Q
pyruvate -> lactate (enzyme and cofactor used)
A
pyruvate dehydrogenase (NADH -> NAD+)
25
Where does glycolysis, pyruvate oxidation of acetyl CoA, Kreb cycle, and ECT occur
cytosol
matrix of mitochondria
matrix of mitochondria
intermembrane space
26
Thermogenin (UCP-1)
acts as an uncoupler in brown adipose to provide heat
27
DNP
unnatural uncoupler that binds H+ in high concentration and release H+ at low concentrations
28
Rotenone
Cyanide and carbone monoxide
oligomycin
complex I
complex III
ATP synthase
29
Thiamine
B1
| part of pyruvate dehydrogenase complex
30
Niacin
B3
| component of NAD (contains part that gets reduced)
31
Pantothenic Acid
B5
| component of CoA
32
Cobalamin
B12
one carbon carrier
stored in the liver
33
Absorption of B12
- R-binders (gastric mucosa) bind B12 and are carried to small intestine where protease (pancreases) break down R-binders releasing B12 so intrinsic factors (parietal cells) can bind to B12 and the complex can be absorbed in the ileum
- intrinsic factor unbinds B12 in blood where transcobalamin binds B12 and carries it to liver (storage) or other tissues (use)
34
primary protein bond
covalent
35
secondary protein bond
hydrogen
36
Tertiary and Quaternary bonds
hydrogen bonds, LDF, Salt bridges, disulfide bonds
37
Phosphorylation post translation modification (amino acids and why)
add phosphate to serine, threonine, and tyrosine
| -OH group on the side chain undergoes condensation reaction with phosphate
38
Glycosylation post translation modification
attach N (asparagine) or O (serine threonine and tyrosine) to amino acid side chain
39
Ubiquination post translation modification
add ubiquitin to lysine residue of a target protein for degradation
40
Cofactor
An inorganic or organic molecule require by a protein for activity (e.g. Zn++)
41
Coenzyme
An ORGANIC cofactor (e.g NAD, FAD)
42
Prosthetic group
a tightly bound co-factor (e.g. Heme) that is COVALENTLY bonded
43
Forces that stabilize proteins (covalent and non covalent)
Covalent: disulfide
| Non covalent: H bonds, Ionic (salt bridges), Hydrophobic
44
How do reducing agents denature proteins
they break sulfide bonds
45
Denaturing of proteins
```
Heat
pH
Organic solvents
Detergents
Ionic Strength
Reducing agents (break disulfides)
Mechanical stress (shaking)
```
46
Lysosomal Protein Turnover
EXTRACELLULAR proteins taken into cell and shuttled to lysosome where they are broken down by proteases called CATHEPSIN (cysteine derivative)
47
The Ubiquitin-Proteosome Pathway
INTRACELLULAR proteins are tagged by 4 ubiquitin at a lysine residue and carried to proteasome were they are degraded and recycled
-(ATP dependent process)
48
Metabolic acidosis
Low pH
Low HCO3-
-Increased production of metabolic acids (eg. lactate from anaerobic respiration) (low o2) or failure to excrete acids (kidney problems)
49
Metabolic alkalosis
High pH
| High HCO3-
50
Respiratory acidosis
Low pH
High CO2
-hypoventilation (shallowing breathing)
51
Respiratory alkalosis
High pH
Low CO2
-hyperventilating
52
Ferrous
2+
53
Ferric
3+
54
Cooperativity bindig
as more oxygen binds to Hb the affinity for oxygen increases (sigmoidal curve)
55
Bohr effect
```
Higher CO2 (lower pH; tissue side) -> O2 affinity drops
-RIGHT SHIFT
```
56
Where does CO2 and 2,3 BPG binds on Hb
- terminal amine (not heme)
| - middle negative region (squeezes O2 out)
57
Haldane effect
high affinity for CO2 decreases when high O2 concentrations
58
why does HbF have a higher affinity for HbA
2,3 BPG cant bind to HbF
59
Hydroxyurea
medication used to induce more HbF in sickle cell pateints
60
sickle cell anemia cause
Glutamate (negative) -> valine (no charge)
61
Cyanosis
is the appearance of a blue or purple coloration of the skin or mucous membranes due to the tissues near the skin surface having low oxygen saturation.
62
Left shift and right shift in sigmoid curve caused by
carbon monoxide poisoning and Bohr effect
63
hydrolase
A + H2O -> B + C
64
Oxidoreductase
catalyzes oxidation or reduction reactions
65
Lyase
cleaves C-C, C-S, or C-N bonds
66
Transferase
Ax + B -> A + Bx
67
Isomerase
two compounds with same formula but different arrangements
68
Ligase
A + B -> AB
69
allosteric reg. binds
non covalently at a site away from active site (allosteric site)
70
Acetylcholinesterase catalytic triad
serine histidine and glutamate
71
Uncompetitive inhibitor
Inhibitor binds ES but ONLY WHEN active site is occupied by substrate.
72
Suicide inhibitor
bind to active site (covalently), modifying active site
73
α-amylase
cleaves α-1,4 linkages between glucose residues
| -Product: Dextrins (linear and branched oligosaccharides)
74
Pancreatic α-amylase
cleaves α-1,4 linkages
| - Product: dissacharides (maltose, isomaltose), trisaccharides (maltotriose), oligosaccharides (limit dextrins)
75
Sucrase-isomaltase
splits sucrose, maltase, maltotriose, dextrins
76
Lactase
hydrolyzes ß-1,4 bond of glucose and galactose
77
Sucrase
hydrolyzes α-1,2 bond of glucose and fructose
78
Maltose =
glucose + glucose
79
Lactose =
galactose + glucose
80
Lactose intolerance
Lactase Deficiency
81
Glycogen polymer form and why
polymer of (α1,4)-linked glucosyl units with (α1,6)-linked branches every 8-12 residues.
- Minimizes osmotic effects of intracellular glucose
- The highly branched structure permits rapid glucose release from glycogen stores
82
GLUT1
RBC
83
GLUT2
Liver & pancreatic B cells (insulin release)
84
GLUT3
Brain
85
GLUT4
Skeletal muscle & adipose
| -insulin responsive
86
GLUT5
Fructose transporter in intestine luminal epithelium and sperm
87
Mutarotation
Beta glucose (break) Alpha glucose
88
PRPP is used in
1. De novo synthesis of both purine & pyrimidine nucleotides
2. The salvage of both purine & pyrimidine bases
3. The synthesis of NAD from tryptophan
89
Inhibitors and activators of purine synthesis?
Inhibitors: AMP ADP GMP ATP GDP GTP
Activator: PRPP
90
Lesch-Nyhan Disease
Deficiency in HGPRTase
91
Purine synthesis
ribose sugar -> phosphate -> base
92
Hereditary Orotic Aciduria
(high level of orotic acid)
| -Orotate phosphoribosyl transferase def.
93
Thioredoixin
UDP -> dUDP then dUMP -> dUTP through folate cycle
94
Thioredoixin
UDP -> dUDP then dUMP -> dUTP through folate cycle
95
phospholipase 1
cleave at sn1
96
phospholipase 2
cleaves at sn2
97
phospholipase C
cleaves phosphate closer to sn3
98
phospholipase D
Cleves phosphate closer to charged head group
99
HMG-CoA pathway
makes cholesterol
100
7-a-hydroxylase
makes bile salts out of cholesterol
101
VLDL
takes TAGs from liver to tissue (endogenous)
102
Chylomicron
take TAGs from intestine to liver (exogenous)
103
LCAT
in HDL takes cholesterol -> cholesteryl ester
| -keeps cholesterol gradient
104
ApoCII
activates LPL (tags -> glycerol + FA)
105
glycerolkinase
take glycerol from VLDL and chylomicron to make TAG
106
acetyl CoA carboxylase
FAs synthesis rate limiting enzyme
| -needs B7 (biotin)
107
Thromboxane
- TXA2
- promates aggregation of platelets and vasocontriction
- COX1
- inhibits prostacycylin
108
Prostacyclin
- PGI2
- inhibits platelet aggregation and stimulates vasodilation
- COX2
109
Leukotrienes
- mediate allergic response inflammation
| - 5LOX
110
NSAIDS inhibit
COX1/2
111
Tocopherols (vitamin E)
stabilize lipid membrane by reacting with ROS
112
Sphingolipids
myelin sheath lipid membrane
113
Phosphatidyl Inositol
inositol connected to C3 of DAG (IP3 messenger -> PLC (Ca2+ release))
114
Cardiolipin
stabilizes ETC complexes
115
Depolarization
decrease Vm
116
Hyperpolarization
increase Vm
117
I = G (V - E)
Current = Conductance (Driving Force)
Driving force = membrane potential - equilibrium potential
permeability = conductance
- Na higher driving force than K
118
Intracrine
signals are produced by the target cell that stay within the target cell. Example: secondary messengers
119
Autocrine
signals are produced by the target cell, are secreted, and affect the target cell itself or a near by cell of the same type via a receptor. An example of this are immune cells.
120
Paracrine
signals target cells in the vicinity of the emitting cell. E.g. neurotransmitters.
121
Endocrine
signals target distant cells. Endocrine cells produce hormones that travel through bloodstream to reach all parts of the body. E.g. hormones.
122
Juxtacrine
signals target adjacent (touching) cells. These signals are transmitted along cell membranes via protein or lipid components integral to the membrane and are capable of affecting either the emitting cell or cells immediately adjacent. E.g. gap (tight junctions, notch signaling, etc).
123
GEF
GDP -> GTP
124
GAP
GTP -> GDP
125
Phosphodiesterase
breaks down cAMP
126
RTK mutations
- RTK: becomes dimerized and phosphorylated with out ligand bound
- Overexpression: large amount of kinases in the membrane
- Activating mutation: produce a product that mimics phosphorylation or conformational change of kinase
127
kB inhibits
NFkB (inflammatory response)
128
Philadelphia chromosome
BCR-ABL (ATP) complex -> phosphorylated and disassociates causing cell proliferation
129
graded potential vs action potential
- summation (cell body)
| - all or nothing (axon hillocks)
130
Conduction Velocity of the Action Potential
Diameter of axon
Myelination
Resistance
131
2 Types of Synapses
-Chemical synapses use neurotransmitters (most!)
One way transmission
-Electrical synapses pass electrical signals via gap junctions.
Often both directions
Eye
132
Postsynaptic Effects
-Alter chemically gated ion channel (open or close)
EPSP (excitatory)
IPSP (inhibitory)
-Activate 2nd messenger systems
1. Open specific ion channels on the postsynaptic membrane
2. Activation of cAMP or cGMP
3. Activation of one or more intracellular enzymes
4. Activation of gene transcription
133
classic neurotransmitter inhibitors
GABA
| glycine
134
MAO
breaks down serotonin (5 HT)
135
Choline acetyltransferase
makes acetylcholine out of choline + acetyl CoA
136
Inactivation of Neurotransmitters
glial cells
enzymes break down neurotransmitters
diffuse out of synaptic cleft to blood stream
137
Spatial Summation
net sum of inputs spatially (surface area) on the presynaptic neuron determine the level of excitability.
138
Temporal Summation
net sum of inputs per unit of time on the presynaptic neuron determine the level of excitability.
139
effect of acidosis on neuro
depresses neuronal activity (Na+ (in) exchanged for H+ (out))
-high H+ outside no exchange for Na+ and
140
effect of alkalosis on neuro
increases neuronal excitability
141
C peptide (insulin)
proinsulin contains C peptide and when C peptide is cleaved out to make mature insulin
142
Fasting state AMP vs ADP
more AMP than ADP in fasting state because of adenylate cyclase enzyme reaction
143
Adenylate cyclase
ADP + ADP = AMP + ATP
144
Acetyl CoA carboxylase activator and inhibitor
activator: citrate
inhibitor: palmitoyl CoA (A CoA carb is phosphorylated)
145
Where do e- leak from
I and III not IV
146
myeloperoxidase
makes bleach (literally, HOCl) from H2O2 + Cl-
147
NO normally involved in vasorelaxation via
soluble guanylate cyclase
148
Constitutive isoforms
vasorelaxation
149
Inducible isoform
iNOS (NOS2), in macrophages and microglia (brain macrophages)
150
Nrf2/Keap1
Nrf2 disassociated in stress times (inc ROS) and promotes antioxidant
151
Cori Cycle
lactic acid taken in by the liver and made back into glucose
152
beriberi (Wernicke-korsakoff syndrome)
B1 def (a-ketoglutarat dehydrogenase)
153
pelagra
B3 (NADH)
154
Sulfonylurea
blocks K+ leak channels in pancreatic B cells causing depolarization and release of insulin
155
Malate-Aspartate Shuttle
OAA -> malate in cytosol (NADH -> NAD)
| Malate -> OAA in mitochondria (NAD -> NADH)
156
Glycerol 3P Shuttle
Cytosol: DHAP -> Glycerol 3-P (NADH -> NAD+)
| Mitochondrial membrane: Glycerol 3-P -> DHAP (FAD -> FADH2)
157
Pyruvate Dehydrogenase Complex
Pyruvate -> Acetyl CoA
- Irreversible reaction
- occurs in mitochondrial matrix
- releases CO2
158
Pyruvate Dehydrogenase Complex uses 5 cofactors
TPP (B1), lipoate, FAD (B2), NAD+ (B3), and CoA (B5)
159
When energy level of the cell is high or oxygen is lacking, PDC activity is
turned off
160
pyruvate carboxylase
pyruvate -> OAA
- occurs in mitochondria
- requires CO2 (biotin)
161
Acetyl CoA effect on PDH and Pyruvate carboxylase
(- PDH)
| + pyruvate carboxylase
162
von Gierke disease
Glucose 6-phosphatase deficiency
| -glycogen stuck in the liver
163
Glycogenesis enzyme
synthesis of glucagon
| -glycogenin
164
glycogenolysis
Glycogen degradation
165
Sympathetic Innervation Only (non-dually innervated)
- Arteriolar smooth muscle – blood pressure
- Kidney – body fluid balance and blood pressure
- Sweat glands
- Adipose (lipolysis)
- Clotting
166
alpha 1
Smooth muscle contraction (NE>EPI)
167
alpha 2
Also presynaptic inhibition of NE release (NE>EPI)
168
beta 1
Cardiac, renin release from kidney, lipolysis (NE=EPI)
169
beta 2
Smooth muscle relaxation (EPI>> NE)
170
Sympathetic Branch: Stimulation
```
Pupil dilation (mydriasis)
Dry mouth
Sweat production
Increased heart rate & force of contraction
Bronchiole dilation
Fuel mobilization (glucose, lipolysis)
Blood vessel constriction
Coagulation
Ejaculation/orgasm
```
171
Sympathetic Branch: Inhibition
```
Increased digestion
Pancreas secretion
Urination
Slow heart rate
Reduce blood pressure
```
172
Adrenal Medulla Primary neurotransmitter
Epinephrine (80%)
| NE 20%
173
Parasympathetic Branch: Actions
```
Digestion
Salivation
Insulin release
Urination
Erections (arousal)
```
174
what does the vagus nerve not innervate
eye
175
Organophosphate poisoning causes
S.L.U.D.G.E.(M)
| -Salivation, lacrimation, urination, defecation, gastrointestinal, emesis, muscle spasm/miosis (pinpoint pupil)
176
Parasympathetic Branch: Inhibition
Inhibit digestion
Reduces secretory functions (dry mouth)
Increases heart rate
177
stress sweat gland vs thermoregulation sweat gland
stress: alpha 1
thermo: muscarinic
178
alpha 1 g protein cascade
inc IP3/DAG -> inc Ca2+ ->vasoconstriciton
179
beta 1
inc cAMP -> inc HR
| -key to increase HR
180
Inc. NE (bp)
Inc. bp (more alpha than beta but beta has higher affinity for NE)
181
Dec. NE (bp)
Dec. bp (more alpha than beta but beta has higher affinity for NE)
182
b stimulation to lung and heart
bronchodilation
| inc HR
183
Helicase
separates the helix by breaking the hydrogen bonds between complementary bases
184
SSBP
prevent reannealing of the duplex
185
Topoisomerase
prevents supercoiling
186
Primase
lays down the RNA primer
187
DNA Pol I
replaces the RNA bases of the primer with DNA bases
188
Ligase
facilitates the formation of phosphodiester bonds and joins Okazaki fragments.
189
shelterin
protein complexes that specifically bind to telomeric DNA repeats and protects them from being recognized by DNA repair proteins
190
exonuclease activity
-3'-to-5'
-Replication errors produce a DNA mismatch and inability of the mismatched bases to form the appropriate H bonds
This leads to displacement of the 3-OH into the 3-to-5 exonuclease “site” of the enzyme
191
MYH glycosylase
- Base excision repair
| - Damaged base is recognized and cleaved leaving a sugar with no base attached in the DNA
192
Poly-ADP-ribose polymerase (PARP)
binds to the strand break and recruits other repair proteins.
193
Nucleotide Excision Repair is used to fix
UV radiation thymine dimers
194
Nonhomologous End Joining occurs in what type of cell
non dividing
195
Homologous Recombination Repair occurs in what type of cell
actively dividing
196
HATs vs HDAC
transfer ACoA to lysine removing lysine
| pos. charge (DNA unwind)
197
Methylation
- This favors the incorporation of DNA into heterochromatin (tightly packed, no transcription)
- associates with the 6’ carbon of cytosine and adds a methyl group to the 5’ carbon
- can be passed down
198
Heat shock protein
cortisol has higher affinity for glucocorticoid receptor than HSP
-TAD binds coactivators, DBD binds the hormone response element of the DNA, ultimately leading to transcriptional activation of response genes
199
eIF3 and reg
prevents premature association of 40S and 60S subunits
| -inactive when phosphorylated (times of stress)
200
eIF2-GTP
binds to initiator tRNA
201
eIF4 and reg
bound to mRNA join 40S subunit
| -activated by insulin
202
Peptidyl transferase
catalyzes peptide bond formation between amino acids attached to tRNAs at the P and A sites, elongating the polypeptide and transferring it to the tRNA at the A site
203
eEF2
translocates the ribosome, moving it three nucleotides toward the 3’ end of the mRNA
204
stop codons
UAA, UAG, UGA
205
Release factors (RF)
bind a stop codon in the A site
206
Tetracyclines, including doxycycline
prevent the binding of aminoacyl-tRNA by blocking the A (aminoacyl) site of the 30S ribosome
207
Aminoglycoside antibiotics (Streptomycin Kanamycin and tobramycin)
have an affinity for the 30S ribosome subunit
208
Erythromycin, roxithromycin, and clarithromycin
all prevent elongation at the transpeptidation step of synthesis by blocking the 50S polypeptide export tunnel
209
Lincomycin and clindamycin
are specific inhibitors of peptidyl transferase
210
Diphtheria toxin
inactivate eukaryotic elongation factor eEF2, thereby inhibiting eukaryotic protein synthesis
211
Proto-oncogenes mutations
Mutation in coding region
Regulatory region
Translocation novel protein
Gene amplification
212
BAD
- proapoptotic
| - phos by Akt (inactive)
213
P53 and stimulates
gardian of the genome
-stimulates p21 is a universal cyclin/cdk inhibitor (CKI), it prevents the phosphorylation of Rb, keeping Rb bound to E2F
214
Rb
sequesters the transcription factor E2F
- Ras/Raf leads to induction of transcription of cyclin D
- Cyclin D binds to CDK4/6
- Cyclin D/CDK4/6 phosphorylates Rb
- Rb changes conformation and releases E2F
215
MDM2
tags P53 for degradation when DNA is successfully repaired
216
BAX
stimulated by P53 and causes apoptosis
217
β-catenin and APC
APC bind β-catenin causing APC degradation
| -when not bound to APC β-catenin catenin translocates to the nucleus and activates transcription of myc and cyclin D
218
Autosomal Recessive Inheritance
- The disease is not usually seen in each generation, but if an affected child is produced by unaffected parents, the risk to subsequent children is ¼
- The sex ratio of affected offspring is expected to be equal
- If both parents have the disorder, all children will have it
219
Autosomal Dominant Inheritance
- Each individual who has the disease has at least one affected parent
- Fathers can give to DAUGHTERS and SONS
- Males and females are affected in equal numbers
220
Huntington’s disease is
Autosomal Dominant Inheritance
| -late onset
221
Xeroderma pigmentosum is
Autosomal Recessive Inheritance
222
Hemophilia A is
X-linked Recessive Inheritance
223
X-linked Dominant Inheritance
Males cant pass X linked trait to son
| but all daughters will be effected
224
Congenital hypertrichosis is
X-linked Dominant Inheritance
225
Mosaics
is a type of genetic mosaicism where more than one set of genetic information is found specifically within the gamete cells
-effects child but not parent
226
Apical epidermal ridge
Initiates proximally, grows distally
Proximal elements (humerus, femur) form before distal elements (radius/ulna, tibia/fibula)
-secretes FGF8, FGF4
-problem limb will grow in wrong place
227
paraxial mesoderm
All axial and appendicular skeletal muscles, and all of the skeleton except the cranium
228
surface ectoderm
Limb skin, hair, skin glands, and nails
229
Wnt mutations can cause
osteogenesis imperfecta
230
Zone of Polarizing Activity (ZPA)
-Determines A-P axis of limb bud
-Sonic hedgehog (Shh or SHH) is strongly expressed at the ZPA
-
231
Upper limb rotates
dorsally (laterally)
| -week 8
232
Lower limb rotates
ventrally (medially)
233
Week 5 Week 6 Week 7 Week 8
Week 5: limb bud and plate
Week 6 notches between webbed fingers
Week 7: short fingers slightly webbed
Week 8: fingers and toes separated
234
blood supply to growing arm
axial artery
235
Meromelia
Can be caused by HOX mutations
236
Synaptotagmin
binds Ca2+
237
Synaptobrevin
bound to vesicle
238
RYR1 receptor
found in skeletal muscle SR
| -DHPR bound to RYR
239
RYR2 receptor
found in cardiac muscle SR
240
Twitch vs Treppe
-single stimulation of a muscle fiber
-staircase increase in muscle contraction as more and muscle fibers are stimulated
increase in force produced with each contraction
241
Tetanus vs tetany
tetanus is fatigue caused by bacteria while tetany is fatigue caused by excursion
242
Longer muscle length
greater velocity and less force
243
Shorter muscle length
less velocity and greater force
244
Slow vs Fast twitch
Slowest Type 1 < Type 2a < Type X < Fastest Type 2b
245
Greatest tension (force) occurs between
100-120%
246
myosin light chain phosphatase
removal of phosphate from myosin light chain and
resulting decreases in actin-myosin
cross bridging
247
myosin light chain kinase
phosphorylates myosin during SM contraction
248
Cardiac Muscle force electrical carried via
```
Desmosomes allow force to be transferred
Gap Junctions (connexions) provide electrical connection
```
249
preload
inc length of muscle = inc preload
250
afterload
inc after load = dec contractility
251
contractility
NE and EPI: inc contractility
| Ach: dec contractility
252
Vernix caseosa
Periderm cells and sebum make up
| -protect baby from abiotic fluid
253
fingerprints
Epidermal ridges produce grooves
254
Ichthyosis
Skin is characterized by dryness and fishskin-like scaling (lizard)
255
what all are associated with the hair follicle
- sebaceous gland
| - appocrine sweat glands (axilla and pubic)
256
Eccrine sweat glands
alone sweat gland
257
lanugo hairs
Help hold vernix caseosa on the skin, which protects the skin
258
Alopecia
bald spot
259
lamellar granules
- Their water-resistant glycolipid slows water loss
| - in stratum granulosum
260
Skin physical barrier
resistance to mechanical stress and absorption/evaporation of substances (water)
-Keratin and glycolipids block most water and water- soluble substances
261
skin Chemical Barriers
```
-Skin secretions
Low pH retards bacterial multiplication
Sebum and defensins kill bacteria
-Melanin
Defense against UV radiation damage
```
262
Skin Biological Barriers
```
-Dendritic cells of epidermis
Present foreign antigens to white blood cells
-DNA
Its electrons absorb UV radiation
Radiation converted to heat
```
263
↑ Body Core temp
Thermoreceptors in hypothalamus (primary driver) and skin (secondary) respond -> ↑ cholinergic stimulation -> vasodilation of blood vessels in dermis
264
↓ Body temp
Thermoreceptors in hypothalamus (primary driver) and skin (secondary) respond -> ↑ adrenergic stimulation -> vasoconstriction of blood vessels in dermis
265
type I keratin
acidic keratins (contain acidic acids)
266
type II keratin
basic keratins (contain basic amino acids)
267
Transglutaminase
lysine + glutamine forms amide bond
- gives structural stability to keratins int. filaments
- doesn’t just happen in keratin
268
tyrosine hydroxylase
enzymes used to convert tyrosine to melanin
| -Cu2+ dependent
269
phenylalanine hydroxylase
phenylalanine -> tyrosine (BH4 dependent)
270
Melanin production
P53 -> POMC -> B endorphins and a MSH (MC1R) -> inc cAMP -> MITF -> pigments
