PCOL 832 Exam 2 Flashcards
1
Q
Receptors can be___.
A
Enzymes, ion channels.
2
Q
Endocrine signaling is
A
Signaling through blood. Examples include: steroids, catecholamines.
3
Q
Paracrine signaling is
A
Signaling on neighboring cells in close proximity. Example: insulin release of acetylcholine, neurotransmission
4
Q
Autocrine signaling is
A
Signaling when the secretory cell is the target cell. Ex: T-lymphocytes ligand is the antigen.
5
Q
Juxtacrine signaling is
A
Direct contact between cells, one with the ligand and the other with the receptor, ligand/hormone is not secreted, it is attached to the cell.
6
Q
Which signaling method is this: Macrophages release cytokines, cytokines act on nearby cells lining blood vessels to cause vasodilation.
A
Paracrine signaling
7
Q
which type of signaling method is this: T lymphocytes are presented with an antigen by dendritic cells. T cell is triggered to produce and secrete IL2, a cytokine. IL2 binds receptor on surface of naive T cell and induces it to proliferate.
A
Autocrine signaling
8
Q
Which type of signaling method is this: Naive T lymphocytes are presented with an antigen by dendritic cells. The ligand is the antigen (foreign). It is attached to the DC membrane rather than being secreted. Ligand binds CD28 receptor on a Naive T-cell. Binding triggers immune response against foreign protein or entity, such a s microbe.
A
Juxtacrine
9
Q
A stimulus triggers a cell to secrete a ___
A
chemical messenger
10
Q
A bound receptor triggers a series of events inside the cells that elicit a response. This is referred to as ____.
A
Signal Transduction
11
Q
Cell compartmentalization is achieved mostly by ____
A
Lipid membranes
12
Q
Which organelles are common to most cell types?
A
-Mitochondria
-Cytoplasm
-Golgi
-Lysosomes
13
Q
The plasma membrane and most other organelle membranes are ___
A
lipid bilayers
14
Q
The layers of lipid bilayer are composed of ____ and ____
A
phospholipids and cholesterol
15
Q
____ plays an important role in regulating movement of molecules in and out of the cell.
A
Plasma membrane
16
Q
Hydrophilic ___ face ____ of cell
A
Head, inside and outside
17
Q
Hydrophobic ___ make up the ___ of bilayer.
A
tail, middle
18
Q
Where are integral proteins located?
A
They span the membrane or are embedded in the membrane.
19
Q
Where are peripheral proteins?
A
Associate with membranes via interactions with integral membrane proteins or by covalent attachment to special lipids.
20
Q
Carbohydrates form the ___ on the exterior side of the protein.
A
glycocalyx
21
Q
What does glycocalyx contain?
A
It contains glycoproteins and glycolipids that surround the cell membranes of many cells.
22
Q
Oligosaccharides are attached to proteins through either N-glycosidic (____) or O-glycosidic (____) bonds.
A
Asparagine, serine
23
Q
The ____ makes the cell surface very hydrophilic and restricts the passage of hydrophilic molecules through the ____.
A
glycocalyx, plasma membrane
24
Q
What are the three transport systems for molecules to cross?
A
Active, Passive, Vesicular
25
What does ADME stand for?
Absorption
Distribution
Metabolism
Excretion
26
what are the two mechanisms of passive transport?
1.Simple diffusion
2. Facilitative diffusion
27
In passive transport the ion moves ____ the concentration
With
28
In passive transport ion moves from ____ concentration to ____ concentration.
High to low
29
Which molecules freely cross the membrane? which type of transport is this?
gases (o2, co2), Water, Steroids (lipid-soluble). This is simple diffusion
30
Drugs that are small molecules often use ___ to enter cells.
transport/carrier
31
In active transport, ions move ___ the concentration gradient from ___ concentration to ___ concentrations.
against, low to high
32
what is an example of secondary active transport?
In a Na/glucose transporter, glucose moves from low to high (against) concentration gradient but does not require ATP. It uses the energy from stored Na ion gradient which did involve ATP. Rather it is powered by Na/K pump.
33
Which 3 transporters work together to maintain cellular homeostasis and what type is each?
2 active (Na/K ATPase and Na/glucose)
1 Passive (facilitated diffusion of glucose GLUT)
34
What is efflux pump refer to?
After drug enters the cell, it can be pumped out by active transporters
35
Which type of ions move through vesicular transport?
Macromolecules and macromolecular complexes.
36
What is this called? Plasma membrane invaginates around macromolecules and encloses them in a vesicle which them moves them into cytoplasm.
Endocytosis
37
What does it refer to when pathogens are engulfed?
Phagocytosis
38
What is receptor-mediated endocytosis?
When a ligand binds a receptor on the surface of a cell and the plasma membrane engulfs it into a coated vesicle.
39
what is exocytosis?
When vesicles inside the cell fuse with the plasma membrane and their contents are extruded into extracellular fluid.
40
which cell organelle is surrounded by lipid bilayer membrane?
Lysosomes
41
what is the function of a lysosome?
Break down variety of macromolecules.
42
Lysosomes break down macromolecules at a low PH, how is the acidity maintained?
By ATPase that pump hydrogen against the gradient into the lysosome.
43
Neutrophils/Macrophages engulf pathogens or dead cells to form phagosomes. Phagosomes fuse with _____and their contents are degraded/
Lysosomes
44
Inner membrane of mitochondria is highly impermeable and has ____.
Cristae
45
What is the space inside the inner membrane of mitochondria called?
Mitochondrial Matrix
46
What is contained in the mitochondrial matrix?
Enzymes involved in fuel oxidation as well as DNA that encodes several ETC proteins
47
Glycogen is stored in which cell organelle?
smooth endoplasmic reticulum
48
Which organelle contains enzymes for synthesis of lipids?
Smooth endoplasmic reticulum
49
Drugs and toxins are primarily metabolized in ____ of a cell.
Smooth endoplasmic reticulum
50
Ribosomes are located outside of which cell organelle?
Rough endoplasmic reticulum
51
Where is the site of initial sorting of newly synthesized proteins?
Rough ER
52
Where is the site of initial post-transational modification like N-linked glycosylation?
Rough ER
53
Specialized form of smooth endoplasmic reticulum found specifically in muscle cells is called?
Sarcoplasmic reticulum
54
Which organelle is involved in sorting and distribution of proteins and lipids synthesized in the Endoplasmic Reticulum?
Golgi
55
The ___ further processes the proteins that were initially modified in the ER.
Golgi
56
____ formation is the target of several cancer therapeutics.
Microtubule
57
What are microtubules make of?
Tubulin subunits
58
Which type of filament provide structural support for the plasma and nuclear membranes?
Intermediate filaments
59
Which type of filament control cell shape and cell movement?
actin filament
60
The nucleus is surrounded by a ___ ___ ___ membrane.
double lipid bilayer
61
___ is located in the nucleus.
Nucleolus
62
What is it called when chromatin are tightly compacted?
Heterochromatin
63
What is it called when chromatin are loosley compacted?
Euchromatin
64
__ have XX chromosomes.
Females
65
Hydrophobic ligands are sensed by ___ receptors.
Intracellular
66
Hydrophilic ligands are sensed by ___receptors.
plasma membrane receptors
67
When a ligand binds to an extracellular domain, it causes conformational change that activates the domain. What are the three events that may occur?
1. Opening of a channel in the membrane
2. Activation of an enzyme in the receptor
3. Change in activity of proteins bound to the receptors intracellular domain.
68
MAP kinase signaling is initiated by activation of a ____
tyrosine kinase receptor
69
What are examples of "activation of an enzymatic activity"?
1.tyrosine kinase receptor
2. Serine/threonine kinase receptor
70
What is one example of serine/thyrosine kinase signaling:
TGF-beta signaling
71
What is one example of tyrosine kinase activity?
Jak-Stat
72
Inhibitors of Jak Kinase are approved for treatment of which three diseases?
1.Rheumatoid Arthritis
2.Psoriasis
3.Myelofibrosis
73
True or false: Cytokines are hormones.
False, it is a small protein
74
Cytokines bind ____ receptors.
plasma membrane
75
Define transcription factor:
It is a protein that binds directly to a specific DNA sequence
76
Proteins bound by ___, alter gene expression through regulation of transcription factors.
second messengers
77
signaling pathways regulate _____ to alter gene expression and elicit a cellular response.
transcription factors
78
what is a promoter?
Upstream to the start site of transcription and is where RNA polymerase binds the gene to begin transcription.
79
what is an enhancer?
Can be upstream or downstream the gene body or even in intron regions. They act to strengthen or weaken the promoter's ability to attract RNA polymerase.
80
Sodium is high ___ the cell and low ___the cell.
Outside, inside
81
Moving something with its concentration gradient (H to L) to generate chemical energy to move another molecule against its gradient (L to H) is an example of which transporter?
NA Glucose Co-transporter
82
There is an excess of transporter molecules outside of the cell, they have to bind to proteins but there are a limited number of proteins, so the rate will stabilize. This refers to:
Saturation kinetics
83
What happens to oxygen during fuel oxidation?
It goes to water
84
The fed state is regulated by ___ hormone.
Insulin
85
True or false: Fat and triglycerides are the same.
True
86
Glycerol and fatty acids are connected by ___
lipolysis
87
Esters form between ___ and ____
fatty acids and hydroxyl groups
88
Peptide bonds form between a ___ and ____ group.
carboxylic acid and amino
89
Esters are ____ products between fatty acids and ___
condensation, alcohol
90
Do proteins contain ester groups?
No
91
Which has no double bonds: Saturated or Unsaturated?
Saturated
92
What is a glycerol?
It is a 3 carbon molecule with 3 hydroxyl groups
93
What is a choline?
Quaternary ammonium + alcohol
94
___ is a pathological metabolic state marked by extreme and uncontrolled ketosis.
Ketoacidosis
95
What are three examples of ketone bodies?
-Acetate
-Acetoacetate
-B-Hydroxybutyrate
96
Acetate is formed by the nonenzymatic ___ of acetoacetate.
decarboxylation
97
In the ___ state, the liver takes in more glucose from the blood than it releases.
Fed
98
Which process takes place after insulin release following feeding?
Glycogenesis
99
___ is the process of breakdown of fat into fatty acids and glycerol for energy.
Lipolysis
100
Where does lipolysis take place?
adipose tissue
101
where does glycogenolysis take place?
Liver and muscle cells
102
what is the primay enzyme of glycogen breakdown?
glycogen phosphorylase
103
what is the starting molecule of lipogenesis:
acetyl-CoA
104
Acetyl-CoA is used to synthesize ____ in a process called ____
fatty acids, fatty acid synthesis
105
Fatty acids are combined with ___ to form ___
glycerol, triglycerides
106
which hormone promotes lipogenesis?
Insulin
107
Why is fat an excellent source of energy?
Less oxygen present in fat, don't have to waste energy to carry out. Fat is least oxidized.
108
___ is when something gives away electrons. ___ is the gain of electrons.
Oxidized, Reduction
109
Cell signals ___ when fat storages are full.
leptin
110
which protein peptide is involved in food intake?
Leptin
111
what is a chylomicron?
Lipoproteins that are produced by the gut after fat digestion. Chylomicrons transport triglycerides
112
Muscle stores ___ but only for its ___ use.
Glycogen, own
113
what is the non-toxic form of ammonia called?
Urea
114
___ are the signature metabolites of starvation.
Ketone bodies
115
which two hormones/molecules stimulate glycogenolysis?
Glucagon and epinephrine
116
In a fasted state, the brain and red blood cells use glucose released by the?
Liver
117
Under glucagon control, adipose tissues are induced to release _____ and ___ from stored triaglyceride.
Fatty acids and glycerol
118
___ produces lactate which return to the liver as substrate for gluconeogenesis.
RBC
119
The glycerol released from adipose tissue is used by the ___ for ____.
liver, gluconeogenesis
120
____ (NOT triglycerides) serve as fuel for erythrocytes.
Glucose
121
High glucose diet= ___ urea excretion
small because no need to break down any protein
122
In a fasting state, Urea excretion is ____. Because body has to break down protein for glucose.
High
123
Ketone body formation takes place in the ____ and ____
kidney cortex and liver
124
What does a low Km value indicate?
That less substrate is needed for the enzyme
125
What is the third class of enzymes and what is an example.
Hydrolases: Proteases
126
what is the 2nd class of enzymes and what is an example:
Transferases: Kinases
127
What is the 1st class of enzymes?
Oxidoreductases
128
going from acetoacetate to B-hydroxybutyrate, which rxn is taking place?
Oxidoreductases
129
____ are irreversible inhibitors of the neuronal enzyme acetylcholinesterase.
organophosphates
130
what is AMP in terms of glycolytic flux?
AMP is a potent allosteric activator of glycolytic flux (glucose- pyruvate)
131
Increase in AMP in a cell =
Glycolysis is turned on
132
example of covalent adduction?
Penicillin
133
which inhibitors from covalent adducts that permanently alter the target?
Irreversible covalent inhibitors.
134
Phase 1 reactions include:
Reduction, Oxidation, Hydroxylation, Hydrolysis
135
Phase 2 reaction include:
Conjugation, Sulfation, Methylation, Glucuronidation
136
Low Km = ___ Affinity
high
137
The lower the Km, the ___ the enzyme is capable of turning over a substrate.
better
138
Ethanol to Aldehyde is done through which enzyme?
Alchohol dehydrogenase
139
Aldehyde to Acid is done through which enzyme?
Aldehyde dehydrogenase
140
Write the nucleotide and nucleoside of G
Nucleotide: Guanine, Nucleoside: Guanosine
141
write the nucleotide and nucleoside of C
Nucleotide: Cytosine, Nucleoside: Cytidine
142
ribose is ___ and deoxyribose is ___
OH, H
143
Hydrolysis turns ___ to ____
ADP to ATP
144
what does NAD stand for?
Nicotinamide Adenine Dinucleotide
145
what are coenzymes?
Non-protein organic molecules
146
which coenzyme is part of lactic acid dehydrogenase?
NAD
147
Competitive inhibition ___ Km and ___ Vmax
Increased Km and has no effect on Vmax
148
cAMP has ___ ester bonds.
2
149
which bonds connect phosphate bonds together?
anhydride bonds
150
which rxn converts glucose 6-p to glucose 1-p?
isomerization
151
