Unit 4 Flashcards
(165 cards)
1
Q
What are the three ways that cells appear to communicate with other cells?
A
Indirect signlaing by secreted chemicals
Direct signaling by plasma membrane bound molecules
Direct signaling via gap junctions
2
Q
What are the three classes of mammalian hormones based on?
A
Based on transit of hormone from cell of origin to target site
3
Q
What are the three classes of mammalian hormones?
A
Paracrine
Endocrine
Autocrine
Neuroendocrine signaling
4
Q
_______ hormones are released into extracellular space, diffuse to neighboring target cells
A
Paracrine
5
Q
_______ hormones are released into blood and carried to target cells
A
Endocrine
6
Q
_________ hormones affect the cell where they’re produced by binding to their own surface receptors
A
Autocrine
7
Q
Eicosanoids are examples of ________ hormones
Insulin and glucagon are examples of _________ hormones
A
Paracrine
Endocrine
8
Q
_______ hormones bind to plasma membranes receptors and operates through second messengers
A
Water-soluble
9
Q
How are Water soluble hormones transported in the blood?
A
Free form
10
Q
__________ hormones bind to nuclear receptors and operates through gene regulation
A
Lipid-soluble hormones
11
Q
How are lipid soluble hormones transported in blood?
A
Bound to proteins
12
Q
_________ receptors are involved in Hormone-receptor interactions that generates second messengers
A
Metabotropic receptors
13
Q
Hormone receptors signaling via _______
A
Secondary messengers
14
Q
Receptors present in the plasma membrane that generates second messsengers when bound to a hormone is known as a
A
Metabotropic receptors
15
Q
What are examples of peptide hormones?
A
Insulin and glucagon
16
Q
Peptide hormones are synthesized as _______ and act on plasma membrane receptors to generate ______
A
Prohormones; second messenger
***Prohormone examples preproinsulin -> preinsulin -> insulin
17
Q
Peptides, catecholamines and eicosanoids hormones act by what way?
A
Binding to plasma membrane receptors and generate second messengers
18
Q
Catecholamines are synthesized from ______. What is an example?
A
Tyrosine; epinephrine
19
Q
What are eicosanoids synthesized from?
What is an example?
A
Arachidonate; prostaglandins
20
Q
Steroid is synthesized from ______. And an example is _________
A
Cholesterol; testosterone
21
Q
Vitamin D is synthesized from _______. And example is _____
A
Cholesterol; calcitriol
22
Q
Retinoid is synthesized from _______. An example is _______
A
Vitamin A; Retinoate
23
Q
Thyroid hormones are synthesized from _______. An example is _______
A
Thyroglobulin; Triiodothyronine (T3)
24
Q
What types of hormones act by way of binding to nuclear receptors and regulate gene expression?
A
Steroid, vitamin D, retinoid, thyroid hormones
25
Nitric oxide hormones are synthesized from _____ and _____ and act by way of ________ receptor thus generating a second messenger
From arginine and O2
| Cytosol is receptor
26
What neurotransmitter is active in the CNS and PNS?
Acetylcholine
27
What us the amino acid precursor of acetylcholine?
Serine
28
What two components combine to form Ach?
Choline + Acetyl-CoA
*** Choline is produced by Serine
29
_________ receptor is an ion channel to where the ligand receptor interactions opens up the ion channel. What is an example of this receptor?
Ionotropic
Ex: Ach receptors
30
Propagation of the impulse involves opening of ________ channels
Voltage gated Na+
31
Opening of _________ channels at the end of the axon triggers the release of the neurotransmitter Ach
Voltage gated Ca2+
32
_______ opens the ligand gated ion channel (ionotropic receptor) on the receiving cell
Ach
33
_______ is synthesized by the beta cells of pancreas during the _____ state (after eating a typical meal)
Insulin ; Fed state
34
What are the target cells of insulin?
Liver, muscle, or fat tissue cells
35
What does the binding of insulin to the insulin receptor initiate?
A cascade of event that leads to increased glucose uptake and metabolism
36
What precursor of insulin has the signal sequence, C-peptide, and the alpha and beta chain?
Preproinsulin
37
What precursor molecule of insulin has the signal sequence removed but C peptide is present?
Proinsulin
38
What is the functional insulin made up of?
Alpha and beta chain
** functional once C-peptide is removed from Proinsulin
39
Insulin is a _______ hormone with 51 amino acids
Peptide
40
Where is insulin made?
Beta cells of pancreas
41
Insulin is high in blood during the _____ state. It’s release is stimulated by what?
Fed state; high blood glucose
42
During the fed state when there is high blood glucose, what organs are affected and result in an increase in uptake of glucose?
Muscle
Adipose tissue
Liver
43
When insulin is present, what biomolecules are synthesized?
Glycogen
Fat
Cholesterol
Protein (to lesser extent)
44
Inability to make or respond to insulin results in _______
Diabetes
45
_______ is synthesized by the alpha cells of the pancreas during ______
Glucagon; fasting state
46
What is the precursor of glucagon?
Proglucagon
47
Glucagon is a ______ hormone made up of 29 amino acids
Peptide
48
When is glucagon increases only when ________ is low
Blood glucose
49
Glucagon is high in blood _______ and _____
Between meals and overnight (fasting)
50
What cels do glucagon effect?
Hepatocytes mostly
51
What does glucagon lead to in hepatocytes?
Increase in production and release of glucose
52
High glucagon leads to _____ in degradation of ______ and ______
Increase; Glycogen and fat
53
Increase of glucagon release results in ________ synthesis of cholesterol, fat and glycogen
Decreased
54
Where is epinephrine synthesized from? What causes it to be secreted?
The adrenal glands during stress, like exercise or starvation
55
______ is the end product of modifying tyrosine by sequential chemical reactions that generate other signaling molecules as well
Epinephrine
56
Complete the pathway of synthesis to epinephrine
Tyrosine-> ________ -> dopamine-> _____ -> epinephrine
L-DOPA; Norepineprhine
57
Epinephrine is a _______ Hormone synthesized by ______
Catecholamine; tyrosine
58
______ is produced by the adrenal glands and secreted during times of stress from starvation or exercise
Epinephrine
59
High epinephrine leads to degradation of _____ and ______. Decrease synthesis of ______, _____ and _____.
Increased degradation:
Glycogen, fat
Decreased synthesis of cholesterol, Fat and glycogen
60
Epinephrine secretion leads to increased O2 to tissues resulting in what 3 things?
Increased heart rate
Increased blood pressure
Increased vasodilation
61
What plays vital roles as signaling molecules between near by cells (paracrine signlaing)
Biologically active signaling
62
What are 3 examples of biologically active lipids
Eicosanoids
Steroid hormones
Lipid soluble vitamins (A,D,E,K)
63
What is the vitamin precursor of the coenzyme TPP?
Thiamin
64
What is the vitamin precursor of the coenzyme FAD/FMN?
Riboflavin
65
What is the vitamin precursor of the coenzyme NAD+/NAP+?
Niacin
66
What is the vitamin precursor of the coenzyme CoA and ACP?
Pantothenate
67
What is the vitamin precursor of the coenzyme Biocytin?
Biotin
68
What is the vitamin precursor of the coenzyme PLP?
Vitamin B-6
69
What is the vitamin precursor of the coenzyme THF?
Folate
70
What is the vitamin precursor of the coenzyme methyl and deoxycobalamin?
Vitamin B-12
71
What is the vitamin precursor of the coenzyme Collagen hydroxylation?
Ascorbate
72
What reaction is the coenzyme TPP important in?
Decarboxylation as 2C fragment carrier
73
What reaction is the coenzyme FAD/FMN important in?
Redox as an electron carrier
74
What reaction is the coenzyme NAD+/NADP+ important in?
Redox as electron carrier
75
What reaction is the coenzyme CoA and ACP important in?
Acylation as acyl carrier
76
What reaction is the coenzyme Biocytin important in?
Carboxylation
77
What reaction is the coenzyme PLP important in?
Amino transfer and decarboxylation
78
What reaction is the coenzyme THF important in?
One-C transfer, AA and nucleotide metabolism
79
What reaction is the coenzyme methyl and deoxycobalamin important in?
Oxidation of odd chain FA,
| Folate metabolism and amino acid metabolism
80
What reaction is the coenzyme collagen hydroxylation important in?
Antioxidant
81
What are the fat soluble vitamins?
Vitamin A, D, E, and K
82
What fat soluble vitamins s also referred to retinoids?
Vitamin A
83
What form of vitamin A is present in plants? In animals?
Animals: vitamin A or retinoids
Plants: Pro-vitamin A or carotenoids
84
What are the active forms of Vitamin A?
Retinoic acid: cellular differentiation
| Retinal: Vision
85
______ are vitamin A containing compounds
Retinoids
86
_______ is the aldehyde form of vitamin A
Retinal
87
______ is the alcohol form of vitamin A
Retinol
88
_____ is the acid form of vitamin A
Retinoic acid
89
Vitamin A is stored as ________ in the liver and adipose tissue
Retinyl esters
90
What is the functionally active form of vitamin A in the retina?
11-cis-retinal
91
________ is a Component of the visual pigment rhodopsin
11-cis retinal
92
What is the site of synthesis of vitamin D?
Skin
93
What is the site of action of vitamin D?
Bones, intestine, and kidney
94
What is the vitamin D found in circulation?
25-hydroxyvitamin D
95
What is the active Vitamin D?
1alpha,25-dihydroxyvitaminD
AKA calcitriol
96
What are the two overall functions of vitamin D?
Mineral homeostasis (calcium and phosphorus balance) and gene expression
97
How does vitamin D affect mineral homeostasis?
It reduces kidney excretion of calcium
It regulates calcium deposition in bones
Along with parathyroid hormone (PTH) it regulates calcium levels
98
What is the precursor to Vitamin D synthesis?
7-dehydrocholesterol
99
7-dehydrocholesterol is converted to vitamin D3 (cholecalciferol) in the __________ (location) via _____
Skin via UV light
100
Cholecalciferol that is produced in the skin from UV light is sent to the _____ where it will be converted to ________ and sent into circulation
Liver; calcidiol (25-hydroxyvitamin D)
101
Once cholecalciferol is converted to 25-hydroxyvitamin D in the liver, it is transported in the blood to the _______ where it will become _______ (active vitamin D)
Kidney; 1,25dihydroxyvitamin D AKA calcitriol
102
______ units are important in vitamins E and K and A
Isoprene
| *** she mentioned vitamin A but it is not mentioned in the chart
103
What is the role of vitamin E?
It’s an antioxidant
104
Vitamin E family of compounds is ________
Tocopherols
105
What is the most active tocopherol?
Alpha-tocopherol
106
_______ protects double bonds in unsaturated fats
Vitamin E
107
How does vitamin E protect double bonds in unsaturated fats?
Prevents free radical formation by acting as an electron donor
Also functions to remove peroxides during oxidation of polyunsaturated FAs
108
Vitamin K’s role is a ______
Cofactor
109
How does vitamin K act as a cofactor?
Vitamin K activates gamma-glutamyl carboxylase
**This reaction is important in blood clotting
110
Vitamin K acts as a cofactor in _______ and ______
Blood clotting and bone matrix proteins
111
Where are thyroid hormones synthesized?
Thyroid glands
112
_______ residues are enzymatically iodinated in thryroglobulins in the formation of thyroid hormones T3 and T4
Tyrosine
113
_________ sundergoes carboxylation through the enzyme gamma-glutamyl carboxylase with its cofactor vitamin K
**important in the clot formation cascade
Glutamic acid
114
Condensation of two _____ molecules to form the precursor to thyroxine
Iodotyrosine
115
Release of _____ by proteolysis of the precursor
Thyroxine
116
Underproduction of thyroxine slows metabolism which results in ________
Goiter
117
Nitric oxide is a ______ hormone
Gaseous
118
________ is an important cofactor in the clotting cascade that is important in converting the precursors of clotting factors to mature clotting factors
Vitamin K
119
Nitric oxide synthase catalyzes synthesis of ______ from ______
NO from arginine
120
Nitric Oxide (NO) generates _____, a second messenger
cGMP
121
What are the 3 actions of NO (nitric oxide)?
Regulation of neurotransmission
Stimulating defense to microbial infection
Vasodilation
122
NO acts by stimulating _________ to convert GTP-> cGMP
Guanylate cyclase
123
__________ protein kinase mediates the effects of NO via phosphorylation of key proteins
cGMP-dependent protein kinase
124
Action of cGMP is terminated by ____________ which converts cGMP to GMP
cGMP phosphodiesterase
125
What are the two thyroid hormones?
Thyroxine (T4), triiodothyronine (T3)
126
What is the circulating form of thyroid hormones?
Thyroxine (T4)
127
Which of the thyroid hormones is the functionally active form?
Triiodothyronine (T3)
128
cGMP-dependent protein kinase mediates the effects of NO on what 3 components?
Phosphorylation of contractile proteins in smooth muscle
Surrounding blood vessel relaxes the muscle
Lowers blood pressure (vasodilation)
129
What are the pyrimidine bases?
Cytosine
Thymine
Uracil
130
What are the purine bases?
Adenine and guanosine
Pneumonic: Pure As Gold (Purine Adenine Guanine)
131
______ are derivative so pyrimidine or purine
Nucleobases
132
_______ are nitrogen containing heteroaromatic molecules
Nucleobases
133
What are the 3 functions of nucleotides?
```
Energy metabolism (ATP)
Enzyme cofactors (NAD+)
Signal transduction (cAMP)
```
134
What are the 4 functions of nucleic acids?
Storage of genetic info (DNA)
Transmitting of genetic info (mRNA)
Processing of genetic info (ribozymes)
Protein synthesis (tRNA and rRNA)
135
_______ and ______ are good H bond donors and acceptors
Pyrimidines and purines
136
What are the bases of the nucleotides that are used as an energy source
Adenine, Guanine, Cytosine, Uracil
137
dATP, dAMP, dADP are all examples that pertain to _____
ATP, AMP, and ADP are all examples that pertain to ___
DNA
RNA
138
What are 3 examples of nucleotides that function as coenzymes?
Coenzyme A
NAD+
FAD
ADP is a common motif
139
What is the common motif seen in coenzymes?
ADP
140
_______ and ______ act as second messengers and mediate regulation via cAMP or cGMP dependent phosphorylation of PKA
cAMP and cGMP
141
______ and ______ function as regulatory molecules and act as second messengers
cAMP and cGMP
142
In polynucleotides, covalent bonds are formed via _______linkages
Phosphodiester
143
The backbone of DNA and RNA is _______ charged
Negatively
144
______ backbone is fairly stable
______ backbone is unstable
DNA
RNA
145
Polynucleotides are _____ polymers that have no branching or cross-links
Linear
146
Polynucleotides have ______ where the 5’ end is different from 3’ end
Directionality
147
The sequence of DNA and RNA is read from the ___ end to the ____ end
5’ end to the 3’ end
148
Two bases can hydrogen bond to from a _______
Base pair
149
For ______, large number of base pairs is possible
For _______, only a few possibilities exist
Monomers
| Polynucleotides
150
Watson and crick base pairs predominate in double stranded DNA
A pairs with _____
C pairs with ____
________ pairs with ______
A-T; C-G; Pyrimidines pair with purines
151
Replication of DNA is _______
Semiconservative
152
In _______ model of DNA replication, each strand serves as a template for the synthesis of a new strand
Semiconservative
153
Synthesis of DNA is catalyzed by enzymes known as __________
DNA polymerases
154
Newly made DNA has one ______ strand and one ______ strand
One daughter strand, and one parent strand
155
______ is the synthesis of RNA under the direction of DNA and occurs in the nucleus
Transcription
156
______ is the synthesis of proteins under the direction of RNA and occurs in the cytosol and RER
Translation
157
What is translation mediated by?
Ribosomes
158
What RNA polymerase synthesizes pre-ribosomal RNA
RNA pol I
159
What RNA polymerase is responsible for the synthesis of mRNA?
RNA pol II
160
What RNA polymerase makes tRNAs and some small RNA
RNA pol III
161
Plants appear to have RNA Polymerase _______ that is responsible for the synthesis of small inferring RNAs
RNA pol IV
162
T/F? Mitochondria have their own RNA polymerase
True
163
Eukaryotic mRNA has ______, interrupting sequences that separate ______, the coding regions
Introns
| Exons
164
The flow of information from gene to protein is based on a _________
Triplet code
165
_________ determines its biological function
Protein sequence
