Unit One Flashcards
(218 cards)
1
Q
Multicellular creatures need what in order to maintain homeostasis
A
Cells to communicate
2
Q
What are methods of cell communication
A
Nervous system, endocrine, paracrine/autocrine, gap junctions and neuroendocrine
3
Q
Nervous system uses what for communication
A
Action potentials and neurotransmitters
4
Q
Endocrine uses what for cell communication
A
Hormones and bloodstream
5
Q
Paracrine and autocrine uses what for cell communication
A
Locally secreted chemicals and diffusion
6
Q
Gap junctions use what for cell communication
A
Direct cell to cell communication
7
Q
Neuroendocrine uses what for cell communication
A
Combo of nervous and endocrine, neuron sends neurotransmitter into blood stream
8
Q
Exocrine glands have ducts that lead to
A
Body surface or internal organ
9
Q
What gland is not used for cell to cell communicaiton
A
Exocrine
10
Q
Examples of exocrine glands
A
Sweat, biliary system, salivary
11
Q
What gland is ductless
A
Exocrine
12
Q
Endocrine glands secrete hormones where
A
Directly into the blood
13
Q
Target cells have what
A
Specific hormone receptors
14
Q
What are classic endocrine organs
A
Hypothalamus, pituitary, thyroid, parathyroid, pancreas, andrenal gland and testes/ ovaries
15
Q
Other endocrine organs
A
Pineal gland, stomach, duodenum, kidney, placenta, adipose and heart
16
Q
What are the three classes hormones
A
Protein/peptide, steroid, and amines
17
Q
The Amine class of hormones are derived from
A
Tyrosine
18
Q
Steroid class of hormones are derived from
A
Cholesterol
19
Q
Peptides have how many amino acids long
A
Less than 100
20
Q
Example of peptides
A
TRH- 3 aa long
21
Q
Proteins are how many aa long
A
More than 100
22
Q
Example of protein
A
HCG - 237 aa
23
Q
Are protein/ polypeptide hormones water soluble or insoluble
A
Soluble
24
Q
Protein/polypeptide hormones bind to
A
Cell surface (membrane) receptors
25
How do protein/polypeptide hormones travel in plasma
Dissolved and not bound to something
26
What is an example of peptide synthesis
Insulin
27
What are the common release signals for peptide hormone secretion
Calcium mediated and second messenger mediated
28
What is calcium mediated peptide hormone secretion
Action potential in endocrine cell causes Ca2+ influx and Ca2+ causes hormone release
29
What is second messenger mediated peptide hormone secretion
Chemical binds to receptor, receptor activates G protein to activate cAMP then protein kinase mechanisms leading to hormone release
30
Consequences of protein/peptide in the blood
Move easily from the blood to the target tissue for use, cleared from the blood faster therefore their effects tend to be short lived
31
Steroid hormone are water or lipid soluble
Lipid
32
Since steroid hormones are lipid soluble they can
Diffuse through lipid bilayers easily
33
Steroid hormones are lipid soluble and are not stored in
Vesicles
34
Steroid hormones are secreted as they are
Synthesized
35
Do steroid hormones need cell receptors
No
36
What is the first step of steroid hormone synthesis
Cholesterol to pregnenelone
37
What is the example of steroid synthesis
Cortisol
38
What is the common release signals for steroid secretion
Second messenger mediated
39
How does second messenger mediated in steroid secretion work
Chemical binds to receptor, receptor activate G protein, activates cAMP, activates protein kinase mechanisms leading to hormone release
40
Second messengers in steroid secretion may also lead to
Calcium influx which triggers aspects of steroid synthesis and or release
41
Since steroids are lipid soluble how are they transported in blood
Bind to carrier protein
42
Consequence of steroid bound to protein in blood
Carrier proteins exit blood slowly, steroids remain longer, effects on target cells can linger for a long time, clearance rate for blood is slow
43
What are the two groups of amine hormones
Thyroid hormones and catecholamines
44
Example of thyroid hormones
T3 and T4
45
Example of catecholamines
Epinephrine and norepinephrine
46
Enzymes for biosynthesis of amine hormones are present where
In cell cytoplasm of thyroid and adrenal medulla
47
What is also a catecholamine but mostly used as a neurotransmitter in the CNS
Dopamine
48
How are thyroid hormones stored
Large polymers called thyroglobulin
49
How are thyroid hormones secreted
Amines are split off and secreted into blood
50
How are adrenal medulla catecholamines transported and secreted
Into vesicles and secreted in similar way as peptide hormones
51
What triggers release of thyroid hormones
Chemical binds to receptor, G protein/cAMP/ protein kinase mechanism triggers release
52
How are catecholamines released by signals
Stimulated by sympathetic nervous system
53
Are catecholamines water or lipid soluble
Water
54
How are catecholamines transported
Like peptides
55
Are thyroid hormones water or lipid soluble
Lipid
56
How are thyroid hormones transported
Like steroid, bound to carrier
57
Hormone secretion rate is due to
Stimuli, negative feedback (inhibition) and positive feedback
58
What are the different types of stimuli that triggers hormone stimulation
Hormonal stimuli, other chemical stimuli (humoral), neuronal stimuli
59
Negative feedback is due to
Rising hormone levels itself or one of its products
60
Negative feedback prevents
Over activity of a gland
61
Negative feedback aka
Negative inhibition
62
Positive feedback occurs in
Special circumstances when surges of hormones are needed
63
What are the mechanisms of hormone clearance
Metabolic destruction by target tissues (enzymes), excretion by the liver into the bile, excretion by the kidneys into urine
64
MCR is what
Metabolic clearance rate
65
How to determine MCR
Rate of disappearance of a hormone from the plasma/ concentration of hormone
66
What feedback is the principle way to regulate hormone secretion
Negative feedback
67
What feedback loops are more common
Negative
68
What are the three types of endocrine gland stimuli
Humoral, neural, and hormonal
69
What is humoral stimulus
Something in body not a hormone that stimulates release of hormone, usually in blood
70
What does humoral mean
Of or relating to the body fluids, especially with regard to immune responses involving antibodies in body fluids as distinct from cells
71
No cell can respond to a hormone unless it possesses what
A receptor
72
What are some receptor characteristics
large proteins, may have thousands on cell, highly specific to what binds to it, location of receptor varies
73
Where are the locations of receptors
In or one cell membrane, in cytoplasm, in nucleus
74
What hormones bind to in or on cell membrane
Water soluble
75
What hormones bind to receptors in cytoplasm
Lipid soluble
76
What hormones bind to receptors in nucleus
Lipid soluble
77
Membrane receptors are used for what hormones
Water soluble and neurotransmitters
78
What are examples of membrane receptors
Ion channel linked receptors, G protein linked receptors, enzyme linked receptors
79
G protein linked receptors activate what
Adenylyl cyclase/ cAMP activation, phospholipse C/ IP3 and DAG activation, G protein activated ion channels
80
What happens when binding of neurotransmitter or hormone to ion channel linked receptor
Causes channel to open
81
When is ion channel linked receptors more commonly used
With neurotransmitters in the nervous system
82
Ion channel linked receptors AKA
Ligand gated channel
83
Enzyme linked receptors are made of
An enzyme
84
The best studied enzyme linked receptor is
Tyrosine kinase receptor
85
Enzyme linked receptors often first involves
Autophosphorylation before activation of other enzymes or transcription factors
86
What in tyrosine kinase receptor that is being phosphorylated
Tyrosine
87
G protein linked receptors effects are mediated by
G protein
88
What is a G protein
Complex of three subunits, alpha, beta and gamma
89
How is a G protein activated
When signal molecule binds to the receptor
90
What occurs after signal molecule binds to receptor in G protein receptor
GDP is exchanged for GTP and the complex splits, alpha subunit activates a variety of targets
91
How is the G protein linked receptors deactivated
G protein hydrolyses the GTP and re assembles its subunits
92
When G protein linked receptors become activated what are the possible outcomes
Intracellular enzyme activated, activate gene transcription, activate ion channels, activate membrane enzyme
93
Intracellular receptors are used for what specific hormones
Steroid and thyroid hormones
94
We store energy at what stage
After feeding
95
We release energy at what stage
Fasting
96
Why do we need energy
Maintain blood glucose (brain), available energy for other cells and their activity, thermoregulation, food digestion, physical activity
97
Carbohydrates, fats and proteins can all be used to generate
ATP
98
Carbohydrates are digested to what
Simple sugars (glucose)
99
Carbohydrates are phosphorylated by what enzyme
Hexokinase and glucokinase
100
Glycolysis turns carbs into
Acetyl co a
101
Citric acid cycle turns carbs into
NADH and FADH2
102
Electron transport chain turns carbs into
ATP
103
Proteins are digested into
Amino acids
104
Proteins are converted into what metabolites
Pyruvate, acetyl co a, or an intermediated in the citric acid cycle
105
Fats are digested into what
Fatty acids and glycerol
106
Fats are used in
Beta oxidation to make acetyl co a
107
Early glycolysis is what
Energy investment of 2 ATP
108
Early glycolysis steps
Glucose into fructose 1,6 bisphosphate
109
Intermediate glycolysis involves
Cleavage of 6 carbon sugar into two 3 carbon
110
Intermediate glycolysis involves what step
Fructose 1,6 bisphosphate into glyceraldehyde 3 phosphate
111
Late glycolysis is called what
Energy generation of 4 ATP,
112
Glycolysis has a total net gain of how many ATP
2
113
In late glycolysis glyceraldehyde 3 phosphate turns into
Pyruvate
114
Before entering the Kreb’s cycle, pyruvic acid needs to be converted to wha
Acetyl co a
115
Glycolysis occurs where
Cytosol
116
Kreb’s cycle occurs where
Mitochondria
117
What forms citrate in Kreb’s cycle
Acetyl co a and oxaloacetate
118
What happens to citrate along Kreb’s cycle
Citrate loses two carbons in the form of CO2 and ultimately reforms oxaloacetate
119
What are the products of the Kreb’s cycle
3 NADH, 1 FADH2, 1 GTP (per turn)
120
Aka of electron transport chain
Oxidative phosphorylation
121
ETC is composed of
Electron acceptors imbedded in the inner membrane
122
What is released from NADH and FADH2 in ETC
High energy electrons and H+
123
How are electrons transferred in ETC
From cytochrome to cytochrome releasing energy
124
The energy released from electrons in ETC goes where
Used to pump H+ from the matrix of the intermembrane space creating a H+ gradient
125
Where is ATP synthase used
ETC
126
What is ATP synthase
Enzyme couples diffusion of H+ down its concentration gradient to synthesize ATP from ADP and phosphate
127
What is the final electron acceptor of ETC
Oxygen
128
Why is oxygen final acceptor in ETC
Spent electrons combines with oxygen and H+ to form H2O
129
How many ATP produced by NADH
2.5
130
How many ATP produced per FADH2
1.5
131
In terms of ATP, the total oxidation of one glucose gives how many ATP
30
132
AKA of beta oxidation
Catabolism of fatty acids
133
Fats (triglycerols) are broken down into
Glycerol and fatty acids
134
What is the term used to break down fats
Lipolysis
135
Fatty acids are converted into what during beta oxidation
Acetyl co a
136
What is hormone sensitive lipase
Involved in the hormonal lay regulated release of fatty acids and glycerol from adipocyte lipid stores
137
Hormone sensitive lipase is regulated by
Epinephrine
138
What is ketogenesis
Ketone bodies are formed by breakdown of fatty acids (and ketogenic amino acids)
139
When is acetyl co a metabolized into Ketone bodies
Low availability of carbohydrates and/or a high rate of beta oxidation
140
Ketogenesis occurs where
In liver
141
High levels of Ketone bodies leads to
Ketoacidosis
142
What are the three ketone bodies to know
Acetoacetate, acetone and D-beta-hydroxybutyrate
143
Following protein digestion into individual amino acids, they are what
Delaminates to remove NH4+
144
When amino acid is deaminated, NH4+ enters where
Urea cycle in order to be eliminated by kidneys
145
What in the amino acid is converted into and intermediate of metabolism to form ATP
Carbon skeleton
146
What is the carbon skeleton of amino acids
Everything of amino acid minus the NH4+
147
Glycogen is the storage form of
Glucose
148
Most glycogen is stored where
Liver and skeletal muscle
149
What is glycogenesis
Formation of glycogen from glucose
150
What is the major enzyme of glygenesis
Glycogen synthase
151
Does the liver store glycogen for itself or everyone
Everyone
152
Does the skeletal muscle store glycogen for itself or everyone
Itself
153
What is glycogenolysis
Breakdown of glycogen back into glucose
154
Major enzyme of glycogenolysis
Glycogen phosphorylase
155
Glycogen is similar to what other molecules
Starch and cellulose
156
What is gluconeogenesis
Making glucose from scratch
157
What is depleted in your body so new glucose can be synthesized
Glucose and glycogen
158
What depends on blood glucose for energy
Brain and red blood cells
159
What is an important alternative source of glucose
Gluconeogenesis
160
What provides the raw material for gluconeogenesis
Glycerol, lactate and several amino acids (alanine)
161
Where does gluconeogenesis occur
Kidneys and liver
162
What is lipogenesis
Making new fatty acids
163
Fatty acids synthesis starts with
Acetyl co a and builds up by the addition of two carbon units
164
Where does lipogenesis occur
Cytoplasm
165
Major enzyme of lipogenesis
Fatty acid synthase
166
Majors sites of fatty acid synthesis is
Adipose tissue and liver
167
Fatty acids can be assembled with what to form triacylglycerols
Glycerol
168
AKA of triacylglycerols
Neutral fats
169
Glycerol for fat synthesis comes from
An intermediate of glycolysis (from glucose)
170
What is the fed state
Time of food Ingestion, through absorption of energy yielding nutrients into the body
171
What metabolism is favored in the fed state
Anabolic
172
Energy in fed state is mostly stored in the form of
Fat and glycogen but also as ATP, phosphocreatine and protein
173
What are the principle storage forms of energy
Fat and glycogen
174
What is the fasting state
After food is both digested and absorbed, and continues as long as no more food is ingested
175
What metabolism is favored in the fasting state
Catabolic
176
The liver receives blood from
GI tract and pancreas
177
During fed state, the liver takes up
Carbs, lipids and most amino acids
178
Fed state liver carb metabolism
Increased phosphorylation of glucose, increased glycogen synthesis, increased glycolysis, decreased gluconeogenesis, decreased glycogenolysis
179
What hormone influences the fed state liver carb metabolism
Insulin
180
Fed state liver fats
Increased de novo fatty acid synthesis, increased triacylglycerol synthesis
181
Fed state liver amino acids
Increased amino acid degradation (to be used for fat synthesis or for energy) and increased protein synthesis
182
Fed state liver fats and amino acids influenced by what hormone
Insulin
183
Fed state adipose carb metabolism
Increased glucose transport into adipocytes, increased glycolysis
184
During fed state adipose carb metabolism, why is there increase in glucose transport into adipocyte
Glucose can be used in fatty acid synthesis
185
Fed state adipose carb metabolism increases glycolysis due to
Supplying substrates for glycerol in TAG synthesis
186
Increase glucose transport into adipocytes of fed state of adipose carb metabolism in influenced by what hormone
Insulin
187
Fed state adipose fat metabolism
Increased synthesis of fatty acids, increased TAG synthesis, decrease TAG degradation
188
Adipocytes get most of their fatty acids from what two sources
Chylomicrons and VLDL
189
What are chylomicrons
Droplets of cholesterol and TAGS from digestive tract
190
What are VLDL
Droplets of fats from liver
191
Increased TAG synthesis and decreased TAG degradation in fed state adipose fat metabolism is influenced by what hormone
Insulin
192
Fed state skeletal muscle carb metabolism
Increases glucose transport, increases glycogen synthesis
193
Carb metabolism in fed state of skeletal muscle is influenced by what hormone
Insulin
194
Fed state skeletal muscle fat metabolism
Fatty acids are secondary fuel source and primary being glucose
195
Fed state skeletal muscle amino acid metabolism
Increased protein synthesis
196
What is protein synthesis increased during fed state of skeletal muscle
To replace functional protein that may have been lost during the last fasting period
197
What hormone influences fed state of skeletal muscle Amino acid metabolism
Insulin
198
What is the primary fuel for the Brain
Glucose
199
Is the brain insulin dependent or independent
Independent but has been evidence stating insulin can be transported in CSF and leads to feelings of satiety
200
In fasting state, liver carb metabolism has what stages
Uses glycogen degradation first then gluconeogenesis
201
Glycogen degradation in liver carb metabolism of fasting state is influenced by what hormone
Glucagon
202
Gluconeogenesis in liver carb metabolism of fasting state uses what hormone of influence
Norepinephrine
203
What does the liver have that can release free glucose into the blood
Glucose 6-phosphatase
204
Fasting state liver fat metabolism
Increased fatty acid oxidation, increased synthesis of ketone bodies
205
How does liver use fat metabolism in fasting state
From fats obtained from TAG hydrolysis in adipose
206
Fasting state adipose carb metabolism
Decreased in glucose transport into adipocytes due to low insulin
207
Fasting state adipose fat metabolism
Increase degradation of TAG, increased release of fatty acids, decreased uptake of fatty acids from VLDL or chylomicrons
208
Increase degradation of TAG in fasting state of adipose fat metabolism is influenced by what hormone
Glucagon and norepinephrine
209
Increased degradation of TAG in fasting state of adipose fat metabolism causes activation of what hormone
Hormone sensitive lipase
210
Fasting state in skeletal muscle carb metabolism
Lowered rate of glucose uptake due to low levels of insulin
211
Fasting state skeletal muscle fat metabolism
Uses fatty acids from adipose tissue and ketone bodies from the liver as primary fuels
212
What occurs in kidneys of fasting state
Gluconeogenesis during prolonged fasting and compensation for the acidosis due to ketogenesis
213
In the early few days of fasting state in skeletal muscle protein metabolism
Rapid breakdown of muscle protein to be used by liver for gluconeogenesis
214
Fasting state early few days of protein metabolism in skeletal muscle is influenced by what hormone
Cortisol
215
After several weeks, fasting state of skeletal muscle protein metabolism
Proteolysis declines as more ketone bodies are produced and used to help spare protein
216
Do skeletal muscles have glucagon receptors
No
217
First few days of fasting state of brain metabolism in general
Brain still uses glucose exclusively due to supplied by gluconeogenesis and glycogenolysis from liver
218
Prolonged fasting in fasting state of brain metabolism in general
Ketone bodies replace glucose as primary fuel and helps reduce dependency on protein catabolism
