PRE-LIM3 Flashcards
1
Q
What is Symbiosis?
A
interaction and possible cp evolution with microbes and organisms
2
Q
What are the 3 modalities of interaction for symbiotic organisms?
A
Mutualism, Commensalism and Parasitism
3
Q
Mutualism
A
has benefits for both species. Ex: flower and a bee
4
Q
Commensalism
A
has benefits top one species and is neutral for the other. EX: barnacles on whales
5
Q
Parasitism
A
has benefits for one species and costs for the other. EX: a Tick on a dog
6
Q
2 main categories of symbiotic microorganisms
A
Endosymaints and Microbita
7
Q
Endosymbionts
A
microbes that reside within the body or cell of an organism. They cannot really live in an outside environment
8
Q
2 Examples of Endosymbionts
A
Endophytic rhizobia - in root nodules
Wolbachia - is a reproductive parasite of insects and nematodes
9
Q
Endosymbiosis Theory
A
2 microbes engaging in symbiosis lead to eukaryotic cells
10
Q
Symbiogenesis
A
Mitochondria and chloroplasts evolved from certain bacteria engulfed by primitive prokaryotic cells
11
Q
Microbiota
A
the ecological community of microorganisms associated with a host. EX: Skin Microbiota
12
Q
Gut Microbiota
A
is not endosymbiotic because the gut lumen is outside the body and the community is tightly associated
13
Q
What type of relationship do plants and soil have?
A
Mutualistic Relationship
14
Q
Most interactions with bacteria and fungi in plants and soil occur where?
A
Rhizosphere
15
Q
Rhizosphere
A
the surroundings of the root sytem
16
Q
2 Types of bacteria are found in the rhizosphere
A
Rizobacteria- occupies the rhizosphere and stay on the surface of the root
Rhizobacteria- are endophytic and live between the cells of the host plant tissues and form root nodules
17
Q
Complex Community
A
composed of many fungi and bacteria and shapes host physiology
18
Q
Rhizobacteria depend on what?
A
nutrients secreted by plant cells
19
Q
How do rhizobacteria help enhance the growth of plants?
A
Produce chemicals that stimulate growth
Producing antibiotics that protect roots from disease
Absorbing toxic metals or increasing nutrient availability
20
Q
Some bacterias are
A
pathogenic
21
Q
Plants can absorb nitrogen as
A
NO3- or NH4+
22
Q
Most nitrogen available from plants comes from
A
actions of soil bacteria that generate NO3- or NH4+
23
Q
Nitrogen cycle
A
transforms nitrogen and nitrogen-containing compounds into NH4+ and NO3- that can be taken up at the root
24
Q
Explain in detail the nitrogen cycle
A
- nitrogen-fixing bacteria generate H$+ from N2. Along with ammonifying bacteria that also generate NH4+
- nitrifying bacteria generates NO3- from H4+
- Denitrying bacteria that generates N2 from NO3-
25
Ammonifying bacteria
proteins from dead organic molecules that decomposes to amino acids that become the bacteria
26
Rhizobia
are endosymbionts of legumes
27
Nodules
along a legume's roots, composed of plant cells "colonized' NY nitrogen-fixing Rhizobium
28
Rhizobium
obtains sugar and an anaerobic environment for bacteria growth
29
What does the development of nitrogen-fixing root nodules depend on?
Chemical dialogue between root cells,flavonoids, and Rhizobia,nod factors,
30
Flavonoids
triggers nod factors production
31
Nod factors
alter root cell activity
32
Describe the cycle of root nodules
1. Rhizobia attach to root hair
2. an infection thread is formed through which bacteria enter root cells
3. Bacteria change into bacteroids: packed root cells enlarge
4. Enlarged root cells form a nodule
33
Your body has more of what cells
microbial cells
34
Microbes include what species
bacteria, archaea, eukarya (fungi & yeasts)
35
Next generation sequencing
directly sequencing DNA without culturing
36
Metagenomics
sequence-based analysis of the genome of entire microbial communities does not require culturing
37
Most of the microbiota is where
GI tract, 70 % in colon
38
2 types of microbiota in the GI tract
firmicutes and Bacteroidetes, very selective in the gut
39
Gut Microbiota is central to
intestinal homeostasis and physiology
40
Keys function of the gut microbiota
Immunity, metabolic rate, and chemical modulator
41
immunity
- prevents colonization by pathogens
- educates the immune system (gut skin, lung) without it won't develop properly
- stabilizes gut barrier function (decreased leakage) gut epithelium is scaled
42
Metabolic role
- Caloric salvage
- produces short chain fatty acids
- produces vitamin K and folate
43
Chemical modulator
- participates in drug metabolism (activation or catabolism)
- deconjugates bile acids
44
Gut microbiota influences
digestion and behavior
45
Gut-Brain Axis
the gut is the 2nd most neuron-rich group, talks with the brain: Systemic Communications and Neural communication
46
Mircrobta is affected by our experienced
Hormonal axis- influences gut microbes
Innervation- directly influences physiology neurons
47
Microbes send chemical signals
Neurotransmitters and SCFAs- all located in the gut and affect memory emotions and behavior
48
perturbation
diseases, allegories metabolic, obesity, and infections
49
Where does gut microbiota come from?
During passage through the birth canal. It is influenced by the mother and can be altered by the environment.
50
Effect of Maternal Exposures
Antiepis, Antibiotics, Diet, Genetics/Epigenetics and C Section
51
Bacterial abundance
is reached around 1 years is maintained, while the composition continues to vary
52
What factors shape the Gut?
host genetics, stress, diet, pollution, psychological status, microbial exposures, pharmaceuticals
53
Dysbiosis
microbial imbalance in the body
54
Nutrition
a set process by which organisms obtain and use the nutrients required for maintaining life
55
2 strategies of nutrition
Autotrophs & heterotrophs
56
Autotrophs
- Nutrition consists in acquiring non-organic compounds
- DO NOT REQUIRE A SOURCE OF ORGANIC CARBON
-Primary producers, build their organic molecules
- Depends on other organisms for nutrients other than carbon
57
Heterotrophs
- NUTRIENTS REQUIRE ORGANIC COMPOUNDS AS PART OF THE DIET
- requires autotrophs to feed on
- ^^to obtain: organic molecules including sources of carbon, nitrogen, etc
-^^ most heterotrophs require this source of carbon for energy
- to obtain vitamins
58
Photoautotroph
doesn't obtain carbon elsewhere and gets energy from light
59
Photoheterotroph
obtains carbon from elsewhere and gets energy from light
Ex: microbes
60
Chemoautotroph
Doesn't obtain carbon from elsewhere and gets energy from inorganic oxidation
Ex: Archae/Bacteria
61
Chemoheterotroph
obtains carbon elsewhere and energy from inorganic oxidation
EX: Microbes, E coli
62
Ogranotroph
Obtains carbon elsewhere and doesn't get energy from inorganic oxidation.
Its a HETEROTROPH
Ex: Bacteria, Fungi, Animals
63
Autotrophic diet
Does not mean autonomous
Requires essential chemical elements + energy
64
Heterotrophic diet
- Often requires chemical energy
- Organic building blocks for macromolecules
- Essential nutrients
65
Plant Nutrition
- Acquire their nutrients from soil and air
- Roots absorb water minerals and some O2 from the soil
- Leave absorb CO2
66
Root Hairs
take up dissolved oxygen, ions, and water from the film of soil water that surrounds them
67
Cation exchange
a positive ion is exchanged to the soil particle & releases the Ca2+ or Mg2+ needed because Ca2+ and Mg2+ are stuck to the soil because of the negatively charged soil
- KEY FOR PLANT NUTRITION
68
Describe Cation Exchange
1. roots acidify the soil solution
2. CO2 reacts with H20
3. Minerals Cations are released
4. Roots absorb released cations
69
How do organisms/organs MAXIMIZE the surface/ volume ratio?
Minimum of tissue with Maximum the surface of contact to the environment to get nutrients ---- FRACTAL STRUCTURES
70
Does root hairs greatly increase a roots absorptive surface
YES
71
Mycorrhizae
symbiotic relationships with fungal thread increase plant's absorption
72
Digestion includes
nutrient breakdown and absorption
73
Intracellular Digestion
Phagocytosis: good for small organisms
74
Extracellular digestion
is the breakdown of food particles outside of cells
Ex: gastrovascular cavity
75
Gut Lumen
continuous with the outside of the animal's body, 1 opening
76
Gastrovascular Cavity
2-way digestive tract, functions in both digestion and distribution of nutrients. ANIMALS WITH SIMPLE BODY PLANS
-not the most efficient
77
Flow through the digestive tract
2 openings, mouth and anus
78
Stages of food processing
1. ingestion
2. digestion
3. absorption
4. elimination
- Mechanical breakdown and breakdown of nutrients by enzymatic hydrolysis
79
2 things need to build the digestive system
Alimentary canal and accessory glands
80
Alimentary canal
Mouth,esophagus, stomach, small intestine, large intestine, rectum
81
Accessory canal
salivary glands, pancreas, liver, gallbladder
82
3 basic types of digestive systems
- Monogastric: simple chambered stomach
- Ruminant (cranial fermentor): multi-compartmented stomach
- Hindgut fermentor: simple stomach but complex intestine
83
Phase 1: Oral cavity and the cephalic phase
- mechanical breakdown of food in the oral cavity
- salivary glands lubricate food and secretes salivary amylase initiating the breakdown of carbohydrates
- Ends with deglutition (the process of swallowing)
PRIMES the secretion of the stomach (cephalic phase o stomach secretion)
84
Phase 2: in the Stomach
- the stomach stores food and secretes gastric juice which converts food bolus into chyme
- Filling of the stomach promotes secretion (gastric phase)
- protein degradation
TIGHT REGULATION
85
Protein degradation
- initiated by proteolytic enzyme pepsin: cleaves and degrades other proteins
- protein denaturation by acidic low pH (pH= 2)
86
Mucus Layer
stomach protection and produces bicarbonate secretion to diffuse in the layer and acts as a buffer
87
Bicarbonate
[HCO3-] buffering of acid
88
Production of gastric acid
1. Pepsinogen and H+Cl are secreted into the lumen
2. HCl converts proenzyme (zymogen) pepsinogen to active enzyme pepsin {acidification of the lumen}
3. Pepsin activates more pepsinogen starting a positive feedback loop (chain reaction)
89
Pepsinogen
generator of pepsin needs to be matured in the lumen to become active
IT ACTIVATES WHEN THE PEPTIDE IS REMOVED
90
Phase 3: in the small intestine
- Duodenal digestion, most digestion occurs here
- chymes from the stomach mixes with the digestive juices from the pancreas, liver, gallbladder, and the small intestine
91
Pancreas secretes
- Buffer HCO3
-Trypsin
-Chymotrypsin
-Nucleases
-Amylases
-Lipases
92
Duodenum secretes
- Disaccharides Dipeptidases
- Dipeptidases
- Nucleosidases
They act on the products of degradtion
93
Liver/ Gallbladder
Bile emulsifies lipids
94
Small intestine and pancreas both produce
Lipases
95
Gallbladder
is just a storage organ
96
Steatorrhea is the presence of increased fat in feces. Which organ is least likely to be the cause of this?
GALLBLADDER
97
Enteropeptidase in brush border activates
trypsin
98
Absorbed lipids enter
the lymphatic system
99
Absorbed amino acids and sugars, EXCEPT LIPIDS enter
hepatic portal vein
100
Main site of absorption of lipids, sugars, and amino acids
small intestine
101
The mouth and stomach are heavily involved
breakdown of sugar and protein
102
Water is reabsorbed in
the large intestine
103
Transport across the epithelium
can be active or passive
104
Enormous Villar/ microvillar surface
greatly increases nutrient absorption, huge optimization
105
Absorption in the small intestine needs
a huge surface area
106
Parietal cells
secrete H+ and Cl- (HCl; hydrochloric acid) into the lumen of the stomach. One way to remember: parietal cells pump the protons.
107
Pancreatic lipase
is an enzyme that contributes to fat breakdown.
108
Hydrochloric acid in the stomach
(1) denatures proteins and (2) converts pepsinogen to pepsin.
109
Two transporters are needed to transport glucose into an epithelial cell in the small intestine.
Na+ and cotransport glucose
110
The bile salts function in fat digestion by
dispersing big droplets of fats to small droplets
111
Proper physiological responses cells need to
-Adjust their function to changes in their environment
- coordinate their behavior
112
How does cell-cell communication influence physiology
- by regulating cell activity
- by regulating gene expression and or protein activities => changing cell activity/function
113
Cells can exchange information through
-directly through cytoplasmic exchanges of diffusible chemicals
- directly receptor/ligand interaction on cell surfaces
114
Examples of cell-cell communication
cell junctions and cell-cell recognition
115
Long-range regulation and communication are based on
the secretion of chemical signals
116
Neurotransmitters Signal
fast, short-range diffusion. It triggers changes in post synaptic cell and most communication & coordination is achieved by electrical signal
117
Hormones signal
- can achieve long-range diffusion.
- It doesn't rely on axonal transmission & electoral transmission.
-They are released in the circulatory system. Its produced by non-neural endocrine cells and produced by neurosecretory cells.
- Reaches target cells & induces regulatory change needed
118
Hormones 3 ranges of action
- Autocrine (short): hormones released by a cell can act on the exact same cell that released the hormone.
- Pacarine (middle): acts on neighboring cells but on the same tissue
- Endocrine (long): requires circulation
119
Chemical signals
hormones, neurotransmitters, grow factors, cytokines
120
Hormones are key signals in
Feedback loops that comprise more than one cell type
121
Feedback systems
the product of a process is used to regulate the production of that product.
- negative and positive
122
Negative feedback loops
act on the stimulus and bring it back to normal (homeostasis). It opposed the initial stimulus
123
Hormones are defined by
1. source- specialized secretory cells
2. mode of transport- releases into the circulatory system
3. physiological role- cellular regulators
4. Relative effectiveness- hormones work at very low concentration
5. concentration is regulated- via the rate of synthesis, secretion & degradation
NOT DEFINED BY CHEMICAL IDENTITY
124
hydrophilic hormones
water soluble hormones are secreted by exocytosis, travel freely in the bloodstream, and binds to cell-surface receptors
125
Lipophilic Hormones
lipid soluble hormones diffuse across cell membranes, travel in the bloodstream bound to transport proteins, and diffuse through the membrane of target cells. They bind to receptors in the cytoplasm or nucleus of the target cells
126
Lipid soluble hormone
sex steroids (testosterone, progesterone, oestrogen)
glucocorticoids
mineralocorticoids
127
Binding of hormones changes
the activity of the nuclear receptor and modifies gene expression
128
Transduce the signal
linking surface receptor binding to an effect in the cell
129
Hydrophilic Hormones example
Catecholamines
thyroid-stimulating hormone
human growth hormone
130
Hydrophilic hormones use transduction pathways
- The receptor has an enzymatic function and triggers signaling cascades= transduction pathways
- involves the synthesis of 2nd messengers or sequential protein modifications
131
Transduction pathways examples
- a receptor and a kinase cascade
- GPCRs and cAmp
- GPCRs and calcium signaling
132
receptor and a kinase cascade
Phosphorylation of inactive kinases activates their kinase function. this active kinase then phosphorylates and activates a more downstream kinase
133
GPCRs and cAMP
The binding of the ligand activates GTP binding to the G protein. Enzymes are activated and they trigger the synthesis of the second messengers. these trigger cellular responses often through activation of kinases
134
2 main pathways downstream of GPCRs
adenylate cyclase and phospholipase c
135
endocrine glands
endocrine cells that are often grouped into ductless organs.
ex: thyroid and parathyroid glands, tests and ovaries
136
pineal gland
melatonin=> circadian rythms
137
Hypothalamus and Pituitary gland
hypothalamic-anterior pituitary=> tropic hormones
posterior pituitary => adh oxytocin
138
Thyroid glands
thyroid hormones => metabolism
139
Adrenal glands
cortex: corticosteroids=> stress immunity metabolism
Medulla: epinephrine (adrenaline) => fight or flight response
140
Pancreas
insulin, glucagon=> glucose levels
141
Ovaries & testes
androgen, estrogens=> reprodcution
142
Same Hormones depend on
- depend on the receptor for the hormone ( different receptors trigger different responses)
- depend on the transduction pathway which varies with cell type
143
Example of the multiple effects of hormones
epinephrine increases blood flow to the muscle, and decreases blood flow to the digestive tract
144
Case of a simple negative feedback loop
regulate the secretion of the pancreas and stomach
endocrine
s cells of duodenum- secret hormones- to pancreatic cells- bicarbonate releases - low pH in duodenum
145
Case of simple positive feedback loop
milk release by mammary glands
neuroendocrine
146
endocrine axes
tropic hormones are engaged in its regulation. They are hormones that have other endocrine glands as their targets
147
Examples of endocrine axes
Hypothalamus/ Pituitary/ Thyroid system (HPT)
hypothalamus/pituitary/adrenal cortex axis (HPA)
148
A master regulator
the hypothalamus-pituitary gland
149
Hypothalamus
receives the information from the nervous system in initiates responses to the endocrine system
150
Pituitary gland
is attached to the hypothalamus, composed of the posterior pituitary and anterior pituitary
- heterogeneous tissue
151
Neurohypophysis
is it an outgrown of the hypothalamus. the reason why the hypothalamus & pituitary glands go together
- POSTERIOR PITUITARY
152
Adenohypohysis
anterior pituitary
153
2 Key functions of the Hypothalamus
1. neurosecretory cells secrete two posterior pituitary hormones (ADH, oxytocin) => released in circulation. These hormones are stored in posterior
2. Hypothalamic cells control the endocrine activity of the anterior pituitary gland (adenohypophysis)
154
Neurohypohysis initiates
- secretion of ADH or vasopressin in the posterior pituitary gland (stimulates reabsorption in the kidney)
- Secretion of Oxytocin (contraction of the mammary gland, uterine muscles)
- evolutionary related peptides hormones: ADH & Oxytocin
155
adenohypophysis regulates
complex endocrine axes
156
Hormone production in the anterior pituitary
is controlled by releasing hormones and inhibiting hormones secreted by the hypothalamus
157
Hormones production in the posterior act to
- modulate physiological targets (non-tropic effects)
- to regulate the endocrine function of distant endocrine tissues (endocrine axis = tropic effects)
158
Glandular anterior lobe
a major organ the endocrine system
159
regulation of organismal metabolism
- protein synthesis/cell diviso/ cell growth (anabolic effect)
- energy expenditure/ reserve mobilization (catabolic effect)
- levels of circulating metabolites (glucose in the blood or glycemia)
160
what are the key endocrine axes regulating metabolism
1. growth hormones (GH) and insulin-like growth factor (IGF-1)
2. the hypothalamus/ pituitary/ thyroid (HPT) axis
3. Insulin and Glucagon
161
growth hormone
has tropic (release of another hormone) and non-tropic effects
- promotes growth and metabolic changes directly in target cells
- stimulates the release of additional growth factors (insulin-like GF or IGF-1
- combines stimulation of growth and resources mobilization
162
Master regulator of organismal metabolism
thyroid
163
Thyroid
endocrine gland in the neck (final gland of hpt axis
secretes amine hormones tri-iodo-thyronine (t3) and thyroxine (t4)
t3 increases basal metallic rate, protein, synthesis, growth, and elevated body temp
t3 stimulates fat mobilization
164
Hypothyroidy
weight gain, lethargy, cold tolerance, requires iodine
165
Grave's disease
: autoimmune disease triggering hyperthyroid (too much t3 and t4
=> high temp, sweating weight loss, high blood pressure
166
beta cells of Langerhans islets
produced insulin
167
alpha cells of langherans islets
produced glucagon
168
Insulin
is a storage hormone produced in the pancreas
- increase protein translation
- promotes glycogen synthesis and uptake of sugar cells
169
glucagon
is a regulator of blood sugar produced in the pancreas and with opposing effects to insulin (hyperglycemic :high blood sugar)
170
Adrenal glands
they sit on top of the kidneys
- 2 glands: cortex outer portion & medulla inner portion
THEY DO NOT SYNTHESIZE AND RELEASE THE SAME HORMONES
171
Cortex
hormone: corticosteroids (glucocorticoids)
stimulus: stress
Regulated by: HPA axis
172
Medulla
hormone: adrenaline 9epinephrine) noradrenaline
stimulus: stress
regulated by: the autonomic nervous system
173
autonomic nervous system
is a division of the peripheral nervous system that influences internal organs function
174
What are the two divisions of the autonomic nervous system?
Sympathetic and Parasympathetic
175
Sympathetic
1. relaxes airways
2. accelerates the heartbeat
3. decreases gut mobility: less blood to digestive tract
176
Sympathetic regulates
the adrenal medulla and promotes the systemic release of adrenaline
Fight or flight , postgangilonic neurons => NE
177
Parasympathetic
rest and digest
neuro transmitter
178
Pathway of stress
brain -> hypthalemus -> piutiary -> adrenal cortex -> stress adaptation
179
cortisol
main glucocorticoid that responds to stress of HPA axis
180
cortisol levels are regulated by
a negative feedback loop
181
autonomic NS & HPA axis coordinates
stress response
182
Adrenal medulla secretes
epinephrine & adrenaline
183
adrenal cortex secretes
glucorticoids
184
hypercortisolism
long term high levels of cortisol
Complications: diabetes, frequent infections, loss of muscle mass and strength, osteerporosis
