Exam 1 Flashcards
1
Q
Animals are classified as
A
Multicellular eukaryotes that can move from one place to another
2
Q
Locomotion
A
the ability to move from place to place using muscle and nervous tissue
3
Q
Physiology
A
The study of how animals work
4
Q
Some animals are sessile, but it is an important distinction for animals that
A
They have some sort of locomotion during their lives ex. sponge, coral, sea anemone
5
Q
Physiological processes
A
Obey the laws of physics and chemistry
6
Q
Physiological phenotypes are
A
Influenced by genetics and the environment
7
Q
Evolution changes
A
The genotype of a population over many generations
8
Q
Levels of biological organization
A
Atom, Molecule, Cells, Tissues, Organs, Organ Systems, Organisms, Populations, Communities, Ecosystems, Biosphere
9
Q
Phenotype
A
Observable characteristics including morphologym, physiology, and behavior
10
Q
Structure/Morphology vs Physiology
A
Structure is Anatomy, Physiology is function
11
Q
Adaptation
A
Changes in population over evolutionary time as a result of natural selection that improve the survivability or reproductive fitness of the species
12
Q
Conformers vs Regulators
A
- Conformers = body temperature and chemistry varies directly with the environment
- Regulators = body temperature and chemistry remain constantly regardless of the changing environment
13
Q
Endothermy
A
Organisms with bodies that are warmed by heat generated by metabolism. This heat is usually used to maintain a relatively stable body temperature higher than that of the external environment (warm blooded)
14
Q
Ectothermy
A
Determination of body temperature primarily by external thermal conditions.
15
Q
Regulatory Mechanisms
A
Negative Feedback, Positive Feedback, Feed-Forward (Anticipatory) Action, Acclimatization
16
Q
Feed-forward (Anticipatory) Action/Mechanism
A
Mechanism to anticipate a change in a regulated variable and improve the speed of the homeostatic response, ex. belly growling at lunch time or putting jacket on before going out in the cold
17
Q
When placental mammals are ready to give birth, the placenta of the fetus starts to
produce oxytocin which causes the mothers uterus to begin to contract. These contractions
in-turn produce prostaglandins which leads to more oxytocin production. Eventually, this
leads to birth of the offspring. Which of the following types of feedback does this
exemplify?
A
Positive Feedback
18
Q
Acclimatization
A
Adjustment in physiological function(s) in response to changes in the environment (multiple factors)
-typically reversible
-example: recovering from jetlag
19
Q
Acclimation
A
A laboratory phenomenon in response to only one factor
20
Q
Chemical composition of Cells
A
Water (70%) organic molecules including carbohydrates, lipids, proteins, nucleic acids, and inorganic ions (less than 1%) Na+, K+, Mg2+, Ca2+, Cl-, bicarbonate, phosphate, etc.
21
Q
Basic Cell Structure
A
Plasma Membrane, Cytoplasm, Nucleus, Mitochondria
22
Q
Plasma Membrane
A
Helps to maintain the composition of intra and extracellular fluids
-regulates traffic in and out of cell
Forms a framework for protein components of cell
Detects chemical messengers at cell surface
Links adjacent cells together
23
Q
Membrane Junctions
A
Tight junctions: impermeable barrier
Desmosomes (spots)/Adherens junctions (band): anchoring
Gap Junctions: communication
24
Q
Plasma membrane structure
A
phospholipid bilayer, channel protein, cholesterol, integral proteins, peripheral proteins, sugar resides of glycoprotein and glycoprotein
25
What can travel through the phospholipid bilayer
Hydrophobic molecules including O2, CO2, N2, lipids and cholesterol. Also small, uncharged polar molecules including glycerol
26
What cannot travel through the phospholipid bilayer
Large, uncharged polar molecules including glucose and sucrose. Ions such as H+, Na+, NCO3-, Ca2+, Cl-, Mg2+, K+. Charged polar molecules such as Amino Acids and ATP
27
Steroid molecules, such as cholesterol and vitamin D, pass easily across the membrane.
These are fairly large molecules. The reason they can pass easily across the membrane is
because they (mark all that apply):
They are lipids and hydrophobic
28
Simple (Passive) Diffusion
Concentrated to One Region -> Uniform Distribution
29
Electrochemical Gradients
Gradients can be chemical, electrical, or both (electrochemical) Form of energy storage (Potential Energy)
30
Net Flux
The difference between the two one-way fluxes. The measure of the net gain of molecules by one side and the net loss from the other side
31
Does diffusion stop once equilibrium is reached
No, the movement in and out is just equal
32
Passive Diffusion
Movement of molecules due to the intrinsic kinetic energy of molecules. No metabolic energy (ATP) used, Movement from higher to lower concentration, At equilibrium Net Flux = 0
33
The direction and magnitude of net flux depend on
Permeability, concentration gradient, temperature, surface area, size of molecule, distance
34
Can water pass through the plasma membrane by simple diffusion
No, water is excluded by the hydrophobic tails of the phospholipid bilayer
35
Osmosis
Passive transport of water, The net diffusion of water from a region of high water concentration to a region of low water concentration
Facilitated by aquaporins
36
Hypertonic vs Hypotonic
Hyper-more concentrated, Hypo less concentrated
37
Osmolarity
Total concentration of solutes in a solution, depends on the total number of molecules NOT individual type
Relative terms for comparing the osmolarity of two
solutions
* Isosmotic
* Hyperosmotic
* Hyposmotic
38
Osmotic pressure
Pressure generated by water moving based on osmolarity
39
Hydrostatic pressure
Pressure exerted by the standing column of water - gravity
40
Molecules that are too large and/or polar to diffuse are transported across plasma membrane by mediated transport mechanisms
Facilitated diffusion, active transport, bulk transport
41
Facilitated diffusion
Transmembrane proteins facilitate
diffusion of some polar or charged
molecules across the plasma membrane
Molecules move down their
electrochemical gradient
No metabolic energy (ATP) required for
transport
42
Channels
provide corridors for polar or charged molecules to pass through the
plasma membrane
43
Ion channels
may be selective or non-selective
44
Selective ion channels
Na+ channels, K+ channels, Cl- channels
45
Non-selective ion channels
Monovalent cation channels allow Na+, K+, and Li+ ions
46
Constitutive channels
always open such as aquaporins
47
Gated channels
Open transiently in response to stimulus such as ligand-gated channels, voltage-gated channels, and mechanically-gated channels
48
Ligand-gated channels
A signal molecule (ligand) binds to the receptor/channel regulating the opening and closing of the gates (ex. acetylcholine regulates entry of Na+ into muscle cells
49
Voltage-Gated Channels
Regulated by electrical state of the cell (ex. voltage-gated Na+ channels activated by membrane)
50
Mechanically-Gated Channels
Regulated by a physical change ex. pressure
51
Facilitated diffusion by permease/carrier
binds the substrate, undergoes a conformational change, and releases substrate to other side
ATP not needed
Transport down the concentration gradient by proteins (ex. GLUT transporters)
52
Active Transport
Differs from facilitated diffusion in that transported molecules must bind to the transporters
53
Primary Active Transport
Requires ATP, movement of solutes against their gradients
54
Ca2+ ATPase/Pump
Hydrolysis of ATP directly required for the function of the carriers
Molecule or ion binds to
“recognition site” on one side of carrier protein
Binding stimulates phosphorylation
(breakdown of ATP) of carrier
Carrier protein undergoes
conformational change
Hinge-like motion releases
transported molecules to opposite side of membrane.
55
Na+/K+ ATPase/Pump
Carrier protein is also an ATPase enzyme that converts ATP to ADP and Pi
Actively exports 3 Na + and imports 2 K+ inward against concentration gradient.
Functions of steep gradient:
Involvement in electrochemical impulses
Promotes osmotic flow
Regulates resting calorie expenditure
and basal metabolic rate
Provides energy for “coupled transport”
of other molecules
56
Secondary Active Transport
No direct input of energy required, but depends on the electrochemical difference established by the primary active transport
“Coupled” transport
Energy needed for “uphill” movement obtained from “downhill” transport of Na +.
Hydrolysis of ATP by Na +/K+ pump required indirectly to maintain Na + gradient
57
Ion channels
Move single ions down electrochemical or concentration gradients i.e. CFTR
58
Antiporters
Transport similarly charged molecules in opposite directions ie NA+/K+ ATPase
59
Symporters
transport move molecules the same direction. Both may or may not be charged. ie. SGLT transporters move sodium
down its electrochemical gradient to concentrate glucose
60
Electroneutral cotransporters
move anions and cations in the same direction.
61
Electroneutral exchangers
reversible transporters driven by
electrochemical gradients i.e. the Cl - /HCO3- exchanger in red blood cells
62
Bulk transport
Simultaneous movement of many large molecules that cannot be transported by carriers
63
Exocytosis
Fusion of the membrane-bound vesicles that contains cellular products with the plasma membrane
64
Endocytosis
Specific molecules can be taken into the cell because of the interaction of the molecule and protein receptor
65
How are epithelial cells transporters distributed
Asymmetrically, some on the apical side and others on the basolateral side
66
How are epithelial cells connected
Protein linkages including tight junctions, leaky, junctions, and leaky tight junctions
67
What organelle is abundant in epithelial cells
Mitochondria
68
What do we know about the different types of cells in epithelial tissue
There is a high level of cell type diversity
69
Simple epithelium
Single layer of cells, in direct contact with the basement membrane (lungs)
70
Stratified epithelium
Multilayered, usually found where body linings are under mechanical pressure, generally flatten as they are farther away from basement membrane. (skin, urethra, esophagus)
71
Keratinized
Mostly dead, lack nuclei and cytoplasm, contain tough resistant protein called keratin – found mostly in the outer layers of the skin
72
Parakeratinzied
Contains keratin, retain nuclei but it is reduced (pyknotic) – found in the esophagus and oral mucosa
73
Transitional
stretchy, appears to be stratified cuboidal – mostly in the bladder, ureters, and urethra
74
Simple squamous epithelium
Allows materials to pass through by diffusion and filtration, and secretes lubricating substance. Lungs and blood vessels
75
Simple cuboidal epithelium
Secretes and absorbs, in ducts and secretory portions of small glands and in kidney tubules
76
Simple columnar epithelium
Absorbs and secretes mucous and enzymes, ciliated tissues are in bronchi, uterine tubes, and uterus; in the digestive tract and bladder
77
Stratified squamous epithelium
Protects against abrasion in esophagus, mouth and vagina
78
Transitional epithelium
Allows the urinary organs to expand and stretch, lines the bladder urethra and ureters
79
Energy
The basic unit for energy is the Joule
80
Enzymes
Organic catalysts that reduce activation energy, they are dissolved solutes and do not make reactions happen but reduce activation energy.
81
Energy carrying molecules
Often involves a phosphate bond, common molecules include (ATP, ADP, GTP, PCr), acetyl-CoA uses a CoA instead of phosphate
82
Proteins
polymers of amino acids that are bound by peptide bonds. Some amino acids are polar and some are nonpolar.
83
What leads to protein structure
Primary, Secondary, Tertiary and Quaternary Structure
84
What helps to fold proteins correctly
Chaperones. Heat shock proteins (HsP) help to maintain or refold proteins, not all chaperones are responsive to heat, but all are referred to as Hsp (ex. Hsp70)
85
What can denature proteins
Head/pH changes
86
Carbohydrates
Making up largest part of intake, polymers made of monosaccharides joined by glycosidic bonds
87
How are polysaccharides composed?
Linear or branched fashion (amylose, amylopectin, glycogen)
88
Gluceneogenesis
Input starts with amino acid, pyruvate, or small lipids
Occurs in the mitochondria and cytoplasm
The end product is glucose or glycogen
89
Glycolysis
Starts with glucose (other hexoses are converted to glucose)
Occurs in the cytoplasm
End product is pyruvate
Under anaerobic conditions there are three possible outcomes both species and condition dependent
90
The breakdown of glycolysis produces pyruvate which can be converted into pyruvate. What is the anaerobic product of pyruvate oxidation? What is the aerobic product?
Lactic acid; acetyl-CoA
91
Lipids
- Composed of glycerol and up to three fatty acids
- Fatty acids are long changes of hydrocarbons
- Highly non -polar
92
Saturated fatty acids
no double bonds
animal products, solid at room temperature
93
Monounsaturated
one double bond
94
Polyunsaturated
more than one double bond
95
Fatty acid oxidation
Fatty acids are broken down to produce acetyl-CoA
Each pair of carbons in the FA chain are used to produce 1 acetyl-CoA
96
Direct cell signaling
Signaling cell > Gap Junction > Chemical Messenger > Response from Target Cell
97
Ligand
A chemical message sent from one cell to another
98
Receptor
the target for a ligand on binding either elicits a response or prevents a response
99
Natural Ligand
Endogenously produced
100
Agonist
Mimics the natural ligand
101
Antagonist
binds to prevent ligand binding (inhibits)
102
Signal Transduction
A cascade of molecular events triggered by ligand/receptor binding
103
Gap junctions
-direct connections between cells
-cells need to be in contact
-tunnels for messages from one cell to another
104
Autocrine signaling
Cell sends a message to the outside of the cell and then sends it back to the cell
105
Paracrine signaling
Message from one cell gets sent out of the cell and then gets sent into another cell
106
Endocrine signaling
the target cells are distant to the releasing cells via hormones
107
Neural signaling
Always involves connection between neural cells and other neural cells or tissues/sensors
Involves the change in membrane potential due to changes in ion locations inside or outside the neural cells
108
Hormones
Chemical substances produced by specialized organs called endocrine glands and transported through the bloodstream to other tissues where they act to elicit a specific physiological response
109
Endocrine glands
no ducts, highly vascularized ex. hypothalamus, pineal, pituitary, thyroid, adrenal, testes/ovaries
110
Cushing's Syndrome
Too much cortisol (hypercortisolism)
111
Addison's Disease
too little (hypocortisolism)
112
Broad Definition of Hormones
Chemical substances released by one cell which act on another cell
113
Six types of chemical messengers
Peptides, steroids, amines, lipids, purines, gases
114
Hydrophilic messengers
intracellular vesicles, exocytosis, dissolved in extracellular fluids, transmembrane receptors, rapid effect
115
Hydrophobic messengers
synthesized on demand diffusion across membrane, short distances: dissolved in extracellular fluid, long distances: bound to carrier proteins, transmembrane or intracellular receptors, slower or rapid effect
116
Steroid hormones
derived from cholesterol, synthesized by smooth ER or mitochondria, three classes of them, hydrophobic, synthesized on demand, can diffuse through plasma membrane, cannot be stored in the cell
117
Mineralocorticoids
Electrolyte balance (water ion balance)
118
Glucocorticoids
Stress hormones
119
Reproductive hormones
Regulate sex-specific characteristics
120
Amine hormones
Hormones that posess amine group (NH2) ex, acetylcholine, catecholamines, dopamine, epinephrine, serotonin, melatonin, histamine, thyroid hormones
121
Are amine hormones hydrophilic or hydrophobic
Hydrophilic aside from thyroid hormones
122
Peptide/Protein Hormones
Hydrophilic, soluble in aqueous solutions, travels to target cell dissolved in extracellular fluids, binds to transmembrane receptors (signal transduction), effects are rapid
123
Peptide Hormone Production and Release
mRNA transcribes polypeptide in rough ER, polypeptide becomes Preprohormone, this gets cleaved and is exocytosed from the cell as a prohormone, this prohormone travels through the golgi apparatus (still as a prohormone), prohormone is moved into a secretory vesicle and is broken into active hormone and peptide fragment, is then exocytosed into the extracellular fluid
124
how are steroid hormones transported to the target cell
carrier proteins
125
What kind of receptors do hydrophilic messengers bind to
transmembrane receptors
126
What kind of receptors do hydrophobic messengers bind to
intracellular receptors
127
What happens to receptors when ligands bind
Change conformation
128
Law of mass action
Receptors can become saturated at high levels
129
What does a high Kd indicate
low-affinity receptor
130
What does a low Kd indicate
high-affinity receptor
131
How can the ligand-receptor complex be inactivated
1. ligand removed by distant tissues (bloodstream)
2. ligand taken up by adjacent cells (endocytosis)
3. ligand degraded by extracellular enzymes
4. ligand-receptor complex removed by endocytosis
5. receptor inactivation (phosphorylation)
6. inactivation of signal transduction pathway
132
Receptor isoform
Expressed on different target cells, different responses to the same ligand
133
Intracellular receptors
Ligand diffuses across the cell membrane, binds to receptors in the cytoplasm or nucleus, L-R complex binds to specific DNA sequences, regulates transcription of target genes
134
Guanylate Cyclase
1. Ligand binds to a receptor guanylate cyclase, changing its conformation
2. The activated receptor catalyzes the conversion of GTP to cGMP
3. The cGMP acts as a second messenger and binds to PKG
4. The activated G-kinase phosphorylates proteins on serine or threonine residues
135
Tyrosine Kinase Receptor
1. Ligand binds to receptor
2. Receptors dimerize and autophosphorylate
3. Phosphorylated receptors interact with protein kinases
4. Protein kinases signal to Ras protein
5. Ras switches between the active and inactive forms
136
MAPKKK pathway
Ras stimulates MAPKKK which gets phosphorylated to MAPKK which gets phosphorylated to MAPK which phosphorylates other protein kinases, transcription factors, and cellular proteins
137
Serine/Threonine Kinase Receptor
1. ligand binds to the type I TGF-Beta receptor
2. The bound receptor dimerizes with the Type II receptor
3. The type II receptor phosphorylates the type I receptor, activating it
4. The activated receptor phosphorylates a SMAD Protein
5. The activated SMADs enter the nucleus and regulate gene expression
138
G-Protein Coupled Receptors
1. Ligand binds to a Gs-protein-coupled receptor, causing a conformational change
2. The As subunit releases GDP, bind to GTP, moves through the membrane, and activates adenylate cyclase
3. Activated adenylate cyclase catalyzes the conversion of ATP to cAMP
4. cAMP binds to the regulatory subunit of protein kinase A (PKA), which dissociates from the catalytic subunit, activating it
5. The activated catalytic subunit phosphorylates proteins, causing a response
6. The phosphorylated proteins are rapidly phosphorylated by serine/threonine phosphatases, terminating the response
7. When ligand binds to a Gi-protein-coupled receptor, the ai subunit inhibits adenylate cyclase, inhibiting the signal transduction pathway
139
Classical endocrine glands
pineal, hypothalamus, pituitary, thyroid, parathyroid, thymus, adrenal, pancreas, ovaries, testis
140
What pituitary gland is the hypothalamus directly attached to
Posterior
141
Hypothalamus-Pituitary Axis
Hypothalamus synthesizes and secretes neurohormones -> hypothalamic-pituitary portal system -> anterior pituitary releases hormones
142
Tropic hormones
hormones which target other endocrine glands and cause the release of other hormones
143
Gigantism
increased GH early in life
144
Acromegaly
increased GH later in life
145
GH deficient
short stature or dwarfism
146
Growth hormone receptor insensitivity
dwarfism
147
Role of oxytocin and prolactin in human milk production
Prolactin stimulates milk synthesis, oxytocin causes milk release
148
Type I Diabetes
loss of beta cells, little or no insulin is produced
149
Type II diabetes
Characterized by insulin receptors become resistant to insulin, insulin levels may be normal or high
150
Medulla
produces catecholamines (epinephrine and norepinephrine)
151
Cortex
corticosteroids (glucocorticoids-cortisol, mineralocorticoids-aldosterone, androgens and estrogens)
152
Adrenal Steroid Hormones
All steroids begin as cholesterol, cholesterol is converted into pregnenolone and progesterone, pregnenolone and progesterone can be converted into the androgens such as testosterone
153
Stress endocrine response (HPA)
H- secretes corticotropin-releasing hormone (CRH)
P- Secretes ACTH
A- Adrenal cortex- Secretes cortisol, Stimulates target cells to increase blood glucose level, Inhibits cytokines, Increases proteolysis and lipolysis
154
What kind of relationship do insulin and glucagon have
Antagonistic
