Exam 2 Flashcards

1
Q

what are carbohydrates? types?

A

monosaccharides- used for energy and biosynthesis (glucose and fructose)
disaccharides- two monosaccharides connected by a covalent bond, bonds broken during metabolism (sucrose)
polysaccharides- complex carbohydrates, energy storage(glycogen and starch) and structural molecules (chitin, cellulose)

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2
Q

what are lipids? types?

A

used for energy metabolism, long-term energy storage, cell structure, and signaling
hydrophobic
fatty acids, triglycerides, phospholipids, steroids (testosterone, cortisone, vitamin D, cholesterol)

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3
Q

cell membrane structure

A

isolate cells from the environment- control intracellular conditions
organize intracellular pathways into sub-cellular compartments
contains membrane proteins
-integral membrane proteins: tightly bound to the membrane, embedded in bilayer or spanning the entire membrane
-peripheral membrane proteins: weaker association with the lipid bilayer
-glycoproteins and their sugar residues

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4
Q

cell membrane permeability

A
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5
Q

cell membrane receptors

A
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6
Q

cell membrane transport and channels

A

passive diffusion: lipid soluble molecules, no specific transporters needed, molecules cross bilayer, no energy needed, depends on concentration gradient
facilitated diffusion: hydrophilic molecules that cannot diffuse through bilayer, protein transporter–ion channel, porin (like ion channel, for larger molecules), permease (function more like enzyme, carrie molecules across membrane– is needed, no energy is needed, depends on concentration gradient
active transport: protein transporter needed, energy is required, molecules can move against concentration gradient

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7
Q

chemical concentration gradients

A
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8
Q

electrical gradients

A
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9
Q

electrochemical gradient relationship

A
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10
Q

membrane potential

A

the relative charge of the inside of the cell compared to the outside of the cell, standardly negative
varying permeability
mostly dependent on Na+, K+, Cl- gradients

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11
Q

pumps

A

Na+/K+ ATPase pump maintains Na+ and K+ gradients across membrane using ATP

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12
Q

ion channels

A

voltage gated
ligand gated
mechano gated

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13
Q

equilibrium potential

A

unique to each ion
electrochemical equilibrium potential
ion does not want to move anymore with completely open pores
ion diffuses down its own concentration gradient but also responds to the overall electrical gradient

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14
Q

mechanisms for influencing membrane potential

A

depolarization and repolarization

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15
Q

depolarization

A

cell becomes more positive on the inside- Na+ entering cell

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16
Q

repolarization

A

cell becomes more negative on the inside- K+ leaving cell

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17
Q

hyperpolarization

A

K+ channels are slow to react- too much K+ flows out of cell causing the membrane potential to become too negative

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18
Q

what kind of work do cells do?

A

chemical, transport, mechanical
anabolic reactions: muscle building
catabolic reactions: cracking sugar molecules requires some ATP investment

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19
Q

what is the main energy source for work?

A

ATP- adenosine triphosphate
the energy from the exergonic reaction of ATP hydrolysis can be used to power an endergonic reaction–> overall the coupled reactions are exergonic (releases heat)

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20
Q

what is ATP? what does it look like? where is energy stored? what is hydrolysis? phosphorylation?

A

adenosine triphosphate
composed of ribose (sugar), adenine (a nitrogenous base), and three phosphate groups
the phosphate groups repel each others negative charges- bonds are very easy to break (via hydrolysis) and release energy upon breakage

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21
Q

why are exergonic and endergonic reactions coupled?

A

ATP drives endergonic reactions by phosphorylation, transferring of a phosphate group to another molecule- changes confirmation and affinity for other molecules
building high energy molecules

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22
Q

how is ecosystem respiration similar to cellular respiration?

A

energy flows into an ecosystem as sunlight and leaves as heat
photosynthesis releases oxygen gas and builds organic molecules which are used in cellular respiration
cells use chemical energy stored in organic molecules to regenerate ATP, which powers work

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23
Q

aerobic respiration

A

consumes organic molecules and oxygen gas
yields ATP

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24
Q

anaerobic respiration

A

consumes non-oxygen compounds

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25
Q

what are redox reactions? oxidation? reduction? reducing agents versus oxidizing agent?

A

the transfer of electrons during chemical reactions releases energy stored in organic molecules
lost electrons- oxidized; the oxidized is the reducing agent
gain electrons- reduced; the reduced is the oxidizing agent
in cellular respiration: glucose becomes oxidized to carbon dioxide and oxygen gets reduced to water

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26
Q

what is NAD? NADH?

A

coenzyme that gain electrons from organic compounds= reduced form is NADH (stored energy that is tapped to synthesize ATP)
NADH passes electrons to the electron transport chain

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27
Q

glycolysis?
what is produced that is necessary for aerobic respiration?

A

glucose is cleaved into 2 three carbon pyruvate and NADH and electrons through investment of 2 ATP–> produces 4 ATP, net 2 ATP
2 pyruvate enter citric acid cycle/krebs cycle = 2 net ATP
NADH and electrons enter ETC= hydrogen ions pumped across membrane- gradient will be used to generate ATP (34-36)

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28
Q

direct versus indirect signaling

A

direct: signal and target cell connected by gap junctions, directly from one cell to another–specialized protein complexes create an aqueous pore between adjacent cells
indirect: signaling cell releases a chemical messenger into extracellular fluid, chemical messenger binds to a receptor on target cell–activation of signal transduction pathway–action inside cell via signal reception on outside membrane

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29
Q

indirect signaling over short and long distance

A

short
-paracrine: chemical messenger diffuse to nearby cells
-autocrine: chemical message diffuses back to signaling cell
long
-endocrine system: chemical messenger transported by circulatory system
-nervous system: electrical signal, axon terminal, neurotransmitter, action

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30
Q

structures associated with direct and indirect signaling

A

gap junctions in direct signaling

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31
Q

signaling molecules

A
32
Q

endocrine versus exocrine

A
33
Q

why don’t messenger just pile up around cells?

A

scavengers

34
Q

3 classes of steroids? functions, transport, storage

A

synthesized by smooth ER or inside mitochondria, derived from cholesterol
mineralocorticoids- electrolyte and water balance, acts strong on kidneys
glucocorticoids- stress hormones, adrenal gland, can suppress pain, wide range of effects
reproductive hormones- regulate sex-specific characteristics

35
Q

cell receptors- ligand-receptor interactions

A
36
Q

affinity of receptors? down/up regulation?

A

down regulation of insulin receptors because cells were continuously screamed at by insulin because there was too much sugar

37
Q

stages of cell signaling, processes and players involved

A
38
Q

3 main receptor types, how do they differ, how are they similar

A
39
Q

what are hormones

A

released from endocrine cell in order to travel through bloodstream and interact with a receptor or target cell to cause a physiological response

40
Q

what is epinephrine and what does it do? role in glucose metabolism? role in fight or flight response?

A

binds to receptors on the GPCR in plasma membrane of liver cells- this triggers the release of messenger molecules that activate enzymes and result in the release of glucose in the bloodstream
activated G protein binds adenylyl cyclase causing cAMP 2nd messenger to activate protein kinase A which inhibits glycogen synthesis- leave glucose in bloodstream and promotoes glycogen breakdown- release glucose into bloodstream (fuels muscles during fight or flight)

41
Q

epinephrine continued- skeletal muscle blood vessel

A

epinephrine binds to beta receptor on vessel causing vessel to dilate- muscle relaxes allowing for greater blood flow for fight or flight
also binds to alpha receptors on intestinal blood vessels, constricting them– diverts blood from digestive tract to muscles

42
Q

negative and positive feedback loops

A
43
Q

antagonistic hormone pairs

A

insulin and glucagon

44
Q

insulin and glucagon, source, pathways, actions

A

antagonistic pair
insulin lowers blood glucose levels (encourages glycogen formation/glucose uptake and prevents glycogen breakdown in liver, promotes fat storage)
glucagon raises blood glucose levels (acts on liver cells, tells glycogen to breakdown and release glucose into blood stream, stimulates breakdown of fat and muscles)
pancreatic cells:
clusters of endocrine cells = islets of Langerhans
alpha cells- produce glucagon
beta cells- produce insulin

45
Q

type 2 diabetes, contributing factors, basic pathology

A

adult onset diabetes
blood glucose too low- brain cannot function
blood glucose too high- osmotic balance of blood disturbed; glucose will punch out capillaries to move toward lower concentrations
insulin deficiency or reduced response of target cells due to change in insulin receptors

46
Q

additivity versus synergism

A

additivity: response of target cell to some combination of hormones is the sum of each of their separate responses
synergism: amplified; response of a target cell to a combination of hormones is more than the individual responses

47
Q

hypothalamus, pituitary, thyroid, adrenals

A

hypothalamus: “top dawg”, endocrine and nervous organ, receives info from the nervous system and initiates responses through the endocrine system
pituitary: attached to hypothalamus, composed of posterior and anterior pituitary
-posterior pituitary: stores and secretes hormones that are delivered from the hypothalamus
-anterior pituitary: makes and releases hormones under regulation of the hypothalamus

48
Q

posterior pituitary hormones

A

act directly on non-endocrine tissues
oxytocin: induces uterine contractions and the release of milk
positive feedback loops-stimulus leads to an even greater repsonse
increases suckling, increases stimulus, more hormone and milk

49
Q

anterior pituitary hormones

A

thyrotropin releasing hormone (TRH) in the hypothalamus stimulates secretion of the thyroid stimulating hormone (TSH) from the anterior pituitary

50
Q

tropic hormones

A

regulates the function of endocrine cells or glands
thyroid stimulating hormone (TSH)
follicle stimulating hormone (FSH)
luteinizing hormone (LH)
adrenocorticotropic hormone (ACTH)

51
Q

non tropic hormones

A

target non-endocrine tissues
prolactin (PRL): stimulates lactation in mammals
melanocyte-stimulating hormone (MSH): influences skin pigmentation in some mammals and fat metabolism in other vertebrates
both produced by anterior pituitary

52
Q

TRH to TSH to T3 to T4. where, when, why?

A

stimulus on a sensory neuron, hypothalamus secretes TRH into bloodstream, anterior pituitary secretes TSH/thyrotropin into bloodstream, thyroid gland secretes thyroid hormones T3 and T4 into bloodstream, hormones reach body tissues/target cells, triggers a response (increased cellular metabolism)
negative feedback loop- when enough heat is produced, pathway is shut off

53
Q

how is resting potential maintained

A
54
Q

electrochemical gradients and how they are used to trigger action potentials

A
55
Q

depolarization

A
56
Q

repolarization

A
57
Q

hyperpolarization

A
58
Q

graded potentials. what are they? what causes them? why don’t they always trigger an action potential?

A
59
Q

sequence of events that lead to an action potential

A
60
Q

spatial summation

A
61
Q

temporal summation

A
62
Q

refractory periods

A
63
Q

how do action potentials move down axon and how is information encoded?

A
64
Q

what are neurotransmitters

A
65
Q

acetylcholine

A
66
Q

antagonist

A
67
Q

agonist

A
68
Q

calcium ion role in transmitting signals

A
69
Q

sequence of events at axon terminal from AP arrival to neurotransmitter clean up in synapse

A
70
Q

inhibitory vs excitatory neurotransmitters

A
71
Q

muscle structure and functions down to myosin and actin filaments

A
72
Q

how does an action potential trigger a muscle contraction

A
73
Q

role of ATP and calcium in muscle contraction

A
74
Q

role of SR

A
75
Q

smooth muscle versus striated muscle

A