Download KNPE 125 Unit 1: Homeostasis, Flow, Feedback, and Cellular Processes and more Exams Health sciences in PDF only on Docsity!
KNPE 125 UNIT 1 WITH COMPLETE SOLUTIONS 100 % VERIFIED!!
homeostasis - ANSWER>>the maintenance of internal conditions
- regulated by controlling infow and outflow
- altered by feed back and feed forward systems conservation of mass - ANSWER>>/\ mass = inflow - outflow flow - ANSWER>>the movement of mass from one location to another flow = gradient x conductance gradient - ANSWER>>change in mass from one area to another /\ P = P1 - P equilibrium - ANSWER>>no difference in pressure between areas (no /_\ P) conductance -conductor = roads ANSWER>>the ability of a mass to pass between 2 areas
- in a traffic jam conductance is LOW*electricity has a LOW conductance in rubber
feedback -CORRECT the change ANSWER>>error signal is sensed and a controlled response is triggered to ex. regulated variable= speedsensor= speedometer
feedback controller= increased gas flow to engine effector= increase in speed feed forward -directly thus the responses can be wild and uncontrolled) ANSWER>>happens before the error signal is detected (do not respond
negative feedback - ANSWER>>ex. heart rate
- changes are sensed and a response is triggered to bring the regulated variable backto normal
**MORE CONTROLLED THAN FEEDFORWARD positive feedback - ANSWER>>ex. LH hormone
- changes are sensed and a response is triggered-ex. the variable increases, the response will continue to increase the variable
**MORE CONTROLLED THAN FEEDFORWARD feed forward - ANSWER>>ex. muscle metabolism
- anticipatory response that triggers a change in one variable due to feedback fromanother variable (not the regulated variable)
- the disturbance is measured prior to the change
- ex. thinking about standing up BP hormones -only acts on cells with the appropriate receptors ANSWER>>- secreted by endocrine glands
neurotransmitters - ANSWER>>chemical secreted by neurons
engergonic - ANSWER>>"energy in"
- energy required to proceed
- must be coupled with exergonic reaction- NOT spontaneous
- /_\E ** most reactions are endergonic ex. synthesis of cellular components ex. muscle contraction ex. active transport across membranes exergonic - ANSWER>>"energy out"
- give off energy- can occur spontaneously
- /_\ E adenosine triphosphate - ANSWER>>fuels the majority of endergonic reactions ATP -> ADP + P (energy released)
- high energy bonds can be reformed by the break down of fat, carb, protein ** inflow should = outflow activation energy - ANSWER>>the energy required for a reaction to occur
- enzymes function to lower activation energy (thus speed the rate of reaction) enzymes - ANSWER>>highly specific protein
- speeds the rate of chemical reactions ("catalyze")
- facilitates the combining of substrates **increased enzyme concentration = increased rate of reaction (more susbtrate binding) law of mass action - ANSWER>>increased substrate will increase the rate of reaction Endoplasmic reticulum -- important for intracellular signalling ANSWER>>- made up of lipid membrane
rough endoplasmic reticulum -synthesis) ANSWER>>- covered with ribosomes (Site of protein
smoothendoplasmic reticulum -- lipid synthesis ANSWER>>- intracellular transport
- NO ribosomes golgi apparatus -the cells ANSWER>>- transport of substances from the ER to other parts of
- between ER and nucleus mitochondria -- localized around muscle cells ANSWER>>- generates ATP
- mitochondira increase with exercise training (more ATP = greater performance) ** mitochondria decrease the capacity of fatty acid storage thus decreasing the risk ofdiabetes
- using APT mRNA start to move thru the ribosome elongation (steps of translation) -is formed ANSWER>>- as mRNA moves thru ribosome protein
termination -protein is released (moves to its proper cellular location) ANSWER>>- when it gets to the end of the mRNA the newly formed
- uses ATP amino acids - ANSWER>>mRNA codes for a specific sequence of AA -determine the proteins function lipid bilayer -outside of a cell ANSWER>>- forms a hydrophobic barrier between the inside and the
- water soluble substances DONT pass (carbs, protein)
- fat soluble substances DO pass (CO2, O2) simple diffusion -membrane ANSWER>>membrane permeable substances diffuse thru the OR diffuse thru channels facilitated diffusion - ANSWER>>thru carrier proteins
- reaches plateau when the reaction reaches the vmax (max rate a reaction canproceed).
- determined by the # of transporters active transport -- requires ATP ANSWER>>movement against concentration gradient
primary active transport - ANSWER>>energy for transport is derive from ATP ex. sodium - potassium pump secondary active transport -from an electrochemical gradient made by pumping ions out of the cell) ANSWER>>utilizes energy other than ATP (energy comes ex. sodium - glucose co-transport co transport - ANSWER>>both substrates move in the same direction counter transport - ANSWER>>substances move in different directions osmosis - ANSWER>>H2O from high concentration to low concentration epithelial transport - ANSWER>>transport of substances thru the blood ex. absorption of food in the stomach Nernst equation -the membrane) ANSWER>>considers just the gradient of the ions (on either side of ex. -94 means the resting potential is negative goldman equation - ANSWER>>considers the permeability of the membrane membrane potential ( /_\ P) -membrane (determined by the concentration gradient) ANSWER>>- the potential for movement across a
/_\ P = P1 - P
parasympathetic
- all our bodies automatic functions gullien barre syndrom - ANSWER>>attacks neurons of peripheral nervous system
- paralysis, possible loss of autonomic function
- longer the nerve the greater the potential for the action potential to degrade type 1 receptors - ANSWER>>- on the end of the afferent neuron
- induces an action potential by opening/closing ion channels type 2 receptors - ANSWER>>- own cell (not on the afferent nerve)
- induces a release of transmitter that depolarizes the neuron local anesthetics MOA -from being spread ANSWER>>na+ channel blockers, inhibit action potentials
how do we sense touch -initiated ANSWER>>1. sensory nerve disturbed, action potential
- afferent neuron -> spinal cord (thru dorsal roots)
- afferent signal up spinal cord into brain stem4. synapses at medulla and the thallamus
interneurons -subconciously) ANSWER>>processing center of the spinal cord (can function
spinal cord reflex - ANSWER>>1. afferent neuron enters sensory root
- synapses with interneurons
- efferent signal exits via motor root
- signal is conducted to periphery ** does not involve the brain the knee jerk reflex - ANSWER>>- used to test the muscle stretch reflex
- to minimize the stretch on a muscle- stretched muscle contracts
- antagonist muscle relaxes
- in healthy people voluntary movement inhibits the stretch reflex the withdrawal reflex -- spinal cord reflex ANSWER>>functions to remove body from painful stimulus
- flexion and extension of the appropriate muscles to remove the limb from the stimuli golgi tendon reflex -(Senses change in muscle tension) ANSWER>>-golgi tendon is located in the tendon of a muscle
- wants to prevent stress on the tendon
- turns the muscle "off" when under stress, turns the antagonist muscle on to decreaseforce on the tendon
concious movements -ganglia rather than the interneurons ANSWER>>synapse with neurons in the cerebellum and basal
Membranes of neurons at rest are very permeable to ________ but only slightlypermeable to _______ - ANSWER>>K+ ; Na+
Facilitated diffusion -plasma membrane, but does not require ATP. ANSWER>>Transport process that uses transport proteins in the
Simple diffusion -along a concentration gradient. ANSWER>>Movement of solutes through the plasma membrane
NO transporters are required. The majority of water molecules moving across plasma membranes by osmosis do sovia a process that is similar to: - ANSWER>>Facilitated diffusion
Primary active transport -sodium-potassium ions across the plasma membrane. ANSWER>>The sodium-potassium pump uses ATP to move
Activated by ATP. Activation allows the pump to transport sodium and potassium ions against theirgradients.
Exocytosis -contents to the extracellular fluid. ANSWER>>A vesicle fuses with the plasma membrane and releases its
Initial segment - ANSWER>>Most action potentials originate here. First part of the axon is known as the initial segment. Adjacent to the tapered end of the cell body, known as the axon hillock.
What opens first in response to a threshold stimulus? -channels. Activation gates of voltage-gated Na+ channels open, and Na+ diffuses into ANSWER>>Voltage-gated Na+ the cytoplasm. Depolarization -The membrane potential changes from a negative value to a positive value. ANSWER>>First phase of action potential.
Repolarization -depolarizes to a peal value of +30mV, it re-polarizes to its negative resting value of ANSWER>>Second phase of action potential. Once the membrane -70mV. What event triggers the generation of an action potential? -potential must depolarize from the resting voltage of -70mV to a threshold value of ANSWER>>The membrane -55mV. This is the minimum value required to open enough voltage gated Na+ channelsso that depolarization is irreversible.
What is the first change to occur in response to a threshold stimulus? -ANSWER>>Voltage-gated Na+ channels change shape, and their activation gates open.
Activation gates of voltage-gated Na+ channels open rapidly in response to thresholdstimuli, compare to K+ which are slow.
Homeostasis -environment. ANSWER>>Process whereby the body maintains a constant internal
Changes in the external environment alter the ______, which is detected by the _______,and that information is sent to the integrator. - ANSWER>>Regulated variable ; sensor
The process of maintaining the internal environment in a state compatible for life iscalled _________, and it occurs primarily through _________. - ANSWER>>Homeostasis ; negative feedback
How does the body increase the enzyme concentration? -synthesis. ANSWER>>Through protein
During translation, _______ is synthesized in the ____________. -cytoplasm ANSWER>>Protein ;
Template strand - ANSWER>>The strand of DNA that gets translated to mRNA. What causes DNA to uncoil during transcription? -polymerase to the promoter sequence. ANSWER>>Binding of RNA
Steps for initiating translation -mRNA ANSWER>>1. Binding of small ribosomal subunit to
- Binding of initiator tRNA to mRNA
- Binding of large ribosomal subunit to mRNA
- Binding of a second tRNA with its amino acid to the A site5. Formation of covalent bond between methionine and the second amino acid
Starting with the chemical reaction at equilibrium, A <--> B, and added product B to thesystem from a separate pathway, what change in the reaction occurs? - ANSWER>>The rate of the reverse reaction increases.
