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Wednesday, April 17, 2024
post quiz one
cell have plassma memrane
phoespholipid molecules -polar hydrophillice and hydrophobics
substance move in to the cell
passive
active
pass do not require energy
active reequire energy
- simple ( sugar cube dissolve ) substance between two are high concentration to low contration cytosol outside the cell or inside the cell , form plasma membrane some of the substances can move down the concentration gradient without assistance
- facilitate diffusion.= small charge polar non polar phospholipbilayer - plasma membrane protein channel mediated diffusion ( charge particles number of )
leak channel
stay fraction for a second continously open only open for certian channel
carrier protein ( glucose molecules move to the other side of membrane
- carrieer mediate diffusion
- osmosis = water can slipped into the other side of membrane , not permeable to solute (one side ) cytosol water move down the other side to achieve equalibrium . active transport- vescicular transport is large substance accross the plasma membrane primary and secondary active transport move ion across the membrane ( na + K+ with protein pump ) release energy ATP break down to ADP change shape relase ion to the cytosol of the cell
- reverse back into the original shape secondary active transport _ hight to low concentration second substance low to high contration ( same direction- two substance into opposite direction ) glucose molecule to low to high contration
- each positive
- protein
- across the plasma membrance
- outside the cell
- golgi appratus
- phospholipid mke up the vesicle
- vesicle -
- lipid bilayer
concentration gradient pushing Na ion
pulling K+
electrostatic gradient
concentration gradient
K+
equal
membrane transport
plasma membrane- move into the cell membrane
phospholipid
hydrophobic
inner part of the cell
two main process
active transport
passive transport
passive transport -diffusion high concentration to low contration
- simple diffusion ( small and non polar ) gases oxygen , small fatty acide
- down the concentration gradient across
- co2 molecules can move across the membrane without assistance
- facilitated diffusion
sugar molecules
cellular across the plasma membrane- high concentration
facilitated diffusion- non polar phospholipid bilayer
plasma membrane proden
channel mediated ( charge particle total number of ion water protein channnel )
leak channels continious open
ion postitive channel continously open
carrier protein ( change the shape by process )
glucose molecules change
selective permeableity
plasma membranep
protein water channell
charge polar
one side of the membrane - more solute than the other
cytosol = 99%
interstitial side
cellular energy
active transport- against the concentration gradient
large substance _ membrane bound sac
primary active transport- move ion across the membrane
na + k+ ( atp bind to the pump) release the energy break down to ADP change shape
2+ K+ ion into the cytosol
back to original shape
pump is ready to do the job again
using energy
down it concentration gradient
high concentration to low concentration
same direction
opposite direction
positive sodium
inside the cell
low concentration
using the energy
high concentration outside the cell
outside the cell
largerst subse
poly sacchride
exocytosis
materiral secret from the cell
from golgi - phospholipid
vesicle membrance
endocytosis- folding inward
three main form
phagocytosis
pinocytosis
new vesicle - fused in lysosome
pinocytotis- interstitial fluid -
using recepteor bind with interstitial fluid
transport wihtiin the cell
endocytosis and exocytosis -require energy
carrier
Nervous system
A glial cell is one of a variety of cells that provide a framework of tissue that supports the neurons and their activities.
Stimuli that are received by sensory structures are communicated to the nervous system where that information is processed. ( eye , ear, touch, taste ,smell)
What does the membrane potential have to do with neurons?
The membrane potential of neurons is the difference in electrical charge between the inside and the outside of the neuron1.
In most neurons, the membrane potential is between −60 and −75 millivolts2.
A resting neuron has a voltage across its membrane called the resting membrane potential, which is determined by concentration gradients of ions across the membrane and by membrane permeability to each type of ion3.
For neurons, resting potential is defined as ranging from –80 to –70 millivolts4.
Quizz
- Still learning (1)
- You've started learning these terms. Keep it up!
- Select this one
- Na+ (Sodium) is mostly where?
- ECF
- K+ (Potassium) is mostly where?
- ICF
- Ca+2 (calcium) is mostly where?
- ECF
- Cl- (chloride) is mostly where?
- ECF
- What is the concentration of Na+ in the ECF?
- 145
- What is the concentration of K+ in the ECF?
- 4
- What is the concentration of Ca+2 in the ECF?
- 1.5
- What is the concentration of Cl- in the ECF?
- 110
- What is the concentration of Na+ in the ICF?
- 15
- What is the concentration of K+ in the ICF?
- 150
- What is the concentration of Ca+2 in the ICF?
- .0001
- What is the concentration of Cl- in the ICF?
- 10
- Where is sodium mostly found (in the cell or out the cell)?
- out the cell
- Where is potassium mostly found (in the cell or out the cell)?
- in the cell
- where is calcium mostly found (in the cell or out the cell)?
- out the cell
- Where is chloride mostly found (in the cell or out the cell)?
describe the mechanism of the na+/k+ pump and explain how it contributes to describe the mechanism of the na+/k+ pump and explain how it contributes to the resting membrane potential of a cell.
describe the mechanism of the na+/k+ pump and explain how it contributes to describe the mechanism of the na+/k+ pump and explain how it contributes to the resting membrane potential of a cell.
what would happen to the resting membrane potential if the na+/k+ pump was mutated and not working?
Copilot
Certainly! Let’s dive into the fascinating world of the sodium-potassium pump (Na+/K+ pump) and its role in maintaining the resting membrane potential of cells.
Structure of the Sodium-Potassium Pump:
The sodium-potassium pump, also known as Na+/K±ATPase, is a large transmembrane protein found in most animal cells’ plasma membranes.
Its structure includes several key components:
Alpha subunit: This is the largest subunit of the pump. It contains active sites for binding sodium (Na+), potassium (K+), and ATP. Additionally, it houses the ion translocation pathway and the phosphorylation site.
Beta subunit: A smaller subunit that stabilizes the alpha subunit and regulates its activity.
Ion translocation pathway: This channel allows sodium and potassium ions to pass through the membrane. It consists of transmembrane helices spanning the membrane.
Phosphorylation site: Located on the alpha subunit, this site is where ATP is hydrolyzed to provide the energy needed for ion transport.
Extracellular domain: Contains sodium and potassium binding sites on the outermost layer of the membrane.
Cytoplasmic domain: Includes the ATP binding site and the phosphorylation site on the interior side of the membrane1.
Mechanism of the Sodium-Potassium Pump:
The pump actively transports sodium ions out of the cell and potassium ions into the cell against their concentration gradients.
Here’s a simplified mechanism:
Binding and Phosphorylation: The pump binds three sodium ions (Na+) from the cytoplasm. ATP is hydrolyzed, and a phosphate group is added to the pump.
Conformational Change: The phosphorylated pump undergoes a conformational change, releasing the sodium ions outside the cell.
Binding of Potassium Ions: Two potassium ions (K+) from the extracellular fluid bind to the pump.
Dephosphorylation: ATP binds again, leading to dephosphorylation of the pump.
Conformational Change: The pump changes shape, releasing potassium ions into the cytoplasm.
The cycle repeats, maintaining the sodium and potassium gradients across the membrane.
Role in Resting Membrane Potential:
The Na+/K+ pump contributes significantly to the resting membrane potential (RMP) of cells.
By pumping sodium out and potassium in, it establishes a concentration gradient:
Higher sodium concentration extracellularly.
Higher potassium concentration intracellularly.
This gradient is essential for:
Stabilizing RMP: The difference in ion concentrations helps maintain the negative charge inside the cell, contributing to the RMP.
Cell Volume Control: Proper ion balance prevents cell swelling or shrinkage.
Cell Signaling: Ion gradients influence cell signaling pathways.
Kidney Filtration: The pump aids in waste removal by maintaining proper ion balance in kidney cells.
Neural Action Potential: Necessary for nerve cell function1.
Impact of Mutated or Non-Functioning Na+/K+ Pump:
If the Na+/K+ pump were mutated or not working:
Sodium ions would accumulate intracellularly, disrupting the concentration gradient.
Potassium ions might leak out, affecting RMP.
Cells could become depolarized (less negative), leading to altered cell function.
Nerve cells might fail to generate action potentials properly.
Overall, cellular homeostasis would be compromised.
In summary, the Na+/K+ pump is a critical player in maintaining cell health, RMP, and physiological processes. Its dysfunction can have significant consequences for cellular function and overall well-being12. 🧪🔬
Describe what a concentration gradient is and how it leads to diffusion and the establishment of a dynamic equilibrium.
Describe what a concentration gradient is and how it leads to diffusion and the establishment of a dynamic equilibrium.
This spread of particles through random motion from an area of high concentration to an area of lower concentration is known as diffusion. This unequal distribution of molecules is called a concentration gradient. Once the molecules become uniformly distributed, dynamic equilibrium exists.
Describe what a concentration gradient is and how it leads to diffusion and the establishment of a dynamic equilibrium.
Concentration Gradient:
A concentration gradient refers to the variation in solute concentration across a space or membrane. Imagine it as a slope—a difference in the number of particles (ions or molecules) between two regions.
It can exist within a single cell, between adjacent cells, or across cell membranes.
Concentration gradients are essential for various biological processes, including nutrient uptake, waste removal, and cell signaling.
Diffusion:
Diffusion is the spontaneous movement of particles (such as ions or molecules) from an area of higher concentration to an area of lower concentration.
It occurs due to the random motion of particles. Think of it as a crowd dispersing naturally—people move from crowded areas to less crowded ones.
Diffusion doesn’t require energy input; it’s a passive process.
Examples:
Oxygen and Carbon Dioxide Exchange: In our lungs, oxygen diffuses from the air sacs (high concentration) into the bloodstream (lower concentration), while carbon dioxide moves in the opposite direction.
Nutrient Absorption in Intestines: Nutrients (glucose, amino acids) diffuse from the intestinal lumen (high concentration) into the blood vessels (lower concentration).
Dynamic Equilibrium:
When diffusion occurs, particles move down their concentration gradient until they reach a state of equilibrium.
Dynamic equilibrium is a balanced state where the rate of movement in both directions is equal.
Key points:
No Net Change: Although particles continue to move, there’s no net change in concentration.
Steady State: The system remains stable over time.
Example:
Consider a container with a semi-permeable membrane separating two solutions—one with more solute (higher concentration) and the other with less solute (lower concentration).
Initially, solute molecules move from the high-concentration side to the low-concentration side.
Over time, the movement becomes bidirectional, with equal rates of diffusion in both directions.
The system reaches dynamic equilibrium when the concentrations on both sides stabilize.
Factors Influencing Diffusion:
Temperature: Higher temperatures increase the rate of diffusion.
Concentration Gradient: Steeper gradients lead to faster diffusion.
Membrane Permeability: Membranes with higher permeability allow faster movement.
Particle Size: Smaller particles diffuse more rapidly.
In summary, concentration gradients drive diffusion, and dynamic equilibrium ensures a balanced distribution of particles. Whether it’s oxygen entering our cells or nutrients crossing membranes, these processes rely on the delicate dance of concentration gradients and diffusion. 🌟🔬
cell membrane
One of the great wonders of the cell membrane is its ability to regulate the concentration of substances inside the cell. These substances include ions such as Ca++, Na+, K+, and Cl–; nutrients including sugars, fatty acids, and amino acids; and waste products, particularly carbon dioxide (CO2), which must leave the cell.
The sodium-potassium pump, which is also called Na+/K+ ATPase, transports sodium out of a cell while moving potassium into the cell.
The Na+/K+ pump is an important ion pump found in the membranes of many types of cells.
Sodium-Potassium Pump The sodium-potassium pump is found in many cell (plasma) membranes.
Powered by ATP, the pump moves sodium and potassium ions in opposite directions, each against its concentration gradient.
In a single cycle of the pump, three sodium ions are extruded from and two potassium ions are imported into the cell.
These pumps are particularly abundant in nerve cells, which are constantly pumping out sodium ions and pulling in potassium ions to maintain an electrical gradient across their cell membranes.
Facilitated diffusion is the diffusion process used for those substances that cannot cross the lipid bilayer due to their size, charge, and/or polarity (Figure 3.6). A common example of facilitated diffusion is the movement of glucose into the cell, where it is used to make ATP.
A membrane that has selective permeability.
Diffusion is the movement of particles from an area of higher concentration to an area of lower concentration.
The structure of the lipid bilayer allows small, uncharged substances such as oxygen and carbon dioxide, and hydrophobic molecules such as lipids, to pass through the cell membrane, down their concentration gradient, by simple diffusion.
Consider substances that can easily diffuse through the lipid bilayer of the cell membrane, such as the gases oxygen (O2) and CO2.
Passive transport is the movement of substances across the membrane without the expenditure of cellular energy.
In contrast, active transport is the movement of substances across the membrane using energy from adenosine triphosphate (ATP).
Describe several ways that intracellular fluid (ICF) differs from extracellular fluid (ECF). What ions are higher in the ICF vs ECF?
Copilot
Certainly! Let’s delve into the fascinating world of cellular fluids. 🧪
Location:
Intracellular Fluid (ICF): This fluid resides inside the cell, within the cell membrane. It’s like the cell’s private swimming pool.
Extracellular Fluid (ECF): This fluid encompasses all the body fluids outside the cell, including the spaces between cells and the blood plasma. Think of it as the bustling city streets where cells interact.
Composition:
ICF (also known as cytosol):
Water Content: Approximately 70% of the cytosol is water.
pH: The pH of the cytosol ranges from 7.0 to 7.4.
Ions:
Lower Sodium (Na+): The concentration of sodium ions in the cytosol is lower than in the extracellular environment.
Lower Calcium (Ca2+): Calcium ions are also less abundant in the cytosol.
Lower Chloride (Cl-): Chloride ions follow suit and have a lower concentration.
Higher Potassium (K+): Potassium ions, on the other hand, are higher inside the cell.
Higher Magnesium (Mg2+): Magnesium ions also favor the intracellular environment.
Proteins: The cytosol contains various proteins, including those that form the cell’s cytoskeleton (microtubules, microfilaments, and intermediate filaments).
ECF:
Tissue Fluid: This fluid bathes the outside of cells, providing nutrients and removing waste.
Blood Plasma: The liquid component of blood, rich in proteins and ions.
Cerebrospinal Fluid: Found in the brain and spinal cord cavities.
Ions:
Higher Sodium (Na+): The extracellular fluid has a higher concentration of sodium ions.
Higher Chloride (Cl-): Chloride ions are more abundant in the ECF.
Lower Potassium (K+): Potassium ions are less prevalent outside the cell.
Function:
ICF:
Facilitates internal cellular processes such as metabolism, signaling, and energy production.
Provides a medium for enzymes and organelles to function.
ECF:
Aids in nutrient transport, waste removal, and intercellular communication.
Helps maintain osmotic balance and supports overall bodily functions.
In summary, ICF and ECF play distinct roles, with their unique ion compositions contributing to cellular health and overall homeostasis. 🌟1234
ICF ( water content )
ECF (higher con
CNS quizz
brain and spinal cord
1. Communication and coordination
2. intellect and reasoning
2. intellect and reasoning
1. it receives the message from stimuli all over the body
2. the brain interprets the message--it responds to the message--and carries out that activity
2. the brain interprets the message--it responds to the message--and carries out that activity
nerve cell
neuron
1. cell body
2. dendrites
3. axon
2. dendrites
3. axon
cell body
dendrites
axon
myelin sheath
neuroglia and neurons
neuroglia
neurons
irritability and conductivity
irritability
conductivity
sensory, motor, and interneurons
sensory
motor
interneurons
synapse
synaptic cleft
neurotransmitters
CNS, PNS, ANS
peripheral nervous system/ PNS
autonomic nervous system/ ANS
3 pounds
100 billion neurons
1. a bony cranial cavity (Skull)
2. 3 membranous coverings called meninges
3. cerebrospinal fluid
2. 3 membranous coverings called meninges
3. cerebrospinal fluid
The outer cortex/cerebral cortex
white mater
4-8 minutes
1. cerebrum, 2. cerebellum, 3. diencephalon, 4. brain stem
Dura mater, arachnoid, pia mater
Dura mater
Arachnoid
Pia mater
cerebrospinal fluid
Cerebrum
2 pounds
left and right
brainy
creative
1. longitudinal 2. transverse 3. central 4. lateral 5. parieto-occipital
longitudinal
transverse
central
lateral
parieto-occipital
cerebral frontal functions
cerebral parietal functions
cerebral occipital functions
cerebral temporal functions
cerebral cortex
between the cerebrum and the midbrain
thalamus and hypothalamus
Thalamus
Hypothalamus
Limbic system
autonomic nervous control
cardiovascular control
temperature control
appetite control
water balance
manufacture of oxytocin
gastrointestinal control
emotional state
sleep control
behind the pons and below the cerebrum
maintenance of balance, maintenance of muscle tone, coordination of muscle movements
mid brain, pons, and medulla oblongata
mid brain
pons
medulla oblongata
spinal cord
sympathetic
parasympathetic
somatic nervous system
PNS
autonomic nervous system
CNS
PNS
neuroglia
neurons
axonal terminal
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