Homeostasis Study Guide (Chapter 5, Cengage Biology Honors)
Positive | Negative |
|---|---|
Results in amplification | Results in stabilization |
Graphic by Tanisha Kurani
Example | Information |
|---|---|
Blood Clotting | Group of blood cells, platelets, and protein clumped together over a wound to stop bleedingNegative loopBleeding (input) is stopped by clot (output), reverses direction of blood |
Ice-Albedo | Albedo - Amount of sunlight or radiation reflected by a surface |
Body Temperature | Receptors are stimulated by a discrepancy from the normal 98.6 degrees F and send a signal to control centerControl center decides whether to vasodilate (cool down) or vasoconstrict (heat up) and sends a signal to effectors w/ decisionEffectors execute the decision w/ sweat glands or muscle contractionNegative loopThe body loses or retains heat to stabilize yourself to a particular temperature |
Labor/Giving Birth | More pressure on cervix stimulates receptor cells that releases oxytocinOxytocin goes back to cervix and simulates contractionsPositive loop - Contractions go back to more pressure on the cervix until baby is born |
Fruit Ripening | Acidic levels rise and amount of simple sugars increase, activating fruit ripening enzymesEnzymes cause the ripened fruit to ripen more fruit |
Guard Cells/Stomata | Guard cells = 2 epidermal cells that open and close stomatal poresStomata = Tiny substance essential to photosynthesis, made up of guard cellsTakes in CO2, releases O2 |
BIGELOW SLIDES PARAMECIUM GIZMOS __OSMOSIS PRACTICE PROBLEMS__STUDY BOOKLET (HANDED OUT IN CLASS) OSMOSIS GIZMOS PRACTICAL APPLICATION PRACTICAL APPS WORKSHEET |
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Factors that influence diffusion:
Concentration
Temperature
Size
Charge
Pressure
Concentration gradient - adjacent regions with different concentrations
When a cell goes through passive transport or diffusion, it tries to travel from a high concentration gradient to a low concentration gradient.
KEY VOCAB:
Solute: The thing being dissolved
Solvent: The thing dissolving the solute
Solution: The product once it’s dissolved
Diffusion - The movement of atoms/molecules from an area of high concentration to low concentration
Osmosis - Diffusion relating to water
Facilitated diffusion - Diffusion where molecules pass through protein channel
Hypertonic - Outside > InsideIf the solvent is hypertonic, the solute is hypotonicEnds in shriveling up | Isotonic - Outside=InsideIf the solvent is isotonic, the solute is tooThe end goal of all diffusion | Hypotonic - Inside > OutsideIf a solvent is hypotonic, the solute is hypertonicEnds in swelling and ruptures |
|---|---|---|
Turgor Pressure - Plants fill themselves with water to preserve structure
If it loses that water, it stops pushing and becomes soft
Osmotic Pressure - The amount of turgor needed to stop osmosis
Plasmolysis - Cell membrane pulling away from cell wall (opposite of turgor)
Active transport moves against the concentration gradient (low to high) and requires energy.
Protein pump - A pump that moves molecules across the membrane
Endocytosis | Exocytosis |
|---|---|
Into the cell - uses cell membrane to engulf materials | Fuses with cell |
Energy - The ability to do work
Entropy - Unusable dispersed energy
First Law of Thermodynamics: Energy cannot be created or destroyed
Second Law of Thermodynamics: Energy tends to disperse spontaneously, always increasing entropy in a system
Potential energy - Energy that is stored in a fixed position or motion
Chemical energy - form of potential energy due to arrangement of atoms within the molecules
Kinetic energy - Energy of motion
Endergonic | Exergonic |
|---|---|
Reactions that store energy into the moleculeCondensation, photosynthesis | Reactions that have a release of free energyCellular respiration |
Most enzymes not only have an active site, but also an Allosteric Regulation
Allosteric Regulation - Cofactors/Coenzymes bind to atom and change active site of enzymes
Allosteric Activation - Changes shape of active site so enzyme is turned on and works
Allosteric Inhibition - Changes shape of active site so the enzyme is turned off and doesn’t work
Coenzyme - Allows redox reactions to proceed
Ex: ATP - provides activation energy to start reactions whenever needed
Breaks bonds between 2nd and 3rd phosphate groups, giving off the potential energy, can spend and refill
Stores (Endergonic) and releases (Exergonic)
Feedback Inhibition - Final product of a process decreases/stops the process once the product is made
Negative loop
Metabolic reactions may be Redox reactions, Redox reactions transfer electrons between atoms.
REMEMBER: The electron that has a charge is being reduced
Electron Transfer Chains - Can be formed with many Redox reactions over and over, releases energy in small amounts (slow) and fuels many reactions in a cell
Positive | Negative |
|---|---|
Results in amplification | Results in stabilization |
Graphic by Tanisha Kurani
Example | Information |
|---|---|
Blood Clotting | Group of blood cells, platelets, and protein clumped together over a wound to stop bleedingNegative loopBleeding (input) is stopped by clot (output), reverses direction of blood |
Ice-Albedo | Albedo - Amount of sunlight or radiation reflected by a surface |
Body Temperature | Receptors are stimulated by a discrepancy from the normal 98.6 degrees F and send a signal to control centerControl center decides whether to vasodilate (cool down) or vasoconstrict (heat up) and sends a signal to effectors w/ decisionEffectors execute the decision w/ sweat glands or muscle contractionNegative loopThe body loses or retains heat to stabilize yourself to a particular temperature |
Labor/Giving Birth | More pressure on cervix stimulates receptor cells that releases oxytocinOxytocin goes back to cervix and simulates contractionsPositive loop - Contractions go back to more pressure on the cervix until baby is born |
Fruit Ripening | Acidic levels rise and amount of simple sugars increase, activating fruit ripening enzymesEnzymes cause the ripened fruit to ripen more fruit |
Guard Cells/Stomata | Guard cells = 2 epidermal cells that open and close stomatal poresStomata = Tiny substance essential to photosynthesis, made up of guard cellsTakes in CO2, releases O2 |
BIGELOW SLIDES PARAMECIUM GIZMOS __OSMOSIS PRACTICE PROBLEMS__STUDY BOOKLET (HANDED OUT IN CLASS) OSMOSIS GIZMOS PRACTICAL APPLICATION PRACTICAL APPS WORKSHEET |
|---|
Factors that influence diffusion:
Concentration
Temperature
Size
Charge
Pressure
Concentration gradient - adjacent regions with different concentrations
When a cell goes through passive transport or diffusion, it tries to travel from a high concentration gradient to a low concentration gradient.
KEY VOCAB:
Solute: The thing being dissolved
Solvent: The thing dissolving the solute
Solution: The product once it’s dissolved
Diffusion - The movement of atoms/molecules from an area of high concentration to low concentration
Osmosis - Diffusion relating to water
Facilitated diffusion - Diffusion where molecules pass through protein channel
Hypertonic - Outside > InsideIf the solvent is hypertonic, the solute is hypotonicEnds in shriveling up | Isotonic - Outside=InsideIf the solvent is isotonic, the solute is tooThe end goal of all diffusion | Hypotonic - Inside > OutsideIf a solvent is hypotonic, the solute is hypertonicEnds in swelling and ruptures |
|---|---|---|
Turgor Pressure - Plants fill themselves with water to preserve structure
If it loses that water, it stops pushing and becomes soft
Osmotic Pressure - The amount of turgor needed to stop osmosis
Plasmolysis - Cell membrane pulling away from cell wall (opposite of turgor)
Active transport moves against the concentration gradient (low to high) and requires energy.
Protein pump - A pump that moves molecules across the membrane
Endocytosis | Exocytosis |
|---|---|
Into the cell - uses cell membrane to engulf materials | Fuses with cell |
Energy - The ability to do work
Entropy - Unusable dispersed energy
First Law of Thermodynamics: Energy cannot be created or destroyed
Second Law of Thermodynamics: Energy tends to disperse spontaneously, always increasing entropy in a system
Potential energy - Energy that is stored in a fixed position or motion
Chemical energy - form of potential energy due to arrangement of atoms within the molecules
Kinetic energy - Energy of motion
Endergonic | Exergonic |
|---|---|
Reactions that store energy into the moleculeCondensation, photosynthesis | Reactions that have a release of free energyCellular respiration |
Most enzymes not only have an active site, but also an Allosteric Regulation
Allosteric Regulation - Cofactors/Coenzymes bind to atom and change active site of enzymes
Allosteric Activation - Changes shape of active site so enzyme is turned on and works
Allosteric Inhibition - Changes shape of active site so the enzyme is turned off and doesn’t work
Coenzyme - Allows redox reactions to proceed
Ex: ATP - provides activation energy to start reactions whenever needed
Breaks bonds between 2nd and 3rd phosphate groups, giving off the potential energy, can spend and refill
Stores (Endergonic) and releases (Exergonic)
Feedback Inhibition - Final product of a process decreases/stops the process once the product is made
Negative loop
Metabolic reactions may be Redox reactions, Redox reactions transfer electrons between atoms.
REMEMBER: The electron that has a charge is being reduced
Electron Transfer Chains - Can be formed with many Redox reactions over and over, releases energy in small amounts (slow) and fuels many reactions in a cell
Positive loopIce is highly reflective, it reflects some sunlight back to space, heating the ocean up and melting more and more ice.
Stomata must open to release water, but when it opens, leads to water going in and needing to refillNegative loop
