Podcast
Questions and Answers
One of the fundamental principles in biology is that any ______ life performs is always based on a _______ that allows this to happen.
One of the fundamental principles in biology is that any ______ life performs is always based on a _______ that allows this to happen.
function, structure
Homeostasis is primarily maintained through voluntary actions.
Homeostasis is primarily maintained through voluntary actions.
False (B)
Why is homeostasis a constant challenge for living organisms?
Why is homeostasis a constant challenge for living organisms?
- Because organisms must maintain energy
- Because the external environment is always changing (correct)
- Because specific structures maintain it
- Because organisms are only awake for short periods
Match the structural components of the cell membrane with their descriptions:
Match the structural components of the cell membrane with their descriptions:
Which of the following is NOT a primary role of cell membranes in maintaining homeostasis?
Which of the following is NOT a primary role of cell membranes in maintaining homeostasis?
Define diffusion in the context of cellular transport.
Define diffusion in the context of cellular transport.
What best describes a system at equilibrium?
What best describes a system at equilibrium?
Diffusion requires energy input from the cell.
Diffusion requires energy input from the cell.
What is the primary role of the sodium-potassium pump?
What is the primary role of the sodium-potassium pump?
What is the function of the sodium-potassium pump in promoting the facilitated diffusion of other substances?
What is the function of the sodium-potassium pump in promoting the facilitated diffusion of other substances?
Match each molecule type with its most likely method of transport across the cell membrane:
Match each molecule type with its most likely method of transport across the cell membrane:
Explain why active transport requires energy.
Explain why active transport requires energy.
In a hypertonic solution, in which direction will water move?
In a hypertonic solution, in which direction will water move?
What happens to an animal cell placed in a hypotonic solution?
What happens to an animal cell placed in a hypotonic solution?
Explain what it means for molecules to move “down a concentration gradient”.
Explain what it means for molecules to move “down a concentration gradient”.
Active transport transports molecules down their concentration gradient.
Active transport transports molecules down their concentration gradient.
What is the role of a transmembrane protein in facilitated diffusion?
What is the role of a transmembrane protein in facilitated diffusion?
Which way will NaCl move if a semi-permeable vesicle containing 14% NaCl is placed in a solution of 10% NaCl?
Which way will NaCl move if a semi-permeable vesicle containing 14% NaCl is placed in a solution of 10% NaCl?
Which direction will glucose move if a semi-permeable vesicle containing 8% glucose is placed in a solution of 20% glucose?
Which direction will glucose move if a semi-permeable vesicle containing 8% glucose is placed in a solution of 20% glucose?
If a cell is permeable to the ions $\text{Ca}^{++}$, $\text{Mg}^{++}$, and $\text{Cl}^-$, but not $\text{Na}^+$ or $\text{K}^+$, which ion's concentration would cause water to flow into the cell if it was highly concentrated?
If a cell is permeable to the ions $\text{Ca}^{++}$, $\text{Mg}^{++}$, and $\text{Cl}^-$, but not $\text{Na}^+$ or $\text{K}^+$, which ion's concentration would cause water to flow into the cell if it was highly concentrated?
Flashcards
Function-Structure Relationship
Function-Structure Relationship
The fundamental principle where life's functions are based on a structure that facilitates them.
Homeostasis
Homeostasis
The maintenance of a stable internal environment.
Integral Proteins
Integral Proteins
Proteins embedded within the cell membrane.
Hydrophobic Region
Hydrophobic Region
Signup and view all the flashcards
Hydrophilic Heads
Hydrophilic Heads
Signup and view all the flashcards
Membrane Recognition
Membrane Recognition
Signup and view all the flashcards
Diffusion
Diffusion
Signup and view all the flashcards
Equilibrium
Equilibrium
Signup and view all the flashcards
Active Transport
Active Transport
Signup and view all the flashcards
ATP
ATP
Signup and view all the flashcards
Endo/Exocytosis
Endo/Exocytosis
Signup and view all the flashcards
Facilitated Diffusion
Facilitated Diffusion
Signup and view all the flashcards
Move Down the Gradient
Move Down the Gradient
Signup and view all the flashcards
Transmembrane Protein
Transmembrane Protein
Signup and view all the flashcards
Osmosis
Osmosis
Signup and view all the flashcards
Study Notes
- A life function is always based on a structure that allows it to happen
- Life is built with specific structures that enable it to maintain homeostasis in specific ways
- Homeostasis is a constant challenge for life because the external environment is always changing
- Examples of homeostasis include energy, temperature, and blood sugar
- Membranes help maintain homeostasis by recognizing materials, responding to nutrients or toxins
- Membranes maintains homeostasis by providing pressure and acting as gatekeepers
- Diffusion is represented by a lump of sugar dissolving
- Diffusion is the movement of molecules through fluid from an area of high concentration to low concentration
- At equilibrium, the system has reached a stable state
- Diffusion does not require energy
- The sodium-potassium pump involves K+ and Na+ ions
- The sodium-potassium pump moves Na+ ions out of cells and K+ ions into cells
- The sodium-potassium pump promotes homeostasis, electrochemical gradients, and the facilitated diffusion of other substances
- Molecules too large to move through the membrane use endocytosis or exocytosis
- Small nonpolar molecules move via diffusion
- Movement against a concentration gradient requires active transport
- Small, polar molecules (like water) move via facilitated diffusion
- Large, polar molecules (like proteins) move via facilitated diffusion
- Active transport requires ATP
- Active transport packs additional molecules into a region with a high concentration, requiring energy and effort
Tonicity
- Hypertonic solutions are represented by cell A
- Hypotonic solutions are represented by cell C
- Isotonic solutions are represented by cell B
- Plant cells in a hypertonic environment is shown in graphic C
- Plant cells in a hypotonic environment is shown in graphic A
- Plant cells in an isotonic environment is shown in graphic B
Concentration Gradients
- Moving down a concentration gradient means going from an area of high concentration to low concentration
- Molecules traveling down their concentration gradients include options A, B, and C
- Facilitated diffusion is shown in option B
- Option B shows that there is a transmembrane protein aiding in the diffusion
- Option B represents osmosis
- Osmosis is facilitated diffusion
- Active transport is shown in option C
- Active transport is shown via the inclusion of ATP
Solutes
- Balance solutes by calculating the average that can permeate the membrane
- Calculate total solute concentrations in & out
- Determine %water/concentration from the [solute]… (100% ‐ solutes = %water)
- Osmosis occurs from where there is a higher %water to the lower %water.
- Albumin will not move because the vesicle is not permeable to it
- NaCl moves out (from high to low)
- Glucose moves inside (higher outside to lower inside)
- Water moves inside to dilute the albumin
- K+ is the ion that is farthest from equilibrium inside and outside the cell
- Ca++ is the ion that is closest to equilibrium inside and outside the cell
- High concentration of K+ causes water to flow into the cell, causing the cell to swell
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
