Cell Membrane
What are the 2 types of cell transport?
Active transport and passive transport
The cell membrane is semi-permeable, what does that mean?
Only some things can get in or out.
DOUBLE JEOPARDY
Diffusion is when... and stops when...
Name the three types of diffusion
Molecules move down their concentration gradient and stops when they reach equilibrium.
Simple, Facilitated and Osmosis
What is osmosis
The movement of water across a cell membrane from areas of lower solute concentration to areas of higher solute concentration
What is (are) the main difference(s) between passive transport and active transport?
A. Active transport works against gravity (for example, upwards from the roots of a tree); passive transport works with gravity
B. Active transport requires cellular energy for substances to cross the cell membrane; passive transport does not
C. Passive transport occurs primarily in single-cell organisms; active transport occurs primarily in multi-cellular organisms
D. Passive transport does not require any cellular proteins; active transport requires cellular proteins
B. Active transport requires cellular energy for substances to cross the cell membrane; passive transport does not
What is the makeup of the phospholipid bilayer?
Hydrophobic tails made up fatty acids
Hydrophilic heads made of phosphates
What is the movement of water call?
osmosis.
What is exocytosis?
Molecules are moved out of the cell using membrane-bound vesicles.
What is turgor pressure
The outward pressure exerted on the plant cell wall by the cell contents when water is taken in by osmosis
Glucose is not able to pass through a semipermeable cell membrane. If the cells need sugar to make ATP and carry out cellular processes, how does the sugar get into the cell?
A. active transport using ATP and carrier proteins
B passive transport by osmosis through the proteins
C. active transport using a process called phagocytosis
D. passive transport by diffusion through proteins
D. passive transport by diffusion through proteins
What is embedded in the cell membrane to aid in flexibility?
Cholesterol
Which molecules are involved in simple diffusion?
Oxygen (O2) Carbon Dioxide (CO2) ----> SMALL!
When will diffusion stop occurring?
When dynamic equilibrium is reached
What is the difference between osmosis and diffusion?
Osmosis is the movement of water and diffusion is the movement of molecules (can occur in all mediums)
What is homeostasis?
The need of an organism to stay stable by regulating internal conditions
What is embedded in the phospholipid bilayer to aid in movement of large/charged particles?
Channel proteins
Name some molecules that are a part of facilitated diffusion.
Sugar/Glucose (C6H12O6), Calcium (Ca+2) Chlorine (Cl-) Sodium (Na+) [These are big]
What is endocytosis?
Molecules are moved into the cell in membrane-bound vesicles.
DOUBLE JEOPARDY
A cell with an internal solute concentration of 24% is sitting in a solution of 47% solute. How will the water move and what is the name of this solution?
Water will move out of the cell because the solution is hypertonic
What are positive feedback mechanisms?
Can you name examples?
Positive feedback drives towards/amplifies a change, driving a process for completion.
Ex: Childbirth, fruit ripening, blood clotting when you cut yourself.
What is the cell membrane's job?
To maintain homeostasis by regulating what enters/exits the cell
What does diffusion never require?
Energy!
Describe the difference between active and passive transport?
Active transport requires energy to occur while passive transport does not because it moves down the concentration gradient (from high to low)
In what solution do animal cells prefer? In what solution do plant cells prefer?
Plant cells = Hypotonic solutions
What are negative feedback mechanisms?
Can you provide examples?
Negative feedback maintain stability counteracting a change.
Ex: blood sugar, body temperature, pH/respiration