HOMEOSTASIS
1. Keeping an organism’s internal environment stable
2. Examples
HOMEOSTASIS
1. “the tendency of an organism or cell to regulate its internal environment and maintain equilibrium, usually by a system of feedback controls, so as to stabilize health and functioning”
FEEDBACK MECHANISMS
1. Help the organism respond to stimuli and maintain homeostasis on a ______(whole body)
a) ______Feedback
b) ______Feedback
NEGATIVE FEEDBACK
1. When a situation causes a response that ______the first condition
2. Most common in the body
POSITIVE FEEDBACK
1. When a situation causes a response that amplifies (______) the initial (1st) condition
2. Ex. Milk production, labor pains, ______
CELLULAR HOMEOSTASIS
1. ______, individual cells maintain homeostasis by controlling what gets into and out of a cell.
CELL TRANSPORT
1. Cells move molecules in and out 2 ways:
a) ______TRANSPORT: does ______use energy, moves from ______concentration.
b) ______TRANSPORT: ______, moves from ______concentration.
HOW DO MATERIALS MOVE IN OUT OF THE CELL?
1. Materials like glucose, water, solutes, and oxygen can move through the cell membrane in one of two ways:
a) ______
b) ______
MOVING BETWEEN PHOSPHOLIPIDS
1. There is a small amount of space between the round heads of the phospholipids that make up a majority of the cell membrane.
MOVING THROUGH CARRIER PROTEINS
1. Carrier (______) proteins allow larger molecules to pass through
a) Sugars, amino acids, small proteins
b) Molecules “too big” to fit between phospholipids
SOLUTIONS
1. Solutions are mixtures of different substances:
a) ______: the medium in which a substance is dissolved
b) ______: the substance dissolved in the solvent
c) ______: the uniform mixture of the solute and solvent
i. Example – Kool-Aid (solution) = Solvent is water and powder is the solute
PASSIVE TRANSPORT
1. Molecules move with the flow, from ______concentrations.
2. ______
3. This will continue until they are evenly spread out or reached equilibrium
4. 3 Types:
a) ______
b) ______
c) ______
PASSIVE TRANSPORT - DIFFUSION
1. ______: the movement of molecules from areas of ______concentration to areas of ______concentration.
PASSIVE TRANSPORT – FACILITATED DIFFUSION
1. ______: Movement of molecules from ______.
2. A ______in the membrane ______in the membrane.
3. Movement of larger molecules (ex. glucose) form high concentration to low concentration with the help of a carrier protein.
PASSIVE TRANSPORT - OSMOSIS
1. Osmosis: movement of ______from ______.
- Specific type of Diffusion – ______
i. The movement of water across a membrane from an area of high concentration of water to an area of lower water concentration
PASSIVE TRANSPORT - OSMOSIS
1. Need to understand the concentrations of solvents solutes on either side of the membrane.
DIFFUSION / OSMOSIS AND CELLS
1. Solutions are classified in 3 ways based on their concentrations of water in relation to the inside of cells
a) ______: Higher H2O concentration inside the cell
b) ______: Higher H2O concentration outside the cell
c) ______: Equal concentrations of H2O inside and outside the cell
ISOTONIC SOLUTION
1. When the cell is at equilibrium with its environment, ______move into and out of the cell
HYPERTONIC SOLUTION
1. When there is more ______.
a. This can cause a cell to ______
HYPTOTONIC SOLUTION
1. When there is more water outside a cell than inside of a cell
a. Water will enter the cell
b. This can be bad, if too much water enters then the cell may lyse (burst) à ______
THE EFFECTS OF DIFFUSION OSMOSIS ON LIVING CELLS
1. Both diffusion and osmosis will result in changes to living cells
- The movement of water other solutes back and forth across the membrane will change the volume and pressure inside of the cell
- Since plant cells are surrounded by a rigid outer layer, the overall shape will NOT change, but the pressure inside will
PLASMOLYSIS
1. ______respond differently to osmosis because of their ______.
2. When water leaves a plant cell the cell wall’s shape does not change, but the cell membrane pulls away and creates an air pocket between the two. This causes the plant to ______.
TURGOR PRESSURE
1. When water enters a plant cell, the cell membrane ______.
ACTIVE TRANSPORT
1. Move molecules against the flow, ______concentration.
2. ______
3. It’s like pushing something up hill instead of letting it roll downhill
ACTIVE TRANSPORT
1. For Multicellular Organisms:
2. Uses a carrier protein, to carry them across the membrane
ACTIVE TRANSPORT
1. For Unicellular Organisms
2. ______à organelle that transports materials through, into, or out of a cell
3. ______àinto the cell
4. ______àout of the cell