Honors Biology Unit 2

Positive Feedback Loop

Response to a stimulus that increases change from your set point (More common when rapid changes are needed.)

Negative Feedback Loop

Response to a stimulus that minimizes change from your set point (EX, When your hot, your body works to minimize your temp change by producing sweat)

Homeostasis

Maintaining stable internal conditions, despite changers to the outside world.

Thermoregulation

keeps body temperature near 37°C

Control center:

hypothalamus

Type of feedback:

negative feedback only

Vasodilation

Blood vessels widen to release heat from your body when you are hot (To maintain homeostasis)

Vasoconstriction

Blood Vessels narrow to keep heat when you are cold (To maintain homeostasis)

Ecotherm

the organism doesn’t spend any of its energy on maintaining its body temperature

Endotherm

The organism uses some of its energy to keep its body temperature constant.

Solution

Solvent (water) dissolves the solute (salt)

If there is 10% glucose then there is..

90% water

Diffusion

Molecules move from high to low concentration, and will do so until they are in equilibrium

Facilitated Diffusion

When channel proteins help larger molecules or charged molecules pass through the membrane (Still Passive transport)

Osmosis

The diffusion of water across a membrane

Water goes through?

aquaporins

Hypertonic

When there is a HIGHER concentration of solutes outside of the cell. (more salt outside, so water will also move out)

Hypotonic

When there is a LOWER concentration of solutes outside of the cell. (More salt inside so water will move in, causing cell to get big like a hippo)

Isotonic

equal concentrations of solute

High SA: V =

efficient transport, small or folded cells. (More surface area/entrypoints)

Low SA: V

inefficient transport, big cells must adapt or divide. (Less Surface area, less entry points