BIO12 - HOMEOSTASIS

I missed 3 days of school and now there's quiz wtf

What is homeostasis? (2) [2] (1)

• Body keeping internal environment stable

• Internally in fragile chem balance

  • Thousands of precise chem rxns occur

    • Ex. temp, heart rate, O₂ levels, H₂O levels

• Disruption → tries to go back to eq^m

Role of water in humans (2)

• Makes up ~60% of mass

• Vital - needed for many body processes

What aspect of water makes it important to life? (3)

• POLAR molec.

• O₂ = EN ↑

  • Takes more e^-

• Creates H-bonds

What 7 characteristics make water important to life? (7)

• High molecular cohesion

• Adhesion to other polar molecs

• Solid = less dense than liquid

• Good lubricant

• High specific heat capacity

• Universal solvent

• Common on Earth

High molecular cohesion (3)

• Molecs stick to each other

• Creates surface tension

  • Insects can walk on water

  • Water beads up

• Gives joints good cushioning

Adhesion (2)

• Attaches to other polar molecs

  • Why H₂O spreads so easily

• Cohesion + Adhesion =CAPILLARY ACTION

  • How H₂O goes up xylem

Low density solid (2)

• Caused by H-bonding

• Bodies of water freezes top down

  • Insulating ice layer

Good lubricant (2)

• Less friction

• Smooth movement + cushioning between bones (joints)

  • Cohesion = strong under pressure

High specific heat capacity

• More kJ to change states

  • Needs to break H-bonds betw. H₂O molecs

• Warms/cools slowly

  • Temp doesn’t change easily = stable body temp

Good solvent (3)

• Materials moves through easily

• Attracts ions + polar molecs

  • Easily dissolves them

• Body uses as solvent

Common substance (1)

• Easy to get = sustains life