Unit One Bio Notes

Water o Water is a polar molecule. A polar molecule is when there is both a positive charge and a negative charge. this causes an unequal sharing of electrons o Why is water polar? ↳ water is polar b/c it contains a slightly negative oxygen atoms(o) and 2 Slightly positive hydrogen (H).

What does a hydrogen bond allow water to do? • surface tension- the amount of force required to break the surface of a liquid. o adhesion-water's attraction to other substances BESIDES water. o cohesion- water's attraction to other water molecules. • expanding ice causes ice to float. Properties of water o capillary action-the rising of water through a thin tube; is caused by adhesions and cohesion. PH pH scale- a measure of the amount of Hydrogen/ hydroxide ions in a substance acid-contains more H; 0-6 on scale neutral- contains equal OH- & H; 7 on scale base contains more OH-; 8- 14 on scale.

Enzymes are made up of protiens and speed up a reaction by lowering the activation energy. • Catalyst-a substance that speeds up a reaction by lowering activation energy needed to start a reaction. ↳ enzymes are catalysts, but not all catalysts are enzymes.

 Lock and key method

  1. Enzyme and substrate are in the same area.
  2. The enzyme has an active site that the substrate fits into.
  3. The substrate and enzyme combine-catalysis occurs; when the substrate changes
  4. The changed substrate is the product. The enzyme is ready to do another reaction.

Enzymes too hot?- denature & no longer works are catalysts

Enzymes are found in all living things o exist in our body @ different pHs

4 types of macromolecules: carbohydrates proteins lipids nucleic acids

we counsume all of the macromolecules in our foods.

dehydration synthesis -> remove water = new substance/product

hydrolysis ↳ add water = breakdown of substance