Science Comp CH. 2

How does a catalyst affect the activation energy of a chemical reaction?

A catalyst is a substance that decreases the activation energy and increases the chemical reaction.

Cells have a higher H+ concentration than blood. Which of these has a higher pH? Why?

A healthy human cell has a pH of around 7.35. Blood is 7.4. Blood has a higher pH and is slightly more basic.

What does it mean for a molecule or atom to be stable? Neutral?

A molecule or atom to be stable or neutral needs to have 8 valence electrons.

What's the difference between an ionic and covalent bond?

An ionic bond forms trough electrical force between oppositely charged ions. A covalent bond forms when atoms share a pair of electrons.

What happens to the function on an enzyme if you increase the temperature or change the pH? What is this called?

Change in temperature and pH can break hydrogen bonds.

What is cohesion? Give an example.

Cohesion is the attraction between molecules of the same substance. An example is when cohesion forms when water molecules stick together.

How does the structure of an enzyme affect its function?

Each shape allows certain reactants to bind to the enzyme. If the structure of an enzyme change, it loses its ability to function and may not work at all.

How do exothermic and endothermic reactions differ?

Exothermic reactions release more energy than it absorbs. Endothermic reactions absorb more energy than it releases.

What determines whether an atom becomes a positive or negative ion?

If a neutral atom gains electrons, it'll be negatively charged. If a neutral atom loses electrons, it'll be positively charged.

What's a hydrogen bond? How's it similar to an ionic bond?

It's an attraction between a slightly positively hydrogen atom and slightly negative atom often oxygen or nitrogen. It's similar to an ionic bond because both are based on attraction between atoms that carry differences in electrical charge.

What does it mean for water to be polar?

It's polar because there's an uneven distribution of electrons between the oxygen and hydrogen atoms.

Monomers for carbohydrates, nucleic acids, proteins, and lipids?

Monosaccharides (carbs), nucleotides (nucleic acids), amino acids (proteins), glycerol and fatty acids (lipids)

What are the parts of an atom and what are their electrical charges?

Neutron (no charge), proton (+), and electrons (-)

Solute and solvent...

Solute dissolved in the solvent.