Ch 2

Question 1

What is a dalton?

Answer 1

represents the mass that one mol of an atom (ion, or molecule) will have in grams.

Question 2

What are the three types of bonds present in the body?

Answer 2

1. covalent bonds
   - electrons shared (not always equally)
2. ionic bonds
3. noncovalent bonds
   ex. hydrogen bonds

Question 3

How do hydrophilic molecules and hydrophobic molecules interact in water?

Answer 3

hydrophillic molecules dissolve
- forms + breaks hydrogen bonds with polar water molecules
hydrophobic molecules
–> do not dissolve but aggregate together to reduce the free energy

Question 4

what is pH

Answer 4

measure of the concentration of hydronium ions in solution (describes acidity when less then 7 otherwise alkaline )

Question 5

Why are electrostatic attractions weak?

Answer 5

1. depends on the distance between partially charged molecules (greater distance = less attraction)
2. In water –> water molecules get in the way
3. inorganic ions can also congregate around the partially charge groups –> hampers attraction

Question 6

What are van der waals attractions?

Answer 6

van der waals radius –> “size” of an atom before it strongly repels other atoms
during covalent bonding –> distance between nucleus is less then sum of van der waal radii.

Question 7

What are the four organic building blocks of the cell and what macromolecules do they make up?

Answer 7

1. sugars –> poly/oligosaccharides
2. fatty acids –> fats + membrane lipids
3. Amino acids –> proteins
4. Nucleotides –> nucleic acids

Question 8

What is an example of an isomer in biology?

Answer 8

isomer –> same chemical formula, different spatial arrangement

ex. glucose and galactose
spatial differences –> diff chemical properties (recognized differently by proteins)

Question 9

what is the bond between each glucose monomer in a poly/oligosaccharide?

Answer 9

glycosidic bond

Question 10

Difference between oligosaccharides + polysaccharides

Answer 10

oligo –> short
poly –> long

Question 11

Which reaction is energetically favorable?
condensation or hydrolysis

Answer 11

hydrolysis
energy needed to form bond
energy released to break bonds

ex. ATP provides energy by breaking down (hydrolyzing into ADP)

Question 12

How are triaclyglycerols formed?

Answer 12

fatty acids forms ester linkage with glycerol

Question 13

Difference between saturated + unsaturated fatty acids?

Answer 13

saturated –> straight
unsaturated –> kinks (due to double bonds)

Question 14

What are phospholipids made up?

Answer 14

(head) phosphoric acid w/ polar group such as choline
(body) glycerol
(tail) hydrophobic fatty acids

Question 15

nucleotides vs nucleosides

Answer 15

both nucleotides and nucleosides have nitrogenous base and five-carbon sugar
nucleotides contain phosphate groups whereas nucleosides don’t

Question 16

Which bases are pyrimidine and pruine?

Answer 16

pyrimidine:
cytoside
thymine
uracil (replaces thymine in RNA)

purine:
adenosine
guanine
(A -T) (C - G)

Question 17

what bonds make up nucleic acids?

Answer 17

nucleotides joined by phosphodiester bonds between 5’ and 3’ carbon atoms on sugar rings