chapter 1 final

Question 1

biomolecules are made up of -

Answer 1

70% water

30% chemicals

Question 2

what are the chemicals and % of them that are in biomolecules

Answer 2

15% proteins

4% small molecules

6% RNA

2% phospholipids

1% DNA

2% polysaccharides

Question 3

what are the building blocks

Answer 3

amino acids, carbohydrates, nucleotides, lipids

Question 4

what are the polymers

Answer 4

proteins, polysaccharides, nucleic acids

Question 5

what are the supra-molecular assemblies

Answer 5

ribosomes

chromatin

membranes

lipids

Question 6

what are the 4 major classes of biomolecules

Answer 6

amino acids

carbohydrates

nucleotides

lipids
-fatty acids
-cholesterol

Question 7

know functional groups and linkages

Question 8

monomers

Answer 8

amino acids

nucleotides

monosaccarides

Question 9

directionality

Answer 9

all covelent bonds are in the same orientation

Question 10

residues

Answer 10

monomers that are part of a polymer

Question 11

amino acids -> protein =

Answer 11

peptide bonds

Question 12

nucleotides -> nucleic acids =

Answer 12

phosphodiester bonds

Question 13

monosaccharides -> polysaccharides =

Answer 13

glycosidic bond

Question 14

water as a solvent

Answer 14

-excellent solvent for polar and ionic (hydrophilic) materials

-poor solvent for non-polar (hydrophobic) substances

Question 15

most biological molecules have both polar and non-polar segments. what does that mean?

Answer 15

polar = are hydrated (contact water)

non-polar = are excluded ( do not contact water)

Question 16

structure of water

Answer 16

-highly polar solvent

-liquid = rapidly changing and moving

-hydrogen bonds

Question 17

hydrogen bonds

Answer 17

strong non-covalent bond

-20 kJ mol

Question 18

covalents bonds

Answer 18

= 456 kJ ( O-H water)

Question 19

hydrogen bond: donor

Answer 19

a hydrogen bondedd to an electronegative atom (O or N)

Question 20

hydrogen bond: acceptor

Answer 20

a lone pair of electrons associated with an electronegative atom

Question 21

how many H-bonds can a water molecule form?

Answer 21

4 H-bonds for ice (regular lattice)

Question 22

water h bond structure

Answer 22

3 H bonds per water molecule

2 H-bonds as acceptor

2 H- bonds as donor

Question 23

water is a weak-

Answer 23

acid/base

Question 24

bronseted acids

Answer 24

donate protons

Question 25

bronsted bases

Answer 25

accept protons

Question 26

the pH pf a solution is determined by the-

Answer 26

realtive concentrations of acids and bases

Question 27

buffer region

Answer 27

at pH close to it's pka a buffer resists changes in pH with added acid or base

Question 28

when [HA] = [A-] the pH =

Answer 28

pKa -exactly half dissociated

Question 29

at a pH above pKa, the acid exists predominately as-

Answer 29

A- deprotonated form/conjugate base

Question 30

at a pH below pKa, the acid exists predominately as-

Answer 30

AH protonated form/acid

Question 32

What is a zwitterion?

Answer 32

A zwitterion is a molecule that contains both positive and negative charges but is overall electrically neutral. ## Footnote Zwitterions are commonly found in amino acids and play a crucial role in biochemistry.