Lecture 3 - How Do The Properties of Biomolecules Affect Their Interactions With Each Other?

Question 1

What is a chemical reaction?

Answer 1

rearrangement of valance electrons

Question 2

What is a chemical bond?

Answer 2

a directed, attractive interaction between atoms

Question 3

What is the definition of electronegativity?

Answer 3

a measure of how much an atom attracts its electrons

Question 4

What is a structural isomer?

Answer 4

same molecular, but different structural formula

Question 5

what is a stereoisomer?

Answer 5

have the same number of molecules but different arrangement of atoms in space

Question 6

What is cis + trans?

Answer 6

no rotation around a double bond

Question 7

What is an optical isomer?

Answer 7

c is bonded to 4 different groups (chiral carbons)

Question 8

What are 4 different types of intermolecular forces?

Answer 8

• permanent dipole interactions
• hydrogen bonds
• London dispersion forces
  ionic bonding

Question 9

What 3 factors impact intermolecular bond strength?

Answer 9

1) strength:
LFDs < dipole < Ionic bond

2) size and shape - larger = more force, shape, closer together = more force

3) distance, closer = more force

Question 10

How many forms can glucose convert between?

Answer 10

3

Question 11

What are the functional groups in glucose?

Answer 11

• COH (aldehyde)
• OH (hydroxyl)

Question 12

Is glucose hydrophobic or hydrophilic?

Answer 12

C=O. OH == hydrophilic

Question 13

What isomers are there of glucose and what form does biology use

Answer 13

• structural
• stereo
• optical
  biology only uses D form

Question 14

When and how does glucose structure change?

Answer 14

• folds into a ring
• when in water

Question 15

What are the functional groups in nucleotides and what are their polarity?

Answer 15

• OH - polar
• NH2 - hydrophobic
• PO4- - charged
• purine - hydrophobic

Question 16

What is a nitrogenous base with two rings called?

Answer 16

purine

Question 17

What is a nitrogenous base with one ring called?

Answer 17

pyrimidine

Question 18

Are nucleotides hydrophobic or hydrophilic?

Answer 18

hydrophilic

Question 19

What are the isomers of nucleotides?

Answer 19

stereoisomers at 1’ and 4’ positions

Question 20

What functional groups are in amino acids and what are their polarity?

Answer 20

• COO- = charged
• NH3+ = charged
  -and others in the R group

Question 21

What is the alpa carbon in amino acids?

Answer 21

The carbon in the middle of the amino acid

Question 22

What different isomers can you get of amino acids?

Answer 22

Optical - chiral at alpha carbon
biology uses L form of amino acids

Question 23

What happens if you put amino acids in pH7 water?

Answer 23

• amino group gains H and becomes NH3
• COOH group loses H and becomes COO-

Question 24

What functional groups are in fatty acids?

Answer 24

• COOH
• alkene
• alkyl

Question 25

What can happen to a fatty acid in water?

Answer 25

The acid head can form a negative charge by dissociation in water

Question 26

What is the property of a fatty acid dependent on?

Answer 26

the non polar hydrocarbon tail

Question 27

Are fatty acids hydrophobic or hydrophilic overall?

Answer 27

hydrophobic

Question 28

What isomers are there of fatty acids?

Answer 28

• many structural isomers
• stereo isomers at C=C (cis and trans)

Question 29

What is the omega carbon of a fatty acid?

Answer 29

the end carbon

Question 30

How is the double bond in a fatty acid labeled?

Answer 30

with respect to the omega carbon
(how many carbons away from the omega carbon inclusive)