Chapter 4 - Carbon; The Basis of Molecular Biology

Question 1

7 important functional groups

Answer 1

1) hydroxyl (-OH)
2) carbonyl (C=O)
3) carboxyl (-COOH)
4) amino (-NH2)
5) sulfhydryl (-SH)
6) phosphate (PO4 3-)
7) methyl (-CH3)

Question 2

Hydroxyl group

Answer 2

• contains -OH
• compound name: alcohol (-ol)
• role: polar, increases solubility
• example: estradiol

Question 3

Carbonyl group

Answer 3

• contains C=O
• compound name:
  1) ketone (C=O bond in the middle) (-one)
  2) aldehyde (C=O bond at the end) (-al)
• role: acts as acid
• carbohydrates: ketone sugar (ketose), aldehyde sugar (aldose)
• example: testosterone, retinal

Question 4

Carboxyl group

Answer 4

-contains C=O (carbonyl) + -OH (hydroxyl)
(-COOH)
-compound name: carboxylic acid (-ic/-oic acid)
-role: acts as acid
-example: citric acid

Question 5

Amino group

Answer 5

• contains -NH2
• compound name: amine (-ine)
• role: acts as base
• example: histamine, glycine

Question 6

Sulfhydryl group

Answer 6

• contains -SH
• compound name: thiol
• role:
  1) makes disulfide bridge (S-S),
  2) stabilizes tertiary structure of proteins
  3) antibody structure formation
• example: cysteine, methionine

Question 7

Phosphate group

Answer 7

• contains PO4 3- or OPO3 2-
• compound name: organic phosphate
• role: contribute -1 charge (inside phosphate chain) and -2 charge (when at the end)
• example: Adenosine triphosphate, phospholipid, nucleotides

Question 8

Methyl group

Answer 8

• contains -CH3
• compound name: methylated compound
• role: involved in gene expression on DNA
• example: 7-methyl guanosine in 5’ capping, X-chromosome inactivation (methyl cytosine)

Question 9

Most abundant element

Answer 9

Oxygen

70% of body mass

Question 10

Miller’s experiment

Answer 10

• abiotic synthesis of simple organic molecules
• conducted under ancient Earthly conditions:
  1) high temp, high gas pressure
  2) reducing gas (H2, NH3, CH4)
  3) spark - mimic lightning
• result: synthesis of simple amino acids, urea, HCN

Question 11

Sydney Fox’s experiment

Answer 11

• complex organic molecules abiotically synthesized from simple organic molecules
• result: simple oligonucleotide, oligopeptide

Question 12

protocell

Answer 12

abiotic precursor of living cell

• cannot reproduce
• surrounded by membrane - homeostasis is possible

Question 13

Ribozyme

Answer 13

RNA catalyst

-RNA world hypothesis - explains how ribozyme was used as genetic material _ enzyme

Question 14

Types of isomers

Answer 14

1) Structural (constitutional) isomer
2) Cis-trans (stereo/geometric) isomer
3) Enantiomer (stereoisomer, optical isomer)

Question 15

Structural (constitutional) isomer

Answer 15

• same molecular formula, differ in arrangement of covalent bond
  e. g. butane, methyl propane

Question 16

Cis-trans (stereo/geometric) isomer

Answer 16

• same molecular formula and arrangement of covalent bond, differ in spatial arrangement of the same atom
• occur due to inflexibility of double covalent bond
• cis (same side) / trans (different side)

Question 17

Enantiomer (stereoisomer, optical isomer)

Answer 17

• same molecular formula but differ in spatial arrangement of the same atom - mirror image of each other
• they don’t overlap because of presence of chiral carbon
  e. g. left and right hand, S-Ibuprofen (effective enantiomer) vs. R-Ibuprofen (ineffective enantiomer)

Question 18

Ibuprofen

Answer 18

reduces inflammation and pain

Question 19

Friedrich Wohler

Answer 19

Abiotic synthesis of organic compound urea