Biology Chp 4

Question 1

Carbon is the basis for all biological molecules

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Answer 1

• Carbon can form up to four bonds
• Carbon bond with carbon results in carbon skeletons
• Commonly bonds to nitrogen, hydrogen, and oxygen

Question 2

Organic Chemistry

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Answer 2

the study of compounds containing carbon or organic compounds

organic compounds range from simple molecules to colossal ones

Question 3

Stanley Miller’s Experiment

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Answer 3

Conclusion: Complex organic molecules could arise spontaneously under conditions thought at that time to have existed on early Earth/abiotically
- abiotic synthesis of organic compounds could have been early stage in the origin of life

Question 4

Characteristics of an atom

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Answer 4

• e-configuration is key
• determines the kinds and number of bonds an atom will form with another atom
• valence e- are the e- available to form bond with other atoms

Question 5

Bonds with Carbon

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Answer 5

• Carbon has 6 e- and 4 valence e-
• Usually shares its valence e- with other atoms, resulting in 8e- in its valence shell (covalent bonds)
• Usually forms single or double covalent bonds in organic molecules

When a carbon forms four single bonds, the arrangement of its 4 hybrid orbitals cause the bonds to angle towards the corners of an imaginary tetrahedron

Question 6

Valence

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Answer 6

The electrons required to fill an atom’s valence shell

Question 7

Shape variation in carbon chains

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Answer 7

one important source of molecular complexity and diversity that characterize living matter

Question 8

Hydrocarbons

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Answer 8

Organic molecules consisting of only hydrogen and carbon. Can undergo reactions that release a relatively large amount of energy

Question 9

Four ways carbon skeletons can vary

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Answer 9

Length, branching, double bond position, and presence of rings

Question 10

Hydrophobic compounds

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Answer 10

have a great majority of relatively nonpolar carbon to hydrogen linkages

Question 11

Isomers

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Answer 11

compounds that have the same numbers of atoms of the same elements but different structures and hence different properties
Three Types:
- Structural, cis-trans (aka geometric), and enantiomers

Question 12

Structural Isomers

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Answer 12

isomers that differ in the covalent arrangements of their atoms

may also differ in the location of double bonds
ex.) pentane and 2-Methylbutane C5H12

Question 13

Cis-Trans Isomers (AKA Geometric Isomers)

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Answer 13

Carbons have covalent bonds to the same atoms, but these atoms differ in their spacial arrangements due to the inflexibility of double bonds
- double bonds do not permit same level of rotation as single bonds

Cis isomer (X atoms/group of atoms on same side), Trans isomer (X atoms/group of atoms on opposite sides)

Question 14

Enantiomers

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Answer 14

Isomers that are mirror images of eachother and that differ in shape due to the presence of an assymetric carbon. If one exists the other has to exist, not necessarily equally. Carbon must be bonded to four different groups

Thalidomide (R - anti-nausea) (S - causes birth defects)

Question 15

What affects a molecule’s shape and function?

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Answer 15

Differing chemical groups along the carbon skeleton’s arrangement

ex.) estradiol and testosterone

Question 16

Functional groups

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Answer 16

chemical groups that are directly involved in chemical reactions.
Shape and charge (and other properties) contribute to participation in chemical reactions

Question 17

7 Chemical groups most important in biological processes

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Answer 17

hydroxyl, carboxyl, carbonyl, amino, sulfhydryl, phosphate, and methyl groups

first 6 groups can be chemically reactive; they are hydrophillic and increase the solubility of organic compounds in water.
Methyl group is not reactive, but instead often serves as a recognizable tag on biological molecules