Test 2C

Question 1

SAM

Answer 1

cosubstrate coenzyme

Question 2

NAD+ function

Answer 2

electron Carrier -accepts electrons -cosubstrate

Question 3

NADH function

Answer 3

electron carrier -accepts electrons -transfers two electrons -cosubstrate

Question 4

FAD

Answer 4

prosthetic group -forms double bonds -has intermediate radical -oxidize reduce double bonds -Stronger Oxidizing agent than NAD+ **3 6 sided Rings!

Question 5

FADH2

Answer 5

transfer 1 or 2 electrons -prosthetic group -can hold the proton while NADH cannot and carries a hydride

Question 6

Fatty acids with double bonds and Tm, van der waals

Answer 6

double bond “kink” causes the fatty acid to behave like a much shorter tail. -the kink pushes other fatty acids away inhibiting the formation of van der waals interactions

Question 7

Nucleosomes

Answer 7

Neutralize most the of the remaining negative charge of the DNA strand (NUCLEOSOMES)

Question 8

Arginine Grooves in DNA

Answer 8

attract negatively charged DNA strands, wrap themselves around the histone

Question 9

DNA

Answer 9

wraps around 1 and 3/4 times -involves 146 base pairs about the histone octamer -54 base pairs between histones 200 BP per histone unit

Question 10

Triacylglycerol function

Answer 10

used for fat storage (energy storage), insulation

Question 11

Hydrophobic Effect and Nitrogenous Bases

Answer 11

nitrogenous bases are relatively hydrophobic and orient themselves inward to avoid the external hydrophillic enviroment. -The guanine/cytosine pairing is more hydrophobic than the adenosine/thymine thus forms first and is more stable

Question 12

DNA stability

Answer 12

Counterions -dilute the negative charge of the DNA strands allowing them to hybridize or anneal together -WITH OUT countering NO DOUBLE STRANDED DNA Results: the DNA strands are metastable -allows for replication with little expenditure of energy

Question 13

How to determine concentration of DNA?

Answer 13

Absorbance @ 260 -A260=E260 b c -2 ssDNA absorbe more light due to a lack of BASE STACKING

Question 14

Explain the difference in composition between A and B in

Answer 14

?

Question 15

Explain the forces involved in hyperchromaticity

Answer 15

Base Stacking(least), H-bonding, MORE HYDROPHOBIC AFFECT

• increase temp/denature/melting to go to ssDNA
• decrease temp/renature/hybridizing to go to dsDNA

Question 16

What are the two types of cofactors?

Answer 16

Essential Ions:

• ACTIVATOR IONS:Mg2+ (ATP), Ca2+ (phosphotases), Zn2+(zinc fingers)–loosely bound
• Transition Metals(d orbitals):Fe2+, Zn2+, Co2+—tightly bound with active sight

Coenzymes:

• cosubstrates:co-reactant donate/accept functional groups DOES NOT NEED TO BE REGENERATED. ATP, NAD, NAD/NADH, CoA-SH
• prosthetic groups:tightly bound, part of the active site of the enzyme. MUST BE REGENERATED FAD/FADH2/FMN, PLP

Question 17

Mg2+

Answer 17

• neutralizes charge-charge repulsion
• creates a six sided ring
• makes a good nucleophilic center