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Flashcards in 3 - Nucleic acids & RNA Deck (21)

What are the three substances that comprise a nucleotide?

1) Phosphate group
2) Sugar
3) Nitrogenous containing base


Nucleic acids are comprised of a sugar, phospate group and a nitrogen containing base. Name the two groups of bases and their components

Pyrimidines: Uracil (RNA), Thymine, and Cytosine - single ring
Purine: Guanine, Adenine - double ring


What kind of sugar does DNA have? RNA?

DNA - Deoxyribose
RNA - Ribose


What is the nemonic to remember the parent of Adenine, Guanine & Cytosine, Uracil, Thymine

Purine is pure like silver = Ag (Adenine & Guanine

Pyrimidine is shaped like a pie and you can CUT it (Cytosine, Uracil, Thymine)


In the DNA structure, why doesn't the pyrimidine's stick together?



What type of bond holds the strands of DNA together to form the double helix?

hydrogen bonds


Phosphodiester linkage is a __________ reaction

a dehydration reaction

H2O out
forms links in the nucleotide sequence


The chain of the carbon on the sugar binds to the phosphate group in a reaction called a phosphodiester linkage. Which pint on the sugar molecule does the link occur

form the 5' to the 3'


The DNA sequence runs in opposite directions - what is this term that describes this structure?

antiparallel helix


Which base pairs link up in the DNA sequencing?

A-T - 2 H pairing
G-C 3 H pairing


contrast and compare the molecules of DNA & RNA

RNA - sugar is ribose
single strand - can helix with itself + loop
nitrogen containing base Uracil instead of Thymine
RNA the daughter of DNA

DNA - sugar is deoxyribose
double strand
nitrogen containing base Thymine instead of Uracil
DNA the template


What are the purposes of RNA?

to process DNA information, DNA's workhorse to synthesize proteins, defend agains viruses, storage of info, enzymatic


What are the three steps to copying a DNA strand?

1 - Unzipping the helix either through heat or an enzyme
2 - polymerization- bonding each side to complementary base pairs = template strand
3 - copy of exact, originals strand zips back up


What is holding the antiparallel nucleotide chins together?

hydrogen bonds


Can RNA form a helix?

yes, it can form a helix with itself, yet that requires a loop at the top


give an example of an enzyme that is used to synthesize proteins



Are double helix strands hydrophilic of hydrophobic?

hydrophilic in general


Molecules that have phosphate groups attached are said to be _____________

the addition of one or more phosphate group raises the potential energy of the substrate molecules enough to make and otherwise endergonic reaction possible


Nucleotides are in RNA are connected to one another in the polynucleotide by:

Covalent bands between sugar and phosphate


Enzymes that break down DNA catalyze the hydrolysis of the covalent bonds that join nucleotides together. What would happen to the DNA molecules treated with these enzymes?

the phosphodiester linkages of the backbone would be broken


A certain enzyme can break glycosidic linkages between glucose monomers only if the are in the a form. Which of the following enzyme could this break down?
a) starch, amylopectin & cellulose
b) glycogen & cellulose
c) glycogen, starch & amylopectin
d) cellulose and chitin