nucleotides

Question 1

phosphoric acid

Answer 1

inorganic acid with potential to donate three protons, usually significantly dissociated at physiological pH, existing largely in anionic form

Question 2

what is true about the hydrolysis of pyrophosphate?

Answer 2

it is very thermodynamically favorable

Question 3

what is true about phosphate anhydride bonds

Answer 3

They store a large amount of energy

Question 4

nucleotides

Answer 4

building blocks of nucleic acids, phosphate esters of nucleosides, which are a ribose containing a purine or pyrimidine linked to the 1’carbon

contains a purine or pyrimidine base joined to carbon number one of the ribose ring
also contains 1,2, or 3 phosphate units joined to carbon five of the ribose ring

Question 5

ATP function

Answer 5

universal short term energy storage molecule, where energy extracted from oxidation of foodstuffs is immediately stored

Question 6

building block of DNA

Answer 6

deoxyribonucleoside 5’ triphosphate, where the nucleoside is adenine, guanine, cytosine, or thymine.

Question 7

invariant part of nucleotide

Answer 7

sugar-phosphate backbone

Question 8

variable portion of nucleotide building block

Answer 8

the base

Question 9

how are nucleotides linked

Answer 9

phosphodiester bonds between the 3’ hydroxy group of the sugar in one nucleotide and the 5’ phosphate group of the sugar in the next nucleotide.

Question 10

Watson-Crick DNA model

Answer 10

DNA is a right-handed double helix held together by hydrogen bonds and hydrophobic forces between bases.

double stranded DNA contains polynucleotide chains hydrogen bonded together in an antiparallel orientation with A bonded to T and G bonded to C (Purine +pyrimidine)

Question 11

How many bonds hold GC and AT?

Answer 11

three and two

Question 12

annealing and melting

Answer 12

binding of two complementary DNA strands into a double stranded structure and separating the strands

Question 13

Tm

Answer 13

temperature at which 50 parent of a solution of DNA molecules is melted

Question 14

base and phosphate backbone position in DNA

Answer 14

bases are on the interior and the ribose/phosphate backbone is on the exterior

Question 15

length of a base pair

Answer 15

3.4 angstroms, or 3.4 *10-10 m

Question 16

DNA gyrase

Answer 16

twists the gigantic circular chromosome of prokaryotes by breaking DNA and twisting the two sides of the circle around each other, forms supercoils

Question 17

histones

Answer 17

globular proteins in which eukaryotic DNA is wrapped around

Question 18

nucleosomes

Answer 18

composed of DNA wrapped around an octamer of histones

Question 19

chromatin

Answer 19

fully packed DNA

Question 20

heterochromatin vs euchromatin

Answer 20

euchromatin is less dense and has higher transcription rates

Question 21

centromeres

Answer 21

region of the chromosome to which spindle fibers attach during cell division, fibers attach via kinetochores, which act as anchor attachment sites for spindle fibers

Question 22

centromere positions

Answer 22

metacentric (p=q)

submetracentric (p

Question 23

telomere function

Answer 23

at ends of linear chromosome, distinguished by presence of distinct nucleotide sequences repeated 50 to several hundred times, blocks the ends of chromosomes and prevents chromosome deterioration

Question 24

How is RNA distinct from DNA?

Answer 24

It is single stranded, contains uracil instead of thymine, and has a ribose as a pentose ring instead of 2’deoxyribose, making it less stable

Question 25

mRNA function

Answer 25

only type of coding RNA, carries genetic info to ribosome

Question 26

hnRNA

Answer 26

first RNA transcribed from DNA, precursor to mRNA preceding addition of a cap and tail and splicing

Question 27

two types of noncoding RNA

Answer 27

transfer RNA, which translates the genetic code, and ribosomal RNA which is a major component of the ribosome.