DNA & RNA Structure

DNA

deoxyribonucleic acid

DNA is made up of two ___________ strands that wind around each other in a ___________ ___________

linked, double helix

Each strand that makes up DNA has a background of alternating deoxyribose ___________ and ___________ groups

sugar, phosphate

Attached to each sugar is one of four ___________: ___________, ___________, ___________, ___________

bases, cytosine, adenine, guanine, thymine

nucelotides

the basic building blocks of nucleic acids (DNA and RNA)

a nucleotide consists of a ___________ molecule attached to a ___________ group and a ___________ containing base

sugar, phosphate, nitrogen

transforming principle

bacteria are capable of transferring genetic information through a process known as transformation

DNase

enzyme that catalyzes the hydrolytic cleavage of phosphideesther linkages in the DNA backbone (breaks down DNA)

Rnase

nuclease that catalyses the degradation of RNA

Protease

enzyme that catalyses proteolysis, breaking down proteins

Phosphodiesther bond

occurs when exactly 2 hydroxyl griyps in phosphopric acid react with hydroxyl groups for form two esther bonds, used in backbone

hydrogen bond

partial covalent character in base pairing

Chargaff's Rule

(amounts of) C=G and A=T

RNA

ribonucleic acid present in all living cells, similar to DNA but has uracil instead of thymine and is single stranded

central dogma

a theory stating that genetic information flows in one direction from DNA to RNA to protein or from RNA directly to protein

Is the melting temperature of DNA or RNA lower

RNA

RNA stability depends on the

RNA nucleotide sequence

for a gene to become function it's information must be passed to an ___________ molecule

RNA

a single nucleotide is made up of what 3 parts

a phosophate molecule, a sugar molecule, and a nitrogenous base

ribozyme

RNA molecules with catalytic activity that allows them to initiate chemical reactions without additional proteins

Structural RNA

ribosomal RNA, used in protein for structural scaffolding to form core of ribosome for protein synthesis

miRNA

controls gene expression mainly by binding with mRNA

snRNA

play a role in splicing pre-mRNA molecules by forming part of the spliceosome complex

tRNA

carries amino acids to the ribosome during the process of protein synthesis (translation)

Watson and Crick used ball and stick molecules to prove ___________ ___________ and ___________ ___________ twist

double helix, right stranded

there are 2 hydrogen bonds between

A and T

there are 3 hydrogen bonds between

C and G

DNA is ___________ bases per turn

10

Linus Pauling

proposed alph helix in proteins

Rosalind Franklin

used x ray diffraction to show helical structure

Erwin Chrgaff

determined DNA base composition from many organisms

Frederick griffith discovered the

transforming principle

Avery, MacLeod, McCarty

DNA responsible for transformation

Hershey and Chase

DNA is genetic material in T2 phage

4 properties of DNA

information, transmission, replication, variation

information

DNA contains information needed to build an organism

transmission

DNA can be transmitted from parent to offspring

replication

DNA can be replicated to be passed to the next generation

variation

DNA is capable of variation to account for phenotypic differences of a species

phosophodiesther bonds

5' phosphate of one nucleotide is linked to 3' OH of another

nucleotide strans has ___________ from ___________ to 3'

directionality, 5'

Purines

Adenine and Guanine (2 rings)

pyrimidine

Cytosine and Thymine (1 ring)