Bio 001 - Q2

Nucleic acid

polymers made up of nucleotides

nucleic acid parts

phosphate group, 5 carbon sugar, nitrogenous base

ribonucleotides

monomers of RNA

What sugar is in RNA?

ribose 

-OH at the 2' carbon

Deoxyribonucleotides

monomers of DNA

Sugar in DNA?

deoxyribose

no oxygen at ‘2, only H

What bonds are between phosphate group and sugar, and nitrogenous base and sugar in nucleic acids?

covalent bonds

phosphodiester linkage

covalent bond between nucleotides

bond of hydroxyl on sugar of 1 nucleotide and phosphate group of another nucleotide

water is released

DNA primary structure

sugar phosphate backbone (phosphodiester bonds)

sequence of 4 nitrogenous bases (A, T, G, C)

DNA secondary structure

sugar-phosphate backbones on outside and bases on inside

base pairing allows H-bonds with certain bases

antiparallel strands (5’ → 3’ and 3’ → 5’)

double helix

DNA tertiary sequence

less dependent on primary structure

supercoils (tight or loosely bound DNA)

can wrap around histones

DNA synthesis

• forms its own template

• strands separate (H-bonds break)

• each strand is a new template

• polymerization

RNA primary structure

• four nitrogenous bases (A, U, G, C)

• ribose

• uracil (U) instead of thymine (T)

• more reactive hydroxyl

RNA secondary structure

A forms H-bonds with U

G forms 3 H-bonds with cytosine

single nucleic strand

RNA tertiary structure

folds into more complex shapes

more diversity in shape and size than DNA

RNA versatility

mRNA transmits info to synthesis polypeptides

regulates production of mRNA

catalyzes and synthesis of proteins

Ribozymes

RNA enzymes

catalyze reactions similar to protein enzymes

mRNA (messenger RNA)

carries info from DNA out of nucleus to site of protein synthesis in cytoplasm

RNA polymerase

polymerizes ribonucleotides into strands of RNA

does not require a primer

central dogma

DNA → RNA → proteins

transcription

using DNA to make RNA with RNA polymerase

Translation

base sequence mRNA to make proteins with ribosomes

genotype

determined by sequence of bases in DNA (DNA sequence)

phenotype

product of the proteins it produces (physical traits)