nucleic acid, dna, rna Flashcards
name and describe the 4 genetic processes in macromolecular synthesis
- replication- DNA synthesis from existing DNA
- transcription- RNA synthesis from DNA
- translation- protein synthesis from decoding RNA
- RNA modification- modify RNA in nucleus
describe the structure of a nucleotide
pentose sugar- deoxyribose, ribose
phosphate
nitrogenous base- adenine, thymine, uracil, guanine, cytosine
sugar phosphate backbone is formed from phosphodiester bonds, hydrogen bonding occurs between bases, always from 5’ to 3’
what are purines and pyrimidines
purines have 2 rings and pyrimidines have 1 ring
-purine: A G
-pyrimidine: U T C
structure of DNA
-double stranded
-ATCG
-asymmetrically aligned causing major and minor grooves which allow factors to interact with the bases
-46 chromosomes
-DNA packed into chromatin then into chromosomes
-DNA wraps around nucleosome
-centromere= constricted region of chromosome that’s involved in the segregation of chromosomes
-end of each chromosome has a telomere (noncoding region that protects structure)
-telomere shortens with each successive replication to prevent more replication
-nucleosome regulates gene expression by determining if DNA can be accessed by transcription factors
-modification of amino group of histone changes shape and electrical charge to prepare chromatin for DNA rep/transcip.
what are nucleosomes and what do they regulate
histones, regulate gene expression by determining if DNA can be accessed by transcription factors
what is a telomere and what happens to it when replication occurs
non coding region that protects the structure, shortens with each successive replication to prevent more replication
what is a centromere
what does enzymatic modification of amino terminal of histones do
describe the structure of RNA
-AUGC
-3’ to 5’
-phosphodiester bonds, single stranded
-forms secondary and tertiary structures by folding and pairing with itself
name the types of RNA
mRNA
tRNA
rRNA
what is mRNA
carries genetic information from DNA to cytoplasm for translation
what is tRNA
carries amino acids to ribosome to make proteins, cloverleaf shape
name other uses of nucleotides
-energy
-intracellular communication
differences between DNA and RNA
DNA- double stranded, ATCG, deoxyribose
RNA- single stranded, AUCG, ribose, can catalyse reactions, different types
DNA replication how